| Message ID | 201308280013.52076.heiko@sntech.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Heiko, First of all, big thanks for you work on this, letting our dream about getting rid of S3C DMA API get closer to the reality. ;) Overall the driver looks very good, but let me share some comments inline. On Wednesday 28 of August 2013 00:13:51 Heiko Stübner wrote: > This adds a new driver to support the s3c24xx dma using the dmaengine > and makes the old one in mach-s3c24xx obsolete in the long run. > > Conceptually the s3c24xx-dma feels like a distant relative of the pl08x > with numerous virtual channels being mapped to a lot less physical ones. > The driver therefore borrows a lot from the amba-pl08x driver in this > regard. Functionality-wise the driver gains a memcpy ability in > addition to the slave_sg one. > > The driver supports both the method for requesting the peripheral used > by SoCs before the S3C2443 and the different method for S3C2443 and > later. > > On earlier SoCs the hardware channels usable for specific peripherals is > constrainted while on later SoCs all channels can be used for any > peripheral. > > Tested on a s3c2416-based board, memcpy using the dmatest module and > slave_sg partially using the spi-s3c64xx driver. > > Signed-off-by: Heiko Stuebner <heiko@sntech.de> > Acked-by: Linus Walleij <linus.walleij@linaro.org> > --- > changes since v2: > - add missing channel validation in s3c24xx_dma_phy_free when > repurposing a physical channel for another virtual channel > - address comments from Vinod Koul: > - fix naming of constants to prevent conflicts > - better handle the unlikely case of an interrupt happening on an > unused channel > > changes since v1: > - address comments from Linus Walleij > - support sg-lists with more than 1 element > - add support for earlier s3c24xx SoCs > - redo the channeldata definitions: > - no need for static ids for the virtual channels > - provide a way to encode constraints for earlier variants > - better base for later dt bindings > > drivers/dma/Kconfig | 12 + > drivers/dma/Makefile | 1 + > drivers/dma/s3c24xx-dma.c | 1285 > +++++++++++++++++++++++++++++ include/linux/platform_data/dma-s3c24xx.h > | 43 + > 4 files changed, 1341 insertions(+) > create mode 100644 drivers/dma/s3c24xx-dma.c > create mode 100644 include/linux/platform_data/dma-s3c24xx.h > > diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig > index 6825957..9f17c27 100644 > --- a/drivers/dma/Kconfig > +++ b/drivers/dma/Kconfig > @@ -154,6 +154,18 @@ config TEGRA20_APB_DMA > This DMA controller transfers data from memory to peripheral fifo > or vice versa. It does not support memory to memory data transfer. > > +config S3C24XX_DMAC > + bool "Samsung S3C24XX DMA support" > + depends on ARCH_S3C24XX && !S3C24XX_DMA > + select DMA_ENGINE > + select DMA_VIRTUAL_CHANNELS > + help > + Support for the Samsung S3C24XX DMA controller driver. The > + DMA controller is having multiple DMA channels which can be > + configured for different peripherals like audio, UART, SPI. > + The DMA controller can transfer data from memory to peripheral, > + periphal to memory, periphal to periphal and memory to memory. > + > source "drivers/dma/sh/Kconfig" > > config COH901318 > diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile > index 5e0f2ef..5c1655a 100644 > --- a/drivers/dma/Makefile > +++ b/drivers/dma/Makefile > @@ -30,6 +30,7 @@ obj-$(CONFIG_SIRF_DMA) += sirf-dma.o > obj-$(CONFIG_TI_EDMA) += edma.o > obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o > obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o > +obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o > obj-$(CONFIG_PL330_DMA) += pl330.o > obj-$(CONFIG_PCH_DMA) += pch_dma.o > obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o > diff --git a/drivers/dma/s3c24xx-dma.c b/drivers/dma/s3c24xx-dma.c > new file mode 100644 > index 0000000..66cd20b > --- /dev/null > +++ b/drivers/dma/s3c24xx-dma.c > @@ -0,0 +1,1285 @@ > +/* > + * S3C24XX DMA handling > + * > + * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de> > + * > + * based on amba-pl08x.c > + * > + * Copyright (c) 2006 ARM Ltd. > + * Copyright (c) 2010 ST-Ericsson SA > + * > + * Author: Peter Pearse <peter.pearse@arm.com> > + * Author: Linus Walleij <linus.walleij@stericsson.com> > + * > + * This program is free software; you can redistribute it and/or modify > it + * under the terms of the GNU General Public License as published > by the Free + * Software Foundation; either version 2 of the License, > or (at your option) + * any later version. > + * > + * The DMA controllers in S3C24XX SoCs have a varying number of DMA > signals + * that can be routed to any of the 4 to 8 hardware-channels. > + * > + * Therefore on these DMA controllers the number of channels > + * and the number of incoming DMA signals are two totally different > things. + * It is usually not possible to theoretically handle all > physical signals, + * so a multiplexing scheme with possible denial of > use is necessary. + * > + * Open items: > + * - bursts > + */ > + > +#include <linux/platform_device.h> > +#include <linux/types.h> > +#include <linux/dmaengine.h> > +#include <linux/dma-mapping.h> > +#include <linux/interrupt.h> > +#include <linux/clk.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include <linux/platform_data/dma-s3c24xx.h> > + > +#include "dmaengine.h" > +#include "virt-dma.h" > + > +#define MAX_DMA_CHANNELS 8 > + > +#define S3C24XX_DISRC (0x00) > +#define S3C24XX_DISRCC (0x04) nit: You don't have to use parentheses for simple numbers. > +#define S3C24XX_DISRCC_INC_INCREMENT (0 << 0) > +#define S3C24XX_DISRCC_INC_FIXED (1 << 0) nit: You could use BIT() macro to define bits. > +#define S3C24XX_DISRCC_LOC_AHB (0 << 1) > +#define S3C24XX_DISRCC_LOC_APB (1 << 1) > + > +#define S3C24XX_DIDST (0x08) > +#define S3C24XX_DIDSTC (0x0C) nit: Lower case is prefered for hex numbers. > +#define S3C24XX_DIDSTC_INC_INCREMENT (0 << 0) > +#define S3C24XX_DIDSTC_INC_FIXED (1 << 0) > +#define S3C24XX_DIDSTC_LOC_AHB (0 << 1) > +#define S3C24XX_DIDSTC_LOC_APB (1 << 1) > +#define S3C24XX_DIDSTC_INT_TC0 (0 << 2) > +#define S3C24XX_DIDSTC_INT_RELOAD (1 << 2) > + > +#define S3C24XX_DCON (0x10) > + > +#define S3C24XX_DCON_TC_MASK 0xfffff > +#define S3C24XX_DCON_DSZ_BYTE (0 << 20) > +#define S3C24XX_DCON_DSZ_HALFWORD (1 << 20) > +#define S3C24XX_DCON_DSZ_WORD (2 << 20) > +#define S3C24XX_DCON_DSZ_MASK (3 << 20) > +#define S3C24XX_DCON_DSZ_SHIFT 20 > +#define S3C24XX_DCON_AUTORELOAD (0 << 22) > +#define S3C24XX_DCON_NORELOAD (1 << 22) > +#define S3C24XX_DCON_HWTRIG (1 << 23) > +#define S3C24XX_DCON_HWSRC_SHIFT 24 > +#define S3C24XX_DCON_SERV_SINGLE (0 << 27) > +#define S3C24XX_DCON_SERV_WHOLE (1 << 27) > +#define S3C24XX_DCON_TSZ_UNIT (0 << 28) > +#define S3C24XX_DCON_TSZ_BURST4 (1 << 28) > +#define S3C24XX_DCON_INT (1 << 29) > +#define S3C24XX_DCON_SYNC_PCLK (0 << 30) > +#define S3C24XX_DCON_SYNC_HCLK (1 << 30) > +#define S3C24XX_DCON_DEMAND (0 << 31) > +#define S3C24XX_DCON_HANDSHAKE (1 << 31) > + > +#define S3C24XX_DSTAT (0x14) > +#define S3C24XX_DSTAT_STAT_BUSY (1 << 20) > +#define S3C24XX_DSTAT_CURRTC_MASK 0xfffff > + > +#define S3C24XX_DMASKTRIG (0x20) > +#define S3C24XX_DMASKTRIG_STOP (1 << 2) > +#define S3C24XX_DMASKTRIG_ON (1 << 1) > +#define S3C24XX_DMASKTRIG_SWTRIG (1 << 0) > + > +#define S3C24XX_DMAREQSEL (0x24) > +#define S3C24XX_DMAREQSEL_HW (1 << 0) > + > +/* > + * S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel > + * for a DMA source. Instead only specific channels are valid. + * All > of these SoCs have 4 physical channels and the number of request + * > source bits is 3. Additionally we also need 1 bit to mark the channel + > * as valid. > + * Therefore we separate the chansel element of the channel data into 4 > + * parts of 4 bits each, to hold the information if the channel is > valid + * and the hw request source to use. > + * > + * Example: > + * SDI is valid on channels 0, 2 and 3 - with varying hw request > sources. + * For it the chansel field would look like > + * > + * ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1 > + * ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2 > + * ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2 > + */ > +#define S3C24XX_CHANSEL_WIDTH 4 > +#define S3C24XX_CHANSEL_VALID BIT(3) > +#define S3C24XX_CHANSEL_REQ_MASK 7 > + > +/* > + * struct soc_data - vendor-specific config parameters for individual > SoCs + * @stride: spacing between the registers of each channel > + * @has_reqsel: does the controller use the newer requestselection > mechanism + * @has_clocks: are controllable dma-clocks present > + */ > +struct soc_data { > + int stride; > + bool has_reqsel; > + bool has_clocks; > +}; > + > +/* > + * enum s3c24xx_dma_chan_state - holds the virtual channel states > + * @S3C24XX_DMA_CHAN_IDLE: the channel is idle > + * @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical > transport + * channel and is running a transfer on it > + * @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical > transport + * channel to become available (only pertains to memcpy > channels) + */ > +enum s3c24xx_dma_chan_state { > + S3C24XX_DMA_CHAN_IDLE, > + S3C24XX_DMA_CHAN_RUNNING, > + S3C24XX_DMA_CHAN_WAITING, > +}; > + > +/* > + * struct s3c24xx_sg - structure containing data per sg > + * @src_addr: src address of sg > + * @dst_addr: dst address of sg > + * @len: transfer len in bytes > + * @node: node for txd's dsg_list > + */ > +struct s3c24xx_sg { > + dma_addr_t src_addr; > + dma_addr_t dst_addr; > + size_t len; > + struct list_head node; > +}; > + > +/* > + * struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor > + * @vd: virtual DMA descriptor > + * @dsg_list: list of children sg's > + * @at: sg currently being transfered > + * @width: transfer width > + * @disrcc: value for source control register > + * @didstc: value for destination control register > + * @dcon: base value for dcon register > + */ > +struct s3c24xx_txd { > + struct virt_dma_desc vd; > + struct list_head dsg_list; > + struct list_head *at; > + u8 width; > + u32 disrcc; > + u32 didstc; > + u32 dcon; > +}; > + > +struct s3c24xx_dma_chan; > + > +/* > + * struct s3c24xx_dma_phy - holder for the physical channels > + * @id: physical index to this channel > + * @valid: does the channel have all required elements > + * @base: virtual memory base (remapped) for the this channel > + * @irq: interrupt for this channel > + * @clk: clock for this channel > + * @lock: a lock to use when altering an instance of this struct > + * @serving: virtual channel currently being served by this > physicalchannel + * @host: a pointer to the host (internal use) > + */ > +struct s3c24xx_dma_phy { > + unsigned int id; > + bool valid; > + void __iomem *base; > + unsigned int irq; > + struct clk *clk; > + spinlock_t lock; > + struct s3c24xx_dma_chan *serving; > + struct s3c24xx_dma_engine *host; > +}; > + > +/* > + * struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel > + * @id: the id of the channel > + * @name: name of the channel > + * @vc: wrappped virtual channel > + * @phy: the physical channel utilized by this channel, if there is one > + * @runtime_addr: address for RX/TX according to the runtime config + > * @at: active transaction on this channel > + * @lock: a lock for this channel data > + * @host: a pointer to the host (internal use) > + * @state: whether the channel is idle, running etc > + * @slave: whether this channel is a device (slave) or for memcpy > + */ > +struct s3c24xx_dma_chan { > + int id; > + const char *name; > + struct virt_dma_chan vc; > + struct s3c24xx_dma_phy *phy; > + struct dma_slave_config cfg; > + struct s3c24xx_txd *at; > + struct s3c24xx_dma_engine *host; > + enum s3c24xx_dma_chan_state state; > + bool slave; > +}; > + > +/* > + * struct s3c24xx_dma_engine - the local state holder for the S3C24XX > + * @pdev: the corresponding platform device > + * @pdata: platform data passed in from the platform/machine > + * @base: virtual memory base (remapped) > + * @slave: slave engine for this instance > + * @memcpy: memcpy engine for this instance > + * @phy_chans: array of data for the physical channels > + */ > +struct s3c24xx_dma_engine { > + struct platform_device *pdev; > + const struct s3c24xx_dma_platdata *pdata; > + struct soc_data *sdata; > + void __iomem *base; > + struct dma_device slave; > + struct dma_device memcpy; > + struct s3c24xx_dma_phy *phy_chans; > +}; > + > +/* > + * Physical channel handling > + */ > + > +/* > + * Check whether a certain channel is busy or not. > + */ > +static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy) > +{ > + unsigned int val = readl(phy->base + S3C24XX_DSTAT); > + return val & S3C24XX_DSTAT_STAT_BUSY; > +} > + > +static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan, > + struct s3c24xx_dma_phy *phy) > +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; > + struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; > + int phyvalid; > + > + /* every phy is valid for memcopy channels */ > + if (!s3cchan->slave) > + return true; > + > + /* On newer variants all phys can be used for all virtual channels */ > + if (s3cdma->sdata->has_reqsel) > + return true; > + > + phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH)); > + return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false; > +} > + > +/* > + * Allocate a physical channel for a virtual channel > + * > + * Try to locate a physical channel to be used for this transfer. If > all + * are taken return NULL and the requester will have to cope by > using + * some fallback PIO mode or retrying later. > + */ > +static > +struct s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan > *s3cchan) +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; > + struct s3c24xx_dma_channel *cdata; > + struct s3c24xx_dma_phy *phy = NULL; > + unsigned long flags; > + int i; > + int ret; > + > + if (s3cchan->slave) > + cdata = &pdata->channels[s3cchan->id]; > + > + for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) { > + phy = &s3cdma->phy_chans[i]; > + > + if (!phy || !phy->valid) Hmm, is it even possible here for phy to be NULL? This would happen only at i == 0 and s3cdma->phy_chans == NULL. > + continue; > + > + if (!s3c24xx_dma_phy_valid(s3cchan, phy)) > + continue; > + > + spin_lock_irqsave(&phy->lock, flags); > + > + if (!phy->serving) { > + phy->serving = s3cchan; > + spin_unlock_irqrestore(&phy->lock, flags); > + break; > + } > + > + spin_unlock_irqrestore(&phy->lock, flags); > + } > + > + /* No physical channel available, cope with it */ > + if (i == s3cdma->pdata->num_phy_channels) { > + dev_warn(&s3cdma->pdev->dev, "no phy channel available\n"); > + return NULL; > + } > + > + /* start the phy clock */ > + if (s3cdma->sdata->has_clocks) { > + ret = clk_enable(phy->clk); > + if (ret) { nit: Some error message could be printed here. > + phy->serving = NULL; > + return NULL; > + } > + } > + > + return phy; > +} > + > +/* > + * Mark the physical channel as free. > + * > + * This drops the link between the physical and virtual channel. > + */ > +static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy) > +{ > + struct s3c24xx_dma_engine *s3cdma = phy->host; > + > + if (s3cdma->sdata->has_clocks) > + clk_disable(phy->clk); > + > + phy->serving = NULL; > +} > + > +/* > + * Stops the channel by writing the stop bit. > + * This should not be used for an on-going transfer, but as a method of > + * shutting down a channel (eg, when it's no longer used) or > terminating a + * transfer. > + */ > +static void s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy) > +{ > + writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG); > +} > + > +/* > + * Virtual channel handling > + */ > + > +static inline > +struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan) > +{ > + return container_of(chan, struct s3c24xx_dma_chan, vc.chan); > +} > + > +static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan) > +{ > + struct s3c24xx_dma_phy *phy = s3cchan->phy; > + struct s3c24xx_txd *txd = s3cchan->at; > + u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK; > + > + return tc * txd->width; > +} > + > +static int s3c24xx_dma_set_runtime_config(struct s3c24xx_dma_chan > *s3cchan, + struct dma_slave_config *config) > +{ > + if (!s3cchan->slave) > + return -EINVAL; > + > + /* Reject definitely invalid configurations */ > + if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || > + config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) > + return -EINVAL; > + > + s3cchan->cfg = *config; > + > + return 0; > +} > + > +/* > + * Transfer handling > + */ > + > +static inline > +struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx) > +{ > + return container_of(tx, struct s3c24xx_txd, vd.tx); > +} > + > +static struct s3c24xx_txd *s3c24xx_dma_get_txd(void) > +{ > + struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT); > + > + if (txd) { > + INIT_LIST_HEAD(&txd->dsg_list); > + txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD; > + } > + > + return txd; > +} > + > +static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd) > +{ > + struct s3c24xx_sg *dsg, *_dsg; > + > + list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) { > + list_del(&dsg->node); > + kfree(dsg); > + } > + > + kfree(txd); > +} > + > +static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan, > + struct s3c24xx_txd *txd) > +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + struct s3c24xx_dma_phy *phy = s3cchan->phy; > + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; > + struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node); > + u32 dcon = txd->dcon; > + u32 val; > + > + /* transfer-size and -count from len and width */ > + switch (txd->width) { > + case 1: > + dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len; > + break; > + case 2: > + dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2); > + break; > + case 4: > + dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4); > + break; > + } > + > + if (s3cchan->slave) { > + struct s3c24xx_dma_channel *cdata = > + &pdata->channels[s3cchan->id]; Coding style: A blank line should be present between variable declarations and code. > + if (s3cdma->sdata->has_reqsel) { > + writel_relaxed((cdata->chansel << 1) | > + S3C24XX_DMAREQSEL_HW, > + phy->base + S3C24XX_DMAREQSEL); > + } else { > + int csel = cdata->chansel >> (phy->id * > + S3C24XX_CHANSEL_WIDTH); Ditto. > + csel &= S3C24XX_CHANSEL_REQ_MASK; > + dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT; > + dcon |= S3C24XX_DCON_HWTRIG; > + } > + } else { > + if (s3cdma->sdata->has_reqsel) > + writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL); > + } > + > + writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC); > + writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC); > + writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST); > + writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC); > + writel_relaxed(dcon, phy->base + S3C24XX_DCON); > + > + val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG); > + val &= ~S3C24XX_DMASKTRIG_STOP; > + val |= S3C24XX_DMASKTRIG_ON; > + > + /* trigger the dma operation for memcpy transfers */ > + if (!s3cchan->slave) > + val |= S3C24XX_DMASKTRIG_SWTRIG; > + > + writel(val, phy->base + S3C24XX_DMASKTRIG); > +} > + > +/* > + * Set the initial DMA register values and start first sg. > + */ > +static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan > *s3cchan) +{ > + struct s3c24xx_dma_phy *phy = s3cchan->phy; > + struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc); > + struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); > + > + list_del(&txd->vd.node); > + > + s3cchan->at = txd; > + > + /* Wait for channel inactive */ > + while (s3c24xx_dma_phy_busy(phy)) > + cpu_relax(); > + > + /* point to the first element of the sg list */ > + txd->at = txd->dsg_list.next; > + s3c24xx_dma_start_next_sg(s3cchan, txd); > +} > + > +static void s3c24xx_dma_free_txd_list(struct s3c24xx_dma_engine > *s3cdma, + struct s3c24xx_dma_chan *s3cchan) > +{ > + LIST_HEAD(head); > + > + vchan_get_all_descriptors(&s3cchan->vc, &head); > + vchan_dma_desc_free_list(&s3cchan->vc, &head); > +} > + > +/* > + * Try to allocate a physical channel. When successful, assign it to > + * this virtual channel, and initiate the next descriptor. The > + * virtual channel lock must be held at this point. > + */ > +static void s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan > *s3cchan) +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + struct s3c24xx_dma_phy *phy; > + > + phy = s3c24xx_dma_get_phy(s3cchan); > + if (!phy) { > + dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer > on %s\n", + s3cchan->name); > + s3cchan->state = S3C24XX_DMA_CHAN_WAITING; > + return; > + } > + > + dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on > %s\n", + phy->id, s3cchan->name); > + > + s3cchan->phy = phy; > + s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; > + > + s3c24xx_dma_start_next_txd(s3cchan); > +} > + > +static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy, > + struct s3c24xx_dma_chan *s3cchan) > +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + > + dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer > on %s\n", + phy->id, s3cchan->name); > + > + /* > + * We do this without taking the lock; we're really only concerned > + * about whether this pointer is NULL or not, and we're guaranteed > + * that this will only be called when it _already_ is non-NULL. > + */ > + phy->serving = s3cchan; > + s3cchan->phy = phy; > + s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; > + s3c24xx_dma_start_next_txd(s3cchan); > +} > + > +/* > + * Free a physical DMA channel, potentially reallocating it to another > + * virtual channel if we have any pending. > + */ > +static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan) > +{ > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + struct s3c24xx_dma_chan *p, *next; > + > +retry: > + next = NULL; > + > + /* Find a waiting virtual channel for the next transfer. */ > + list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node) > + if (p->state == S3C24XX_DMA_CHAN_WAITING) { > + next = p; > + break; > + } > + > + if (!next) { > + list_for_each_entry(p, &s3cdma->slave.channels, > + vc.chan.device_node) > + if (p->state == S3C24XX_DMA_CHAN_WAITING && > + s3c24xx_dma_phy_valid(p, s3cchan- >phy)) { > + next = p; > + break; > + } > + } > + > + /* Ensure that the physical channel is stopped */ > + s3c24xx_dma_terminate_phy(s3cchan->phy); > + > + if (next) { > + bool success; > + > + /* > + * Eww. We know this isn't going to deadlock > + * but lockdep probably doesn't. > + */ > + spin_lock(&next->vc.lock); > + /* Re-check the state now that we have the lock */ > + success = next->state == S3C24XX_DMA_CHAN_WAITING; > + if (success) > + s3c24xx_dma_phy_reassign_start(s3cchan->phy, next); > + spin_unlock(&next->vc.lock); > + > + /* If the state changed, try to find another channel */ > + if (!success) > + goto retry; > + } else { > + /* No more jobs, so free up the physical channel */ > + s3c24xx_dma_put_phy(s3cchan->phy); > + } > + > + s3cchan->phy = NULL; > + s3cchan->state = S3C24XX_DMA_CHAN_IDLE; > +} > + > +static void s3c24xx_dma_unmap_buffers(struct s3c24xx_txd *txd) > +{ > + struct device *dev = txd->vd.tx.chan->device->dev; > + struct s3c24xx_sg *dsg; > + > + if (!(txd->vd.tx.flags & DMA_COMPL_SKIP_SRC_UNMAP)) { > + if (txd->vd.tx.flags & DMA_COMPL_SRC_UNMAP_SINGLE) > + list_for_each_entry(dsg, &txd->dsg_list, node) > + dma_unmap_single(dev, dsg->src_addr, dsg- >len, > + DMA_TO_DEVICE); > + else { > + list_for_each_entry(dsg, &txd->dsg_list, node) > + dma_unmap_page(dev, dsg->src_addr, dsg- >len, > + DMA_TO_DEVICE); > + } > + } > + > + if (!(txd->vd.tx.flags & DMA_COMPL_SKIP_DEST_UNMAP)) { > + if (txd->vd.tx.flags & DMA_COMPL_DEST_UNMAP_SINGLE) > + list_for_each_entry(dsg, &txd->dsg_list, node) > + dma_unmap_single(dev, dsg->dst_addr, dsg- >len, > + DMA_FROM_DEVICE); > + else > + list_for_each_entry(dsg, &txd->dsg_list, node) > + dma_unmap_page(dev, dsg->dst_addr, dsg- >len, > + DMA_FROM_DEVICE); > + } > +} > + > +static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd) > +{ > + struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd- >tx.chan); > + > + if (!s3cchan->slave) > + s3c24xx_dma_unmap_buffers(txd); > + > + s3c24xx_dma_free_txd(txd); > +} > + > +static irqreturn_t s3c24xx_dma_irq(int irq, void *data) > +{ > + struct s3c24xx_dma_phy *phy = data; > + struct s3c24xx_dma_chan *s3cchan = phy->serving; > + struct s3c24xx_txd *txd; > + > + dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy- >id); > + > + /* > + * Interrupts happen to notify the completion of a transfer and the > + * channel should have moved into its stop state already on its own. > + * Therefore interrupts on channels not bound to a virtual channel > + * should never happen. Nevertheless send a terminate command to the > + * channel if the unlikely case happens. > + */ > + if (unlikely(!s3cchan)) { > + dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n", > + phy->id); > + > + s3c24xx_dma_terminate_phy(phy); > + > + return IRQ_HANDLED; > + } > + > + spin_lock(&s3cchan->vc.lock); > + txd = s3cchan->at; > + if (txd) { > + /* when more sg's are in this txd, start the next one */ > + if (!list_is_last(txd->at, &txd->dsg_list)) { > + txd->at = txd->at->next; > + s3c24xx_dma_start_next_sg(s3cchan, txd); > + } else { > + s3cchan->at = NULL; > + vchan_cookie_complete(&txd->vd); > + > + /* > + * And start the next descriptor (if any), > + * otherwise free this channel. > + */ > + if (vchan_next_desc(&s3cchan->vc)) > + s3c24xx_dma_start_next_txd(s3cchan); > + else > + s3c24xx_dma_phy_free(s3cchan); > + } > + } > + spin_unlock(&s3cchan->vc.lock); > + > + return IRQ_HANDLED; > +} > + > +/* > + * The DMA ENGINE API > + */ > + > +static int s3c24xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd > cmd, + unsigned long arg) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + unsigned long flags; > + int ret = 0; > + > + /* Controls applicable to inactive channels */ > + if (cmd == DMA_SLAVE_CONFIG) > + return s3c24xx_dma_set_runtime_config(s3cchan, > + (struct dma_slave_config *)arg); > + > + /* > + * Anything succeeds on channels with no physical allocation and > + * no queued transfers. > + */ > + spin_lock_irqsave(&s3cchan->vc.lock, flags); > + if (!s3cchan->phy && !s3cchan->at) { > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > + return 0; > + } > + > + switch (cmd) { > + case DMA_TERMINATE_ALL: > + s3cchan->state = S3C24XX_DMA_CHAN_IDLE; > + > + /* Mark physical channel as free */ > + if (s3cchan->phy) > + s3c24xx_dma_phy_free(s3cchan); > + > + /* Dequeue current job */ > + if (s3cchan->at) { > + s3c24xx_dma_desc_free(&s3cchan->at->vd); > + s3cchan->at = NULL; > + } > + > + /* Dequeue jobs not yet fired as well */ > + s3c24xx_dma_free_txd_list(s3cdma, s3cchan); > + break; > + default: > + /* Unknown command */ > + ret = -ENXIO; > + break; > + } > + > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > + > + return ret; > +} > + > +static int s3c24xx_dma_alloc_chan_resources(struct dma_chan *chan) > +{ > + return 0; > +} > + > +static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan) > +{ > + /* Ensure all queued descriptors are freed */ > + vchan_free_chan_resources(to_virt_chan(chan)); > +} > + > +static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan, > + dma_cookie_t cookie, struct dma_tx_state *txstate) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct virt_dma_desc *vd; > + unsigned long flags; > + enum dma_status ret; > + size_t bytes = 0; > + > + ret = dma_cookie_status(chan, cookie, txstate); > + if (ret == DMA_SUCCESS) > + return ret; > + > + /* > + * There's no point calculating the residue if there's > + * no txstate to store the value. > + */ > + if (!txstate) > + return ret; > + > + spin_lock_irqsave(&s3cchan->vc.lock, flags); > + ret = dma_cookie_status(chan, cookie, txstate); > + if (ret != DMA_SUCCESS) { > + struct s3c24xx_txd *txd; > + struct s3c24xx_sg *dsg; > + > + vd = vchan_find_desc(&s3cchan->vc, cookie); > + if (vd) { > + /* On the issued list, so hasn't been processed yet */ > + txd = to_s3c24xx_txd(&vd->tx); > + > + list_for_each_entry(dsg, &txd->dsg_list, node) > + bytes += dsg->len; > + } else { > + /* > + * Currently running, so sum over the pending sg's and > + * the currently active one. > + */ > + txd = s3cchan->at; > + > + dsg = list_entry(txd->at, struct s3c24xx_sg, node); > + list_for_each_entry_from(dsg, &txd->dsg_list, node); > + bytes += dsg->len; > + > + bytes += s3c24xx_dma_getbytes_chan(s3cchan); > + } > + } > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > + > + /* > + * This cookie not complete yet > + * Get number of bytes left in the active transactions and queue > + */ > + dma_set_residue(txstate, bytes); > + > + /* Whether waiting or running, we're in progress */ > + return ret; > +} > + > +/* > + * Initialize a descriptor to be used by memcpy submit > + */ > +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy( > + struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, > + size_t len, unsigned long flags) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + struct s3c24xx_txd *txd; > + struct s3c24xx_sg *dsg; > + > + dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n", > + len, s3cchan->name); > + > + if ((len & S3C24XX_DCON_TC_MASK) != len) { > + dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len); > + return NULL; > + } > + > + txd = s3c24xx_dma_get_txd(); > + if (!txd) > + return NULL; > + > + dsg = kzalloc(sizeof(struct s3c24xx_sg), GFP_NOWAIT); > + if (!dsg) { > + s3c24xx_dma_free_txd(txd); > + return NULL; > + } > + list_add_tail(&dsg->node, &txd->dsg_list); > + > + dsg->src_addr = src; > + dsg->dst_addr = dest; > + dsg->len = len; > + > + txd->width = 1; Hmm, should memcpy transfers be really 1-byte wide? Not that it would be used by anything anyway, as the only users of DMA on Samsung platforms currently are SPI and ASoC... > + txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT; > + txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT; > + txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK | > + S3C24XX_DCON_SERV_WHOLE; > + > + return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); > +} > + > +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg( > + struct dma_chan *chan, struct scatterlist *sgl, > + unsigned int sg_len, enum dma_transfer_direction direction, > + unsigned long flags, void *context) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; > + struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; > + struct s3c24xx_txd *txd; > + struct s3c24xx_sg *dsg; > + struct scatterlist *sg; > + dma_addr_t slave_addr; > + u32 hwcfg = 0; > + int tmp; > + > + dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from > %s\n", + sg_dma_len(sgl), s3cchan->name); > + > + txd = s3c24xx_dma_get_txd(); > + if (!txd) > + return NULL; > + > + if (cdata->handshake) > + txd->dcon |= S3C24XX_DCON_HANDSHAKE; > + > + switch (cdata->bus) { > + case S3C24XX_DMA_APB: > + txd->dcon |= S3C24XX_DCON_SYNC_PCLK; > + hwcfg |= S3C24XX_DISRCC_LOC_APB; > + break; > + case S3C24XX_DMA_AHB: > + txd->dcon |= S3C24XX_DCON_SYNC_HCLK; > + hwcfg |= S3C24XX_DISRCC_LOC_AHB; > + break; > + } > + > + /* always assume our peripheral desintation is a fixed > + * address in memory. */ coding style: Multiline comments should start and end with one empty line. > + hwcfg |= S3C24XX_DISRCC_INC_FIXED; > + > + /* individual dma operations are requested by the slave, > + * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE). > + */ Ditto. > + txd->dcon |= S3C24XX_DCON_SERV_SINGLE; > + > + if (direction == DMA_MEM_TO_DEV) { > + txd->disrcc = S3C24XX_DISRCC_LOC_AHB | > + S3C24XX_DISRCC_INC_INCREMENT; > + txd->didstc = hwcfg; > + slave_addr = s3cchan->cfg.dst_addr; > + txd->width = s3cchan->cfg.dst_addr_width; > + } else if (direction == DMA_DEV_TO_MEM) { > + txd->disrcc = hwcfg; > + txd->didstc = S3C24XX_DIDSTC_LOC_AHB | > + S3C24XX_DIDSTC_INC_INCREMENT; > + slave_addr = s3cchan->cfg.src_addr; > + txd->width = s3cchan->cfg.src_addr_width; > + } else { > + s3c24xx_dma_free_txd(txd); > + dev_err(&s3cdma->pdev->dev, > + "direction %d unsupported\n", direction); > + return NULL; > + } > + > + for_each_sg(sgl, sg, sg_len, tmp) { > + dsg = kzalloc(sizeof(struct s3c24xx_sg), GFP_NOWAIT); > + if (!dsg) { > + s3c24xx_dma_free_txd(txd); > + return NULL; > + } > + list_add_tail(&dsg->node, &txd->dsg_list); > + > + dsg->len = sg_dma_len(sg); > + if (direction == DMA_MEM_TO_DEV) { > + dsg->src_addr = sg_dma_address(sg); > + dsg->dst_addr = slave_addr; > + } else { /* DMA_DEV_TO_MEM */ > + dsg->src_addr = slave_addr; > + dsg->dst_addr = sg_dma_address(sg); > + } > + break; > + } > + > + return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); > +} > + > +/* > + * Slave transactions callback to the slave device to allow > + * synchronization of slave DMA signals with the DMAC enable > + */ > +static void s3c24xx_dma_issue_pending(struct dma_chan *chan) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + unsigned long flags; > + > + spin_lock_irqsave(&s3cchan->vc.lock, flags); > + if (vchan_issue_pending(&s3cchan->vc)) { > + if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING) > + s3c24xx_dma_phy_alloc_and_start(s3cchan); > + } > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > +} > + > +/* > + * Bringup and teardown > + */ > + > +/* > + * Initialise the DMAC memcpy/slave channels. > + * Make a local wrapper to hold required data > + */ > +static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine > *s3cdma, + struct dma_device *dmadev, unsigned int channels, bool > slave) +{ > + struct s3c24xx_dma_chan *chan; > + int i; > + > + INIT_LIST_HEAD(&dmadev->channels); > + > + /* > + * Register as many many memcpy as we have physical channels, > + * we won't always be able to use all but the code will have > + * to cope with that situation. > + */ > + for (i = 0; i < channels; i++) { > + chan = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL); > + if (!chan) { > + dev_err(dmadev->dev, > + "%s no memory for channel\n", __func__); > + return -ENOMEM; > + } > + > + chan->id = i; > + chan->host = s3cdma; > + chan->state = S3C24XX_DMA_CHAN_IDLE; > + > + if (slave) { > + chan->slave = true; > + chan->name = kasprintf(GFP_KERNEL, "slave%d", i); > + if (!chan->name) > + return -ENOMEM; > + } else { > + chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i); > + if (!chan->name) > + return -ENOMEM; > + } > + dev_dbg(dmadev->dev, > + "initialize virtual channel \"%s\"\n", > + chan->name); > + > + chan->vc.desc_free = s3c24xx_dma_desc_free; > + vchan_init(&chan->vc, dmadev); > + } > + dev_info(dmadev->dev, "initialized %d virtual %s channels\n", > + i, slave ? "slave" : "memcpy"); > + return i; > +} > + > +static void s3c24xx_dma_free_virtual_channels(struct dma_device > *dmadev) +{ > + struct s3c24xx_dma_chan *chan = NULL; > + struct s3c24xx_dma_chan *next; > + > + list_for_each_entry_safe(chan, > + next, &dmadev->channels, vc.chan.device_node) > + list_del(&chan->vc.chan.device_node); > +} > + > +/* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */ > +static struct soc_data soc_s3c2412 = { > + .stride = 0x40, > + .has_reqsel = true, > + .has_clocks = true, > +}; > + > +/* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */ > +static struct soc_data soc_s3c2443 = { > + .stride = 0x100, > + .has_reqsel = true, > + .has_clocks = true, > +}; > + > +static struct platform_device_id s3c24xx_dma_driver_ids[] = { > + { > + .name = "s3c2412-dma", > + .driver_data = (kernel_ulong_t)&soc_s3c2412, > + }, { > + .name = "s3c2443-dma", > + .driver_data = (kernel_ulong_t)&soc_s3c2443, > + }, > + { }, > +}; > + > +static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device > *pdev) +{ > + return (struct soc_data *) > + platform_get_device_id(pdev)->driver_data; > +} > + > +static int s3c24xx_dma_probe(struct platform_device *pdev) > +{ > + const struct s3c24xx_dma_platdata *pdata = > dev_get_platdata(&pdev->dev); + struct soc_data *sdata; > + struct s3c24xx_dma_engine *s3cdma; > + struct resource *res; > + int ret; > + int i; > + > + if (!pdata) { > + dev_err(&pdev->dev, "platform data missing\n"); > + return -ENODEV; > + } > + > + /* Basic sanity check */ > + if (pdata->num_phy_channels > MAX_DMA_CHANNELS) { > + dev_err(&pdev->dev, "to many dma channels %d, max %d\n", > + pdata->num_phy_channels, MAX_DMA_CHANNELS); > + return -EINVAL; > + } > + > + sdata = s3c24xx_dma_get_soc_data(pdev); > + if (!sdata) > + return -EINVAL; > + > + s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL); > + if (!s3cdma) > + return -ENOMEM; > + > + s3cdma->pdev = pdev; > + s3cdma->pdata = pdata; > + s3cdma->sdata = sdata; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + s3cdma->base = devm_request_and_ioremap(&pdev->dev, res); nit: devm_request_and_ioremap() is deprecated and devm_ioremap_resource() should be used instead (remembering that it returns ERR_PTR() not NULL on errors). > + if (!s3cdma->base) { > + dev_err(&pdev->dev, "could not map dma registers\n"); > + return -EBUSY; > + } > + > + s3cdma->phy_chans = devm_kzalloc(&pdev->dev, > + sizeof(struct s3c24xx_dma_phy) * > + pdata- >num_phy_channels, > + GFP_KERNEL); > + if (!s3cdma->phy_chans) > + return -ENOMEM; > + > + /* aquire irqs and clocks for all physical channels */ > + for (i = 0; i < pdata->num_phy_channels; i++) { > + struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i]; > + char clk_name[6]; > + > + phy->id = i; > + phy->base = s3cdma->base + (i * sdata->stride); > + phy->host = s3cdma; > + > + sprintf(clk_name, "dma.%d", i); > + phy->clk = devm_clk_get(&pdev->dev, clk_name); > + if (IS_ERR(phy->clk) && sdata->has_clocks) { > + dev_err(&pdev->dev, "unable to aquire clock for channel %d, error > %lu", + i, PTR_ERR(phy->clk)); > + continue; > + } Shouldn't the above clock getting code be simply moved under the if clause below? > + > + if (sdata->has_clocks) { > + ret = clk_prepare(phy->clk); > + if (ret) { > + dev_err(&pdev->dev, "clock for phy %d failed, error %d\n", > + i, ret); > + continue; > + } > + } > + > + res = platform_get_resource(pdev, IORESOURCE_IRQ, i); > + if (res) > + phy->irq = res->start; nit: platform_get_irq() could be used here. > + if (!phy->irq) { > + dev_err(&pdev->dev, "failed to get irq %d\n", i); > + continue; > + } > + > + ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq, > + 0, pdev->name, phy); > + if (ret) { > + dev_err(&pdev->dev, "Unable to request irq for channel %d, error > %d\n", + i, ret); > + continue; > + } > + > + spin_lock_init(&phy->lock); > + phy->valid = true; > + > + dev_dbg(&pdev->dev, "physical channel %d is %s\n", > + i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE"); > + } > + > + /* Initialize memcpy engine */ > + dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask); > + dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask); > + s3cdma->memcpy.dev = &pdev->dev; > + s3cdma->memcpy.device_alloc_chan_resources = > + s3c24xx_dma_alloc_chan_resources; > + s3cdma->memcpy.device_free_chan_resources = > + s3c24xx_dma_free_chan_resources; > + s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy; > + s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status; > + s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending; > + s3cdma->memcpy.device_control = s3c24xx_dma_control; > + > + /* Initialize slave engine for SoC internal dedicated peripherals */ > + dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask); > + dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask); > + s3cdma->slave.dev = &pdev->dev; > + s3cdma->slave.device_alloc_chan_resources = > + s3c24xx_dma_alloc_chan_resources; > + s3cdma->slave.device_free_chan_resources = > + s3c24xx_dma_free_chan_resources; > + s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status; > + s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending; > + s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg; > + s3cdma->slave.device_control = s3c24xx_dma_control; > + > + /* Register as many memcpy channels as there are physical channels */ > + ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy, > + pdata->num_phy_channels, false); > + if (ret <= 0) { > + dev_warn(&pdev->dev, > + "%s failed to enumerate memcpy channels - %d\n", > + __func__, ret); > + goto err_memcpy; > + } > + > + /* Register slave channels */ > + ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave, > + pdata->num_channels, true); > + if (ret <= 0) { > + dev_warn(&pdev->dev, > + "%s failed to enumerate slave channels - %d\n", > + __func__, ret); > + goto err_slave; > + } > + > + ret = dma_async_device_register(&s3cdma->memcpy); > + if (ret) { > + dev_warn(&pdev->dev, > + "%s failed to register memcpy as an async device - %d\n", > + __func__, ret); > + goto err_memcpy_reg; > + } > + > + ret = dma_async_device_register(&s3cdma->slave); > + if (ret) { > + dev_warn(&pdev->dev, > + "%s failed to register slave as an async device - %d\n", > + __func__, ret); > + goto err_slave_reg; > + } > + > + platform_set_drvdata(pdev, s3cdma); > + dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n", > + pdata->num_phy_channels); > + > + return 0; > + > +err_slave_reg: > + dma_async_device_unregister(&s3cdma->memcpy); > +err_memcpy_reg: > + s3c24xx_dma_free_virtual_channels(&s3cdma->slave); > +err_slave: > + s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy); > +err_memcpy: > + > + return ret; > +} > + > +static struct platform_driver s3c24xx_dma_driver = { > + .driver = { Hmm, what about .owner field? > + .name = "s3c24xx-dma", > + }, > + .id_table = s3c24xx_dma_driver_ids, > +}; > + > +bool s3c24xx_dma_filter(struct dma_chan *chan, void *param) > +{ > + struct s3c24xx_dma_chan *s3cchan; > + > + if (chan->device->dev->driver != &s3c24xx_dma_driver.driver) > + return false; > + > + s3cchan = to_s3c24xx_dma_chan(chan); > + > + return s3cchan->id == (int)param; > +} > +EXPORT_SYMBOL(s3c24xx_dma_filter); > + > +static int __init s3c24xx_dma_module_init(void) > +{ > + return platform_driver_probe(&s3c24xx_dma_driver, s3c24xx_dma_probe); Hmm, I don't really see any reason to not allow this driver to be compiled as a module. IMHO DMA is not necessary for basic system start-up and you might want to load DMA driver as a module along with any DMA consumer drivers. Otherwise the driver looks pretty good. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Aug 28, 2013 at 12:13:51AM +0200, Heiko Stübner wrote: > This adds a new driver to support the s3c24xx dma using the dmaengine > and makes the old one in mach-s3c24xx obsolete in the long run. > > Conceptually the s3c24xx-dma feels like a distant relative of the pl08x > with numerous virtual channels being mapped to a lot less physical ones. > The driver therefore borrows a lot from the amba-pl08x driver in this > regard. Functionality-wise the driver gains a memcpy ability in addition > to the slave_sg one. > > The driver supports both the method for requesting the peripheral used > by SoCs before the S3C2443 and the different method for S3C2443 and later. > > On earlier SoCs the hardware channels usable for specific peripherals is > constrainted while on later SoCs all channels can be used for any peripheral. > > Tested on a s3c2416-based board, memcpy using the dmatest module and > slave_sg partially using the spi-s3c64xx driver. > > +static int s3c24xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, > + unsigned long arg) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + unsigned long flags; > + int ret = 0; > + > + /* Controls applicable to inactive channels */ > + if (cmd == DMA_SLAVE_CONFIG) > + return s3c24xx_dma_set_runtime_config(s3cchan, > + (struct dma_slave_config *)arg); > + > + /* > + * Anything succeeds on channels with no physical allocation and > + * no queued transfers. > + */ > + spin_lock_irqsave(&s3cchan->vc.lock, flags); > + if (!s3cchan->phy && !s3cchan->at) { > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > + return 0; this can be bad cmd or terminating already closed channel, return 0 doesnt make sense > + } > + > + switch (cmd) { > + case DMA_TERMINATE_ALL: why not DMA_SLAVE_CONFIG in this switch to make it look simpler... > +static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan, > + dma_cookie_t cookie, struct dma_tx_state *txstate) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct virt_dma_desc *vd; > + unsigned long flags; > + enum dma_status ret; > + size_t bytes = 0; > + > + ret = dma_cookie_status(chan, cookie, txstate); > + if (ret == DMA_SUCCESS) > + return ret; > + > + /* > + * There's no point calculating the residue if there's > + * no txstate to store the value. > + */ > + if (!txstate) > + return ret; > + > + spin_lock_irqsave(&s3cchan->vc.lock, flags); > + ret = dma_cookie_status(chan, cookie, txstate); you are checking the cookie status twice, if you check txstate (which should be valid anyways), then you avoid the duplication > + if (ret != DMA_SUCCESS) { > + struct s3c24xx_txd *txd; > + struct s3c24xx_sg *dsg; > + > + vd = vchan_find_desc(&s3cchan->vc, cookie); > + if (vd) { > + /* On the issued list, so hasn't been processed yet */ > + txd = to_s3c24xx_txd(&vd->tx); > + > + list_for_each_entry(dsg, &txd->dsg_list, node) > + bytes += dsg->len; > + } else { > + /* > + * Currently running, so sum over the pending sg's and > + * the currently active one. > + */ > + txd = s3cchan->at; > + > + dsg = list_entry(txd->at, struct s3c24xx_sg, node); > + list_for_each_entry_from(dsg, &txd->dsg_list, node); > + bytes += dsg->len; > + > + bytes += s3c24xx_dma_getbytes_chan(s3cchan); > + } > + } > + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); > + > + /* > + * This cookie not complete yet > + * Get number of bytes left in the active transactions and queue > + */ > + dma_set_residue(txstate, bytes); > + > + /* Whether waiting or running, we're in progress */ > + return ret; > +} > + > +/* > + * Initialize a descriptor to be used by memcpy submit > + */ > +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy( > + struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, > + size_t len, unsigned long flags) > +{ > + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); > + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; > + struct s3c24xx_txd *txd; > + struct s3c24xx_sg *dsg; > + > + dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n", > + len, s3cchan->name); > + > + if ((len & S3C24XX_DCON_TC_MASK) != len) { > + dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len); > + return NULL; > + } > + > + txd = s3c24xx_dma_get_txd(); > + if (!txd) > + return NULL; > + > + dsg = kzalloc(sizeof(struct s3c24xx_sg), GFP_NOWAIT); sizeof(*dsg) ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 6825957..9f17c27 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -154,6 +154,18 @@ config TEGRA20_APB_DMA This DMA controller transfers data from memory to peripheral fifo or vice versa. It does not support memory to memory data transfer. +config S3C24XX_DMAC + bool "Samsung S3C24XX DMA support" + depends on ARCH_S3C24XX && !S3C24XX_DMA + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Support for the Samsung S3C24XX DMA controller driver. The + DMA controller is having multiple DMA channels which can be + configured for different peripherals like audio, UART, SPI. + The DMA controller can transfer data from memory to peripheral, + periphal to memory, periphal to periphal and memory to memory. + source "drivers/dma/sh/Kconfig" config COH901318 diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 5e0f2ef..5c1655a 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_SIRF_DMA) += sirf-dma.o obj-$(CONFIG_TI_EDMA) += edma.o obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o +obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o obj-$(CONFIG_PL330_DMA) += pl330.o obj-$(CONFIG_PCH_DMA) += pch_dma.o obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o diff --git a/drivers/dma/s3c24xx-dma.c b/drivers/dma/s3c24xx-dma.c new file mode 100644 index 0000000..66cd20b --- /dev/null +++ b/drivers/dma/s3c24xx-dma.c @@ -0,0 +1,1285 @@ +/* + * S3C24XX DMA handling + * + * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de> + * + * based on amba-pl08x.c + * + * Copyright (c) 2006 ARM Ltd. + * Copyright (c) 2010 ST-Ericsson SA + * + * Author: Peter Pearse <peter.pearse@arm.com> + * Author: Linus Walleij <linus.walleij@stericsson.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * The DMA controllers in S3C24XX SoCs have a varying number of DMA signals + * that can be routed to any of the 4 to 8 hardware-channels. + * + * Therefore on these DMA controllers the number of channels + * and the number of incoming DMA signals are two totally different things. + * It is usually not possible to theoretically handle all physical signals, + * so a multiplexing scheme with possible denial of use is necessary. + * + * Open items: + * - bursts + */ + +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/platform_data/dma-s3c24xx.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +#define MAX_DMA_CHANNELS 8 + +#define S3C24XX_DISRC (0x00) +#define S3C24XX_DISRCC (0x04) +#define S3C24XX_DISRCC_INC_INCREMENT (0 << 0) +#define S3C24XX_DISRCC_INC_FIXED (1 << 0) +#define S3C24XX_DISRCC_LOC_AHB (0 << 1) +#define S3C24XX_DISRCC_LOC_APB (1 << 1) + +#define S3C24XX_DIDST (0x08) +#define S3C24XX_DIDSTC (0x0C) +#define S3C24XX_DIDSTC_INC_INCREMENT (0 << 0) +#define S3C24XX_DIDSTC_INC_FIXED (1 << 0) +#define S3C24XX_DIDSTC_LOC_AHB (0 << 1) +#define S3C24XX_DIDSTC_LOC_APB (1 << 1) +#define S3C24XX_DIDSTC_INT_TC0 (0 << 2) +#define S3C24XX_DIDSTC_INT_RELOAD (1 << 2) + +#define S3C24XX_DCON (0x10) + +#define S3C24XX_DCON_TC_MASK 0xfffff +#define S3C24XX_DCON_DSZ_BYTE (0 << 20) +#define S3C24XX_DCON_DSZ_HALFWORD (1 << 20) +#define S3C24XX_DCON_DSZ_WORD (2 << 20) +#define S3C24XX_DCON_DSZ_MASK (3 << 20) +#define S3C24XX_DCON_DSZ_SHIFT 20 +#define S3C24XX_DCON_AUTORELOAD (0 << 22) +#define S3C24XX_DCON_NORELOAD (1 << 22) +#define S3C24XX_DCON_HWTRIG (1 << 23) +#define S3C24XX_DCON_HWSRC_SHIFT 24 +#define S3C24XX_DCON_SERV_SINGLE (0 << 27) +#define S3C24XX_DCON_SERV_WHOLE (1 << 27) +#define S3C24XX_DCON_TSZ_UNIT (0 << 28) +#define S3C24XX_DCON_TSZ_BURST4 (1 << 28) +#define S3C24XX_DCON_INT (1 << 29) +#define S3C24XX_DCON_SYNC_PCLK (0 << 30) +#define S3C24XX_DCON_SYNC_HCLK (1 << 30) +#define S3C24XX_DCON_DEMAND (0 << 31) +#define S3C24XX_DCON_HANDSHAKE (1 << 31) + +#define S3C24XX_DSTAT (0x14) +#define S3C24XX_DSTAT_STAT_BUSY (1 << 20) +#define S3C24XX_DSTAT_CURRTC_MASK 0xfffff + +#define S3C24XX_DMASKTRIG (0x20) +#define S3C24XX_DMASKTRIG_STOP (1 << 2) +#define S3C24XX_DMASKTRIG_ON (1 << 1) +#define S3C24XX_DMASKTRIG_SWTRIG (1 << 0) + +#define S3C24XX_DMAREQSEL (0x24) +#define S3C24XX_DMAREQSEL_HW (1 << 0) + +/* + * S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel + * for a DMA source. Instead only specific channels are valid. + * All of these SoCs have 4 physical channels and the number of request + * source bits is 3. Additionally we also need 1 bit to mark the channel + * as valid. + * Therefore we separate the chansel element of the channel data into 4 + * parts of 4 bits each, to hold the information if the channel is valid + * and the hw request source to use. + * + * Example: + * SDI is valid on channels 0, 2 and 3 - with varying hw request sources. + * For it the chansel field would look like + * + * ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1 + * ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2 + * ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2 + */ +#define S3C24XX_CHANSEL_WIDTH 4 +#define S3C24XX_CHANSEL_VALID BIT(3) +#define S3C24XX_CHANSEL_REQ_MASK 7 + +/* + * struct soc_data - vendor-specific config parameters for individual SoCs + * @stride: spacing between the registers of each channel + * @has_reqsel: does the controller use the newer requestselection mechanism + * @has_clocks: are controllable dma-clocks present + */ +struct soc_data { + int stride; + bool has_reqsel; + bool has_clocks; +}; + +/* + * enum s3c24xx_dma_chan_state - holds the virtual channel states + * @S3C24XX_DMA_CHAN_IDLE: the channel is idle + * @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical transport + * channel and is running a transfer on it + * @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical transport + * channel to become available (only pertains to memcpy channels) + */ +enum s3c24xx_dma_chan_state { + S3C24XX_DMA_CHAN_IDLE, + S3C24XX_DMA_CHAN_RUNNING, + S3C24XX_DMA_CHAN_WAITING, +}; + +/* + * struct s3c24xx_sg - structure containing data per sg + * @src_addr: src address of sg + * @dst_addr: dst address of sg + * @len: transfer len in bytes + * @node: node for txd's dsg_list + */ +struct s3c24xx_sg { + dma_addr_t src_addr; + dma_addr_t dst_addr; + size_t len; + struct list_head node; +}; + +/* + * struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor + * @vd: virtual DMA descriptor + * @dsg_list: list of children sg's + * @at: sg currently being transfered + * @width: transfer width + * @disrcc: value for source control register + * @didstc: value for destination control register + * @dcon: base value for dcon register + */ +struct s3c24xx_txd { + struct virt_dma_desc vd; + struct list_head dsg_list; + struct list_head *at; + u8 width; + u32 disrcc; + u32 didstc; + u32 dcon; +}; + +struct s3c24xx_dma_chan; + +/* + * struct s3c24xx_dma_phy - holder for the physical channels + * @id: physical index to this channel + * @valid: does the channel have all required elements + * @base: virtual memory base (remapped) for the this channel + * @irq: interrupt for this channel + * @clk: clock for this channel + * @lock: a lock to use when altering an instance of this struct + * @serving: virtual channel currently being served by this physicalchannel + * @host: a pointer to the host (internal use) + */ +struct s3c24xx_dma_phy { + unsigned int id; + bool valid; + void __iomem *base; + unsigned int irq; + struct clk *clk; + spinlock_t lock; + struct s3c24xx_dma_chan *serving; + struct s3c24xx_dma_engine *host; +}; + +/* + * struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel + * @id: the id of the channel + * @name: name of the channel + * @vc: wrappped virtual channel + * @phy: the physical channel utilized by this channel, if there is one + * @runtime_addr: address for RX/TX according to the runtime config + * @at: active transaction on this channel + * @lock: a lock for this channel data + * @host: a pointer to the host (internal use) + * @state: whether the channel is idle, running etc + * @slave: whether this channel is a device (slave) or for memcpy + */ +struct s3c24xx_dma_chan { + int id; + const char *name; + struct virt_dma_chan vc; + struct s3c24xx_dma_phy *phy; + struct dma_slave_config cfg; + struct s3c24xx_txd *at; + struct s3c24xx_dma_engine *host; + enum s3c24xx_dma_chan_state state; + bool slave; +}; + +/* + * struct s3c24xx_dma_engine - the local state holder for the S3C24XX + * @pdev: the corresponding platform device + * @pdata: platform data passed in from the platform/machine + * @base: virtual memory base (remapped) + * @slave: slave engine for this instance + * @memcpy: memcpy engine for this instance + * @phy_chans: array of data for the physical channels + */ +struct s3c24xx_dma_engine { + struct platform_device *pdev; + const struct s3c24xx_dma_platdata *pdata; + struct soc_data *sdata; + void __iomem *base; + struct dma_device slave; + struct dma_device memcpy; + struct s3c24xx_dma_phy *phy_chans; +}; + +/* + * Physical channel handling + */ + +/* + * Check whether a certain channel is busy or not. + */ +static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy) +{ + unsigned int val = readl(phy->base + S3C24XX_DSTAT); + return val & S3C24XX_DSTAT_STAT_BUSY; +} + +static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan, + struct s3c24xx_dma_phy *phy) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; + struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; + int phyvalid; + + /* every phy is valid for memcopy channels */ + if (!s3cchan->slave) + return true; + + /* On newer variants all phys can be used for all virtual channels */ + if (s3cdma->sdata->has_reqsel) + return true; + + phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH)); + return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false; +} + +/* + * Allocate a physical channel for a virtual channel + * + * Try to locate a physical channel to be used for this transfer. If all + * are taken return NULL and the requester will have to cope by using + * some fallback PIO mode or retrying later. + */ +static +struct s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; + struct s3c24xx_dma_channel *cdata; + struct s3c24xx_dma_phy *phy = NULL; + unsigned long flags; + int i; + int ret; + + if (s3cchan->slave) + cdata = &pdata->channels[s3cchan->id]; + + for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) { + phy = &s3cdma->phy_chans[i]; + + if (!phy || !phy->valid) + continue; + + if (!s3c24xx_dma_phy_valid(s3cchan, phy)) + continue; + + spin_lock_irqsave(&phy->lock, flags); + + if (!phy->serving) { + phy->serving = s3cchan; + spin_unlock_irqrestore(&phy->lock, flags); + break; + } + + spin_unlock_irqrestore(&phy->lock, flags); + } + + /* No physical channel available, cope with it */ + if (i == s3cdma->pdata->num_phy_channels) { + dev_warn(&s3cdma->pdev->dev, "no phy channel available\n"); + return NULL; + } + + /* start the phy clock */ + if (s3cdma->sdata->has_clocks) { + ret = clk_enable(phy->clk); + if (ret) { + phy->serving = NULL; + return NULL; + } + } + + return phy; +} + +/* + * Mark the physical channel as free. + * + * This drops the link between the physical and virtual channel. + */ +static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy) +{ + struct s3c24xx_dma_engine *s3cdma = phy->host; + + if (s3cdma->sdata->has_clocks) + clk_disable(phy->clk); + + phy->serving = NULL; +} + +/* + * Stops the channel by writing the stop bit. + * This should not be used for an on-going transfer, but as a method of + * shutting down a channel (eg, when it's no longer used) or terminating a + * transfer. + */ +static void s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy) +{ + writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG); +} + +/* + * Virtual channel handling + */ + +static inline +struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan) +{ + return container_of(chan, struct s3c24xx_dma_chan, vc.chan); +} + +static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_phy *phy = s3cchan->phy; + struct s3c24xx_txd *txd = s3cchan->at; + u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK; + + return tc * txd->width; +} + +static int s3c24xx_dma_set_runtime_config(struct s3c24xx_dma_chan *s3cchan, + struct dma_slave_config *config) +{ + if (!s3cchan->slave) + return -EINVAL; + + /* Reject definitely invalid configurations */ + if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || + config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) + return -EINVAL; + + s3cchan->cfg = *config; + + return 0; +} + +/* + * Transfer handling + */ + +static inline +struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct s3c24xx_txd, vd.tx); +} + +static struct s3c24xx_txd *s3c24xx_dma_get_txd(void) +{ + struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT); + + if (txd) { + INIT_LIST_HEAD(&txd->dsg_list); + txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD; + } + + return txd; +} + +static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd) +{ + struct s3c24xx_sg *dsg, *_dsg; + + list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) { + list_del(&dsg->node); + kfree(dsg); + } + + kfree(txd); +} + +static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan, + struct s3c24xx_txd *txd) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + struct s3c24xx_dma_phy *phy = s3cchan->phy; + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; + struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node); + u32 dcon = txd->dcon; + u32 val; + + /* transfer-size and -count from len and width */ + switch (txd->width) { + case 1: + dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len; + break; + case 2: + dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2); + break; + case 4: + dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4); + break; + } + + if (s3cchan->slave) { + struct s3c24xx_dma_channel *cdata = + &pdata->channels[s3cchan->id]; + if (s3cdma->sdata->has_reqsel) { + writel_relaxed((cdata->chansel << 1) | + S3C24XX_DMAREQSEL_HW, + phy->base + S3C24XX_DMAREQSEL); + } else { + int csel = cdata->chansel >> (phy->id * + S3C24XX_CHANSEL_WIDTH); + csel &= S3C24XX_CHANSEL_REQ_MASK; + dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT; + dcon |= S3C24XX_DCON_HWTRIG; + } + } else { + if (s3cdma->sdata->has_reqsel) + writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL); + } + + writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC); + writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC); + writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST); + writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC); + writel_relaxed(dcon, phy->base + S3C24XX_DCON); + + val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG); + val &= ~S3C24XX_DMASKTRIG_STOP; + val |= S3C24XX_DMASKTRIG_ON; + + /* trigger the dma operation for memcpy transfers */ + if (!s3cchan->slave) + val |= S3C24XX_DMASKTRIG_SWTRIG; + + writel(val, phy->base + S3C24XX_DMASKTRIG); +} + +/* + * Set the initial DMA register values and start first sg. + */ +static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_phy *phy = s3cchan->phy; + struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc); + struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); + + list_del(&txd->vd.node); + + s3cchan->at = txd; + + /* Wait for channel inactive */ + while (s3c24xx_dma_phy_busy(phy)) + cpu_relax(); + + /* point to the first element of the sg list */ + txd->at = txd->dsg_list.next; + s3c24xx_dma_start_next_sg(s3cchan, txd); +} + +static void s3c24xx_dma_free_txd_list(struct s3c24xx_dma_engine *s3cdma, + struct s3c24xx_dma_chan *s3cchan) +{ + LIST_HEAD(head); + + vchan_get_all_descriptors(&s3cchan->vc, &head); + vchan_dma_desc_free_list(&s3cchan->vc, &head); +} + +/* + * Try to allocate a physical channel. When successful, assign it to + * this virtual channel, and initiate the next descriptor. The + * virtual channel lock must be held at this point. + */ +static void s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + struct s3c24xx_dma_phy *phy; + + phy = s3c24xx_dma_get_phy(s3cchan); + if (!phy) { + dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer on %s\n", + s3cchan->name); + s3cchan->state = S3C24XX_DMA_CHAN_WAITING; + return; + } + + dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on %s\n", + phy->id, s3cchan->name); + + s3cchan->phy = phy; + s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; + + s3c24xx_dma_start_next_txd(s3cchan); +} + +static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy, + struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + + dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer on %s\n", + phy->id, s3cchan->name); + + /* + * We do this without taking the lock; we're really only concerned + * about whether this pointer is NULL or not, and we're guaranteed + * that this will only be called when it _already_ is non-NULL. + */ + phy->serving = s3cchan; + s3cchan->phy = phy; + s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; + s3c24xx_dma_start_next_txd(s3cchan); +} + +/* + * Free a physical DMA channel, potentially reallocating it to another + * virtual channel if we have any pending. + */ +static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan) +{ + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + struct s3c24xx_dma_chan *p, *next; + +retry: + next = NULL; + + /* Find a waiting virtual channel for the next transfer. */ + list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node) + if (p->state == S3C24XX_DMA_CHAN_WAITING) { + next = p; + break; + } + + if (!next) { + list_for_each_entry(p, &s3cdma->slave.channels, + vc.chan.device_node) + if (p->state == S3C24XX_DMA_CHAN_WAITING && + s3c24xx_dma_phy_valid(p, s3cchan->phy)) { + next = p; + break; + } + } + + /* Ensure that the physical channel is stopped */ + s3c24xx_dma_terminate_phy(s3cchan->phy); + + if (next) { + bool success; + + /* + * Eww. We know this isn't going to deadlock + * but lockdep probably doesn't. + */ + spin_lock(&next->vc.lock); + /* Re-check the state now that we have the lock */ + success = next->state == S3C24XX_DMA_CHAN_WAITING; + if (success) + s3c24xx_dma_phy_reassign_start(s3cchan->phy, next); + spin_unlock(&next->vc.lock); + + /* If the state changed, try to find another channel */ + if (!success) + goto retry; + } else { + /* No more jobs, so free up the physical channel */ + s3c24xx_dma_put_phy(s3cchan->phy); + } + + s3cchan->phy = NULL; + s3cchan->state = S3C24XX_DMA_CHAN_IDLE; +} + +static void s3c24xx_dma_unmap_buffers(struct s3c24xx_txd *txd) +{ + struct device *dev = txd->vd.tx.chan->device->dev; + struct s3c24xx_sg *dsg; + + if (!(txd->vd.tx.flags & DMA_COMPL_SKIP_SRC_UNMAP)) { + if (txd->vd.tx.flags & DMA_COMPL_SRC_UNMAP_SINGLE) + list_for_each_entry(dsg, &txd->dsg_list, node) + dma_unmap_single(dev, dsg->src_addr, dsg->len, + DMA_TO_DEVICE); + else { + list_for_each_entry(dsg, &txd->dsg_list, node) + dma_unmap_page(dev, dsg->src_addr, dsg->len, + DMA_TO_DEVICE); + } + } + + if (!(txd->vd.tx.flags & DMA_COMPL_SKIP_DEST_UNMAP)) { + if (txd->vd.tx.flags & DMA_COMPL_DEST_UNMAP_SINGLE) + list_for_each_entry(dsg, &txd->dsg_list, node) + dma_unmap_single(dev, dsg->dst_addr, dsg->len, + DMA_FROM_DEVICE); + else + list_for_each_entry(dsg, &txd->dsg_list, node) + dma_unmap_page(dev, dsg->dst_addr, dsg->len, + DMA_FROM_DEVICE); + } +} + +static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd) +{ + struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd->tx.chan); + + if (!s3cchan->slave) + s3c24xx_dma_unmap_buffers(txd); + + s3c24xx_dma_free_txd(txd); +} + +static irqreturn_t s3c24xx_dma_irq(int irq, void *data) +{ + struct s3c24xx_dma_phy *phy = data; + struct s3c24xx_dma_chan *s3cchan = phy->serving; + struct s3c24xx_txd *txd; + + dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy->id); + + /* + * Interrupts happen to notify the completion of a transfer and the + * channel should have moved into its stop state already on its own. + * Therefore interrupts on channels not bound to a virtual channel + * should never happen. Nevertheless send a terminate command to the + * channel if the unlikely case happens. + */ + if (unlikely(!s3cchan)) { + dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n", + phy->id); + + s3c24xx_dma_terminate_phy(phy); + + return IRQ_HANDLED; + } + + spin_lock(&s3cchan->vc.lock); + txd = s3cchan->at; + if (txd) { + /* when more sg's are in this txd, start the next one */ + if (!list_is_last(txd->at, &txd->dsg_list)) { + txd->at = txd->at->next; + s3c24xx_dma_start_next_sg(s3cchan, txd); + } else { + s3cchan->at = NULL; + vchan_cookie_complete(&txd->vd); + + /* + * And start the next descriptor (if any), + * otherwise free this channel. + */ + if (vchan_next_desc(&s3cchan->vc)) + s3c24xx_dma_start_next_txd(s3cchan); + else + s3c24xx_dma_phy_free(s3cchan); + } + } + spin_unlock(&s3cchan->vc.lock); + + return IRQ_HANDLED; +} + +/* + * The DMA ENGINE API + */ + +static int s3c24xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, + unsigned long arg) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + unsigned long flags; + int ret = 0; + + /* Controls applicable to inactive channels */ + if (cmd == DMA_SLAVE_CONFIG) + return s3c24xx_dma_set_runtime_config(s3cchan, + (struct dma_slave_config *)arg); + + /* + * Anything succeeds on channels with no physical allocation and + * no queued transfers. + */ + spin_lock_irqsave(&s3cchan->vc.lock, flags); + if (!s3cchan->phy && !s3cchan->at) { + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); + return 0; + } + + switch (cmd) { + case DMA_TERMINATE_ALL: + s3cchan->state = S3C24XX_DMA_CHAN_IDLE; + + /* Mark physical channel as free */ + if (s3cchan->phy) + s3c24xx_dma_phy_free(s3cchan); + + /* Dequeue current job */ + if (s3cchan->at) { + s3c24xx_dma_desc_free(&s3cchan->at->vd); + s3cchan->at = NULL; + } + + /* Dequeue jobs not yet fired as well */ + s3c24xx_dma_free_txd_list(s3cdma, s3cchan); + break; + default: + /* Unknown command */ + ret = -ENXIO; + break; + } + + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); + + return ret; +} + +static int s3c24xx_dma_alloc_chan_resources(struct dma_chan *chan) +{ + return 0; +} + +static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan) +{ + /* Ensure all queued descriptors are freed */ + vchan_free_chan_resources(to_virt_chan(chan)); +} + +static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *txstate) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + struct virt_dma_desc *vd; + unsigned long flags; + enum dma_status ret; + size_t bytes = 0; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_SUCCESS) + return ret; + + /* + * There's no point calculating the residue if there's + * no txstate to store the value. + */ + if (!txstate) + return ret; + + spin_lock_irqsave(&s3cchan->vc.lock, flags); + ret = dma_cookie_status(chan, cookie, txstate); + if (ret != DMA_SUCCESS) { + struct s3c24xx_txd *txd; + struct s3c24xx_sg *dsg; + + vd = vchan_find_desc(&s3cchan->vc, cookie); + if (vd) { + /* On the issued list, so hasn't been processed yet */ + txd = to_s3c24xx_txd(&vd->tx); + + list_for_each_entry(dsg, &txd->dsg_list, node) + bytes += dsg->len; + } else { + /* + * Currently running, so sum over the pending sg's and + * the currently active one. + */ + txd = s3cchan->at; + + dsg = list_entry(txd->at, struct s3c24xx_sg, node); + list_for_each_entry_from(dsg, &txd->dsg_list, node); + bytes += dsg->len; + + bytes += s3c24xx_dma_getbytes_chan(s3cchan); + } + } + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); + + /* + * This cookie not complete yet + * Get number of bytes left in the active transactions and queue + */ + dma_set_residue(txstate, bytes); + + /* Whether waiting or running, we're in progress */ + return ret; +} + +/* + * Initialize a descriptor to be used by memcpy submit + */ +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy( + struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + struct s3c24xx_txd *txd; + struct s3c24xx_sg *dsg; + + dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n", + len, s3cchan->name); + + if ((len & S3C24XX_DCON_TC_MASK) != len) { + dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len); + return NULL; + } + + txd = s3c24xx_dma_get_txd(); + if (!txd) + return NULL; + + dsg = kzalloc(sizeof(struct s3c24xx_sg), GFP_NOWAIT); + if (!dsg) { + s3c24xx_dma_free_txd(txd); + return NULL; + } + list_add_tail(&dsg->node, &txd->dsg_list); + + dsg->src_addr = src; + dsg->dst_addr = dest; + dsg->len = len; + + txd->width = 1; + txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT; + txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT; + txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK | + S3C24XX_DCON_SERV_WHOLE; + + return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); +} + +static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + struct s3c24xx_dma_engine *s3cdma = s3cchan->host; + const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; + struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; + struct s3c24xx_txd *txd; + struct s3c24xx_sg *dsg; + struct scatterlist *sg; + dma_addr_t slave_addr; + u32 hwcfg = 0; + int tmp; + + dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from %s\n", + sg_dma_len(sgl), s3cchan->name); + + txd = s3c24xx_dma_get_txd(); + if (!txd) + return NULL; + + if (cdata->handshake) + txd->dcon |= S3C24XX_DCON_HANDSHAKE; + + switch (cdata->bus) { + case S3C24XX_DMA_APB: + txd->dcon |= S3C24XX_DCON_SYNC_PCLK; + hwcfg |= S3C24XX_DISRCC_LOC_APB; + break; + case S3C24XX_DMA_AHB: + txd->dcon |= S3C24XX_DCON_SYNC_HCLK; + hwcfg |= S3C24XX_DISRCC_LOC_AHB; + break; + } + + /* always assume our peripheral desintation is a fixed + * address in memory. */ + hwcfg |= S3C24XX_DISRCC_INC_FIXED; + + /* individual dma operations are requested by the slave, + * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE). + */ + txd->dcon |= S3C24XX_DCON_SERV_SINGLE; + + if (direction == DMA_MEM_TO_DEV) { + txd->disrcc = S3C24XX_DISRCC_LOC_AHB | + S3C24XX_DISRCC_INC_INCREMENT; + txd->didstc = hwcfg; + slave_addr = s3cchan->cfg.dst_addr; + txd->width = s3cchan->cfg.dst_addr_width; + } else if (direction == DMA_DEV_TO_MEM) { + txd->disrcc = hwcfg; + txd->didstc = S3C24XX_DIDSTC_LOC_AHB | + S3C24XX_DIDSTC_INC_INCREMENT; + slave_addr = s3cchan->cfg.src_addr; + txd->width = s3cchan->cfg.src_addr_width; + } else { + s3c24xx_dma_free_txd(txd); + dev_err(&s3cdma->pdev->dev, + "direction %d unsupported\n", direction); + return NULL; + } + + for_each_sg(sgl, sg, sg_len, tmp) { + dsg = kzalloc(sizeof(struct s3c24xx_sg), GFP_NOWAIT); + if (!dsg) { + s3c24xx_dma_free_txd(txd); + return NULL; + } + list_add_tail(&dsg->node, &txd->dsg_list); + + dsg->len = sg_dma_len(sg); + if (direction == DMA_MEM_TO_DEV) { + dsg->src_addr = sg_dma_address(sg); + dsg->dst_addr = slave_addr; + } else { /* DMA_DEV_TO_MEM */ + dsg->src_addr = slave_addr; + dsg->dst_addr = sg_dma_address(sg); + } + break; + } + + return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); +} + +/* + * Slave transactions callback to the slave device to allow + * synchronization of slave DMA signals with the DMAC enable + */ +static void s3c24xx_dma_issue_pending(struct dma_chan *chan) +{ + struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&s3cchan->vc.lock, flags); + if (vchan_issue_pending(&s3cchan->vc)) { + if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING) + s3c24xx_dma_phy_alloc_and_start(s3cchan); + } + spin_unlock_irqrestore(&s3cchan->vc.lock, flags); +} + +/* + * Bringup and teardown + */ + +/* + * Initialise the DMAC memcpy/slave channels. + * Make a local wrapper to hold required data + */ +static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine *s3cdma, + struct dma_device *dmadev, unsigned int channels, bool slave) +{ + struct s3c24xx_dma_chan *chan; + int i; + + INIT_LIST_HEAD(&dmadev->channels); + + /* + * Register as many many memcpy as we have physical channels, + * we won't always be able to use all but the code will have + * to cope with that situation. + */ + for (i = 0; i < channels; i++) { + chan = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL); + if (!chan) { + dev_err(dmadev->dev, + "%s no memory for channel\n", __func__); + return -ENOMEM; + } + + chan->id = i; + chan->host = s3cdma; + chan->state = S3C24XX_DMA_CHAN_IDLE; + + if (slave) { + chan->slave = true; + chan->name = kasprintf(GFP_KERNEL, "slave%d", i); + if (!chan->name) + return -ENOMEM; + } else { + chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i); + if (!chan->name) + return -ENOMEM; + } + dev_dbg(dmadev->dev, + "initialize virtual channel \"%s\"\n", + chan->name); + + chan->vc.desc_free = s3c24xx_dma_desc_free; + vchan_init(&chan->vc, dmadev); + } + dev_info(dmadev->dev, "initialized %d virtual %s channels\n", + i, slave ? "slave" : "memcpy"); + return i; +} + +static void s3c24xx_dma_free_virtual_channels(struct dma_device *dmadev) +{ + struct s3c24xx_dma_chan *chan = NULL; + struct s3c24xx_dma_chan *next; + + list_for_each_entry_safe(chan, + next, &dmadev->channels, vc.chan.device_node) + list_del(&chan->vc.chan.device_node); +} + +/* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */ +static struct soc_data soc_s3c2412 = { + .stride = 0x40, + .has_reqsel = true, + .has_clocks = true, +}; + +/* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */ +static struct soc_data soc_s3c2443 = { + .stride = 0x100, + .has_reqsel = true, + .has_clocks = true, +}; + +static struct platform_device_id s3c24xx_dma_driver_ids[] = { + { + .name = "s3c2412-dma", + .driver_data = (kernel_ulong_t)&soc_s3c2412, + }, { + .name = "s3c2443-dma", + .driver_data = (kernel_ulong_t)&soc_s3c2443, + }, + { }, +}; + +static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device *pdev) +{ + return (struct soc_data *) + platform_get_device_id(pdev)->driver_data; +} + +static int s3c24xx_dma_probe(struct platform_device *pdev) +{ + const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev); + struct soc_data *sdata; + struct s3c24xx_dma_engine *s3cdma; + struct resource *res; + int ret; + int i; + + if (!pdata) { + dev_err(&pdev->dev, "platform data missing\n"); + return -ENODEV; + } + + /* Basic sanity check */ + if (pdata->num_phy_channels > MAX_DMA_CHANNELS) { + dev_err(&pdev->dev, "to many dma channels %d, max %d\n", + pdata->num_phy_channels, MAX_DMA_CHANNELS); + return -EINVAL; + } + + sdata = s3c24xx_dma_get_soc_data(pdev); + if (!sdata) + return -EINVAL; + + s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL); + if (!s3cdma) + return -ENOMEM; + + s3cdma->pdev = pdev; + s3cdma->pdata = pdata; + s3cdma->sdata = sdata; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + s3cdma->base = devm_request_and_ioremap(&pdev->dev, res); + if (!s3cdma->base) { + dev_err(&pdev->dev, "could not map dma registers\n"); + return -EBUSY; + } + + s3cdma->phy_chans = devm_kzalloc(&pdev->dev, + sizeof(struct s3c24xx_dma_phy) * + pdata->num_phy_channels, + GFP_KERNEL); + if (!s3cdma->phy_chans) + return -ENOMEM; + + /* aquire irqs and clocks for all physical channels */ + for (i = 0; i < pdata->num_phy_channels; i++) { + struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i]; + char clk_name[6]; + + phy->id = i; + phy->base = s3cdma->base + (i * sdata->stride); + phy->host = s3cdma; + + sprintf(clk_name, "dma.%d", i); + phy->clk = devm_clk_get(&pdev->dev, clk_name); + if (IS_ERR(phy->clk) && sdata->has_clocks) { + dev_err(&pdev->dev, "unable to aquire clock for channel %d, error %lu", + i, PTR_ERR(phy->clk)); + continue; + } + + if (sdata->has_clocks) { + ret = clk_prepare(phy->clk); + if (ret) { + dev_err(&pdev->dev, "clock for phy %d failed, error %d\n", + i, ret); + continue; + } + } + + res = platform_get_resource(pdev, IORESOURCE_IRQ, i); + if (res) + phy->irq = res->start; + if (!phy->irq) { + dev_err(&pdev->dev, "failed to get irq %d\n", i); + continue; + } + + ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq, + 0, pdev->name, phy); + if (ret) { + dev_err(&pdev->dev, "Unable to request irq for channel %d, error %d\n", + i, ret); + continue; + } + + spin_lock_init(&phy->lock); + phy->valid = true; + + dev_dbg(&pdev->dev, "physical channel %d is %s\n", + i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE"); + } + + /* Initialize memcpy engine */ + dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask); + dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask); + s3cdma->memcpy.dev = &pdev->dev; + s3cdma->memcpy.device_alloc_chan_resources = + s3c24xx_dma_alloc_chan_resources; + s3cdma->memcpy.device_free_chan_resources = + s3c24xx_dma_free_chan_resources; + s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy; + s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status; + s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending; + s3cdma->memcpy.device_control = s3c24xx_dma_control; + + /* Initialize slave engine for SoC internal dedicated peripherals */ + dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask); + dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask); + s3cdma->slave.dev = &pdev->dev; + s3cdma->slave.device_alloc_chan_resources = + s3c24xx_dma_alloc_chan_resources; + s3cdma->slave.device_free_chan_resources = + s3c24xx_dma_free_chan_resources; + s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status; + s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending; + s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg; + s3cdma->slave.device_control = s3c24xx_dma_control; + + /* Register as many memcpy channels as there are physical channels */ + ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy, + pdata->num_phy_channels, false); + if (ret <= 0) { + dev_warn(&pdev->dev, + "%s failed to enumerate memcpy channels - %d\n", + __func__, ret); + goto err_memcpy; + } + + /* Register slave channels */ + ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave, + pdata->num_channels, true); + if (ret <= 0) { + dev_warn(&pdev->dev, + "%s failed to enumerate slave channels - %d\n", + __func__, ret); + goto err_slave; + } + + ret = dma_async_device_register(&s3cdma->memcpy); + if (ret) { + dev_warn(&pdev->dev, + "%s failed to register memcpy as an async device - %d\n", + __func__, ret); + goto err_memcpy_reg; + } + + ret = dma_async_device_register(&s3cdma->slave); + if (ret) { + dev_warn(&pdev->dev, + "%s failed to register slave as an async device - %d\n", + __func__, ret); + goto err_slave_reg; + } + + platform_set_drvdata(pdev, s3cdma); + dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n", + pdata->num_phy_channels); + + return 0; + +err_slave_reg: + dma_async_device_unregister(&s3cdma->memcpy); +err_memcpy_reg: + s3c24xx_dma_free_virtual_channels(&s3cdma->slave); +err_slave: + s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy); +err_memcpy: + + return ret; +} + +static struct platform_driver s3c24xx_dma_driver = { + .driver = { + .name = "s3c24xx-dma", + }, + .id_table = s3c24xx_dma_driver_ids, +}; + +bool s3c24xx_dma_filter(struct dma_chan *chan, void *param) +{ + struct s3c24xx_dma_chan *s3cchan; + + if (chan->device->dev->driver != &s3c24xx_dma_driver.driver) + return false; + + s3cchan = to_s3c24xx_dma_chan(chan); + + return s3cchan->id == (int)param; +} +EXPORT_SYMBOL(s3c24xx_dma_filter); + +static int __init s3c24xx_dma_module_init(void) +{ + return platform_driver_probe(&s3c24xx_dma_driver, s3c24xx_dma_probe); +} +subsys_initcall(s3c24xx_dma_module_init); diff --git a/include/linux/platform_data/dma-s3c24xx.h b/include/linux/platform_data/dma-s3c24xx.h new file mode 100644 index 0000000..5a0cfff --- /dev/null +++ b/include/linux/platform_data/dma-s3c24xx.h @@ -0,0 +1,43 @@ +/* + * S3C24XX DMA handling + * + * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ + +enum s3c24xx_dma_bus { + S3C24XX_DMA_APB, + S3C24XX_DMA_AHB, +}; + +/** + * @bus: on which bus does the peripheral reside - AHB or APB. + * @handshake: is a handshake with the peripheral necessary + * @chansel: channel selection information, depending on variant; reqsel for + * s3c2443 and later and channel-selection map for earlier SoCs + * see CHANSEL doc in s3c2443-dma.c + */ +struct s3c24xx_dma_channel { + enum s3c24xx_dma_bus bus; + bool handshake; + u16 chansel; +}; + +/** + * struct s3c24xx_dma_platdata - platform specific settings + * @num_phy_channels: number of physical channels + * @channels: array of virtual channel descriptions + * @num_channels: number of virtual channels + */ +struct s3c24xx_dma_platdata { + int num_phy_channels; + struct s3c24xx_dma_channel *channels; + int num_channels; +}; + +struct dma_chan; +bool s3c24xx_dma_filter(struct dma_chan *chan, void *param);