[PATCHv5,2/2] mailbox: Adding driver for Xilinx LogiCORE IP mailbox.

Message ID	1435082402-29239-3-git-send-email-moritz.fischer@ettus.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Moritz Fischer <moritz.fischer@ettus.com> To: jassisinghbrar@gmail.com Subject: [PATCHv5 2/2] mailbox: Adding driver for Xilinx LogiCORE IP mailbox. Date: Tue, 23 Jun 2015 11:00:02 -0700 Message-Id: <1435082402-29239-3-git-send-email-moritz.fischer@ettus.com> In-Reply-To: <1435082402-29239-1-git-send-email-moritz.fischer@ettus.com> References: <1435082402-29239-1-git-send-email-moritz.fischer@ettus.com> Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Moritz Fischer <moritz.fischer@ettus.com>, arnd@arndb.de, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, gregkh@linuxfoundation.org, mchehab@osg.samsung.com, linux-kernel@vger.kernel.org, michal.simek@xilinx.com, jingoohan1@gmail.com, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, galak@codeaurora.org, joe@perches.com, akpm@linux-foundation.org, soren.brinkmann@xilinx.com Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/MAINTAINERS b/MAINTAINERS index 4f1e79b..cb88b4a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10998,6 +10998,13 @@ M: John Linn <John.Linn@xilinx.com> S: Maintained F: drivers/net/ethernet/xilinx/xilinx_axienet* +XILINX MAILBOX DRIVER +M: Moritz Fischer <moritz.fischer@ettus.com> +L: linux-kernel@vger.kernel.org +S: Maintained +F: drivers/mailbox/mailbox-xilinx.c +F: Documentation/devicetree/bindings/mailbox/xilinx-mailbox.txt + XILINX UARTLITE SERIAL DRIVER M: Peter Korsgaard <jacmet@sunsite.dk> L: linux-serial@vger.kernel.org diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index 84b0a2d..e11e4b2 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig @@ -60,4 +60,12 @@ config ALTERA_MBOX An implementation of the Altera Mailbox soft core. It is used to send message between processors. Say Y here if you want to use the Altera mailbox support. + +config XILINX_MBOX + tristate "Xilinx Mailbox" + help + An implementation of the Xilinx Mailbox soft core. It is used + to send message between processors. Say Y here if you want to use the + Xilinx mailbox support. + endif diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index b18201e..d28a028 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile @@ -11,3 +11,5 @@ obj-$(CONFIG_OMAP2PLUS_MBOX) += omap-mailbox.o obj-$(CONFIG_PCC) += pcc.o obj-$(CONFIG_ALTERA_MBOX) += mailbox-altera.o + +obj-$(CONFIG_XILINX_MBOX) += mailbox-xilinx.o diff --git a/drivers/mailbox/mailbox-xilinx.c b/drivers/mailbox/mailbox-xilinx.c new file mode 100644 index 0000000..9d6364c --- /dev/null +++ b/drivers/mailbox/mailbox-xilinx.c @@ -0,0 +1,375 @@ +/* + * Copyright (c) 2015, National Instruments Corp. All rights reserved. + * + * Driver for the Xilinx LogiCORE mailbox IP block + * + * 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; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mailbox_controller.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +/* register offsets */ +#define MAILBOX_REG_WRDATA 0x00 +#define MAILBOX_REG_RDDATA 0x08 +#define MAILBOX_REG_STATUS 0x10 +#define MAILBOX_REG_ERROR 0x14 +#define MAILBOX_REG_SIT 0x18 +#define MAILBOX_REG_RIT 0x1c +#define MAILBOX_REG_IS 0x20 +#define MAILBOX_REG_IE 0x24 +#define MAILBOX_REG_IP 0x28 + +/* status register */ +#define STS_RTA BIT(3) +#define STS_STA BIT(2) +#define STS_FULL BIT(1) +#define STS_EMPTY BIT(0) + +/* error register */ +#define ERR_FULL BIT(1) +#define ERR_EMPTY BIT(0) + +/* mailbox interrupt status register */ +#define INT_STATUS_ERR BIT(2) +#define INT_STATUS_RTI BIT(1) +#define INT_STATUS_STI BIT(0) + +/* mailbox interrupt enable register */ +#define INT_ENABLE_ERR BIT(2) +#define INT_ENABLE_RTI BIT(1) +#define INT_ENABLE_STI BIT(0) + +#define MBOX_POLLING_MS 5 /* polling interval 5ms */ + +struct xilinx_mbox { + int irq; + void __iomem *mbox_base; + struct clk *clk; + struct device *dev; + struct mbox_controller controller; + struct mbox_chan chan; + + /* if the controller supports only RX polling mode */ + struct timer_list rxpoll_timer; +}; + +static struct xilinx_mbox *mbox_chan_to_xilinx_mbox(struct mbox_chan *chan) +{ + return container_of(chan, struct xilinx_mbox, chan); +} + +static inline bool xilinx_mbox_full(struct xilinx_mbox *mbox) +{ + u32 status; + + status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS); + + return status & STS_FULL; +} + +static inline bool xilinx_mbox_pending(struct xilinx_mbox *mbox) +{ + u32 status; + + status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS); + + return !(status & STS_EMPTY); +} + +static void xilinx_mbox_intmask(struct xilinx_mbox *mbox, u32 mask, bool enable) +{ + u32 mask_reg; + + mask_reg = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IE); + if (enable) + mask_reg |= mask; + else + mask_reg &= ~mask; + + writel_relaxed(mask_reg, mbox->mbox_base + MAILBOX_REG_IE); +} + +static inline void xilinx_mbox_rx_intmask(struct xilinx_mbox *mbox, bool enable) +{ + xilinx_mbox_intmask(mbox, INT_ENABLE_RTI, enable); +} + +static inline void xilinx_mbox_tx_intmask(struct xilinx_mbox *mbox, bool enable) +{ + xilinx_mbox_intmask(mbox, INT_ENABLE_STI, enable); +} + +static void xilinx_mbox_rx_data(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + u32 data; + + if (xilinx_mbox_pending(mbox)) { + data = readl_relaxed(mbox->mbox_base + MAILBOX_REG_RDDATA); + mbox_chan_received_data(chan, (void *)data); + } +} + +static void xilinx_mbox_poll_rx(unsigned long data) +{ + struct mbox_chan *chan = (struct mbox_chan *)data; + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + xilinx_mbox_rx_data(chan); + + mod_timer(&mbox->rxpoll_timer, + jiffies + msecs_to_jiffies(MBOX_POLLING_MS)); +} + +static irqreturn_t xilinx_mbox_interrupt(int irq, void *p) +{ + u32 mask; + struct mbox_chan *chan = (struct mbox_chan *)p; + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + mask = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IS); + if (mask & INT_STATUS_RTI) + xilinx_mbox_rx_data(chan); + + /* mask irqs *before* notifying done, require tx_block=true */ + if (mask & INT_STATUS_STI) { + xilinx_mbox_tx_intmask(mbox, false); + mbox_chan_txdone(chan, 0); + } + + writel_relaxed(mask, mbox->mbox_base + MAILBOX_REG_IS); + + return IRQ_HANDLED; +} + +static int xilinx_mbox_irq_startup(struct mbox_chan *chan) +{ + int ret; + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + ret = request_irq(mbox->irq, xilinx_mbox_interrupt, 0, + dev_name(mbox->dev), chan); + if (unlikely(ret)) { + dev_err(mbox->dev, + "failed to register mailbox interrupt:%d\n", + ret); + return ret; + } + + /* prep and enable the clock */ + clk_prepare_enable(mbox->clk); + + xilinx_mbox_rx_intmask(mbox, true); + + /* if fifo was full already, we didn't get an interrupt */ + while (xilinx_mbox_pending(mbox)) + xilinx_mbox_rx_data(chan); + + return 0; +} + +static int xilinx_mbox_poll_startup(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + /* prep and enable the clock */ + clk_prepare_enable(mbox->clk); + + /* setup polling timer */ + setup_timer(&mbox->rxpoll_timer, xilinx_mbox_poll_rx, + (unsigned long)chan); + mod_timer(&mbox->rxpoll_timer, + jiffies + msecs_to_jiffies(MBOX_POLLING_MS)); + + return 0; +} + +static int xilinx_mbox_irq_send_data(struct mbox_chan *chan, void *data) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + u32 *udata = data; + + if (!mbox || !data) + return -EINVAL; + + if (xilinx_mbox_full(mbox)) + return -EBUSY; + + /* enable interrupt before send */ + xilinx_mbox_tx_intmask(mbox, true); + + writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA); + + return 0; +} + +static int xilinx_mbox_poll_send_data(struct mbox_chan *chan, void *data) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + u32 *udata = data; + + if (!mbox || !data) + return -EINVAL; + + if (xilinx_mbox_full(mbox)) + return -EBUSY; + + writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA); + + return 0; +} + +static bool xilinx_mbox_last_tx_done(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + /* return false if mailbox is full */ + return !xilinx_mbox_full(mbox); +} + +static bool xilinx_mbox_peek_data(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + return xilinx_mbox_pending(mbox); +} + +static void xilinx_mbox_irq_shutdown(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + /* mask all interrupts */ + writel_relaxed(0, mbox->mbox_base + MAILBOX_REG_IE); + + clk_disable_unprepare(mbox->clk); + + free_irq(mbox->irq, chan); +} + +static void xilinx_mbox_poll_shutdown(struct mbox_chan *chan) +{ + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan); + + del_timer_sync(&mbox->rxpoll_timer); + + clk_disable_unprepare(mbox->clk); +} + +static struct mbox_chan_ops xilinx_mbox_irq_ops = { + .send_data = xilinx_mbox_irq_send_data, + .startup = xilinx_mbox_irq_startup, + .shutdown = xilinx_mbox_irq_shutdown, + .last_tx_done = xilinx_mbox_last_tx_done, + .peek_data = xilinx_mbox_peek_data, +}; + +static struct mbox_chan_ops xilinx_mbox_poll_ops = { + .send_data = xilinx_mbox_poll_send_data, + .startup = xilinx_mbox_poll_startup, + .shutdown = xilinx_mbox_poll_shutdown, + .last_tx_done = xilinx_mbox_last_tx_done, + .peek_data = xilinx_mbox_peek_data, +}; + +static int xilinx_mbox_probe(struct platform_device *pdev) +{ + struct xilinx_mbox *mbox; + struct resource *regs; + int ret; + + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); + if (!mbox) + return -ENOMEM; + + /* get clk and enable */ + mbox->clk = devm_clk_get(&pdev->dev, "mbox"); + if (IS_ERR(mbox->clk)) { + dev_err(&pdev->dev, "Couldn't get clk.\n"); + return PTR_ERR(mbox->clk); + } + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs); + if (IS_ERR(mbox->mbox_base)) + return PTR_ERR(mbox->mbox_base); + + mbox->irq = platform_get_irq(pdev, 0); + /* if irq is present, we can use it, otherwise, poll */ + if (mbox->irq > 0) { + mbox->controller.txdone_irq = true; + } else { + dev_info(&pdev->dev, "IRQ not found, fallback to polling.\n"); + mbox->controller.txdone_poll = true; + mbox->controller.txpoll_period = MBOX_POLLING_MS; + } + + mbox->dev = &pdev->dev; + + /* hardware supports only one channel. */ + mbox->controller.dev = mbox->dev; + mbox->controller.num_chans = 1; + mbox->controller.chans = &mbox->chan; + + if (mbox->irq > 0) + mbox->controller.ops = &xilinx_mbox_irq_ops; + else + mbox->controller.ops = &xilinx_mbox_poll_ops; + + ret = mbox_controller_register(&mbox->controller); + if (ret) { + dev_err(&pdev->dev, "Register mailbox failed\n"); + return ret; + } + + platform_set_drvdata(pdev, mbox); + + return 0; +} + +static int xilinx_mbox_remove(struct platform_device *pdev) +{ + struct xilinx_mbox *mbox = platform_get_drvdata(pdev); + + mbox_controller_unregister(&mbox->controller); + + return 0; +} + +static const struct of_device_id xilinx_mbox_match[] = { + { .compatible = "xlnx,mailbox-2.1" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, xilinx_mbox_match); + +static struct platform_driver xilinx_mbox_driver = { + .probe = xilinx_mbox_probe, + .remove = xilinx_mbox_remove, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = xilinx_mbox_match, + }, +}; + +module_platform_driver(xilinx_mbox_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Xilinx mailbox specific functions"); +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>"); +MODULE_ALIAS("platform:xilinx-mailbox");

[PATCHv5,2/2] mailbox: Adding driver for Xilinx LogiCORE IP mailbox.

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