From patchwork Wed Oct 5 09:04:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mugunthan V N X-Patchwork-Id: 9362655 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2F8916077E for ; Wed, 5 Oct 2016 09:09:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EFA22865A for ; Wed, 5 Oct 2016 09:09:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 13B60286E6; Wed, 5 Oct 2016 09:09:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 087972865A for ; Wed, 5 Oct 2016 09:09:05 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1briAt-0002Ly-Tx; Wed, 05 Oct 2016 09:07:39 +0000 Received: from arroyo.ext.ti.com ([198.47.19.12]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1briAe-0002FR-Fb for linux-arm-kernel@lists.infradead.org; Wed, 05 Oct 2016 09:07:28 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id u9596ijb018959; Wed, 5 Oct 2016 04:06:44 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u9596iMB012700; Wed, 5 Oct 2016 04:06:44 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Wed, 5 Oct 2016 04:06:43 -0500 Received: from a0131834lt.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id u9595u5P019776; Wed, 5 Oct 2016 04:06:29 -0500 From: Mugunthan V N To: Subject: [PATCH v3 2/4] drivers: iio: ti_am335x_adc: add dma support Date: Wed, 5 Oct 2016 14:34:41 +0530 Message-ID: <20161005090443.24576-3-mugunthanvnm@ti.com> X-Mailer: git-send-email 2.10.0.372.g6fe1b14 In-Reply-To: <20161005090443.24576-1-mugunthanvnm@ti.com> References: <20161005090443.24576-1-mugunthanvnm@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161005_020724_721153_E4DA28F2 X-CRM114-Status: GOOD ( 17.91 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Lars-Peter Clausen , Vignesh R , Mugunthan V N , Tony Lindgren , linux-kernel@vger.kernel.org, Sekhar Nori , Russell King , "Andrew F . Davis" , John Syne , Rob Herring , linux-arm-kernel@lists.infradead.org, Peter Meerwald-Stadler , Hartmut Knaack , linux-omap@vger.kernel.org, Lee Jones , Jonathan Cameron Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds the required pieces to ti_am335x_adc driver for DMA support Signed-off-by: Mugunthan V N Reviewed-by: Peter Ujfalusi --- drivers/iio/adc/ti_am335x_adc.c | 148 ++++++++++++++++++++++++++++++++++- include/linux/mfd/ti_am335x_tscadc.h | 7 ++ 2 files changed, 152 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index c3cfacca..ad9dec3 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -30,10 +30,28 @@ #include #include +#include +#include + +#define DMA_BUFFER_SIZE SZ_2K + +struct tiadc_dma { + struct dma_slave_config conf; + struct dma_chan *chan; + dma_addr_t addr; + dma_cookie_t cookie; + u8 *buf; + int current_period; + int period_size; + u8 fifo_thresh; +}; + struct tiadc_device { struct ti_tscadc_dev *mfd_tscadc; + struct tiadc_dma dma; struct mutex fifo1_lock; /* to protect fifo access */ int channels; + int total_ch_enabled; u8 channel_line[8]; u8 channel_step[8]; int buffer_en_ch_steps; @@ -198,6 +216,67 @@ static irqreturn_t tiadc_worker_h(int irq, void *private) return IRQ_HANDLED; } +static void tiadc_dma_rx_complete(void *param) +{ + struct iio_dev *indio_dev = param; + struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct tiadc_dma *dma = &adc_dev->dma; + u8 *data; + int i; + + data = dma->buf + dma->current_period * dma->period_size; + dma->current_period = 1 - dma->current_period; /* swap the buffer ID */ + + for (i = 0; i < dma->period_size; i += indio_dev->scan_bytes) { + iio_push_to_buffers(indio_dev, data); + data += indio_dev->scan_bytes; + } +} + +static int tiadc_start_dma(struct iio_dev *indio_dev) +{ + struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct tiadc_dma *dma = &adc_dev->dma; + struct dma_async_tx_descriptor *desc; + + dma->current_period = 0; /* We start to fill period 0 */ + /* + * Make the fifo thresh as the multiple of total number of + * channels enabled, so make sure that cyclic DMA period + * length is also a multiple of total number of channels + * enabled. This ensures that no invalid data is reported + * to the stack via iio_push_to_buffers(). + */ + dma->fifo_thresh = rounddown(FIFO1_THRESHOLD + 1, + adc_dev->total_ch_enabled) - 1; + /* Make sure that period length is multiple of fifo thresh level */ + dma->period_size = rounddown(DMA_BUFFER_SIZE / 2, + (dma->fifo_thresh + 1) * sizeof(u16)); + + dma->conf.src_maxburst = dma->fifo_thresh + 1; + dmaengine_slave_config(dma->chan, &dma->conf); + + desc = dmaengine_prep_dma_cyclic(dma->chan, dma->addr, + dma->period_size * 2, + dma->period_size, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!desc) + return -EBUSY; + + desc->callback = tiadc_dma_rx_complete; + desc->callback_param = indio_dev; + + dma->cookie = dmaengine_submit(desc); + + dma_async_issue_pending(dma->chan); + + tiadc_writel(adc_dev, REG_FIFO1THR, dma->fifo_thresh); + tiadc_writel(adc_dev, REG_DMA1REQ, dma->fifo_thresh); + tiadc_writel(adc_dev, REG_DMAENABLE_SET, DMA_FIFO1); + + return 0; +} + static int tiadc_buffer_preenable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); @@ -218,20 +297,30 @@ static int tiadc_buffer_preenable(struct iio_dev *indio_dev) static int tiadc_buffer_postenable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct tiadc_dma *dma = &adc_dev->dma; + unsigned int irq_enable; unsigned int enb = 0; u8 bit; tiadc_step_config(indio_dev); - for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) + for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) { enb |= (get_adc_step_bit(adc_dev, bit) << 1); + adc_dev->total_ch_enabled++; + } adc_dev->buffer_en_ch_steps = enb; + if (dma->chan) + tiadc_start_dma(indio_dev); + am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb); tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW); - tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES - | IRQENB_FIFO1OVRRUN); + + irq_enable = IRQENB_FIFO1OVRRUN; + if (!dma->chan) + irq_enable |= IRQENB_FIFO1THRES; + tiadc_writel(adc_dev, REG_IRQENABLE, irq_enable); return 0; } @@ -239,12 +328,18 @@ static int tiadc_buffer_postenable(struct iio_dev *indio_dev) static int tiadc_buffer_predisable(struct iio_dev *indio_dev) { struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct tiadc_dma *dma = &adc_dev->dma; int fifo1count, i, read; tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW)); am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps); adc_dev->buffer_en_ch_steps = 0; + adc_dev->total_ch_enabled = 0; + if (dma->chan) { + tiadc_writel(adc_dev, REG_DMAENABLE_CLEAR, 0x2); + dmaengine_terminate_async(dma->chan); + } /* Flush FIFO of leftover data in the time it takes to disable adc */ fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT); @@ -430,6 +525,41 @@ static const struct iio_info tiadc_info = { .driver_module = THIS_MODULE, }; +static int tiadc_request_dma(struct platform_device *pdev, + struct tiadc_device *adc_dev) +{ + struct tiadc_dma *dma = &adc_dev->dma; + dma_cap_mask_t mask; + + /* Default slave configuration parameters */ + dma->conf.direction = DMA_DEV_TO_MEM; + dma->conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + dma->conf.src_addr = adc_dev->mfd_tscadc->tscadc_phys_base + REG_FIFO1; + + dma_cap_zero(mask); + dma_cap_set(DMA_CYCLIC, mask); + + /* Get a channel for RX */ + dma->chan = dma_request_chan(adc_dev->mfd_tscadc->dev, "fifo1"); + if (IS_ERR(dma->chan)) { + int ret = PTR_ERR(dma->chan); + + dma->chan = NULL; + return ret; + } + + /* RX buffer */ + dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, + &dma->addr, GFP_KERNEL); + if (!dma->buf) + goto err; + + return 0; +err: + dma_release_channel(dma->chan); + return -ENOMEM; +} + static int tiadc_parse_dt(struct platform_device *pdev, struct tiadc_device *adc_dev) { @@ -512,8 +642,14 @@ static int tiadc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, indio_dev); + err = tiadc_request_dma(pdev, adc_dev); + if (err && err == -EPROBE_DEFER) + goto err_dma; + return 0; +err_dma: + iio_device_unregister(indio_dev); err_buffer_unregister: tiadc_iio_buffered_hardware_remove(indio_dev); err_free_channels: @@ -525,8 +661,14 @@ static int tiadc_remove(struct platform_device *pdev) { struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct tiadc_device *adc_dev = iio_priv(indio_dev); + struct tiadc_dma *dma = &adc_dev->dma; u32 step_en; + if (dma->chan) { + dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE, + dma->buf, dma->addr); + dma_release_channel(dma->chan); + } iio_device_unregister(indio_dev); tiadc_iio_buffered_hardware_remove(indio_dev); tiadc_channels_remove(indio_dev); diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index e45a208..b9a53e0 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -23,6 +23,8 @@ #define REG_IRQENABLE 0x02C #define REG_IRQCLR 0x030 #define REG_IRQWAKEUP 0x034 +#define REG_DMAENABLE_SET 0x038 +#define REG_DMAENABLE_CLEAR 0x03c #define REG_CTRL 0x040 #define REG_ADCFSM 0x044 #define REG_CLKDIV 0x04C @@ -36,6 +38,7 @@ #define REG_FIFO0THR 0xE8 #define REG_FIFO1CNT 0xF0 #define REG_FIFO1THR 0xF4 +#define REG_DMA1REQ 0xF8 #define REG_FIFO0 0x100 #define REG_FIFO1 0x200 @@ -126,6 +129,10 @@ #define FIFOREAD_DATA_MASK (0xfff << 0) #define FIFOREAD_CHNLID_MASK (0xf << 16) +/* DMA ENABLE/CLEAR Register */ +#define DMA_FIFO0 BIT(0) +#define DMA_FIFO1 BIT(1) + /* Sequencer Status */ #define SEQ_STATUS BIT(5) #define CHARGE_STEP 0x11