+++ /dev/null
-Content-Type: text/plain; charset="utf-8"
-MIME-Version: 1.0
-Content-Transfer-Encoding: 7bit
-Subject: spi: qup: Add DMA capabilities
-From: Andy Gross <agross@codeaurora.org>
-X-Patchwork-Id: 4432401
-Message-Id: <1403816781-31008-1-git-send-email-agross@codeaurora.org>
-To: Mark Brown <broonie@kernel.org>
-Cc: linux-spi@vger.kernel.org, Sagar Dharia <sdharia@codeaurora.org>,
- Daniel Sneddon <dsneddon@codeaurora.org>,
- Bjorn Andersson <bjorn.andersson@sonymobile.com>,
- "Ivan T. Ivanov" <iivanov@mm-sol.com>,
- linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
- linux-arm-msm@vger.kernel.org, Andy Gross <agross@codeaurora.org>
-Date: Thu, 26 Jun 2014 16:06:21 -0500
-
-This patch adds DMA capabilities to the spi-qup driver. If DMA channels are
-present, the QUP will use DMA instead of block mode for transfers to/from SPI
-peripherals for transactions larger than the length of a block.
-
-Signed-off-by: Andy Gross <agross@codeaurora.org>
-
----
-.../devicetree/bindings/spi/qcom,spi-qup.txt | 10 +
- drivers/spi/spi-qup.c | 361 ++++++++++++++++++--
- 2 files changed, 350 insertions(+), 21 deletions(-)
-
---- a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt
-+++ b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt
-@@ -27,6 +27,11 @@ Optional properties:
- - spi-max-frequency: Specifies maximum SPI clock frequency,
- Units - Hz. Definition as per
- Documentation/devicetree/bindings/spi/spi-bus.txt
-+- dmas : Two DMA channel specifiers following the convention outlined
-+ in bindings/dma/dma.txt
-+- dma-names: Names for the dma channels, if present. There must be at
-+ least one channel named "tx" for transmit and named "rx" for
-+ receive.
- - num-cs: total number of chipselects
- - cs-gpios: should specify GPIOs used for chipselects.
- The gpios will be referred to as reg = <index> in the SPI child
-@@ -51,6 +56,10 @@ Example:
- clocks = <&gcc GCC_BLSP2_QUP2_SPI_APPS_CLK>, <&gcc GCC_BLSP2_AHB_CLK>;
- clock-names = "core", "iface";
-
-+ dmas = <&blsp2_bam 2>,
-+ <&blsp2_bam 3>;
-+ dma-names = "rx", "tx";
-+
- pinctrl-names = "default";
- pinctrl-0 = <&spi8_default>;
-
---- a/drivers/spi/spi-qup.c
-+++ b/drivers/spi/spi-qup.c
-@@ -22,6 +22,8 @@
- #include <linux/platform_device.h>
- #include <linux/pm_runtime.h>
- #include <linux/spi/spi.h>
-+#include <linux/dmaengine.h>
-+#include <linux/dma-mapping.h>
-
- #define QUP_CONFIG 0x0000
- #define QUP_STATE 0x0004
-@@ -116,6 +118,8 @@
-
- #define SPI_NUM_CHIPSELECTS 4
-
-+#define SPI_MAX_XFER (SZ_64K - 64)
-+
- /* high speed mode is when bus rate is greater then 26MHz */
- #define SPI_HS_MIN_RATE 26000000
- #define SPI_MAX_RATE 50000000
-@@ -143,6 +147,17 @@ struct spi_qup {
- int tx_bytes;
- int rx_bytes;
- int qup_v1;
-+
-+ int use_dma;
-+
-+ struct dma_chan *rx_chan;
-+ struct dma_slave_config rx_conf;
-+ struct dma_chan *tx_chan;
-+ struct dma_slave_config tx_conf;
-+ dma_addr_t rx_dma;
-+ dma_addr_t tx_dma;
-+ void *dummy;
-+ atomic_t dma_outstanding;
- };
-
-
-@@ -266,6 +281,221 @@ static void spi_qup_fifo_write(struct sp
- }
- }
-
-+static void qup_dma_callback(void *data)
-+{
-+ struct spi_qup *controller = data;
-+
-+ if (atomic_dec_and_test(&controller->dma_outstanding))
-+ complete(&controller->done);
-+}
-+
-+static int spi_qup_do_dma(struct spi_qup *controller, struct spi_transfer *xfer)
-+{
-+ struct dma_async_tx_descriptor *rxd, *txd;
-+ dma_cookie_t rx_cookie, tx_cookie;
-+ u32 xfer_len, rx_align = 0, tx_align = 0, n_words;
-+ struct scatterlist tx_sg[2], rx_sg[2];
-+ int ret = 0;
-+ u32 bytes_to_xfer = xfer->len;
-+ u32 offset = 0;
-+ u32 rx_nents = 0, tx_nents = 0;
-+ dma_addr_t rx_dma = 0, tx_dma = 0, rx_dummy_dma = 0, tx_dummy_dma = 0;
-+
-+
-+ if (xfer->rx_buf) {
-+ rx_dma = dma_map_single(controller->dev, xfer->rx_buf,
-+ xfer->len, DMA_FROM_DEVICE);
-+
-+ if (dma_mapping_error(controller->dev, rx_dma)) {
-+ ret = -ENOMEM;
-+ return ret;
-+ }
-+
-+ /* check to see if we need dummy buffer for leftover bytes */
-+ rx_align = xfer->len % controller->in_blk_sz;
-+ if (rx_align) {
-+ rx_dummy_dma = dma_map_single(controller->dev,
-+ controller->dummy, controller->in_fifo_sz,
-+ DMA_FROM_DEVICE);
-+
-+ if (dma_mapping_error(controller->dev, rx_dummy_dma)) {
-+ ret = -ENOMEM;
-+ goto err_map_rx_dummy;
-+ }
-+ }
-+ }
-+
-+ if (xfer->tx_buf) {
-+ tx_dma = dma_map_single(controller->dev,
-+ (void *)xfer->tx_buf, xfer->len, DMA_TO_DEVICE);
-+
-+ if (dma_mapping_error(controller->dev, tx_dma)) {
-+ ret = -ENOMEM;
-+ goto err_map_tx;
-+ }
-+
-+ /* check to see if we need dummy buffer for leftover bytes */
-+ tx_align = xfer->len % controller->out_blk_sz;
-+ if (tx_align) {
-+ memcpy(controller->dummy + SZ_1K,
-+ xfer->tx_buf + xfer->len - tx_align,
-+ tx_align);
-+ memset(controller->dummy + SZ_1K + tx_align, 0,
-+ controller->out_blk_sz - tx_align);
-+
-+ tx_dummy_dma = dma_map_single(controller->dev,
-+ controller->dummy + SZ_1K,
-+ controller->out_blk_sz, DMA_TO_DEVICE);
-+
-+ if (dma_mapping_error(controller->dev, tx_dummy_dma)) {
-+ ret = -ENOMEM;
-+ goto err_map_tx_dummy;
-+ }
-+ }
-+ }
-+
-+ atomic_set(&controller->dma_outstanding, 0);
-+
-+ while (bytes_to_xfer > 0) {
-+ xfer_len = min_t(u32, bytes_to_xfer, SPI_MAX_XFER);
-+ n_words = DIV_ROUND_UP(xfer_len, controller->w_size);
-+
-+ /* write out current word count to controller */
-+ writel_relaxed(n_words, controller->base + QUP_MX_INPUT_CNT);
-+ writel_relaxed(n_words, controller->base + QUP_MX_OUTPUT_CNT);
-+
-+ reinit_completion(&controller->done);
-+
-+ if (xfer->tx_buf) {
-+ /* recalc align for each transaction */
-+ tx_align = xfer_len % controller->out_blk_sz;
-+
-+ if (tx_align)
-+ tx_nents = 2;
-+ else
-+ tx_nents = 1;
-+
-+ /* initialize scatterlists */
-+ sg_init_table(tx_sg, tx_nents);
-+ sg_dma_len(&tx_sg[0]) = xfer_len - tx_align;
-+ sg_dma_address(&tx_sg[0]) = tx_dma + offset;
-+
-+ /* account for non block size transfer */
-+ if (tx_align) {
-+ sg_dma_len(&tx_sg[1]) = controller->out_blk_sz;
-+ sg_dma_address(&tx_sg[1]) = tx_dummy_dma;
-+ }
-+
-+ txd = dmaengine_prep_slave_sg(controller->tx_chan,
-+ tx_sg, tx_nents, DMA_MEM_TO_DEV, 0);
-+ if (!txd) {
-+ ret = -ENOMEM;
-+ goto err_unmap;
-+ }
-+
-+ atomic_inc(&controller->dma_outstanding);
-+
-+ txd->callback = qup_dma_callback;
-+ txd->callback_param = controller;
-+
-+ tx_cookie = dmaengine_submit(txd);
-+
-+ dma_async_issue_pending(controller->tx_chan);
-+ }
-+
-+ if (xfer->rx_buf) {
-+ /* recalc align for each transaction */
-+ rx_align = xfer_len % controller->in_blk_sz;
-+
-+ if (rx_align)
-+ rx_nents = 2;
-+ else
-+ rx_nents = 1;
-+
-+ /* initialize scatterlists */
-+ sg_init_table(rx_sg, rx_nents);
-+ sg_dma_address(&rx_sg[0]) = rx_dma + offset;
-+ sg_dma_len(&rx_sg[0]) = xfer_len - rx_align;
-+
-+ /* account for non block size transfer */
-+ if (rx_align) {
-+ sg_dma_len(&rx_sg[1]) = controller->in_blk_sz;
-+ sg_dma_address(&rx_sg[1]) = rx_dummy_dma;
-+ }
-+
-+ rxd = dmaengine_prep_slave_sg(controller->rx_chan,
-+ rx_sg, rx_nents, DMA_DEV_TO_MEM, 0);
-+ if (!rxd) {
-+ ret = -ENOMEM;
-+ goto err_unmap;
-+ }
-+
-+ atomic_inc(&controller->dma_outstanding);
-+
-+ rxd->callback = qup_dma_callback;
-+ rxd->callback_param = controller;
-+
-+ rx_cookie = dmaengine_submit(rxd);
-+
-+ dma_async_issue_pending(controller->rx_chan);
-+ }
-+
-+ if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
-+ dev_warn(controller->dev, "cannot set EXECUTE state\n");
-+ goto err_unmap;
-+ }
-+
-+ if (!wait_for_completion_timeout(&controller->done,
-+ msecs_to_jiffies(1000))) {
-+ ret = -ETIMEDOUT;
-+
-+ /* clear out all the DMA transactions */
-+ if (xfer->tx_buf)
-+ dmaengine_terminate_all(controller->tx_chan);
-+ if (xfer->rx_buf)
-+ dmaengine_terminate_all(controller->rx_chan);
-+
-+ goto err_unmap;
-+ }
-+
-+ if (rx_align)
-+ memcpy(xfer->rx_buf + offset + xfer->len - rx_align,
-+ controller->dummy, rx_align);
-+
-+ /* adjust remaining bytes to transfer */
-+ bytes_to_xfer -= xfer_len;
-+ offset += xfer_len;
-+
-+
-+ /* reset mini-core state so we can program next transaction */
-+ if (spi_qup_set_state(controller, QUP_STATE_RESET)) {
-+ dev_err(controller->dev, "cannot set RESET state\n");
-+ goto err_unmap;
-+ }
-+ }
-+
-+ ret = 0;
-+
-+err_unmap:
-+ if (tx_align)
-+ dma_unmap_single(controller->dev, tx_dummy_dma,
-+ controller->out_fifo_sz, DMA_TO_DEVICE);
-+err_map_tx_dummy:
-+ if (xfer->tx_buf)
-+ dma_unmap_single(controller->dev, tx_dma, xfer->len,
-+ DMA_TO_DEVICE);
-+err_map_tx:
-+ if (rx_align)
-+ dma_unmap_single(controller->dev, rx_dummy_dma,
-+ controller->in_fifo_sz, DMA_FROM_DEVICE);
-+err_map_rx_dummy:
-+ if (xfer->rx_buf)
-+ dma_unmap_single(controller->dev, rx_dma, xfer->len,
-+ DMA_FROM_DEVICE);
-+
-+ return ret;
-+}
-+
- static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
- {
- struct spi_qup *controller = dev_id;
-@@ -315,11 +545,13 @@ static irqreturn_t spi_qup_qup_irq(int i
- error = -EIO;
- }
-
-- if (opflags & QUP_OP_IN_SERVICE_FLAG)
-- spi_qup_fifo_read(controller, xfer);
-+ if (!controller->use_dma) {
-+ if (opflags & QUP_OP_IN_SERVICE_FLAG)
-+ spi_qup_fifo_read(controller, xfer);
-
-- if (opflags & QUP_OP_OUT_SERVICE_FLAG)
-- spi_qup_fifo_write(controller, xfer);
-+ if (opflags & QUP_OP_OUT_SERVICE_FLAG)
-+ spi_qup_fifo_write(controller, xfer);
-+ }
-
- spin_lock_irqsave(&controller->lock, flags);
- controller->error = error;
-@@ -339,6 +571,8 @@ static int spi_qup_io_config(struct spi_
- struct spi_qup *controller = spi_master_get_devdata(spi->master);
- u32 config, iomode, mode;
- int ret, n_words, w_size;
-+ size_t dma_align = dma_get_cache_alignment();
-+ u32 dma_available = 0;
-
- if (spi->mode & SPI_LOOP && xfer->len > controller->in_fifo_sz) {
- dev_err(controller->dev, "too big size for loopback %d > %d\n",
-@@ -367,6 +601,11 @@ static int spi_qup_io_config(struct spi_
- n_words = xfer->len / w_size;
- controller->w_size = w_size;
-
-+ if (controller->rx_chan &&
-+ IS_ALIGNED((size_t)xfer->tx_buf, dma_align) &&
-+ IS_ALIGNED((size_t)xfer->rx_buf, dma_align))
-+ dma_available = 1;
-+
- if (n_words <= (controller->in_fifo_sz / sizeof(u32))) {
- mode = QUP_IO_M_MODE_FIFO;
- writel_relaxed(n_words, controller->base + QUP_MX_READ_CNT);
-@@ -374,19 +613,31 @@ static int spi_qup_io_config(struct spi_
- /* must be zero for FIFO */
- writel_relaxed(0, controller->base + QUP_MX_INPUT_CNT);
- writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT);
-- } else {
-+ controller->use_dma = 0;
-+ } else if (!dma_available) {
- mode = QUP_IO_M_MODE_BLOCK;
- writel_relaxed(n_words, controller->base + QUP_MX_INPUT_CNT);
- writel_relaxed(n_words, controller->base + QUP_MX_OUTPUT_CNT);
- /* must be zero for BLOCK and BAM */
- writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
- writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
-+ controller->use_dma = 0;
-+ } else {
-+ mode = QUP_IO_M_MODE_DMOV;
-+ writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
-+ writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
-+ controller->use_dma = 1;
- }
-
- iomode = readl_relaxed(controller->base + QUP_IO_M_MODES);
- /* Set input and output transfer mode */
- iomode &= ~(QUP_IO_M_INPUT_MODE_MASK | QUP_IO_M_OUTPUT_MODE_MASK);
-- iomode &= ~(QUP_IO_M_PACK_EN | QUP_IO_M_UNPACK_EN);
-+
-+ if (!controller->use_dma)
-+ iomode &= ~(QUP_IO_M_PACK_EN | QUP_IO_M_UNPACK_EN);
-+ else
-+ iomode |= QUP_IO_M_PACK_EN | QUP_IO_M_UNPACK_EN;
-+
- iomode |= (mode << QUP_IO_M_OUTPUT_MODE_MASK_SHIFT);
- iomode |= (mode << QUP_IO_M_INPUT_MODE_MASK_SHIFT);
-
-@@ -419,6 +670,14 @@ static int spi_qup_io_config(struct spi_
- config &= ~(QUP_CONFIG_NO_INPUT | QUP_CONFIG_NO_OUTPUT | QUP_CONFIG_N);
- config |= xfer->bits_per_word - 1;
- config |= QUP_CONFIG_SPI_MODE;
-+
-+ if (controller->use_dma) {
-+ if (!xfer->tx_buf)
-+ config |= QUP_CONFIG_NO_OUTPUT;
-+ if (!xfer->rx_buf)
-+ config |= QUP_CONFIG_NO_INPUT;
-+ }
-+
- writel_relaxed(config, controller->base + QUP_CONFIG);
-
- /* only write to OPERATIONAL_MASK when register is present */
-@@ -452,25 +711,29 @@ static int spi_qup_transfer_one(struct s
- controller->tx_bytes = 0;
- spin_unlock_irqrestore(&controller->lock, flags);
-
-- if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
-- dev_warn(controller->dev, "cannot set RUN state\n");
-- goto exit;
-- }
-+ if (controller->use_dma) {
-+ ret = spi_qup_do_dma(controller, xfer);
-+ } else {
-+ if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
-+ dev_warn(controller->dev, "cannot set RUN state\n");
-+ goto exit;
-+ }
-
-- if (spi_qup_set_state(controller, QUP_STATE_PAUSE)) {
-- dev_warn(controller->dev, "cannot set PAUSE state\n");
-- goto exit;
-- }
-+ if (spi_qup_set_state(controller, QUP_STATE_PAUSE)) {
-+ dev_warn(controller->dev, "cannot set PAUSE state\n");
-+ goto exit;
-+ }
-
-- spi_qup_fifo_write(controller, xfer);
-+ spi_qup_fifo_write(controller, xfer);
-
-- if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
-- dev_warn(controller->dev, "cannot set EXECUTE state\n");
-- goto exit;
-- }
-+ if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
-+ dev_warn(controller->dev, "cannot set EXECUTE state\n");
-+ goto exit;
-+ }
-
-- if (!wait_for_completion_timeout(&controller->done, timeout))
-- ret = -ETIMEDOUT;
-+ if (!wait_for_completion_timeout(&controller->done, timeout))
-+ ret = -ETIMEDOUT;
-+ }
- exit:
- spi_qup_set_state(controller, QUP_STATE_RESET);
- spin_lock_irqsave(&controller->lock, flags);
-@@ -554,6 +817,7 @@ static int spi_qup_probe(struct platform
- master->transfer_one = spi_qup_transfer_one;
- master->dev.of_node = pdev->dev.of_node;
- master->auto_runtime_pm = true;
-+ master->dma_alignment = dma_get_cache_alignment();
-
- platform_set_drvdata(pdev, master);
-
-@@ -619,6 +883,56 @@ static int spi_qup_probe(struct platform
- QUP_ERROR_INPUT_UNDER_RUN | QUP_ERROR_OUTPUT_UNDER_RUN,
- base + QUP_ERROR_FLAGS_EN);
-
-+ /* allocate dma resources, if available */
-+ controller->rx_chan = dma_request_slave_channel(&pdev->dev, "rx");
-+ if (controller->rx_chan) {
-+ controller->tx_chan =
-+ dma_request_slave_channel(&pdev->dev, "tx");
-+
-+ if (!controller->tx_chan) {
-+ dev_err(&pdev->dev, "Failed to allocate dma tx chan");
-+ dma_release_channel(controller->rx_chan);
-+ }
-+
-+ /* set DMA parameters */
-+ controller->rx_conf.device_fc = 1;
-+ controller->rx_conf.src_addr = res->start + QUP_INPUT_FIFO;
-+ controller->rx_conf.src_maxburst = controller->in_blk_sz;
-+
-+ controller->tx_conf.device_fc = 1;
-+ controller->tx_conf.dst_addr = res->start + QUP_OUTPUT_FIFO;
-+ controller->tx_conf.dst_maxburst = controller->out_blk_sz;
-+
-+ if (dmaengine_slave_config(controller->rx_chan,
-+ &controller->rx_conf)) {
-+ dev_err(&pdev->dev, "failed to configure RX channel\n");
-+
-+ dma_release_channel(controller->rx_chan);
-+ dma_release_channel(controller->tx_chan);
-+ controller->tx_chan = NULL;
-+ controller->rx_chan = NULL;
-+ } else if (dmaengine_slave_config(controller->tx_chan,
-+ &controller->tx_conf)) {
-+ dev_err(&pdev->dev, "failed to configure TX channel\n");
-+
-+ dma_release_channel(controller->rx_chan);
-+ dma_release_channel(controller->tx_chan);
-+ controller->tx_chan = NULL;
-+ controller->rx_chan = NULL;
-+ }
-+
-+ controller->dummy = devm_kmalloc(controller->dev, PAGE_SIZE,
-+ GFP_KERNEL);
-+
-+ if (!controller->dummy) {
-+ dma_release_channel(controller->rx_chan);
-+ dma_release_channel(controller->tx_chan);
-+ controller->tx_chan = NULL;
-+ controller->rx_chan = NULL;
-+ }
-+ }
-+
-+
- writel_relaxed(0, base + SPI_CONFIG);
- writel_relaxed(SPI_IO_C_NO_TRI_STATE, base + SPI_IO_CONTROL);
-
-@@ -731,6 +1045,11 @@ static int spi_qup_remove(struct platfor
- if (ret)
- return ret;
-
-+ if (controller->rx_chan)
-+ dma_release_channel(controller->rx_chan);
-+ if (controller->tx_chan)
-+ dma_release_channel(controller->tx_chan);
-+
- clk_disable_unprepare(controller->cclk);
- clk_disable_unprepare(controller->iclk);
-
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