From: Andy Gross <agross@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx> --- v2 -> v3 - now using one dma done callback on rx channel if bidirectional transfer and on tx channel if only transmit transfer - rearranged the spi_qup_transfer_one() in order to reuse wait for completion and completion init code - move dma init function early in .probe to avoid controller reset if probe deffer - add function to get controller mode Second version can be found at https://lkml.org/lkml/2015/2/24/316 -------------------------------------------------------------------------------- v1 -> v2 This is reworked version with comments addressed - use SPI core DMA mapping code - implemented .can_dma callback - use dmaengine api's to account deferred_probe First version can be found at https://lkml.org/lkml/2014/6/26/481 regards, Stan .../devicetree/bindings/spi/qcom,spi-qup.txt | 8 + drivers/spi/spi-qup.c | 334 ++++++++++++++++++-- 2 files changed, 311 insertions(+), 31 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt index e2c88df..5c09077 100644 --- a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt +++ b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt @@ -33,6 +33,11 @@ Optional properties: nodes. If unspecified, a single SPI device without a chip select can be used. +- 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. SPI slave nodes must be children of the SPI master node and can contain properties described in Documentation/devicetree/bindings/spi/spi-bus.txt @@ -51,6 +56,9 @@ Example: clocks = <&gcc GCC_BLSP2_QUP2_SPI_APPS_CLK>, <&gcc GCC_BLSP2_AHB_CLK>; clock-names = "core", "iface"; + dmas = <&blsp1_bam 13>, <&blsp1_bam 12>; + dma-names = "rx", "tx"; + pinctrl-names = "default"; pinctrl-0 = <&spi8_default>; diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index e7fb5a0..81539d5 100644 --- 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_DMA_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 @@ -140,9 +144,14 @@ struct spi_qup { struct completion done; int error; int w_size; /* bytes per SPI word */ + int n_words; int tx_bytes; int rx_bytes; int qup_v1; + + int use_dma; + struct dma_slave_config rx_conf; + struct dma_slave_config tx_conf; }; @@ -198,7 +207,6 @@ static int spi_qup_set_state(struct spi_qup *controller, u32 state) return 0; } - static void spi_qup_fifo_read(struct spi_qup *controller, struct spi_transfer *xfer) { @@ -266,6 +274,107 @@ static void spi_qup_fifo_write(struct spi_qup *controller, } } +static void spi_qup_dma_done(void *data) +{ + struct spi_qup *qup = data; + + complete(&qup->done); +} + +static int spi_qup_prep_sg(struct spi_master *master, struct spi_transfer *xfer, + enum dma_transfer_direction dir, + dma_async_tx_callback callback) +{ + struct spi_qup *qup = spi_master_get_devdata(master); + unsigned long flags = DMA_PREP_INTERRUPT | DMA_PREP_FENCE; + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl; + struct dma_chan *chan; + dma_cookie_t cookie; + unsigned int nents; + + if (dir == DMA_MEM_TO_DEV) { + chan = master->dma_tx; + nents = xfer->tx_sg.nents; + sgl = xfer->tx_sg.sgl; + } else { + chan = master->dma_rx; + nents = xfer->rx_sg.nents; + sgl = xfer->rx_sg.sgl; + } + + desc = dmaengine_prep_slave_sg(chan, sgl, nents, dir, flags); + if (!desc) + return -EINVAL; + + desc->callback = callback; + desc->callback_param = qup; + + cookie = dmaengine_submit(desc); + + return dma_submit_error(cookie); +} + +static void spi_qup_dma_terminate(struct spi_master *master, + struct spi_transfer *xfer) +{ + if (xfer->tx_buf) + dmaengine_terminate_all(master->dma_tx); + if (xfer->rx_buf) + dmaengine_terminate_all(master->dma_rx); +} + +static int spi_qup_do_dma(struct spi_master *master, struct spi_transfer *xfer) +{ + dma_async_tx_callback rx_done = NULL, tx_done = NULL; + int ret; + + if (xfer->rx_buf) + rx_done = spi_qup_dma_done; + else if (xfer->tx_buf) + tx_done = spi_qup_dma_done; + + if (xfer->rx_buf) { + ret = spi_qup_prep_sg(master, xfer, DMA_DEV_TO_MEM, rx_done); + if (ret) + return ret; + + dma_async_issue_pending(master->dma_rx); + } + + if (xfer->tx_buf) { + ret = spi_qup_prep_sg(master, xfer, DMA_MEM_TO_DEV, tx_done); + if (ret) + return ret; + + dma_async_issue_pending(master->dma_tx); + } + + return 0; +} + +static int spi_qup_do_pio(struct spi_master *master, struct spi_transfer *xfer) +{ + struct spi_qup *qup = spi_master_get_devdata(master); + int ret; + + ret = spi_qup_set_state(qup, QUP_STATE_RUN); + if (ret) { + dev_warn(qup->dev, "cannot set RUN state\n"); + return ret; + } + + ret = spi_qup_set_state(qup, QUP_STATE_PAUSE); + if (ret) { + dev_warn(qup->dev, "cannot set PAUSE state\n"); + return ret; + } + + spi_qup_fifo_write(qup, xfer); + + return 0; +} + static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) { struct spi_qup *controller = dev_id; @@ -315,11 +424,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) 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; @@ -332,13 +443,35 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static u32 +spi_qup_get_mode(struct spi_master *master, struct spi_transfer *xfer) +{ + struct spi_qup *qup = spi_master_get_devdata(master); + u32 mode; + + qup->w_size = 4; + + if (xfer->bits_per_word <= 8) + qup->w_size = 1; + else if (xfer->bits_per_word <= 16) + qup->w_size = 2; + + qup->n_words = xfer->len / qup->w_size; + + if (qup->n_words <= (qup->in_fifo_sz / sizeof(u32))) + mode = QUP_IO_M_MODE_FIFO; + else + mode = QUP_IO_M_MODE_BLOCK; + + return mode; +} /* set clock freq ... bits per word */ static int spi_qup_io_config(struct spi_device *spi, struct spi_transfer *xfer) { struct spi_qup *controller = spi_master_get_devdata(spi->master); u32 config, iomode, mode; - int ret, n_words, w_size; + int ret, n_words; if (spi->mode & SPI_LOOP && xfer->len > controller->in_fifo_sz) { dev_err(controller->dev, "too big size for loopback %d > %d\n", @@ -358,35 +491,54 @@ static int spi_qup_io_config(struct spi_device *spi, struct spi_transfer *xfer) return -EIO; } - w_size = 4; - if (xfer->bits_per_word <= 8) - w_size = 1; - else if (xfer->bits_per_word <= 16) - w_size = 2; - - n_words = xfer->len / w_size; - controller->w_size = w_size; + mode = spi_qup_get_mode(spi->master, xfer); + n_words = controller->n_words; - if (n_words <= (controller->in_fifo_sz / sizeof(u32))) { - mode = QUP_IO_M_MODE_FIFO; + if (mode == QUP_IO_M_MODE_FIFO) { writel_relaxed(n_words, controller->base + QUP_MX_READ_CNT); writel_relaxed(n_words, controller->base + QUP_MX_WRITE_CNT); /* must be zero for FIFO */ writel_relaxed(0, controller->base + QUP_MX_INPUT_CNT); writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT); - } else { - mode = QUP_IO_M_MODE_BLOCK; + } else if (!controller->use_dma) { 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); + } else { + mode = QUP_IO_M_MODE_BAM; + writel_relaxed(0, controller->base + QUP_MX_READ_CNT); + writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT); + + if (!controller->qup_v1) { + void __iomem *input_cnt; + + input_cnt = controller->base + QUP_MX_INPUT_CNT; + /* + * for DMA transfers, both QUP_MX_INPUT_CNT and + * QUP_MX_OUTPUT_CNT must be zero to all cases but one. + * That case is a non-balanced transfer when there is + * only a rx_buf. + */ + if (xfer->tx_buf) + writel_relaxed(0, input_cnt); + else + writel_relaxed(n_words, input_cnt); + + writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT); + } } 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); @@ -419,11 +571,31 @@ static int spi_qup_io_config(struct spi_device *spi, struct spi_transfer *xfer) 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 */ - if (!controller->qup_v1) - writel_relaxed(0, controller->base + QUP_OPERATIONAL_MASK); + if (!controller->qup_v1) { + u32 mask = 0; + + /* + * mask INPUT and OUTPUT service flags to prevent IRQs on FIFO + * status change in BAM mode + */ + + if (mode == QUP_IO_M_MODE_BAM) + mask = QUP_OP_IN_SERVICE_FLAG | QUP_OP_OUT_SERVICE_FLAG; + + writel_relaxed(mask, controller->base + QUP_OPERATIONAL_MASK); + } + return 0; } @@ -452,17 +624,13 @@ static int spi_qup_transfer_one(struct spi_master *master, 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(master, xfer); + else + ret = spi_qup_do_pio(master, xfer); - if (spi_qup_set_state(controller, QUP_STATE_PAUSE)) { - dev_warn(controller->dev, "cannot set PAUSE state\n"); + if (ret) goto exit; - } - - spi_qup_fifo_write(controller, xfer); if (spi_qup_set_state(controller, QUP_STATE_RUN)) { dev_warn(controller->dev, "cannot set EXECUTE state\n"); @@ -471,6 +639,7 @@ static int spi_qup_transfer_one(struct spi_master *master, 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); @@ -478,6 +647,97 @@ exit: if (!ret) ret = controller->error; spin_unlock_irqrestore(&controller->lock, flags); + + if (ret && controller->use_dma) + spi_qup_dma_terminate(master, xfer); + + return ret; +} + +static bool spi_qup_can_dma(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct spi_qup *qup = spi_master_get_devdata(master); + size_t dma_align = dma_get_cache_alignment(); + u32 mode; + + qup->use_dma = 0; + + if (xfer->rx_buf && (xfer->len % qup->in_blk_sz || + IS_ERR_OR_NULL(master->dma_rx) || + !IS_ALIGNED((size_t)xfer->rx_buf, dma_align))) + return false; + + if (xfer->tx_buf && (xfer->len % qup->out_blk_sz || + IS_ERR_OR_NULL(master->dma_tx) || + !IS_ALIGNED((size_t)xfer->tx_buf, dma_align))) + return false; + + mode = spi_qup_get_mode(master, xfer); + if (mode == QUP_IO_M_MODE_FIFO) + return false; + + qup->use_dma = 1; + + return true; +} + +static void spi_qup_release_dma(struct spi_master *master) +{ + if (!IS_ERR_OR_NULL(master->dma_rx)) + dma_release_channel(master->dma_rx); + if (!IS_ERR_OR_NULL(master->dma_tx)) + dma_release_channel(master->dma_tx); +} + +static int spi_qup_init_dma(struct spi_master *master, resource_size_t base) +{ + struct spi_qup *spi = spi_master_get_devdata(master); + struct dma_slave_config *rx_conf = &spi->rx_conf, + *tx_conf = &spi->tx_conf; + struct device *dev = spi->dev; + int ret; + + /* allocate dma resources, if available */ + master->dma_rx = dma_request_slave_channel_reason(dev, "rx"); + if (IS_ERR(master->dma_rx)) + return PTR_ERR(master->dma_rx); + + master->dma_tx = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(master->dma_tx)) { + ret = PTR_ERR(master->dma_tx); + goto err_tx; + } + + /* set DMA parameters */ + rx_conf->direction = DMA_DEV_TO_MEM; + rx_conf->device_fc = 1; + rx_conf->src_addr = base + QUP_INPUT_FIFO; + rx_conf->src_maxburst = spi->in_blk_sz; + + tx_conf->direction = DMA_MEM_TO_DEV; + tx_conf->device_fc = 1; + tx_conf->dst_addr = base + QUP_OUTPUT_FIFO; + tx_conf->dst_maxburst = spi->out_blk_sz; + + ret = dmaengine_slave_config(master->dma_rx, rx_conf); + if (ret) { + dev_err(dev, "failed to configure RX channel\n"); + goto err; + } + + ret = dmaengine_slave_config(master->dma_tx, tx_conf); + if (ret) { + dev_err(dev, "failed to configure TX channel\n"); + goto err; + } + + return 0; + +err: + dma_release_channel(master->dma_tx); +err_tx: + dma_release_channel(master->dma_rx); return ret; } @@ -553,6 +813,8 @@ static int spi_qup_probe(struct platform_device *pdev) 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(); + master->max_dma_len = SPI_MAX_DMA_XFER; platform_set_drvdata(pdev, master); @@ -564,6 +826,12 @@ static int spi_qup_probe(struct platform_device *pdev) controller->cclk = cclk; controller->irq = irq; + ret = spi_qup_init_dma(master, res->start); + if (ret == -EPROBE_DEFER) + goto error; + else if (!ret) + master->can_dma = spi_qup_can_dma; + /* set v1 flag if device is version 1 */ if (of_device_is_compatible(dev->of_node, "qcom,spi-qup-v1.1.1")) controller->qup_v1 = 1; @@ -624,7 +892,7 @@ static int spi_qup_probe(struct platform_device *pdev) ret = devm_request_irq(dev, irq, spi_qup_qup_irq, IRQF_TRIGGER_HIGH, pdev->name, controller); if (ret) - goto error; + goto error_dma; pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC); pm_runtime_use_autosuspend(dev); @@ -639,6 +907,8 @@ static int spi_qup_probe(struct platform_device *pdev) disable_pm: pm_runtime_disable(&pdev->dev); +error_dma: + spi_qup_release_dma(master); error: clk_disable_unprepare(cclk); clk_disable_unprepare(iclk); @@ -730,6 +1000,8 @@ static int spi_qup_remove(struct platform_device *pdev) if (ret) return ret; + spi_qup_release_dma(master); + clk_disable_unprepare(controller->cclk); clk_disable_unprepare(controller->iclk); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
