From b4e27545224e263d271a9d9aa8763357a7e40eaa Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Fri, 6 Feb 2015 12:27:54 -0800 Subject: [PATCH 1/7] spi: sc18is602: Support multiple devices on a single I2C bus if DT is configured The driver currently only supports a single device per I2C bus since it uses the I2C bus number to set the SPI bus number. This makes it impossible to connect more than one chip to a single I2C bus. We don't want to use dynamic bus numbers unconditionally since this would result in every instantiation getting a different bus number starting with 65,535 counting down unless devicetree is configured. If devicetree is configured, however, the SPI bus number is obtained from devicetree data. So we can use dynamic SPI bus numbers in this case. Reported-and-Tested-by: Marco Menchise Signed-off-by: Guenter Roeck Signed-off-by: Mark Brown --- drivers/spi/spi-sc18is602.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-sc18is602.c b/drivers/spi/spi-sc18is602.c index 237f2e7a7179..c04e601152f1 100644 --- a/drivers/spi/spi-sc18is602.c +++ b/drivers/spi/spi-sc18is602.c @@ -290,7 +290,7 @@ static int sc18is602_probe(struct i2c_client *client, hw->freq = SC18IS602_CLOCK; break; } - master->bus_num = client->adapter->nr; + master->bus_num = np ? -1 : client->adapter->nr; master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST; master->bits_per_word_mask = SPI_BPW_MASK(8); master->setup = sc18is602_setup; From 0744ea2a01cb75a750e8594b046102fc68fa45b3 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Mon, 23 Feb 2015 12:30:46 +0000 Subject: [PATCH 2/7] spi: s3c64xx: fix compiler warning in spi-s3c64xx The Exynos 7 arm64 support now allows the S3C64xx SPI driver to be compiled into an ARM64 kernel, so the cast from the [rt]x_dmach int variable to a void* in this driver now triggers a warning. Add a long cast to silence the compiler. Signed-off-by: Andre Przywara Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 9231c34b5a5c..b1c6731fbf27 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -324,7 +324,7 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi) /* Acquire DMA channels */ sdd->rx_dma.ch = dma_request_slave_channel_compat(mask, filter, - (void *)sdd->rx_dma.dmach, dev, "rx"); + (void *)(long)sdd->rx_dma.dmach, dev, "rx"); if (!sdd->rx_dma.ch) { dev_err(dev, "Failed to get RX DMA channel\n"); ret = -EBUSY; @@ -333,7 +333,7 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi) spi->dma_rx = sdd->rx_dma.ch; sdd->tx_dma.ch = dma_request_slave_channel_compat(mask, filter, - (void *)sdd->tx_dma.dmach, dev, "tx"); + (void *)(long)sdd->tx_dma.dmach, dev, "tx"); if (!sdd->tx_dma.ch) { dev_err(dev, "Failed to get TX DMA channel\n"); ret = -EBUSY; From 2291793cc4c6b1251e28a4ff0f98041147d57e96 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 27 Feb 2015 17:34:16 +0200 Subject: [PATCH 3/7] spi/rockchip: do an error handling in proper time There was handle_err() callback introduced that is dedicated for error handling. The patch moves error handling to this callback. Cc: Heiko Stuebner Cc: linux-rockchip@lists.infradead.org Signed-off-by: Andy Shevchenko Signed-off-by: Mark Brown --- drivers/spi/spi-rockchip.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 1a777dc261d6..25003c408c92 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -302,8 +302,8 @@ static int rockchip_spi_prepare_message(struct spi_master *master, return 0; } -static int rockchip_spi_unprepare_message(struct spi_master *master, - struct spi_message *msg) +static void rockchip_spi_handle_err(struct spi_master *master, + struct spi_message *msg) { unsigned long flags; struct rockchip_spi *rs = spi_master_get_devdata(master); @@ -313,8 +313,8 @@ static int rockchip_spi_unprepare_message(struct spi_master *master, /* * For DMA mode, we need terminate DMA channel and flush * fifo for the next transfer if DMA thansfer timeout. - * unprepare_message() was called by core if transfer complete - * or timeout. Maybe it is reasonable for error handling here. + * handle_err() was called by core if transfer failed. + * Maybe it is reasonable for error handling here. */ if (rs->use_dma) { if (rs->state & RXBUSY) { @@ -327,6 +327,12 @@ static int rockchip_spi_unprepare_message(struct spi_master *master, } spin_unlock_irqrestore(&rs->lock, flags); +} + +static int rockchip_spi_unprepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct rockchip_spi *rs = spi_master_get_devdata(master); spi_enable_chip(rs, 0); @@ -688,6 +694,7 @@ static int rockchip_spi_probe(struct platform_device *pdev) master->prepare_message = rockchip_spi_prepare_message; master->unprepare_message = rockchip_spi_unprepare_message; master->transfer_one = rockchip_spi_transfer_one; + master->handle_err = rockchip_spi_handle_err; rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx"); if (!rs->dma_tx.ch) From 612762e82ae6058d69b4ce734598491bf030afe7 Mon Sep 17 00:00:00 2001 From: Andy Gross Date: Wed, 4 Mar 2015 12:02:05 +0200 Subject: [PATCH 4/7] spi: qup: Add DMA capabilities 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 Signed-off-by: Stanimir Varbanov Reviewed-by: Ivan T. Ivanov --- .../devicetree/bindings/spi/qcom,spi-qup.txt | 8 + drivers/spi/spi-qup.c | 336 ++++++++++++++++-- 2 files changed, 312 insertions(+), 32 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt index e2c88df2cc15..5c090771c016 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 ff9cdbdb6672..4b5fc4d67b6e 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #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, control; - 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; + mode = spi_qup_get_mode(spi->master, xfer); + n_words = controller->n_words; - n_words = xfer->len / w_size; - controller->w_size = w_size; - - 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); @@ -428,11 +580,31 @@ 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; } @@ -461,17 +633,13 @@ 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"); @@ -480,6 +648,7 @@ 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); @@ -487,6 +656,97 @@ 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; } @@ -562,6 +822,8 @@ 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); @@ -573,6 +835,12 @@ 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; @@ -609,7 +877,7 @@ static int spi_qup_probe(struct platform_device *pdev) ret = spi_qup_set_state(controller, QUP_STATE_RESET); if (ret) { dev_err(dev, "cannot set RESET state\n"); - goto error; + goto error_dma; } writel_relaxed(0, base + QUP_OPERATIONAL); @@ -633,7 +901,7 @@ 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); @@ -648,6 +916,8 @@ 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); @@ -739,6 +1009,8 @@ 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); From 76b17e6e4923e4138ed9a4d480cba148ff239dc9 Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Thu, 26 Mar 2015 16:30:25 -0700 Subject: [PATCH 5/7] spi/rockchip: Add device tree property to configure Rx Sample Delay We have found that we can sometimes see read failures on boards with high-capacitance SPI lines. It seems that the controller samples the Rx data line too early, and its register interface has an "Rx Sample Delay" setting to fine-tune against this issue. This patch adds a new optional device tree entry that can configure this delay in terms of nanoseconds. The kernel will calculate the best-fitting amount of parent clock ticks to program the controller with based on that. Signed-off-by: Julius Werner Signed-off-by: Mark Brown --- .../devicetree/bindings/spi/spi-rockchip.txt | 4 ++++ drivers/spi/spi-rockchip.c | 21 +++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/spi-rockchip.txt b/Documentation/devicetree/bindings/spi/spi-rockchip.txt index 467dec441c62..0c491bda4c65 100644 --- a/Documentation/devicetree/bindings/spi/spi-rockchip.txt +++ b/Documentation/devicetree/bindings/spi/spi-rockchip.txt @@ -24,6 +24,9 @@ Optional Properties: - dmas: DMA specifiers for tx and rx dma. See the DMA client binding, Documentation/devicetree/bindings/dma/dma.txt - dma-names: DMA request names should include "tx" and "rx" if present. +- rx-sample-delay-ns: nanoseconds to delay after the SCLK edge before sampling + Rx data (may need to be fine tuned for high capacitance lines). + No delay (0) by default. Example: @@ -33,6 +36,7 @@ Example: reg = <0xff110000 0x1000>; dmas = <&pdma1 11>, <&pdma1 12>; dma-names = "tx", "rx"; + rx-sample-delay-ns = <10>; #address-cells = <1>; #size-cells = <0>; interrupts = ; diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 25003c408c92..f65384b3417f 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -179,6 +179,7 @@ struct rockchip_spi { u8 tmode; u8 bpw; u8 n_bytes; + u8 rsd_nsecs; unsigned len; u32 speed; @@ -499,6 +500,7 @@ static void rockchip_spi_config(struct rockchip_spi *rs) { u32 div = 0; u32 dmacr = 0; + int rsd = 0; u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET) | (CR0_SSD_ONE << CR0_SSD_OFFSET); @@ -528,6 +530,20 @@ static void rockchip_spi_config(struct rockchip_spi *rs) div = max_t(u32, rs->max_freq / rs->speed, 1); div = (div + 1) & 0xfffe; + /* Rx sample delay is expressed in parent clock cycles (max 3) */ + rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8), + 1000000000 >> 8); + if (!rsd && rs->rsd_nsecs) { + pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n", + rs->max_freq, rs->rsd_nsecs); + } else if (rsd > 3) { + rsd = 3; + pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n", + rs->max_freq, rs->rsd_nsecs, + rsd * 1000000000U / rs->max_freq); + } + cr0 |= rsd << CR0_RSD_OFFSET; + writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0); writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1); @@ -620,6 +636,7 @@ static int rockchip_spi_probe(struct platform_device *pdev) struct rockchip_spi *rs; struct spi_master *master; struct resource *mem; + u32 rsd_nsecs; master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi)); if (!master) @@ -671,6 +688,10 @@ static int rockchip_spi_probe(struct platform_device *pdev) rs->dev = &pdev->dev; rs->max_freq = clk_get_rate(rs->spiclk); + if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns", + &rsd_nsecs)) + rs->rsd_nsecs = rsd_nsecs; + rs->fifo_len = get_fifo_len(rs); if (!rs->fifo_len) { dev_err(&pdev->dev, "Failed to get fifo length\n"); From 4b6fe3edcbbaa3d0e5513adcb9577c7e184ad1b5 Mon Sep 17 00:00:00 2001 From: Hiep Cao Minh Date: Thu, 23 Oct 2014 12:14:13 +0900 Subject: [PATCH 6/7] spi: Using Trigger number to transmit/receive data In order to transmit and receive data when have 32 bytes of data that ready has prepared on Transmit/Receive Buffer to transmit or receive. Instead transmits/receives a byte data using Transmit/Receive Buffer Data Triggering Number will improve the speed of transfer data. Signed-off-by: Hiep Cao Minh Signed-off-by: Mark Brown --- drivers/spi/spi-rspi.c | 126 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 118 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index 46ce47076e63..fd276f990d4d 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -177,6 +177,13 @@ #define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset */ #define SPBFCR_TXTRG_MASK 0x30 /* Transmit Buffer Data Triggering Number */ #define SPBFCR_RXTRG_MASK 0x07 /* Receive Buffer Data Triggering Number */ +/* QSPI on R-Car Gen2 */ +#define SPBFCR_TXTRG_1B 0x00 /* 31 bytes (1 byte available) */ +#define SPBFCR_TXTRG_32B 0x30 /* 0 byte (32 bytes available) */ +#define SPBFCR_RXTRG_1B 0x00 /* 1 byte (31 bytes available) */ +#define SPBFCR_RXTRG_32B 0x07 /* 32 bytes (0 byte available) */ + +#define QSPI_BUFFER_SIZE 32u struct rspi_data { void __iomem *addr; @@ -366,6 +373,52 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size) return 0; } +static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg) +{ + u8 data; + + data = rspi_read8(rspi, reg); + data &= ~mask; + data |= (val & mask); + rspi_write8(rspi, data, reg); +} + +static int qspi_set_send_trigger(struct rspi_data *rspi, unsigned int len) +{ + unsigned int n; + + n = min(len, QSPI_BUFFER_SIZE); + + if (len >= QSPI_BUFFER_SIZE) { + /* sets triggering number to 32 bytes */ + qspi_update(rspi, SPBFCR_TXTRG_MASK, + SPBFCR_TXTRG_32B, QSPI_SPBFCR); + } else { + /* sets triggering number to 1 byte */ + qspi_update(rspi, SPBFCR_TXTRG_MASK, + SPBFCR_TXTRG_1B, QSPI_SPBFCR); + } + + return n; +} + +static void qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len) +{ + unsigned int n; + + n = min(len, QSPI_BUFFER_SIZE); + + if (len >= QSPI_BUFFER_SIZE) { + /* sets triggering number to 32 bytes */ + qspi_update(rspi, SPBFCR_RXTRG_MASK, + SPBFCR_RXTRG_32B, QSPI_SPBFCR); + } else { + /* sets triggering number to 1 byte */ + qspi_update(rspi, SPBFCR_RXTRG_MASK, + SPBFCR_RXTRG_1B, QSPI_SPBFCR); + } +} + #define set_config_register(spi, n) spi->ops->set_config_register(spi, n) static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable) @@ -609,18 +662,28 @@ static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi, return __rspi_can_dma(rspi, xfer); } +static int rspi_dma_check_then_transfer(struct rspi_data *rspi, + struct spi_transfer *xfer) +{ + if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) { + /* rx_buf can be NULL on RSPI on SH in TX-only Mode */ + int ret = rspi_dma_transfer(rspi, &xfer->tx_sg, + xfer->rx_buf ? &xfer->rx_sg : NULL); + if (ret != -EAGAIN) + return 0; + } + + return -EAGAIN; +} + static int rspi_common_transfer(struct rspi_data *rspi, struct spi_transfer *xfer) { int ret; - if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) { - /* rx_buf can be NULL on RSPI on SH in TX-only Mode */ - ret = rspi_dma_transfer(rspi, &xfer->tx_sg, - xfer->rx_buf ? &xfer->rx_sg : NULL); - if (ret != -EAGAIN) - return ret; - } + ret = rspi_dma_check_then_transfer(rspi, xfer); + if (ret != -EAGAIN) + return ret; ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len); if (ret < 0) @@ -661,12 +724,59 @@ static int rspi_rz_transfer_one(struct spi_master *master, return rspi_common_transfer(rspi, xfer); } +static int qspi_trigger_transfer_out_int(struct rspi_data *rspi, const u8 *tx, + u8 *rx, unsigned int len) +{ + unsigned int i, n, ret; + int error; + + while (len > 0) { + n = qspi_set_send_trigger(rspi, len); + qspi_set_receive_trigger(rspi, len); + if (n == QSPI_BUFFER_SIZE) { + error = rspi_wait_for_tx_empty(rspi); + if (error < 0) { + dev_err(&rspi->master->dev, "transmit timeout\n"); + return error; + } + for (i = 0; i < n; i++) + rspi_write_data(rspi, *tx++); + + error = rspi_wait_for_rx_full(rspi); + if (error < 0) { + dev_err(&rspi->master->dev, "receive timeout\n"); + return error; + } + for (i = 0; i < n; i++) + *rx++ = rspi_read_data(rspi); + } else { + ret = rspi_pio_transfer(rspi, tx, rx, n); + if (ret < 0) + return ret; + } + len -= n; + } + + return 0; +} + static int qspi_transfer_out_in(struct rspi_data *rspi, struct spi_transfer *xfer) { + int ret; + qspi_receive_init(rspi); - return rspi_common_transfer(rspi, xfer); + ret = rspi_dma_check_then_transfer(rspi, xfer); + if (ret != -EAGAIN) + return ret; + + ret = qspi_trigger_transfer_out_int(rspi, xfer->tx_buf, + xfer->rx_buf, xfer->len); + if (ret < 0) + return ret; + + return 0; } static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer) From c9bc3e8bf04225968f1cee34b50216263ed58000 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 3 Apr 2015 11:45:27 +0300 Subject: [PATCH 7/7] spi: signedness bug in qspi_trigger_transfer_out_int() We need "ret" to be unsigned for the error handling to work. The signedness of "i" and "n" don't matter but qspi_set_send_trigger() returns an int so I've changed them to int as well. Fixes: 4b6fe3edcbba ('spi: Using Trigger number to transmit/receive data') Signed-off-by: Dan Carpenter Signed-off-by: Mark Brown --- drivers/spi/spi-rspi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index fd276f990d4d..186924aa4740 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -727,7 +727,7 @@ static int rspi_rz_transfer_one(struct spi_master *master, static int qspi_trigger_transfer_out_int(struct rspi_data *rspi, const u8 *tx, u8 *rx, unsigned int len) { - unsigned int i, n, ret; + int i, n, ret; int error; while (len > 0) {