Merge remote-tracking branches 'spi/topic/dw', 'spi/topic/dw-mid', 'spi/topic/fsl-espi' and 'spi/topic/imx' into spi-next

drivers/spi/spi-dw-mid.c

@@ -283,7 +283,7 @@ static void mid_spi_dma_stop(struct dw_spi *dws)
 	}
 }
 
-static struct dw_spi_dma_ops mid_dma_ops = {
+static const struct dw_spi_dma_ops mid_dma_ops = {
 	.dma_init	= mid_spi_dma_init,
 	.dma_exit	= mid_spi_dma_exit,
 	.dma_setup	= mid_spi_dma_setup,

drivers/spi/spi-dw.c

@@ -425,7 +425,7 @@ static int dw_spi_setup(struct spi_device *spi)
 		chip->type = chip_info->type;
 	}
 
-	chip->tmode = 0; /* Tx & Rx */
+	chip->tmode = SPI_TMOD_TR;
 
 	if (gpio_is_valid(spi->cs_gpio)) {
 		ret = gpio_direction_output(spi->cs_gpio,

drivers/spi/spi-dw.h

@@ -130,7 +130,7 @@ struct dw_spi {
 	struct dma_chan		*rxchan;
 	unsigned long		dma_chan_busy;
 	dma_addr_t		dma_addr; /* phy address of the Data register */
-	struct dw_spi_dma_ops	*dma_ops;
+	const struct dw_spi_dma_ops *dma_ops;
 	void			*dma_tx;
 	void			*dma_rx;
 

drivers/spi/spi-fsl-espi.c

@@ -643,6 +643,11 @@ static int fsl_espi_runtime_resume(struct device *dev)
 }
 #endif
 
+static size_t fsl_espi_max_transfer_size(struct spi_device *spi)
+{
+	return SPCOM_TRANLEN_MAX;
+}
+
 static struct spi_master * fsl_espi_probe(struct device *dev,
 		struct resource *mem, unsigned int irq)
 {
@@ -670,6 +675,7 @@ static struct spi_master * fsl_espi_probe(struct device *dev,
 	master->cleanup = fsl_espi_cleanup;
 	master->transfer_one_message = fsl_espi_do_one_msg;
 	master->auto_runtime_pm = true;
+	master->max_transfer_size = fsl_espi_max_transfer_size;
 
 	mpc8xxx_spi = spi_master_get_devdata(master);
 

drivers/spi/spi-imx.c

@@ -104,9 +104,7 @@ struct spi_imx_data {
 	unsigned int dma_is_inited;
 	unsigned int dma_finished;
 	bool usedma;
-	u32 rx_wml;
-	u32 tx_wml;
-	u32 rxt_wml;
+	u32 wml;
 	struct completion dma_rx_completion;
 	struct completion dma_tx_completion;
 
@@ -124,9 +122,14 @@ static inline int is_imx35_cspi(struct spi_imx_data *d)
 	return d->devtype_data->devtype == IMX35_CSPI;
 }
 
+static inline int is_imx51_ecspi(struct spi_imx_data *d)
+{
+	return d->devtype_data->devtype == IMX51_ECSPI;
+}
+
 static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
 {
-	return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
+	return is_imx51_ecspi(d) ? 64 : 8;
 }
 
 #define MXC_SPI_BUF_RX(type)						\
@@ -201,9 +204,8 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
 
-	if (spi_imx->dma_is_inited
-	    && transfer->len > spi_imx->rx_wml * sizeof(u32)
-	    && transfer->len > spi_imx->tx_wml * sizeof(u32))
+	if (spi_imx->dma_is_inited &&
+	    transfer->len > spi_imx->wml * sizeof(u32))
 		return true;
 	return false;
 }
@@ -244,6 +246,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_STAT		0x18
 #define MX51_ECSPI_STAT_RR		(1 <<  3)
 
+#define MX51_ECSPI_TESTREG	0x20
+#define MX51_ECSPI_TESTREG_LBC	BIT(31)
+
 /* MX51 eCSPI */
 static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
 				      unsigned int *fres)
@@ -313,7 +318,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 {
 	u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
 	u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
-	u32 clk = config->speed_hz, delay;
+	u32 clk = config->speed_hz, delay, reg;
 
 	/*
 	 * The hardware seems to have a race condition when changing modes. The
@@ -351,7 +356,16 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 	else
 		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs);
 
+	/* CTRL register always go first to bring out controller from reset */
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+
+	reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
+	if (config->mode & SPI_LOOP)
+		reg |= MX51_ECSPI_TESTREG_LBC;
+	else
+		reg &= ~MX51_ECSPI_TESTREG_LBC;
+	writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);
+
 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
 
 	/*
@@ -378,10 +392,9 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 	if (spi_imx->dma_is_inited) {
 		dma = readl(spi_imx->base + MX51_ECSPI_DMA);
 
-		spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
-		rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
-		tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
-		rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
+		rx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
+		tx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
+		rxt_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
 		dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
 			   & ~MX51_ECSPI_DMA_RX_WML_MASK
 			   & ~MX51_ECSPI_DMA_RXT_WML_MASK)
@@ -832,18 +845,21 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		return 0;
 
+	spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
+
 	/* Prepare for TX DMA: */
-	master->dma_tx = dma_request_slave_channel(dev, "tx");
-	if (!master->dma_tx) {
-		dev_err(dev, "cannot get the TX DMA channel!\n");
-		ret = -EINVAL;
+	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+	if (IS_ERR(master->dma_tx)) {
+		ret = PTR_ERR(master->dma_tx);
+		dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
+		master->dma_tx = NULL;
 		goto err;
 	}
 
 	slave_config.direction = DMA_MEM_TO_DEV;
 	slave_config.dst_addr = res->start + MXC_CSPITXDATA;
 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+	slave_config.dst_maxburst = spi_imx->wml;
 	ret = dmaengine_slave_config(master->dma_tx, &slave_config);
 	if (ret) {
 		dev_err(dev, "error in TX dma configuration.\n");
@@ -851,17 +867,18 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	}
 
 	/* Prepare for RX : */
-	master->dma_rx = dma_request_slave_channel(dev, "rx");
-	if (!master->dma_rx) {
-		dev_dbg(dev, "cannot get the DMA channel.\n");
-		ret = -EINVAL;
+	master->dma_rx = dma_request_slave_channel_reason(dev, "rx");
+	if (IS_ERR(master->dma_rx)) {
+		ret = PTR_ERR(master->dma_rx);
+		dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
+		master->dma_rx = NULL;
 		goto err;
 	}
 
 	slave_config.direction = DMA_DEV_TO_MEM;
 	slave_config.src_addr = res->start + MXC_CSPIRXDATA;
 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+	slave_config.src_maxburst = spi_imx->wml;
 	ret = dmaengine_slave_config(master->dma_rx, &slave_config);
 	if (ret) {
 		dev_err(dev, "error in RX dma configuration.\n");
@@ -874,8 +891,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	master->max_dma_len = MAX_SDMA_BD_BYTES;
 	spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
 					 SPI_MASTER_MUST_TX;
-	spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
-	spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
 	spi_imx->dma_is_inited = 1;
 
 	return 0;
@@ -942,14 +957,22 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 	dma = readl(spi_imx->base + MX51_ECSPI_DMA);
 	dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
 	/* Change RX_DMA_LENGTH trigger dma fetch tail data */
-	left = transfer->len % spi_imx->rxt_wml;
+	left = transfer->len % spi_imx->wml;
 	if (left)
 		writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
 				spi_imx->base + MX51_ECSPI_DMA);
+	/*
+	 * Set these order to avoid potential RX overflow. The overflow may
+	 * happen if we enable SPI HW before starting RX DMA due to rescheduling
+	 * for another task and/or interrupt.
+	 * So RX DMA enabled first to make sure data would be read out from FIFO
+	 * ASAP. TX DMA enabled next to start filling TX FIFO with new data.
+	 * And finaly SPI HW enabled to start actual data transfer.
+	 */
+	dma_async_issue_pending(master->dma_rx);
+	dma_async_issue_pending(master->dma_tx);
 	spi_imx->devtype_data->trigger(spi_imx);
 
-	dma_async_issue_pending(master->dma_tx);
-	dma_async_issue_pending(master->dma_rx);
 	/* Wait SDMA to finish the data transfer.*/
 	timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
 						IMX_DMA_TIMEOUT);
@@ -958,6 +981,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 			dev_driver_string(&master->dev),
 			dev_name(&master->dev));
 		dmaengine_terminate_all(master->dma_tx);
+		dmaengine_terminate_all(master->dma_rx);
 	} else {
 		timeout = wait_for_completion_timeout(
 				&spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT);
@@ -968,8 +992,9 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 			spi_imx->devtype_data->reset(spi_imx);
 			dmaengine_terminate_all(master->dma_rx);
 		}
+		dma &= ~MX51_ECSPI_DMA_RXT_WML_MASK;
 		writel(dma |
-		       spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
+		       spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
 		       spi_imx->base + MX51_ECSPI_DMA);
 	}
 
@@ -1117,6 +1142,9 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx = spi_master_get_devdata(master);
 	spi_imx->bitbang.master = master;
 
+	spi_imx->devtype_data = of_id ? of_id->data :
+		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
+
 	for (i = 0; i < master->num_chipselect; i++) {
 		int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
 		if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
@@ -1142,12 +1170,11 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
 	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+	if (is_imx51_ecspi(spi_imx))
+		spi_imx->bitbang.master->mode_bits |= SPI_LOOP;
 
 	init_completion(&spi_imx->xfer_done);
 
-	spi_imx->devtype_data = of_id ? of_id->data :
-		(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(spi_imx->base)) {
@@ -1193,9 +1220,15 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * Only validated on i.mx6 now, can remove the constrain if validated on
 	 * other chips.
 	 */
-	if (spi_imx->devtype_data == &imx51_ecspi_devtype_data
-	    && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res))
-		dev_err(&pdev->dev, "dma setup error,use pio instead\n");
+	if (is_imx51_ecspi(spi_imx)) {
+		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master, res);
+		if (ret == -EPROBE_DEFER)
+			goto out_clk_put;
+
+		if (ret < 0)
+			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
+				ret);
+	}
 
 	spi_imx->devtype_data->reset(spi_imx);
 

include/linux/spi/spi.h

@@ -425,6 +425,12 @@ struct spi_master {
 #define SPI_MASTER_MUST_RX      BIT(3)		/* requires rx */
 #define SPI_MASTER_MUST_TX      BIT(4)		/* requires tx */
 
+	/*
+	 * on some hardware transfer size may be constrained
+	 * the limit may depend on device transfer settings
+	 */
+	size_t (*max_transfer_size)(struct spi_device *spi);
+
 	/* lock and mutex for SPI bus locking */
 	spinlock_t		bus_lock_spinlock;
 	struct mutex		bus_lock_mutex;
@@ -832,6 +838,15 @@ extern int spi_async(struct spi_device *spi, struct spi_message *message);
 extern int spi_async_locked(struct spi_device *spi,
 			    struct spi_message *message);
 
+static inline size_t
+spi_max_transfer_size(struct spi_device *spi)
+{
+	struct spi_master *master = spi->master;
+	if (!master->max_transfer_size)
+		return SIZE_MAX;
+	return master->max_transfer_size(spi);
+}
+
 /*---------------------------------------------------------------------------*/
 
 /* All these synchronous SPI transfer routines are utilities layered