Merge remote-tracking branch 'spi/topic/s3c64xx' into spi-next

drivers/spi/spi-s3c64xx.c

@@ -39,6 +39,7 @@
 #endif
 
 #define MAX_SPI_PORTS		3
+#define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
 
 /* Registers and bit-fields */
 
@@ -130,6 +131,7 @@
 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
 
 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
+#define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
 
 #define RXBUSY    (1<<2)
 #define TXBUSY    (1<<3)
@@ -158,6 +160,7 @@ struct s3c64xx_spi_port_config {
 	int	fifo_lvl_mask[MAX_SPI_PORTS];
 	int	rx_lvl_offset;
 	int	tx_st_done;
+	int	quirks;
 	bool	high_speed;
 	bool	clk_from_cmu;
 };
@@ -205,6 +208,7 @@ struct s3c64xx_spi_driver_data {
 	struct s3c64xx_spi_port_config	*port_conf;
 	unsigned int			port_id;
 	unsigned long			gpios[4];
+	bool				cs_gpio;
 };
 
 static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
@@ -344,8 +348,12 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
 {
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
 
-	/* Acquire DMA channels */
-	while (!acquire_dma(sdd))
+	/*
+	 * If DMA resource was not available during
+	 * probe, no need to continue with dma requests
+	 * else Acquire DMA channels
+	 */
+	while (!is_polling(sdd) && !acquire_dma(sdd))
 		usleep_range(10000, 11000);
 
 	pm_runtime_get_sync(&sdd->pdev->dev);
@@ -358,9 +366,12 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
 
 	/* Free DMA channels */
-	sdd->ops->release((enum dma_ch)sdd->rx_dma.ch, &s3c64xx_spi_dma_client);
-	sdd->ops->release((enum dma_ch)sdd->tx_dma.ch, &s3c64xx_spi_dma_client);
-
+	if (!is_polling(sdd)) {
+		sdd->ops->release((enum dma_ch)sdd->rx_dma.ch,
+					&s3c64xx_spi_dma_client);
+		sdd->ops->release((enum dma_ch)sdd->tx_dma.ch,
+					&s3c64xx_spi_dma_client);
+	}
 	pm_runtime_put(&sdd->pdev->dev);
 
 	return 0;
@@ -464,8 +475,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi)
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
 
 	/* Free DMA channels */
-	dma_release_channel(sdd->rx_dma.ch);
-	dma_release_channel(sdd->tx_dma.ch);
+	if (!is_polling(sdd)) {
+		dma_release_channel(sdd->rx_dma.ch);
+		dma_release_channel(sdd->tx_dma.ch);
+	}
 
 	pm_runtime_put(&sdd->pdev->dev);
 	return 0;
@@ -558,14 +571,40 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
 		if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
 			/* Deselect the last toggled device */
 			cs = sdd->tgl_spi->controller_data;
-			gpio_set_value(cs->line,
-				spi->mode & SPI_CS_HIGH ? 0 : 1);
+			if (sdd->cs_gpio)
+				gpio_set_value(cs->line,
+					spi->mode & SPI_CS_HIGH ? 0 : 1);
 		}
 		sdd->tgl_spi = NULL;
 	}
 
 	cs = spi->controller_data;
-	gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
+	if (sdd->cs_gpio)
+		gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0);
+
+	/* Start the signals */
+	writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+}
+
+static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
+					int timeout_ms)
+{
+	void __iomem *regs = sdd->regs;
+	unsigned long val = 1;
+	u32 status;
+
+	/* max fifo depth available */
+	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+
+	if (timeout_ms)
+		val = msecs_to_loops(timeout_ms);
+
+	do {
+		status = readl(regs + S3C64XX_SPI_STATUS);
+	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
+
+	/* return the actual received data length */
+	return RX_FIFO_LVL(status, sdd);
 }
 
 static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
@@ -590,20 +629,19 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
 		} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
 	}
 
-	if (!val)
-		return -EIO;
-
 	if (dma_mode) {
 		u32 status;
 
 		/*
+		 * If the previous xfer was completed within timeout, then
+		 * proceed further else return -EIO.
 		 * DmaTx returns after simply writing data in the FIFO,
 		 * w/o waiting for real transmission on the bus to finish.
 		 * DmaRx returns only after Dma read data from FIFO which
 		 * needs bus transmission to finish, so we don't worry if
 		 * Xfer involved Rx(with or without Tx).
 		 */
-		if (xfer->rx_buf == NULL) {
+		if (val && !xfer->rx_buf) {
 			val = msecs_to_loops(10);
 			status = readl(regs + S3C64XX_SPI_STATUS);
 			while ((TX_FIFO_LVL(status, sdd)
@@ -613,30 +651,54 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
 				status = readl(regs + S3C64XX_SPI_STATUS);
 			}
 
-			if (!val)
-				return -EIO;
 		}
+
+		/* If timed out while checking rx/tx status return error */
+		if (!val)
+			return -EIO;
 	} else {
+		int loops;
+		u32 cpy_len;
+		u8 *buf;
+
 		/* If it was only Tx */
-		if (xfer->rx_buf == NULL) {
+		if (!xfer->rx_buf) {
 			sdd->state &= ~TXBUSY;
 			return 0;
 		}
 
-		switch (sdd->cur_bpw) {
-		case 32:
-			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
-				xfer->rx_buf, xfer->len / 4);
-			break;
-		case 16:
-			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
-				xfer->rx_buf, xfer->len / 2);
-			break;
-		default:
-			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
-				xfer->rx_buf, xfer->len);
-			break;
-		}
+		/*
+		 * If the receive length is bigger than the controller fifo
+		 * size, calculate the loops and read the fifo as many times.
+		 * loops = length / max fifo size (calculated by using the
+		 * fifo mask).
+		 * For any size less than the fifo size the below code is
+		 * executed atleast once.
+		 */
+		loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
+		buf = xfer->rx_buf;
+		do {
+			/* wait for data to be received in the fifo */
+			cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
+						(loops ? ms : 0));
+
+			switch (sdd->cur_bpw) {
+			case 32:
+				ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
+					buf, cpy_len / 4);
+				break;
+			case 16:
+				ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
+					buf, cpy_len / 2);
+				break;
+			default:
+				ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
+					buf, cpy_len);
+				break;
+			}
+
+			buf = buf + cpy_len;
+		} while (loops--);
 		sdd->state &= ~RXBUSY;
 	}
 
@@ -651,7 +713,11 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
 	if (sdd->tgl_spi == spi)
 		sdd->tgl_spi = NULL;
 
-	gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
+	if (sdd->cs_gpio)
+		gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
+	/* Quiese the signals */
+	writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
 }
 
 static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
@@ -733,7 +799,7 @@ static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
 	struct device *dev = &sdd->pdev->dev;
 	struct spi_transfer *xfer;
 
-	if (msg->is_dma_mapped)
+	if (is_polling(sdd) || msg->is_dma_mapped)
 		return 0;
 
 	/* First mark all xfer unmapped */
@@ -782,7 +848,7 @@ static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
 	struct device *dev = &sdd->pdev->dev;
 	struct spi_transfer *xfer;
 
-	if (msg->is_dma_mapped)
+	if (is_polling(sdd) || msg->is_dma_mapped)
 		return;
 
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
@@ -861,8 +927,9 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
 
 		/* Polling method for xfers not bigger than FIFO capacity */
 		use_dma = 0;
-		if (sdd->rx_dma.ch && sdd->tx_dma.ch &&
-		    (xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1)))
+		if (!is_polling(sdd) &&
+			(sdd->rx_dma.ch && sdd->tx_dma.ch &&
+			(xfer->len > ((FIFO_LVL_MASK(sdd) >> 1) + 1))))
 			use_dma = 1;
 
 		spin_lock_irqsave(&sdd->lock, flags);
@@ -876,17 +943,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
 		/* Slave Select */
 		enable_cs(sdd, spi);
 
-		/* Start the signals */
-		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
 		spin_unlock_irqrestore(&sdd->lock, flags);
 
 		status = wait_for_xfer(sdd, xfer, use_dma);
 
-		/* Quiese the signals */
-		writel(S3C64XX_SPI_SLAVE_SIG_INACT,
-		       sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-
 		if (status) {
 			dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
@@ -942,8 +1002,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
 {
 	struct s3c64xx_spi_csinfo *cs;
 	struct device_node *slave_np, *data_np = NULL;
+	struct s3c64xx_spi_driver_data *sdd;
 	u32 fb_delay = 0;
 
+	sdd = spi_master_get_devdata(spi->master);
 	slave_np = spi->dev.of_node;
 	if (!slave_np) {
 		dev_err(&spi->dev, "device node not found\n");
@@ -963,7 +1025,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
 		return ERR_PTR(-ENOMEM);
 	}
 
-	cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
+	/* The CS line is asserted/deasserted by the gpio pin */
+	if (sdd->cs_gpio)
+		cs->line = of_get_named_gpio(data_np, "cs-gpio", 0);
+
 	if (!gpio_is_valid(cs->line)) {
 		dev_err(&spi->dev, "chip select gpio is not specified or invalid\n");
 		kfree(cs);
@@ -1003,7 +1068,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 		return -ENODEV;
 	}
 
-	if (!spi_get_ctldata(spi)) {
+	/* Request gpio only if cs line is asserted by gpio pins */
+	if (sdd->cs_gpio) {
 		err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH,
 				       dev_name(&spi->dev));
 		if (err) {
@@ -1012,9 +1078,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 				cs->line, err);
 			goto err_gpio_req;
 		}
-		spi_set_ctldata(spi, cs);
 	}
 
+	if (!spi_get_ctldata(spi))
+		spi_set_ctldata(spi, cs);
+
 	sci = sdd->cntrlr_info;
 
 	spin_lock_irqsave(&sdd->lock, flags);
@@ -1092,8 +1160,10 @@ err_gpio_req:
 static void s3c64xx_spi_cleanup(struct spi_device *spi)
 {
 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
+	struct s3c64xx_spi_driver_data *sdd;
 
-	if (cs) {
+	sdd = spi_master_get_devdata(spi->master);
+	if (cs && sdd->cs_gpio) {
 		gpio_free(cs->line);
 		if (spi->dev.of_node)
 			kfree(cs);
@@ -1270,7 +1340,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 	sdd->cntrlr_info = sci;
 	sdd->pdev = pdev;
 	sdd->sfr_start = mem_res->start;
+	sdd->cs_gpio = true;
 	if (pdev->dev.of_node) {
+		if (!of_find_property(pdev->dev.of_node, "cs-gpio", NULL))
+			sdd->cs_gpio = false;
+
 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
 		if (ret < 0) {
 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
@@ -1287,19 +1361,19 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 	if (!sdd->pdev->dev.of_node) {
 		res = platform_get_resource(pdev, IORESOURCE_DMA,  0);
 		if (!res) {
-			dev_err(&pdev->dev, "Unable to get SPI tx dma "
-					"resource\n");
-			return -ENXIO;
-		}
-		sdd->tx_dma.dmach = res->start;
+			dev_warn(&pdev->dev, "Unable to get SPI tx dma "
+					"resource. Switching to poll mode\n");
+			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+		} else
+			sdd->tx_dma.dmach = res->start;
 
 		res = platform_get_resource(pdev, IORESOURCE_DMA,  1);
 		if (!res) {
-			dev_err(&pdev->dev, "Unable to get SPI rx dma "
-					"resource\n");
-			return -ENXIO;
-		}
-		sdd->rx_dma.dmach = res->start;
+			dev_warn(&pdev->dev, "Unable to get SPI rx dma "
+					"resource. Switching to poll mode\n");
+			sdd->port_conf->quirks = S3C64XX_SPI_QUIRK_POLL;
+		} else
+			sdd->rx_dma.dmach = res->start;
 	}
 
 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
@@ -1534,6 +1608,15 @@ static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
 	.clk_from_cmu	= true,
 };
 
+static struct s3c64xx_spi_port_config exynos5440_spi_port_config = {
+	.fifo_lvl_mask	= { 0x1ff },
+	.rx_lvl_offset	= 15,
+	.tx_st_done	= 25,
+	.high_speed	= true,
+	.clk_from_cmu	= true,
+	.quirks		= S3C64XX_SPI_QUIRK_POLL,
+};
+
 static struct platform_device_id s3c64xx_spi_driver_ids[] = {
 	{
 		.name		= "s3c2443-spi",
@@ -1557,15 +1640,16 @@ static struct platform_device_id s3c64xx_spi_driver_ids[] = {
 	{ },
 };
 
-#ifdef CONFIG_OF
 static const struct of_device_id s3c64xx_spi_dt_match[] = {
 	{ .compatible = "samsung,exynos4210-spi",
 			.data = (void *)&exynos4_spi_port_config,
 	},
+	{ .compatible = "samsung,exynos5440-spi",
+			.data = (void *)&exynos5440_spi_port_config,
+	},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
-#endif /* CONFIG_OF */
 
 static struct platform_driver s3c64xx_spi_driver = {
 	.driver = {