spi: s3c64xx: straightforward cleanup

Merge series from Tudor Ambarus <tudor.ambarus@linaro.org>:

Various simple cleanups for the s3c64xx driver.  Tested with gs101-spi.

drivers/spi/spi-s3c64xx.c

@@ -3,19 +3,21 @@
 // Copyright (c) 2009 Samsung Electronics Co., Ltd.
 //      Jaswinder Singh <jassi.brar@samsung.com>
 
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/delay.h>
+#include <linux/bits.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/spi-s3c64xx.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
-#include <linux/of.h>
-
-#include <linux/platform_data/spi-s3c64xx.h>
+#include <linux/types.h>
 
 #define MAX_SPI_PORTS		16
 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
@@ -114,8 +116,6 @@
 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
 #define S3C64XX_SPI_TRAILCNT_OFF	19
 
-#define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
-
 #define S3C64XX_SPI_POLLING_SIZE	32
 
 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
@@ -180,7 +180,7 @@ struct s3c64xx_spi_port_config {
  * @cur_speed: Current clock speed
  * @rx_dma: Local receive DMA data (e.g. chan and direction)
  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
- * @port_conf: Local SPI port configuartion data
+ * @port_conf: Local SPI port configuration data
  * @port_id: Port identification number
  */
 struct s3c64xx_spi_driver_data {
@@ -279,7 +279,7 @@ static void s3c64xx_spi_dmacb(void *data)
 	spin_unlock_irqrestore(&sdd->lock, flags);
 }
 
-static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
+static int s3c64xx_prepare_dma(struct s3c64xx_spi_dma_data *dma,
 			       struct sg_table *sgt)
 {
 	struct s3c64xx_spi_driver_data *sdd;
@@ -292,20 +292,20 @@ static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
 	if (dma->direction == DMA_DEV_TO_MEM) {
 		sdd = container_of((void *)dma,
 			struct s3c64xx_spi_driver_data, rx_dma);
-		config.direction = dma->direction;
 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
 		config.src_addr_width = sdd->cur_bpw / 8;
 		config.src_maxburst = 1;
-		dmaengine_slave_config(dma->ch, &config);
 	} else {
 		sdd = container_of((void *)dma,
 			struct s3c64xx_spi_driver_data, tx_dma);
-		config.direction = dma->direction;
 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
 		config.dst_addr_width = sdd->cur_bpw / 8;
 		config.dst_maxburst = 1;
-		dmaengine_slave_config(dma->ch, &config);
 	}
+	config.direction = dma->direction;
+	ret = dmaengine_slave_config(dma->ch, &config);
+	if (ret)
+		return ret;
 
 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
 				       dma->direction, DMA_PREP_INTERRUPT);
@@ -322,7 +322,7 @@ static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
 	ret = dma_submit_error(dma->cookie);
 	if (ret) {
 		dev_err(&sdd->pdev->dev, "DMA submission failed");
-		return -EIO;
+		return ret;
 	}
 
 	dma_async_issue_pending(dma->ch);
@@ -408,12 +408,10 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host,
 {
 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
 
-	if (sdd->rx_dma.ch && sdd->tx_dma.ch) {
+	if (sdd->rx_dma.ch && sdd->tx_dma.ch)
 		return xfer->len > FIFO_DEPTH(sdd);
-	} else {
-		return false;
-	}
 
+	return false;
 }
 
 static void s3c64xx_iowrite8_32_rep(volatile void __iomem *addr,
@@ -497,7 +495,7 @@ static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
 		if (dma_mode) {
 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
-			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
+			ret = s3c64xx_prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
 		} else {
 			s3c64xx_iowrite_rep(sdd, xfer);
 		}
@@ -516,7 +514,7 @@ static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
 					| S3C64XX_SPI_PACKET_CNT_EN,
 					regs + S3C64XX_SPI_PACKET_CNT);
-			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
+			ret = s3c64xx_prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
 		}
 	}
 
@@ -566,7 +564,7 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 
 	/*
 	 * If the previous xfer was completed within timeout, then
-	 * proceed further else return -EIO.
+	 * proceed further else return -ETIMEDOUT.
 	 * 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
@@ -587,7 +585,7 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 
 	/* If timed out while checking rx/tx status return error */
 	if (!val)
-		return -EIO;
+		return -ETIMEDOUT;
 
 	return 0;
 }
@@ -617,7 +615,7 @@ static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
 	if (use_irq) {
 		val = msecs_to_jiffies(ms);
 		if (!wait_for_completion_timeout(&sdd->xfer_completion, val))
-			return -EIO;
+			return -ETIMEDOUT;
 	}
 
 	val = msecs_to_loops(ms);
@@ -1131,8 +1129,7 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
 
 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
 	val &= ~S3C64XX_SPI_MODE_4BURST;
-	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
-	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
+	val |= (S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
 
 	s3c64xx_flush_fifo(sdd);
@@ -1149,14 +1146,14 @@ static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
 		return ERR_PTR(-ENOMEM);
 
 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
-		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
+		dev_dbg(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
 		sci->src_clk_nr = 0;
 	} else {
 		sci->src_clk_nr = temp;
 	}
 
 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
-		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
+		dev_dbg(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
 		sci->num_cs = 1;
 	} else {
 		sci->num_cs = temp;
@@ -1226,6 +1223,9 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 					     "Failed to get alias id\n");
 		sdd->port_id = ret;
 	} else {
+		if (pdev->id < 0)
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "Negative platform ID is not allowed\n");
 		sdd->port_id = pdev->id;
 	}
 
@@ -1357,8 +1357,9 @@ static int s3c64xx_spi_suspend(struct device *dev)
 {
 	struct spi_controller *host = dev_get_drvdata(dev);
 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
+	int ret;
 
-	int ret = spi_controller_suspend(host);
+	ret = spi_controller_suspend(host);
 	if (ret)
 		return ret;
 
@@ -1563,31 +1564,31 @@ static const struct of_device_id s3c64xx_spi_dt_match[] = {
 			.data = &gs101_spi_port_config,
 	},
 	{ .compatible = "samsung,s3c2443-spi",
-			.data = (void *)&s3c2443_spi_port_config,
+			.data = &s3c2443_spi_port_config,
 	},
 	{ .compatible = "samsung,s3c6410-spi",
-			.data = (void *)&s3c6410_spi_port_config,
+			.data = &s3c6410_spi_port_config,
 	},
 	{ .compatible = "samsung,s5pv210-spi",
-			.data = (void *)&s5pv210_spi_port_config,
+			.data = &s5pv210_spi_port_config,
 	},
 	{ .compatible = "samsung,exynos4210-spi",
-			.data = (void *)&exynos4_spi_port_config,
+			.data = &exynos4_spi_port_config,
 	},
 	{ .compatible = "samsung,exynos7-spi",
-			.data = (void *)&exynos7_spi_port_config,
+			.data = &exynos7_spi_port_config,
 	},
 	{ .compatible = "samsung,exynos5433-spi",
-			.data = (void *)&exynos5433_spi_port_config,
+			.data = &exynos5433_spi_port_config,
 	},
 	{ .compatible = "samsung,exynos850-spi",
-			.data = (void *)&exynos850_spi_port_config,
+			.data = &exynos850_spi_port_config,
 	},
 	{ .compatible = "samsung,exynosautov9-spi",
-			.data = (void *)&exynosautov9_spi_port_config,
+			.data = &exynosautov9_spi_port_config,
 	},
 	{ .compatible = "tesla,fsd-spi",
-			.data = (void *)&fsd_spi_port_config,
+			.data = &fsd_spi_port_config,
 	},
 	{ },
 };