openwrt-xburst/target/linux/ar71xx/patches-3.2/207-spi-ath79-make-chipselect-logic-more-flexible.patch

From b875f877d06acb852342636db4c3d1e6c9fe01ba Mon Sep 17 00:00:00 2001
From: Gabor Juhos <juhosg@openwrt.org>
Date: Wed, 11 Jan 2012 22:25:11 +0100
Subject: [PATCH 7/7] spi/ath79: make chipselect logic more flexible

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
 .../include/asm/mach-ath79/ath79_spi_platform.h    |    8 ++-
 drivers/spi/spi-ath79.c                            |   65 +++++++++++--------
 2 files changed, 45 insertions(+), 28 deletions(-)

--- a/arch/mips/include/asm/mach-ath79/ath79_spi_platform.h
+++ b/arch/mips/include/asm/mach-ath79/ath79_spi_platform.h
@@ -16,8 +16,14 @@ struct ath79_spi_platform_data {
 	unsigned	num_chipselect;
 };
 
+enum ath79_spi_cs_type {
+	ATH79_SPI_CS_TYPE_INTERNAL,
+	ATH79_SPI_CS_TYPE_GPIO,
+};
+
 struct ath79_spi_controller_data {
-	unsigned	gpio;
+	enum ath79_spi_cs_type cs_type;
+	unsigned cs_line;
 };
 
 #endif /* _ATH79_SPI_PLATFORM_H */
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -30,6 +30,8 @@
 
 #define DRV_NAME	"ath79-spi"
 
+#define ATH79_SPI_CS_LINE_MAX	2
+
 struct ath79_spi {
 	struct spi_bitbang	bitbang;
 	u32			ioc_base;
@@ -62,6 +64,7 @@ static void ath79_spi_chipselect(struct
 {
 	struct ath79_spi *sp = ath79_spidev_to_sp(spi);
 	int cs_high = (spi->mode & SPI_CS_HIGH) ? is_active : !is_active;
+	struct ath79_spi_controller_data *cdata = spi->controller_data;
 
 	if (is_active) {
 		/* set initial clock polarity */
@@ -73,20 +76,21 @@ static void ath79_spi_chipselect(struct
 		ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
 	}
 
-	if (spi->chip_select) {
-		struct ath79_spi_controller_data *cdata = spi->controller_data;
-
-		/* SPI is normally active-low */
-		gpio_set_value(cdata->gpio, cs_high);
-	} else {
+	switch (cdata->cs_type) {
+	case ATH79_SPI_CS_TYPE_INTERNAL:
 		if (cs_high)
-			sp->ioc_base |= AR71XX_SPI_IOC_CS0;
+			sp->ioc_base |= AR71XX_SPI_IOC_CS(cdata->cs_line);
 		else
-			sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
+			sp->ioc_base &= ~AR71XX_SPI_IOC_CS(cdata->cs_line);
 
 		ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
-	}
+		break;
 
+	case ATH79_SPI_CS_TYPE_GPIO:
+		/* SPI is normally active-low */
+		gpio_set_value(cdata->cs_line, cs_high);
+		break;
+	}
 }
 
 static void ath79_spi_enable(struct ath79_spi *sp)
@@ -114,24 +118,30 @@ static int ath79_spi_setup_cs(struct spi
 {
 	struct ath79_spi *sp = ath79_spidev_to_sp(spi);
 	struct ath79_spi_controller_data *cdata;
+	unsigned long flags;
 	int status;
 
 	cdata = spi->controller_data;
-	if (spi->chip_select && !cdata)
+	if (!cdata)
 		return -EINVAL;
 
 	status = 0;
-	if (spi->chip_select) {
-		unsigned long flags;
+	switch (cdata->cs_type) {
+	case ATH79_SPI_CS_TYPE_INTERNAL:
+		if (cdata->cs_line > ATH79_SPI_CS_LINE_MAX)
+			status = -EINVAL;
+		break;
 
+	case ATH79_SPI_CS_TYPE_GPIO:
 		flags = GPIOF_DIR_OUT;
 		if (spi->mode & SPI_CS_HIGH)
 			flags |= GPIOF_INIT_HIGH;
 		else
 			flags |= GPIOF_INIT_LOW;
 
-		status = gpio_request_one(cdata->gpio, flags,
+		status = gpio_request_one(cdata->cs_line, flags,
 					  dev_name(&spi->dev));
+		break;
 	}
 
 	return status;
@@ -139,11 +149,15 @@ static int ath79_spi_setup_cs(struct spi
 
 static void ath79_spi_cleanup_cs(struct spi_device *spi)
 {
-	struct ath79_spi *sp = ath79_spidev_to_sp(spi);
+	struct ath79_spi_controller_data *cdata = spi->controller_data;
 
-	if (spi->chip_select) {
-		struct ath79_spi_controller_data *cdata = spi->controller_data;
-		gpio_free(cdata->gpio);
+	switch (cdata->cs_type) {
+	case ATH79_SPI_CS_TYPE_INTERNAL:
+		/* nothing to do */
+		break;
+	case ATH79_SPI_CS_TYPE_GPIO:
+		gpio_free(cdata->cs_line);
+		break;
 	}
 }
 
@@ -209,6 +223,10 @@ static __devinit int ath79_spi_probe(str
 	struct resource	*r;
 	int ret;
 
+	pdata = pdev->dev.platform_data;
+	if (!pdata)
+		return -EINVAL;
+
 	master = spi_alloc_master(&pdev->dev, sizeof(*sp));
 	if (master == NULL) {
 		dev_err(&pdev->dev, "failed to allocate spi master\n");
@@ -218,17 +236,10 @@ static __devinit int ath79_spi_probe(str
 	sp = spi_master_get_devdata(master);
 	platform_set_drvdata(pdev, sp);
 
-	pdata = pdev->dev.platform_data;
-
 	master->setup = ath79_spi_setup;
 	master->cleanup = ath79_spi_cleanup;
-	if (pdata) {
-		master->bus_num = pdata->bus_num;
-		master->num_chipselect = pdata->num_chipselect;
-	} else {
-		master->bus_num = -1;
-		master->num_chipselect = 1;
-	}
+	master->bus_num = pdata->bus_num;
+	master->num_chipselect = pdata->num_chipselect;
 
 	sp->bitbang.master = spi_master_get(master);
 	sp->bitbang.chipselect = ath79_spi_chipselect;