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[09/49] spi: davinci: enable GPIO lines to be used as chip selects

Message ID 1289990661-30126-10-git-send-email-nsekhar@ti.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Sekhar Nori Nov. 17, 2010, 10:43 a.m. UTC 
None
diff mbox

Patch

diff --git a/arch/arm/mach-davinci/include/mach/spi.h b/arch/arm/mach-davinci/include/mach/spi.h
index 2cb326e..734d1fb 100644
--- a/arch/arm/mach-davinci/include/mach/spi.h
+++ b/arch/arm/mach-davinci/include/mach/spi.h
@@ -19,6 +19,8 @@ 
 #ifndef __ARCH_ARM_DAVINCI_SPI_H
 #define __ARCH_ARM_DAVINCI_SPI_H
 
+#define SPI_INTERN_CS	0xFF
+
 enum {
 	SPI_VERSION_1, /* For DM355/DM365/DM6467 */
 	SPI_VERSION_2, /* For DA8xx */
@@ -38,6 +40,7 @@  struct davinci_spi_platform_data {
 	u8	use_dma;
 	u8	c2tdelay;
 	u8	t2cdelay;
+	u8	*chip_sel;
 };
 
 #endif	/* __ARCH_ARM_DAVINCI_SPI_H */
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 82dddf8..d5d7014 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -238,20 +238,32 @@  static void davinci_spi_chipselect(struct spi_device *spi, int value)
 	struct davinci_spi_platform_data *pdata;
 	u8 chip_sel = spi->chip_select;
 	u16 spidat1_cfg = CS_DEFAULT;
+	bool gpio_chipsel = false;
 
 	davinci_spi = spi_master_get_devdata(spi->master);
 	pdata = davinci_spi->pdata;
 
+	if (pdata->chip_sel && chip_sel < pdata->num_chipselect &&
+				pdata->chip_sel[chip_sel] != SPI_INTERN_CS)
+		gpio_chipsel = true;
+
 	/*
 	 * Board specific chip select logic decides the polarity and cs
 	 * line for the controller
 	 */
-	if (value == BITBANG_CS_ACTIVE) {
-		spidat1_cfg |= SPIDAT1_CSHOLD_MASK;
-		spidat1_cfg &= ~(0x1 << chip_sel);
-	}
+	if (gpio_chipsel) {
+		if (value == BITBANG_CS_ACTIVE)
+			gpio_set_value(pdata->chip_sel[chip_sel], 0);
+		else
+			gpio_set_value(pdata->chip_sel[chip_sel], 1);
+	} else {
+		if (value == BITBANG_CS_ACTIVE) {
+			spidat1_cfg |= SPIDAT1_CSHOLD_MASK;
+			spidat1_cfg &= ~(0x1 << chip_sel);
+		}
 
-	iowrite16(spidat1_cfg, davinci_spi->base + SPIDAT1 + 2);
+		iowrite16(spidat1_cfg, davinci_spi->base + SPIDAT1 + 2);
+	}
 }
 
 /**
@@ -546,6 +558,7 @@  static void davinci_spi_cleanup(struct spi_device *spi)
 static int davinci_spi_bufs_prep(struct spi_device *spi,
 				 struct davinci_spi *davinci_spi)
 {
+	struct davinci_spi_platform_data *pdata;
 	int op_mode = 0;
 
 	/*
@@ -558,8 +571,12 @@  static int davinci_spi_bufs_prep(struct spi_device *spi,
 	op_mode = SPIPC0_DIFUN_MASK
 		| SPIPC0_DOFUN_MASK
 		| SPIPC0_CLKFUN_MASK;
-	if (!(spi->mode & SPI_NO_CS))
-		op_mode |= 1 << spi->chip_select;
+	if (!(spi->mode & SPI_NO_CS)) {
+		pdata = davinci_spi->pdata;
+		if (!pdata->chip_sel ||
+		     pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS)
+			op_mode |= 1 << spi->chip_select;
+	}
 	if (spi->mode & SPI_READY)
 		op_mode |= SPIPC0_SPIENA_MASK;
 
@@ -1101,6 +1118,14 @@  static int davinci_spi_probe(struct platform_device *pdev)
 	udelay(100);
 	iowrite32(1, davinci_spi->base + SPIGCR0);
 
+	/* initialize chip selects */
+	if (pdata->chip_sel) {
+		for (i = 0; i < pdata->num_chipselect; i++) {
+			if (pdata->chip_sel[i] != SPI_INTERN_CS)
+				gpio_direction_output(pdata->chip_sel[i], 1);
+		}
+	}
+
 	/* Clock internal */
 	if (davinci_spi->pdata->clk_internal)
 		set_io_bits(davinci_spi->base + SPIGCR1,