X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=drivers%2Fspi%2Fmxs_spi.c;h=7859536a6725569da9ad439b8f4d49e3a5672194;hb=56b0f39408c3d78dacb02db88de15e669dff9669;hp=4c27fef3d183bc9a34ca0dc995cc6d662681bbee;hpb=c829ff2e3d1bec9b2019480d82638149327db99e;p=karo-tx-uboot.git

diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index 4c27fef3d1..7859536a67 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -34,6 +34,8 @@
 
 #define	MXS_SPI_MAX_TIMEOUT	1000000
 #define	MXS_SPI_PORT_OFFSET	0x2000
+#define MXS_SSP_CHIPSELECT_MASK		0x00300000
+#define MXS_SSP_CHIPSELECT_SHIFT	20
 
 struct mxs_spi_slave {
 	struct spi_slave	slave;
@@ -51,14 +53,25 @@ void spi_init(void)
 {
 }
 
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	/* MXS SPI: 4 ports and 3 chip selects maximum */
+	if (bus > 3 || cs > 2)
+		return 0;
+	else
+		return 1;
+}
+
 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 				  unsigned int max_hz, unsigned int mode)
 {
 	struct mxs_spi_slave *mxs_slave;
 	uint32_t addr;
+	struct mx28_ssp_regs *ssp_regs;
+	int reg;
 
-	if (bus > 3) {
-		printf("MXS SPI: Max bus number is 3\n");
+	if (!spi_cs_is_valid(bus, cs)) {
+		printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
 		return NULL;
 	}
 
@@ -73,7 +86,13 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	mxs_slave->max_khz = max_hz / 1000;
 	mxs_slave->mode = mode;
 	mxs_slave->regs = (struct mx28_ssp_regs *)addr;
+	ssp_regs = mxs_slave->regs;
 
+	reg = readl(&ssp_regs->hw_ssp_ctrl0);
+	reg &= ~(MXS_SSP_CHIPSELECT_MASK);
+	reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
+
+	writel(reg, &ssp_regs->hw_ssp_ctrl0);
 	return &mxs_slave->slave;
 }
 
@@ -129,9 +148,15 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 	int len = bitlen / 8;
 	const char *tx = dout;
 	char *rx = din;
-
-	if (bitlen == 0)
-		return 0;
+	char dummy;
+
+	if (bitlen == 0) {
+		if (flags & SPI_XFER_END) {
+			rx = &dummy;
+			len = 1;
+		} else
+			return 0;
+	}
 
 	if (!rx && !tx)
 		return 0;
@@ -156,7 +181,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		if (mx28_wait_mask_set(&ssp_regs->hw_ssp_ctrl0_reg,
 			SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
 			printf("MXS SPI: Timeout waiting for start\n");
-			return -1;
+			return -ETIMEDOUT;
 		}
 
 		if (tx)
@@ -168,7 +193,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 			if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_status_reg,
 				SSP_STATUS_FIFO_EMPTY, MXS_SPI_MAX_TIMEOUT)) {
 				printf("MXS SPI: Timeout waiting for data\n");
-				return -1;
+				return -ETIMEDOUT;
 			}
 
 			*rx = readl(&ssp_regs->hw_ssp_data);
@@ -178,7 +203,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_ctrl0_reg,
 			SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
 			printf("MXS SPI: Timeout waiting for finish\n");
-			return -1;
+			return -ETIMEDOUT;
 		}
 	}