drivers: spi: omap3_spi: Initialize mode for all channels

At first SPI transfers, multiple chip selects can be
enabled simultaneously. This is due to chip select
polarity, which is not properly initialized for all
channels. This patch fixes the issue.

Signed-off-by: Julien Panis <jpanis@baylibre.com>

diff --git a/drivers/spi/omap3_spi.c b/drivers/spi/omap3_spi.c
index 1cbb5d46fd60ac7cee2c1765709ffab13df0b589..ff7b55f8707e8bb9a1ff124ed5f15482ea76988f 100644 (file)
--- a/drivers/spi/omap3_spi.c
+++ b/drivers/spi/omap3_spi.c
@@ -347,20 +347,28 @@ static void _omap3_spi_set_wordlen(struct omap3_spi_priv *priv)
        omap3_spi_write_chconf(priv, confr);
 }
 
-static void spi_reset(struct mcspi *regs)
+static void spi_reset(struct omap3_spi_priv *priv)
 {
        unsigned int tmp;
 
-       writel(OMAP3_MCSPI_SYSCONFIG_SOFTRESET, &regs->sysconfig);
+       writel(OMAP3_MCSPI_SYSCONFIG_SOFTRESET, &priv->regs->sysconfig);
        do {
-               tmp = readl(&regs->sysstatus);
+               tmp = readl(&priv->regs->sysstatus);
        } while (!(tmp & OMAP3_MCSPI_SYSSTATUS_RESETDONE));
 
        writel(OMAP3_MCSPI_SYSCONFIG_AUTOIDLE |
               OMAP3_MCSPI_SYSCONFIG_ENAWAKEUP |
-              OMAP3_MCSPI_SYSCONFIG_SMARTIDLE, &regs->sysconfig);
+              OMAP3_MCSPI_SYSCONFIG_SMARTIDLE, &priv->regs->sysconfig);
 
-       writel(OMAP3_MCSPI_WAKEUPENABLE_WKEN, &regs->wakeupenable);
+       writel(OMAP3_MCSPI_WAKEUPENABLE_WKEN, &priv->regs->wakeupenable);
+
+       /*
+        * Set the same default mode for each channel, especially CS polarity
+        * which must be common for all SPI slaves before any transfer.
+        */
+       for (priv->cs = 0 ; priv->cs < OMAP4_MCSPI_CHAN_NB ; priv->cs++)
+               _omap3_spi_set_mode(priv);
+       priv->cs = 0;
 }
 
 static void _omap3_spi_claim_bus(struct omap3_spi_priv *priv)
@@ -430,7 +438,7 @@ static int omap3_spi_probe(struct udevice *dev)
        priv->pin_dir = plat->pin_dir;
        priv->wordlen = SPI_DEFAULT_WORDLEN;
 
-       spi_reset(priv->regs);
+       spi_reset(priv);
 
        return 0;
 }

diff --git a/include/omap3_spi.h b/include/omap3_spi.h
index cae37705830a465f8964e4818dcffae4a29085a8..5381431d43893f585632dc4094f94395ba04b3f4 100644 (file)
--- a/include/omap3_spi.h
+++ b/include/omap3_spi.h
@@ -46,6 +46,8 @@
 
 #define OMAP4_MCSPI_REG_OFFSET 0x100
 
+#define OMAP4_MCSPI_CHAN_NB    4
+
 /* OMAP3 McSPI registers */
 struct mcspi_channel {
        unsigned int chconf;            /* 0x2C, 0x40, 0x54, 0x68 */
@@ -64,7 +66,7 @@ struct mcspi {
        unsigned int wakeupenable;      /* 0x20 */
        unsigned int syst;              /* 0x24 */
        unsigned int modulctrl;         /* 0x28 */
-       struct mcspi_channel channel[4];
+       struct mcspi_channel channel[OMAP4_MCSPI_CHAN_NB];
        /* channel0: 0x2C - 0x3C, bus 0 & 1 & 2 & 3 */
        /* channel1: 0x40 - 0x50, bus 0 & 1 */
        /* channel2: 0x54 - 0x64, bus 0 & 1 */