[PATCH] ARM: OMAP: omap2_mcspi: use the per transfer wordsize and speed overrides

Each transfer in an SPI message can have its wordsize and speed override.
Add a omap2_mcspi_setup_transfer to handle this.

Interpret spi->bits_per_word == 0 as a default wordsize of 8.

Signed-off-by: Imre Deak <imre.deak@nokia.com>

diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index 5042fc80a0e6e0bb8898625410d64f96f5628714..c98da7e8bc8a0b68da3db6fecba80ec2bdcddd40 100644 (file)
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -88,6 +88,7 @@ struct omap2_mcspi {
 
 struct omap2_mcspi_cs {
        u8 transmit_mode;
+       int word_len;
 };
 
 #define MOD_REG_BIT(val, mask, set) do { \
@@ -164,12 +165,15 @@ static void omap2_mcspi_set_master_mode(struct spi_device *spi, int single_chann
 
 static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
 {
+       struct omap2_mcspi_cs *cs = spi->controller_state;
        unsigned int            count, c;
        u32                     l;
        unsigned long           base, tx_reg, rx_reg, chstat_reg;
+       int                     word_len;
 
        count = xfer->len;
        c = count;
+       word_len = cs->word_len;
 
        l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
        l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
@@ -192,7 +196,7 @@ static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
        if (xfer->tx_buf == NULL)
                __raw_writel(0, tx_reg);
 
-       if (spi->bits_per_word <= 8) {
+       if (word_len <= 8) {
                u8              *rx;
                const u8        *tx;
 
@@ -211,7 +215,7 @@ static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
                                *rx++ = __raw_readl(rx_reg);
                        }
                }
-       } else if (spi->bits_per_word <= 16) {
+       } else if (word_len <= 16) {
                u16             *rx;
                const u16       *tx;
 
@@ -230,7 +234,7 @@ static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
                                *rx++ = __raw_readl(rx_reg);
                        }
                }
-       } else if (spi->bits_per_word <= 32) {
+       } else if (word_len <= 32) {
                u32             *rx;
                const u32       *tx;
 
@@ -258,25 +262,22 @@ static void omap2_mcspi_txrx(struct spi_device *spi, struct spi_transfer *xfer)
        }
 }
 
-static int omap2_mcspi_setup(struct spi_device *spi)
+static int omap2_mcspi_setup_transfer(struct spi_device *spi,
+                                     struct spi_transfer *t)
 {
        struct omap2_mcspi_cs *cs = spi->controller_state;
        struct omap2_mcspi_device_config *conf;
        u32 l = 0, div = 0;
        u8 word_len = spi->bits_per_word;
 
+       if (t != NULL && t->bits_per_word)
+               word_len = t->bits_per_word;
        if (!word_len)
-               return 0;
-
-       if (!cs) {
-               cs = kzalloc(sizeof *cs, SLAB_KERNEL);
-               if (!cs)
-                       return -ENOMEM;
-               spi->controller_state = cs;
-       }
+               word_len = 8;
 
        if (spi->bits_per_word > 32)
                return -EINVAL;
+       cs->word_len = word_len;
 
        conf = (struct omap2_mcspi_device_config *) spi->controller_data;
 
@@ -317,6 +318,20 @@ static int omap2_mcspi_setup(struct spi_device *spi)
        return 0;
 }
 
+static int omap2_mcspi_setup(struct spi_device *spi)
+{
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+
+       if (!cs) {
+               cs = kzalloc(sizeof *cs, SLAB_KERNEL);
+               if (!cs)
+                       return -ENOMEM;
+               spi->controller_state = cs;
+       }
+
+       return omap2_mcspi_setup_transfer(spi, NULL);
+}
+
 static void omap2_mcspi_cleanup(const struct spi_device *spi)
 {
        if (spi->controller_state != NULL)
@@ -337,6 +352,7 @@ static void omap2_mcspi_work(unsigned long arg)
                int                             cs_active;
                struct omap2_mcspi_device_config *conf;
                struct omap2_mcspi_cs           *cs;
+               int                             par_override = 0;
                int status = 0;
 
                m = container_of(mcspi->msg_queue.next, struct spi_message,
@@ -357,6 +373,14 @@ static void omap2_mcspi_work(unsigned long arg)
                                status = -EINVAL;
                                break;
                        }
+                       if (par_override || t->speed_hz || t->bits_per_word) {
+                               par_override = 1;
+                               status = omap2_mcspi_setup_transfer(spi, t);
+                               if (status < 0)
+                                       break;
+                               if (!t->speed_hz && !t->bits_per_word)
+                                       par_override = 0;
+                       }
 
                        if (!cs_active) {
                                omap2_mcspi_force_cs(spi, 1);
@@ -371,6 +395,12 @@ static void omap2_mcspi_work(unsigned long arg)
                        }
                }
 
+               /* Restore defaults they are overriden */
+               if (par_override) {
+                       par_override = 0;
+                       status = omap2_mcspi_setup_transfer(spi, NULL);
+               }
+
                if (cs_active)
                        omap2_mcspi_force_cs(spi, 0);