[PATCH] spi: Update to PXA2xx SPI Driver

Fix two outstanding issues with the pxa2xx_spi driver:

1) Bad cast in the function u32_writer. Thanks to Henrik Bechmann
2) Adds support for per transfer changes to speed and bits per word

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 75 insertions, 7 deletions

diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index 913e1aff0235..596bf820b70c 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -120,6 +120,8 @@ struct driver_data {
         dma_addr_t tx_dma;
         size_t rx_map_len;
         size_t tx_map_len;
+        u8 n_bytes;
+        u32 dma_width;
         int cs_change;
         void (*write)(struct driver_data *drv_data);
         void (*read)(struct driver_data *drv_data);
@@ -139,6 +141,8 @@ struct chip_data {
         u32 threshold;
         u32 dma_threshold;
         u8 enable_dma;
+        u8 bits_per_word;
+        u32 speed_hz;
         void (*write)(struct driver_data *drv_data);
         void (*read)(struct driver_data *drv_data);
         void (*cs_control)(u32 command);
@@ -186,7 +190,7 @@ static void null_cs_control(u32 command)
 static void null_writer(struct driver_data *drv_data)
 {
         void *reg = drv_data->ioaddr;
-        u8 n_bytes = drv_data->cur_chip->n_bytes;
+        u8 n_bytes = drv_data->n_bytes;
 
         while ((read_SSSR(reg) & SSSR_TNF)
                         && (drv_data->tx < drv_data->tx_end)) {
@@ -198,7 +202,7 @@ static void null_writer(struct driver_data *drv_data)
 static void null_reader(struct driver_data *drv_data)
 {
         void *reg = drv_data->ioaddr;
-        u8 n_bytes = drv_data->cur_chip->n_bytes;
+        u8 n_bytes = drv_data->n_bytes;
 
         while ((read_SSSR(reg) & SSSR_RNE)
                         && (drv_data->rx < drv_data->rx_end)) {
@@ -256,7 +260,7 @@ static void u32_writer(struct driver_data *drv_data)
 
         while ((read_SSSR(reg) & SSSR_TNF)
                         && (drv_data->tx < drv_data->tx_end)) {
-                write_SSDR(*(u16 *)(drv_data->tx), reg);
+                write_SSDR(*(u32 *)(drv_data->tx), reg);
                 drv_data->tx += 4;
         }
 }
@@ -677,6 +681,10 @@ static void pump_transfers(unsigned long data)
         struct spi_transfer *previous = NULL;
         struct chip_data *chip = NULL;
         void *reg = drv_data->ioaddr;
+        u32 clk_div = 0;
+        u8 bits = 0;
+        u32 speed = 0;
+        u32 cr0;
 
         /* Get current state information */
         message = drv_data->cur_msg;
@@ -713,6 +721,8 @@ static void pump_transfers(unsigned long data)
                 giveback(message, drv_data);
                 return;
         }
+        drv_data->n_bytes = chip->n_bytes;
+        drv_data->dma_width = chip->dma_width;
         drv_data->cs_control = chip->cs_control;
         drv_data->tx = (void *)transfer->tx_buf;
         drv_data->tx_end = drv_data->tx + transfer->len;
@@ -724,6 +734,62 @@ static void pump_transfers(unsigned long data)
         drv_data->write = drv_data->tx ? chip->write : null_writer;
         drv_data->read = drv_data->rx ? chip->read : null_reader;
         drv_data->cs_change = transfer->cs_change;
+
+        /* Change speed and bit per word on a per transfer */
+        if (transfer->speed_hz || transfer->bits_per_word) {
+
+                /* Disable clock */
+                write_SSCR0(chip->cr0 & ~SSCR0_SSE, reg);
+                cr0 = chip->cr0;
+                bits = chip->bits_per_word;
+                speed = chip->speed_hz;
+
+                if (transfer->speed_hz)
+                        speed = transfer->speed_hz;
+
+                if (transfer->bits_per_word)
+                        bits = transfer->bits_per_word;
+
+                if (reg == SSP1_VIRT)
+                        clk_div = SSP1_SerClkDiv(speed);
+                else if (reg == SSP2_VIRT)
+                        clk_div = SSP2_SerClkDiv(speed);
+                else if (reg == SSP3_VIRT)
+                        clk_div = SSP3_SerClkDiv(speed);
+
+                if (bits <= 8) {
+                        drv_data->n_bytes = 1;
+                        drv_data->dma_width = DCMD_WIDTH1;
+                        drv_data->read = drv_data->read != null_reader ?
+                                                u8_reader : null_reader;
+                        drv_data->write = drv_data->write != null_writer ?
+                                                u8_writer : null_writer;
+                } else if (bits <= 16) {
+                        drv_data->n_bytes = 2;
+                        drv_data->dma_width = DCMD_WIDTH2;
+                        drv_data->read = drv_data->read != null_reader ?
+                                                u16_reader : null_reader;
+                        drv_data->write = drv_data->write != null_writer ?
+                                                u16_writer : null_writer;
+                } else if (bits <= 32) {
+                        drv_data->n_bytes = 4;
+                        drv_data->dma_width = DCMD_WIDTH4;
+                        drv_data->read = drv_data->read != null_reader ?
+                                                u32_reader : null_reader;
+                        drv_data->write = drv_data->write != null_writer ?
+                                                u32_writer : null_writer;
+                }
+
+                cr0 = clk_div
+                        | SSCR0_Motorola
+                        | SSCR0_DataSize(bits & 0x0f)
+                        | SSCR0_SSE
+                        | (bits > 16 ? SSCR0_EDSS : 0);
+
+                /* Start it back up */
+                write_SSCR0(cr0, reg);
+        }
+
         message->state = RUNNING_STATE;
 
         /* Try to map dma buffer and do a dma transfer if successful */
@@ -739,13 +805,13 @@ static void pump_transfers(unsigned long data)
                 if (drv_data->rx == drv_data->null_dma_buf)
                         /* No target address increment */
                         DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
-                                                        | chip->dma_width
+                                                        | drv_data->dma_width
                                                         | chip->dma_burst_size
                                                         | drv_data->len;
                 else
                         DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
                                                         | DCMD_FLOWSRC
-                                                        | chip->dma_width
+                                                        | drv_data->dma_width
                                                         | chip->dma_burst_size
                                                         | drv_data->len;
 
@@ -756,13 +822,13 @@ static void pump_transfers(unsigned long data)
                 if (drv_data->tx == drv_data->null_dma_buf)
                         /* No source address increment */
                         DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
-                                                        | chip->dma_width
+                                                        | drv_data->dma_width
                                                         | chip->dma_burst_size
                                                         | drv_data->len;
                 else
                         DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
                                                         | DCMD_FLOWTRG
-                                                        | chip->dma_width
+                                                        | drv_data->dma_width
                                                         | chip->dma_burst_size
                                                         | drv_data->len;
 
@@ -943,6 +1009,7 @@ static int setup(struct spi_device *spi)
                 clk_div = SSP3_SerClkDiv(spi->max_speed_hz);
         else
                 return -ENODEV;
+        chip->speed_hz = spi->max_speed_hz;
 
         chip->cr0 = clk_div
                         | SSCR0_Motorola
@@ -987,6 +1054,7 @@ static int setup(struct spi_device *spi)
                 kfree(chip);
                 return -ENODEV;
         }
+        chip->bits_per_word = spi->bits_per_word;
 
         spi_set_ctldata(spi, chip);