1 files changed, 67 insertions, 26 deletions

diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index b4f7f1c286e1..5e39bac9c51b 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -51,6 +51,12 @@ struct atmel_spi {
         dma_addr_t              buffer_dma;
 };
 
+/* Controller-specific per-slave state */
+struct atmel_spi_device {
+        unsigned int            npcs_pin;
+        u32                     csr;
+};
+
 #define BUFFER_SIZE             PAGE_SIZE
 #define INVALID_DMA_ADDRESS     0xffffffff
 
@@ -89,39 +95,58 @@ static bool atmel_spi_is_v2(void)
  * Master on Chip Select 0.")  No workaround exists for that ... so for
  * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
  * and (c) will trigger that first erratum in some cases.
+ *
+ * TODO: Test if the atmel_spi_is_v2() branch below works on
+ * AT91RM9200 if we use some other register than CSR0. However, don't
+ * do this unconditionally since AP7000 has an errata where the BITS
+ * field in CSR0 overrides all other CSRs.
  */
 
 static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 {
-        unsigned gpio = (unsigned) spi->controller_data;
+        struct atmel_spi_device *asd = spi->controller_state;
         unsigned active = spi->mode & SPI_CS_HIGH;
         u32 mr;
-        int i;
-        u32 csr;
-        u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
-
-        /* Make sure clock polarity is correct */
-        for (i = 0; i < spi->master->num_chipselect; i++) {
-                csr = spi_readl(as, CSR0 + 4 * i);
-                if ((csr ^ cpol) & SPI_BIT(CPOL))
-                        spi_writel(as, CSR0 + 4 * i, csr ^ SPI_BIT(CPOL));
-        }
 
-        mr = spi_readl(as, MR);
-        mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
+        if (atmel_spi_is_v2()) {
+                /*
+                 * Always use CSR0. This ensures that the clock
+                 * switches to the correct idle polarity before we
+                 * toggle the CS.
+                 */
+                spi_writel(as, CSR0, asd->csr);
+                spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
+                                | SPI_BIT(MSTR));
+                mr = spi_readl(as, MR);
+                gpio_set_value(asd->npcs_pin, active);
+        } else {
+                u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
+                int i;
+                u32 csr;
+
+                /* Make sure clock polarity is correct */
+                for (i = 0; i < spi->master->num_chipselect; i++) {
+                        csr = spi_readl(as, CSR0 + 4 * i);
+                        if ((csr ^ cpol) & SPI_BIT(CPOL))
+                                spi_writel(as, CSR0 + 4 * i,
+                                                csr ^ SPI_BIT(CPOL));
+                }
+
+                mr = spi_readl(as, MR);
+                mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
+                if (spi->chip_select != 0)
+                        gpio_set_value(asd->npcs_pin, active);
+                spi_writel(as, MR, mr);
+        }
 
         dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
-                        gpio, active ? " (high)" : "",
+                        asd->npcs_pin, active ? " (high)" : "",
                         mr);
-
-        if (atmel_spi_is_v2() || spi->chip_select != 0)
-                gpio_set_value(gpio, active);
-        spi_writel(as, MR, mr);
 }
 
 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
 {
-        unsigned gpio = (unsigned) spi->controller_data;
+        struct atmel_spi_device *asd = spi->controller_state;
         unsigned active = spi->mode & SPI_CS_HIGH;
         u32 mr;
 
@@ -135,11 +160,11 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
         }
 
         dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
-                        gpio, active ? " (low)" : "",
+                        asd->npcs_pin, active ? " (low)" : "",
                         mr);
 
         if (atmel_spi_is_v2() || spi->chip_select != 0)
-                gpio_set_value(gpio, !active);
+                gpio_set_value(asd->npcs_pin, !active);
 }
 
 static inline int atmel_spi_xfer_is_last(struct spi_message *msg,
@@ -511,6 +536,7 @@ atmel_spi_interrupt(int irq, void *dev_id)
 static int atmel_spi_setup(struct spi_device *spi)
 {
         struct atmel_spi        *as;
+        struct atmel_spi_device *asd;
         u32                     scbr, csr;
         unsigned int            bits = spi->bits_per_word;
         unsigned long           bus_hz;
@@ -595,11 +621,20 @@ static int atmel_spi_setup(struct spi_device *spi)
 
         /* chipselect must have been muxed as GPIO (e.g. in board setup) */
         npcs_pin = (unsigned int)spi->controller_data;
-        if (!spi->controller_state) {
+        asd = spi->controller_state;
+        if (!asd) {
+                asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
+                if (!asd)
+                        return -ENOMEM;
+
                 ret = gpio_request(npcs_pin, spi->dev.bus_id);
-                if (ret)
+                if (ret) {
+                        kfree(asd);
                         return ret;
-                spi->controller_state = (void *)npcs_pin;
+                }
+
+                asd->npcs_pin = npcs_pin;
+                spi->controller_state = asd;
                 gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH));
         } else {
                 unsigned long           flags;
@@ -611,11 +646,14 @@ static int atmel_spi_setup(struct spi_device *spi)
                 spin_unlock_irqrestore(&as->lock, flags);
         }
 
+        asd->csr = csr;
+
         dev_dbg(&spi->dev,
                 "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
                 bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
 
-        spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
+        if (!atmel_spi_is_v2())
+                spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
 
         return 0;
 }
@@ -690,10 +728,11 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
 static void atmel_spi_cleanup(struct spi_device *spi)
 {
         struct atmel_spi        *as = spi_master_get_devdata(spi->master);
+        struct atmel_spi_device *asd = spi->controller_state;
         unsigned                gpio = (unsigned) spi->controller_data;
         unsigned long           flags;
 
-        if (!spi->controller_state)
+        if (!asd)
                 return;
 
         spin_lock_irqsave(&as->lock, flags);
@@ -703,7 +742,9 @@ static void atmel_spi_cleanup(struct spi_device *spi)
         }
         spin_unlock_irqrestore(&as->lock, flags);
 
+        spi->controller_state = NULL;
         gpio_free(gpio);
+        kfree(asd);
 }
 
 /*-------------------------------------------------------------------------*/