spi/spi-atmel: detect the capabilities of SPI core by reading the VERSION register.

The "has_dma_support" needed for future use with dmaengine driver.

[Fixed some unneded ternery operators -- broonie]

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 656d137..af3dbab 100644 (file)
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -22,9 +22,8 @@
 #include <linux/platform_data/atmel.h>
 #include <linux/of.h>
 
-#include <asm/io.h>
-#include <asm/gpio.h>
-#include <mach/cpu.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
 
 /* SPI register offsets */
 #define SPI_CR                                 0x0000
@@ -39,6 +38,7 @@
 #define SPI_CSR1                               0x0034
 #define SPI_CSR2                               0x0038
 #define SPI_CSR3                               0x003c
+#define SPI_VERSION                            0x00fc
 #define SPI_RPR                                        0x0100
 #define SPI_RCR                                        0x0104
 #define SPI_TPR                                        0x0108
@@ -71,6 +71,8 @@
 #define SPI_FDIV_SIZE                          1
 #define SPI_MODFDIS_OFFSET                     4
 #define SPI_MODFDIS_SIZE                       1
+#define SPI_WDRBT_OFFSET                       5
+#define SPI_WDRBT_SIZE                         1
 #define SPI_LLB_OFFSET                         7
 #define SPI_LLB_SIZE                           1
 #define SPI_PCS_OFFSET                         16
@@ -180,6 +182,11 @@
 #define spi_writel(port,reg,value) \
        __raw_writel((value), (port)->regs + SPI_##reg)
 
+struct atmel_spi_caps {
+       bool    is_spi2;
+       bool    has_wdrbt;
+       bool    has_dma_support;
+};
 
 /*
  * The core SPI transfer engine just talks to a register bank to set up
@@ -204,6 +211,8 @@ struct atmel_spi {
 
        void                    *buffer;
        dma_addr_t              buffer_dma;
+
+       struct atmel_spi_caps   caps;
 };
 
 /* Controller-specific per-slave state */
@@ -222,14 +231,10 @@ struct atmel_spi_device {
  *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
  *  - SPI_CSRx.CSAAT
  *  - SPI_CSRx.SBCR allows faster clocking
- *
- * We can determine the controller version by reading the VERSION
- * register, but I haven't checked that it exists on all chips, and
- * this is cheaper anyway.
  */
-static bool atmel_spi_is_v2(void)
+static bool atmel_spi_is_v2(struct atmel_spi *as)
 {
-       return !cpu_is_at91rm9200();
+       return as->caps.is_spi2;
 }
 
 /*
@@ -263,15 +268,20 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
        unsigned active = spi->mode & SPI_CS_HIGH;
        u32 mr;
 
-       if (atmel_spi_is_v2()) {
+       if (atmel_spi_is_v2(as)) {
                /*
                 * 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)
+               if (as->caps.has_wdrbt) {
+                       spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(WDRBT)
+                               | SPI_BIT(MODFDIS) | SPI_BIT(MSTR));
+               } else {
+                       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 {
@@ -318,7 +328,7 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
                        asd->npcs_pin, active ? " (low)" : "",
                        mr);
 
-       if (atmel_spi_is_v2() || spi->chip_select != 0)
+       if (atmel_spi_is_v2(as) || spi->chip_select != 0)
                gpio_set_value(asd->npcs_pin, !active);
 }
 
@@ -719,7 +729,7 @@ static int atmel_spi_setup(struct spi_device *spi)
        }
 
        /* see notes above re chipselect */
-       if (!atmel_spi_is_v2()
+       if (!atmel_spi_is_v2(as)
                        && spi->chip_select == 0
                        && (spi->mode & SPI_CS_HIGH)) {
                dev_dbg(&spi->dev, "setup: can't be active-high\n");
@@ -728,7 +738,7 @@ static int atmel_spi_setup(struct spi_device *spi)
 
        /* v1 chips start out at half the peripheral bus speed. */
        bus_hz = clk_get_rate(as->clk);
-       if (!atmel_spi_is_v2())
+       if (!atmel_spi_is_v2(as))
                bus_hz /= 2;
 
        if (spi->max_speed_hz) {
@@ -804,7 +814,7 @@ static int atmel_spi_setup(struct spi_device *spi)
                "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
                bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
 
-       if (!atmel_spi_is_v2())
+       if (!atmel_spi_is_v2(as))
                spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
 
        return 0;
@@ -910,6 +920,23 @@ static void atmel_spi_cleanup(struct spi_device *spi)
        kfree(asd);
 }
 
+static inline unsigned int atmel_get_version(struct atmel_spi *as)
+{
+       return spi_readl(as, VERSION) & 0x00000fff;
+}
+
+static void atmel_get_caps(struct atmel_spi *as)
+{
+       unsigned int version;
+
+       version = atmel_get_version(as);
+       dev_info(&as->pdev->dev, "version: 0x%x\n", version);
+
+       as->caps.is_spi2 = version > 0x121;
+       as->caps.has_wdrbt = version >= 0x210;
+       as->caps.has_dma_support = version >= 0x212;
+}
+
 /*-------------------------------------------------------------------------*/
 
 static int atmel_spi_probe(struct platform_device *pdev)
@@ -970,6 +997,8 @@ static int atmel_spi_probe(struct platform_device *pdev)
        as->irq = irq;
        as->clk = clk;
 
+       atmel_get_caps(as);
+
        ret = request_irq(irq, atmel_spi_interrupt, 0,
                        dev_name(&pdev->dev), master);
        if (ret)
@@ -979,7 +1008,12 @@ static int atmel_spi_probe(struct platform_device *pdev)
        clk_enable(clk);
        spi_writel(as, CR, SPI_BIT(SWRST));
        spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
-       spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+       if (as->caps.has_wdrbt) {
+               spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
+                               | SPI_BIT(MSTR));
+       } else {
+               spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+       }
        spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
        spi_writel(as, CR, SPI_BIT(SPIEN));