Merge tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb...

[karo-tx-linux.git] / drivers / spi / spi-ath79.c

diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index 9a5d7791c5fb10baa747a6a5fae6c874a0965305..e504b7636058b4aa31789c26a1be8752a531456b 100644 (file)
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -24,17 +24,24 @@
 #include <linux/spi/spi_bitbang.h>
 #include <linux/bitops.h>
 #include <linux/gpio.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 
 #include <asm/mach-ath79/ar71xx_regs.h>
 #include <asm/mach-ath79/ath79_spi_platform.h>
 
 #define DRV_NAME       "ath79-spi"
 
+#define ATH79_SPI_RRW_DELAY_FACTOR     12000
+#define MHZ                            (1000 * 1000)
+
 struct ath79_spi {
        struct spi_bitbang      bitbang;
        u32                     ioc_base;
        u32                     reg_ctrl;
        void __iomem            *base;
+       struct clk              *clk;
+       unsigned                rrw_delay;
 };
 
 static inline u32 ath79_spi_rr(struct ath79_spi *sp, unsigned reg)
@@ -52,6 +59,12 @@ static inline struct ath79_spi *ath79_spidev_to_sp(struct spi_device *spi)
        return spi_master_get_devdata(spi->master);
 }
 
+static inline void ath79_spi_delay(struct ath79_spi *sp, unsigned nsecs)
+{
+       if (nsecs > sp->rrw_delay)
+               ndelay(nsecs - sp->rrw_delay);
+}
+
 static void ath79_spi_chipselect(struct spi_device *spi, int is_active)
 {
        struct ath79_spi *sp = ath79_spidev_to_sp(spi);
@@ -83,15 +96,8 @@ static void ath79_spi_chipselect(struct spi_device *spi, int is_active)
 
 }
 
-static int ath79_spi_setup_cs(struct spi_device *spi)
+static void ath79_spi_enable(struct ath79_spi *sp)
 {
-       struct ath79_spi *sp = ath79_spidev_to_sp(spi);
-       struct ath79_spi_controller_data *cdata;
-
-       cdata = spi->controller_data;
-       if (spi->chip_select && !cdata)
-               return -EINVAL;
-
        /* enable GPIO mode */
        ath79_spi_wr(sp, AR71XX_SPI_REG_FS, AR71XX_SPI_FS_GPIO);
 
@@ -101,44 +107,48 @@ static int ath79_spi_setup_cs(struct spi_device *spi)
 
        /* TODO: setup speed? */
        ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, 0x43);
+}
 
-       if (spi->chip_select) {
-               int status = 0;
+static void ath79_spi_disable(struct ath79_spi *sp)
+{
+       /* restore CTRL register */
+       ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, sp->reg_ctrl);
+       /* disable GPIO mode */
+       ath79_spi_wr(sp, AR71XX_SPI_REG_FS, 0);
+}
 
-               status = gpio_request(cdata->gpio, dev_name(&spi->dev));
-               if (status)
-                       return status;
+static int ath79_spi_setup_cs(struct spi_device *spi)
+{
+       struct ath79_spi_controller_data *cdata;
+       int status;
 
-               status = gpio_direction_output(cdata->gpio,
-                                              spi->mode & SPI_CS_HIGH);
-               if (status) {
-                       gpio_free(cdata->gpio);
-                       return status;
-               }
-       } else {
+       cdata = spi->controller_data;
+       if (spi->chip_select && !cdata)
+               return -EINVAL;
+
+       status = 0;
+       if (spi->chip_select) {
+               unsigned long flags;
+
+               flags = GPIOF_DIR_OUT;
                if (spi->mode & SPI_CS_HIGH)
-                       sp->ioc_base |= AR71XX_SPI_IOC_CS0;
+                       flags |= GPIOF_INIT_HIGH;
                else
-                       sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
-               ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
+                       flags |= GPIOF_INIT_LOW;
+
+               status = gpio_request_one(cdata->gpio, flags,
+                                         dev_name(&spi->dev));
        }
 
-       return 0;
+       return status;
 }
 
 static void ath79_spi_cleanup_cs(struct spi_device *spi)
 {
-       struct ath79_spi *sp = ath79_spidev_to_sp(spi);
-
        if (spi->chip_select) {
                struct ath79_spi_controller_data *cdata = spi->controller_data;
                gpio_free(cdata->gpio);
        }
-
-       /* restore CTRL register */
-       ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, sp->reg_ctrl);
-       /* disable GPIO mode */
-       ath79_spi_wr(sp, AR71XX_SPI_REG_FS, 0);
 }
 
 static int ath79_spi_setup(struct spi_device *spi)
@@ -184,7 +194,11 @@ static u32 ath79_spi_txrx_mode0(struct spi_device *spi, unsigned nsecs,
 
                /* setup MSB (to slave) on trailing edge */
                ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
+               ath79_spi_delay(sp, nsecs);
                ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
+               ath79_spi_delay(sp, nsecs);
+               if (bits == 1)
+                       ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
 
                word <<= 1;
        }
@@ -198,6 +212,7 @@ static int ath79_spi_probe(struct platform_device *pdev)
        struct ath79_spi *sp;
        struct ath79_spi_platform_data *pdata;
        struct resource *r;
+       unsigned long rate;
        int ret;
 
        master = spi_alloc_master(&pdev->dev, sizeof(*sp));
@@ -236,12 +251,39 @@ static int ath79_spi_probe(struct platform_device *pdev)
                goto err_put_master;
        }
 
+       sp->clk = clk_get(&pdev->dev, "ahb");
+       if (IS_ERR(sp->clk)) {
+               ret = PTR_ERR(sp->clk);
+               goto err_unmap;
+       }
+
+       ret = clk_enable(sp->clk);
+       if (ret)
+               goto err_clk_put;
+
+       rate = DIV_ROUND_UP(clk_get_rate(sp->clk), MHZ);
+       if (!rate) {
+               ret = -EINVAL;
+               goto err_clk_disable;
+       }
+
+       sp->rrw_delay = ATH79_SPI_RRW_DELAY_FACTOR / rate;
+       dev_dbg(&pdev->dev, "register read/write delay is %u nsecs\n",
+               sp->rrw_delay);
+
+       ath79_spi_enable(sp);
        ret = spi_bitbang_start(&sp->bitbang);
        if (ret)
-               goto err_unmap;
+               goto err_disable;
 
        return 0;
 
+err_disable:
+       ath79_spi_disable(sp);
+err_clk_disable:
+       clk_disable(sp->clk);
+err_clk_put:
+       clk_put(sp->clk);
 err_unmap:
        iounmap(sp->base);
 err_put_master:
@@ -256,6 +298,9 @@ static int ath79_spi_remove(struct platform_device *pdev)
        struct ath79_spi *sp = platform_get_drvdata(pdev);
 
        spi_bitbang_stop(&sp->bitbang);
+       ath79_spi_disable(sp);
+       clk_disable(sp->clk);
+       clk_put(sp->clk);
        iounmap(sp->base);
        platform_set_drvdata(pdev, NULL);
        spi_master_put(sp->bitbang.master);
@@ -263,9 +308,15 @@ static int ath79_spi_remove(struct platform_device *pdev)
        return 0;
 }
 
+static void ath79_spi_shutdown(struct platform_device *pdev)
+{
+       ath79_spi_remove(pdev);
+}
+
 static struct platform_driver ath79_spi_driver = {
        .probe          = ath79_spi_probe,
        .remove         = ath79_spi_remove,
+       .shutdown       = ath79_spi_shutdown,
        .driver         = {
                .name   = DRV_NAME,
                .owner  = THIS_MODULE,