[PATCH v5] mmc: sdhci-s3c: Add device tree support

Thomas Abraham thomas.abraham at linaro.org
Tue Sep 18 11:45:22 EST 2012


On 23 August 2012 22:40, Thomas Abraham <thomas.abraham at linaro.org> wrote:
> Add device tree based discovery support for Samsung's sdhci controller
>
> Cc: Ben Dooks <ben-linux at fluff.org>
> Cc: Kukjin Kim <kgene.kim at samsung.com>
> Cc: Chris Ball <cjb at laptop.org>
> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
> ---
> Changes since v4:
> Adapted to new mmc core card detection bindings as specfied in the patch:
> [PATCH] mmc: dt: Add card-detection properties to core binding
> and extends it "samsung,cd-pinmux-gpio" property as suggested by
> Mitch Bradley <wmb at firmworks.com>
>
> Changes since v3:
>
> The patch series that adds device tree support for Samsung sdhci controller
> had six patches in total, of which, the first five patches have been accepted.
> The sixth patch in the series was dropped since it was using custom Samsung
> properties for descrbing the bus-width and card-detect gpio, but had otherwise
> addressed all the comments.
>
> This patch reworks the sixth patch in v3 of the sdhci device tree support
> patch series. The only change in this patch from the v3 version is the use of
> generic mmc bindings for descrbing the bus-width and card-detect gpio.
>
>  .../devicetree/bindings/mmc/samsung-sdhci.txt      |   53 +++++++
>  drivers/mmc/host/sdhci-s3c.c                       |  162 +++++++++++++++++++-
>  2 files changed, 209 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt

Hi Chris,

This patch adds device tree support for sdhci-s3c driver. All the
comments for this patch has been addressed. Can this be queued for
v3.7?

Thanks,
Thomas.


>
> diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> new file mode 100644
> index 0000000..361c2ee
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> @@ -0,0 +1,53 @@
> +* Samsung's SDHCI Controller device tree bindings
> +
> +Samsung's SDHCI controller is used as a connectivity interface with external
> +MMC, SD and eMMC storage mediums. This file documents differences between the
> +core mmc properties described by mmc.txt and the properties used by the
> +Samsung implmentation of the SDHCI controller.
> +
> +Note: The mmc core bindings documentation states that if none of the core
> +card-detect bindings are used, then the standard sdhci card detect mechanism
> +is used. The Samsung's SDHCI controller bindings extends this as listed below.
> +
> +[A] The property "samsung,cd-pinmux-gpio" can be used as stated in the
> +    "Optional Board Specific Properties" section below.
> +
> +[B] If core card-detect bindings and "samsung,cd-pinmux-gpio" property
> +    is not specified, it is assumed that there is no card detection
> +    mechanism used.
> +
> +Required SoC Specific Properties:
> +- compatible: should be one of the following
> +  - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci
> +    controller.
> +  - "samsung,exynos4210-sdhci": For controllers compatible with Exynos4 sdhci
> +    controller.
> +
> +Required Board Specific Properties:
> +- gpios: Should specify the gpios used for clock, command and data lines. The
> +  gpio specifier format depends on the gpio controller.
> +
> +Optional Board Specific Properties:
> +- samsung,cd-pinmux-gpio: Specifies the card detect line that is routed
> +  through a pinmux to the card-detect pin of the card slot. This property
> +  should be used only if none of the mmc core card-detect properties are
> +  used.
> +
> +Example:
> +       sdhci at 12530000 {
> +               compatible = "samsung,exynos4210-sdhci";
> +               reg = <0x12530000 0x100>;
> +               interrupts = <0 75 0>;
> +               bus-width = <4>;
> +               cd-gpios = <&gpk2 2 2 3 3>;
> +               gpios = <&gpk2 0 2 0 3>,  /* clock line */
> +                       <&gpk2 1 2 0 3>,  /* command line */
> +                       <&gpk2 3 2 3 3>,  /* data line 0 */
> +                       <&gpk2 4 2 3 3>,  /* data line 1 */
> +                       <&gpk2 5 2 3 3>,  /* data line 2 */
> +                       <&gpk2 6 2 3 3>;  /* data line 3 */
> +       };
> +
> +       Note: This example shows both SoC specific and board specific properties
> +       in a single device node. The properties can be actually be seperated
> +       into SoC specific node and board specific node.
> diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
> index a50c205..445910e 100644
> --- a/drivers/mmc/host/sdhci-s3c.c
> +++ b/drivers/mmc/host/sdhci-s3c.c
> @@ -34,6 +34,9 @@
>
>  #define MAX_BUS_CLK    (4)
>
> +/* Number of gpio's used is max data bus width + command and clock lines */
> +#define NUM_GPIOS(x)   (x + 2)
> +
>  /**
>   * struct sdhci_s3c - S3C SDHCI instance
>   * @host: The SDHCI host created
> @@ -41,6 +44,7 @@
>   * @ioarea: The resource created when we claimed the IO area.
>   * @pdata: The platform data for this controller.
>   * @cur_clk: The index of the current bus clock.
> + * @gpios: List of gpio numbers parsed from device tree.
>   * @clk_io: The clock for the internal bus interface.
>   * @clk_bus: The clocks that are available for the SD/MMC bus clock.
>   */
> @@ -52,6 +56,7 @@ struct sdhci_s3c {
>         unsigned int            cur_clk;
>         int                     ext_cd_irq;
>         int                     ext_cd_gpio;
> +       int                     *gpios;
>
>         struct clk              *clk_io;
>         struct clk              *clk_bus[MAX_BUS_CLK];
> @@ -419,9 +424,125 @@ static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
>         }
>  }
>
> +#ifdef CONFIG_OF
> +static int __devinit sdhci_s3c_parse_dt(struct device *dev,
> +               struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
> +{
> +       struct device_node *node = dev->of_node;
> +       struct sdhci_s3c *ourhost = to_s3c(host);
> +       u32 max_width;
> +       int gpio, cnt, ret;
> +
> +       /* if the bus-width property is not specified, assume width as 1 */
> +       if (of_property_read_u32(node, "bus-width", &max_width))
> +               max_width = 1;
> +       pdata->max_width = max_width;
> +
> +       ourhost->gpios = devm_kzalloc(dev, NUM_GPIOS(pdata->max_width) *
> +                               sizeof(int), GFP_KERNEL);
> +       if (!ourhost->gpios)
> +               return -ENOMEM;
> +
> +       /* get the card detection method */
> +       if (of_get_property(node, "broken-cd", 0)) {
> +               pdata->cd_type = S3C_SDHCI_CD_NONE;
> +               goto setup_bus;
> +       }
> +
> +       if (of_get_property(node, "non-removable", 0)) {
> +               pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
> +               goto setup_bus;
> +       }
> +
> +       gpio = of_get_named_gpio(node, "cd-gpios", 0);
> +       if (gpio_is_valid(gpio)) {
> +               pdata->cd_type = S3C_SDHCI_CD_GPIO;
> +               goto found_cd;
> +       } else {
> +               if (gpio != -ENOENT) {
> +                       dev_err(dev, "invalid card detect gpio specified\n");
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       gpio = of_get_named_gpio(node, "samsung,cd-pinmux-gpio", 0);
> +       if (gpio_is_valid(gpio)) {
> +               pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
> +               goto found_cd;
> +       } else {
> +               if (gpio != -ENOENT) {
> +                       dev_err(dev, "invalid card detect gpio specified\n");
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       dev_info(dev, "assuming no card detect line available\n");
> +       pdata->cd_type = S3C_SDHCI_CD_NONE;
> +
> + found_cd:
> +       if (pdata->cd_type == S3C_SDHCI_CD_GPIO) {
> +               pdata->ext_cd_gpio = gpio;
> +               ourhost->ext_cd_gpio = -1;
> +               if (of_get_property(node, "cd-inverted", NULL))
> +                       pdata->ext_cd_gpio_invert = 1;
> +       } else if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL) {
> +               ret = gpio_request(gpio, "sdhci-cd");
> +               if (ret) {
> +                       dev_err(dev, "card detect gpio request failed\n");
> +                       return -EINVAL;
> +               }
> +               ourhost->ext_cd_gpio = gpio;
> +       }
> +
> + setup_bus:
> +       /* get the gpios for command, clock and data lines */
> +       for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
> +               gpio = of_get_gpio(node, cnt);
> +               if (!gpio_is_valid(gpio)) {
> +                       dev_err(dev, "invalid gpio[%d]\n", cnt);
> +                       goto err_free_dt_cd_gpio;
> +               }
> +               ourhost->gpios[cnt] = gpio;
> +       }
> +
> +       for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
> +               ret = gpio_request(ourhost->gpios[cnt], "sdhci-gpio");
> +               if (ret) {
> +                       dev_err(dev, "gpio[%d] request failed\n", cnt);
> +                       goto err_free_dt_gpios;
> +               }
> +       }
> +
> +       return 0;
> +
> + err_free_dt_gpios:
> +       while (--cnt >= 0)
> +               gpio_free(ourhost->gpios[cnt]);
> + err_free_dt_cd_gpio:
> +       if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
> +               gpio_free(ourhost->ext_cd_gpio);
> +       return -EINVAL;
> +}
> +#else
> +static int __devinit sdhci_s3c_parse_dt(struct device *dev,
> +               struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
> +{
> +       return -EINVAL;
> +}
> +#endif
> +
> +static const struct of_device_id sdhci_s3c_dt_match[];
> +
>  static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
>                         struct platform_device *pdev)
>  {
> +#ifdef CONFIG_OF
> +       if (pdev->dev.of_node) {
> +               const struct of_device_id *match;
> +               match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
> +               return (struct sdhci_s3c_drv_data *)match->data;
> +       }
> +#endif
>         return (struct sdhci_s3c_drv_data *)
>                         platform_get_device_id(pdev)->driver_data;
>  }
> @@ -436,7 +557,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>         struct resource *res;
>         int ret, irq, ptr, clks;
>
> -       if (!pdev->dev.platform_data) {
> +       if (!pdev->dev.platform_data && !pdev->dev.of_node) {
>                 dev_err(dev, "no device data specified\n");
>                 return -ENOENT;
>         }
> @@ -452,21 +573,28 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>                 dev_err(dev, "sdhci_alloc_host() failed\n");
>                 return PTR_ERR(host);
>         }
> +       sc = sdhci_priv(host);
>
>         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
>         if (!pdata) {
>                 ret = -ENOMEM;
> -               goto err_io_clk;
> +               goto err_pdata;
> +       }
> +
> +       if (pdev->dev.of_node) {
> +               ret = sdhci_s3c_parse_dt(&pdev->dev, host, pdata);
> +               if (ret)
> +                       goto err_pdata;
> +       } else {
> +               memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
> +               sc->ext_cd_gpio = -1; /* invalid gpio number */
>         }
> -       memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
>
>         drv_data = sdhci_s3c_get_driver_data(pdev);
> -       sc = sdhci_priv(host);
>
>         sc->host = host;
>         sc->pdev = pdev;
>         sc->pdata = pdata;
> -       sc->ext_cd_gpio = -1; /* invalid gpio number */
>
>         platform_set_drvdata(pdev, host);
>
> @@ -631,6 +759,12 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>         clk_put(sc->clk_io);
>
>   err_io_clk:
> +       for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
> +               gpio_free(sc->gpios[ptr]);
> +       if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
> +               gpio_free(sc->ext_cd_gpio);
> +
> + err_pdata:
>         sdhci_free_host(host);
>
>         return ret;
> @@ -638,9 +772,9 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>
>  static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
>  {
> -       struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
>         struct sdhci_host *host =  platform_get_drvdata(pdev);
>         struct sdhci_s3c *sc = sdhci_priv(host);
> +       struct s3c_sdhci_platdata *pdata = sc->pdata;
>         int ptr;
>
>         if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
> @@ -665,6 +799,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
>         clk_disable(sc->clk_io);
>         clk_put(sc->clk_io);
>
> +       if (pdev->dev.of_node) {
> +               for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
> +                       gpio_free(sc->gpios[ptr]);
> +       }
> +
>         sdhci_free_host(host);
>         platform_set_drvdata(pdev, NULL);
>
> @@ -737,6 +876,16 @@ static struct platform_device_id sdhci_s3c_driver_ids[] = {
>  };
>  MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);
>
> +#ifdef CONFIG_OF
> +static const struct of_device_id sdhci_s3c_dt_match[] = {
> +       { .compatible = "samsung,s3c6410-sdhci", },
> +       { .compatible = "samsung,exynos4210-sdhci",
> +               .data = (void *)EXYNOS4_SDHCI_DRV_DATA },
> +       {},
> +};
> +MODULE_DEVICE_TABLE(of, sdhci_s3c_dt_match);
> +#endif
> +
>  static struct platform_driver sdhci_s3c_driver = {
>         .probe          = sdhci_s3c_probe,
>         .remove         = __devexit_p(sdhci_s3c_remove),
> @@ -744,6 +893,7 @@ static struct platform_driver sdhci_s3c_driver = {
>         .driver         = {
>                 .owner  = THIS_MODULE,
>                 .name   = "s3c-sdhci",
> +               .of_match_table = of_match_ptr(sdhci_s3c_dt_match),
>                 .pm     = SDHCI_S3C_PMOPS,
>         },
>  };
> --
> 1.6.6.rc2
>
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