[PATCH] mmc: sdhci-s3c: Add device tree support
Tushar Behera
tushar.behera at linaro.org
Fri Aug 17 16:30:58 EST 2012
On 08/16/2012 10:05 PM, Thomas Abraham 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 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 | 51 +++++++
> drivers/mmc/host/sdhci-s3c.c | 146 +++++++++++++++++++-
> 2 files changed, 191 insertions(+), 6 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
>
> diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> new file mode 100644
> index 0000000..398540b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> @@ -0,0 +1,51 @@
> +* 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.
> +
> +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:
> +- One of the following properties for card detect type.
> + - samsung,sdhci-cd-internal: Card detect line from the card slot is
> + connected to the card detect pad of the sdhci controller. A gpio is
> + used for this connection (with possible pin function settings).
> + - samsung,sdhci-cd-gpio: A gpio line (with possible pin function settings)
> + is used a card detect line. This gpio line is not connected to card detect
> + pad of the sdhci controller.
> + - samsung,sdhci-cd-none: There is no card detect line. Polling is used to
> + detect the presence of the card. (DEFAULT, if no card detect property
> + is specified).
> + - samsung,sdhci-cd-permanent: There is no card detect line. The card is
> + permanently connected to the sdhci controller.
> +
> +Example:
> + sdhci at 12530000 {
> + compatible = "samsung,exynos4210-sdhci";
> + reg = <0x12530000 0x100>;
> + interrupts = <<0 75 0>;
Typo: interrupts = <0 75 0>;
> + bus-width = <4>;
> + samsung,sdhci-cd-internal;
> + 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..7fcc642 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 +424,109 @@ 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, "samsung,sdhci-cd-internal", NULL))
> + pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
> + else if (of_get_property(node, "samsung,sdhci-cd-gpio", NULL))
> + pdata->cd_type = S3C_SDHCI_CD_GPIO;
> + else if (of_get_property(node, "samsung,sdhci-cd-none", NULL))
> + pdata->cd_type = S3C_SDHCI_CD_NONE;
> + else if (of_get_property(node, "samsung,sdhci-cd-permanent", NULL))
> + pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
> + else
> + pdata->cd_type = S3C_SDHCI_CD_NONE;
> +
> + /* get the gpio used for card detection */
> + if (pdata->cd_type == S3C_SDHCI_CD_GPIO ||
> + pdata->cd_type == S3C_SDHCI_CD_INTERNAL) {
> + gpio = of_get_named_gpio(node, "cd-gpios", 0);
> + if (!gpio_is_valid(gpio)) {
> + dev_err(dev, "invalid card detect gpio specified\n");
> + return -EINVAL;
> + }
> + }
> +
> + 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;
> + }
> +
> + /* 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 +541,7 @@ 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 +557,28 @@ 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 +743,12 @@ 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 +756,9 @@ 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 +783,11 @@ 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 +860,16 @@ 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 = &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 +877,7 @@ 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,
> },
> };
>
--
Tushar Behera
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