diff mbox

[v3,6/6] mmc: sdhci-s3c: Add device tree support

Message ID 1328032576-9269-7-git-send-email-thomas.abraham@linaro.org
State New
Headers show

Commit Message

thomas.abraham@linaro.org Jan. 31, 2012, 5:56 p.m. UTC
Add device tree based discovery support for Samsung's sdhci controller

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
---
 .../devicetree/bindings/mmc/samsung-sdhci.txt      |   70 +++++++++
 drivers/mmc/host/sdhci-s3c.c                       |  148 +++++++++++++++++++-
 2 files changed, 212 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt

Comments

Grant Likely Jan. 31, 2012, 8:08 p.m. UTC | #1
On Tue, Jan 31, 2012 at 11:26:16PM +0530, Thomas Abraham wrote:
> Add device tree based discovery support for Samsung's sdhci controller
> 
> Cc: Ben Dooks <ben-linux@fluff.org>
> Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
> ---
>  .../devicetree/bindings/mmc/samsung-sdhci.txt      |   70 +++++++++
>  drivers/mmc/host/sdhci-s3c.c                       |  148 +++++++++++++++++++-
>  2 files changed, 212 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt

Looks okay to me on brief review.

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> 
> diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> new file mode 100644
> index 0000000..8cbdd29
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
> @@ -0,0 +1,70 @@
> +* 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.
> +
> +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 controller compatible with Exynos4 sdhci
> +    controller.
> +
> +- reg: physical base address of the controller and length of memory mapped
> +  region.
> +
> +- interrupts: The interrupt number to the cpu. The interrupt specifier format
> +  depends on the interrupt 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. Note: There is no
> +  particular order in which the gpio's have to be listed.
> +
> +
> +Optional Board Specific Properties:
> +- samsung,sdhci-bus-width: Number of data lines connected to the controller.
> +  Note: This excludes the clock,command and card detect lines. If this property
> +  is not specified, default value is 1.
> +
> +- samsung,cd-gpio-invert: If 'samsung,sdhci-cd-gpio' card detect method is
> +  selected, this property can be optionally specified to invert the value of
> +  external card detect gpio line.
> +
> +- 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.
> +
> +- gpio-cd: The gpio to be used as card detect line for
> +  'samsung,sdhci-cd-internal' or 'samsung,sdhci-cd-gpio' card detection method.
> +  The gpio specifier format depends on the gpio controller.
> +
> +Example:
> +	sdhci@12530000 {
> +		compatible = "samsung,exynos4210-sdhci";
> +		reg = <0x12530000 0x100>;
> +		interrupts = <139>;
> +		samsung,sdhci-bus-width = <4>;
> +		samsung,sdhci-cd-internal;
> +		gpio-cd = <&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 1760ba8..6159542 100644
> --- a/drivers/mmc/host/sdhci-s3c.c
> +++ b/drivers/mmc/host/sdhci-s3c.c
> @@ -20,6 +20,8 @@
>  #include <linux/io.h>
>  #include <linux/gpio.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
>  
>  #include <linux/mmc/host.h>
>  
> @@ -29,6 +31,8 @@
>  #include "sdhci.h"
>  
>  #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
> @@ -37,6 +41,7 @@
>   * @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.
>   */
> @@ -48,6 +53,7 @@ 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];
> @@ -415,9 +421,110 @@ 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, "samsung,sdhci-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, "gpio-cd", 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; /* invalid gpio number */
> +		if (of_get_property(node, "samsung,cd-gpio-invert", 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;
>  }
> @@ -432,7 +539,7 @@ 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;
>  	}
> @@ -454,21 +561,28 @@ 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);
>  
> @@ -637,6 +751,12 @@ 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;
> @@ -644,9 +764,9 @@ 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)
> @@ -673,6 +793,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
>  	release_resource(sc->ioarea);
>  	kfree(sc->ioarea);
>  
> +	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);
>  
> @@ -727,6 +852,16 @@ 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),
> @@ -734,6 +869,7 @@ 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
>
Karol Lewandowski Feb. 1, 2012, 6:21 p.m. UTC | #2
On 31.01.2012 18:56, Thomas Abraham wrote:
> Add device tree based discovery support for Samsung's sdhci controller

Works fine on "nuri hardware" using exynos4-dt (with custom dts).

Thanks
Arnd Bergmann March 27, 2012, 4:15 p.m. UTC | #3
On Tuesday 31 January 2012, Thomas Abraham wrote:
> +
> +Optional Board Specific Properties:
> +- samsung,sdhci-bus-width: Number of data lines connected to the controller.
> +  Note: This excludes the clock,command and card detect lines. If this property
> +  is not specified, default value is 1.
> +
> +- samsung,cd-gpio-invert: If 'samsung,sdhci-cd-gpio' card detect method is
> +  selected, this property can be optionally specified to invert the value of
> +  external card detect gpio line.
> +
> +- 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.
> +
> +- gpio-cd: The gpio to be used as card detect line for
> +  'samsung,sdhci-cd-internal' or 'samsung,sdhci-cd-gpio' card detection method.
> +  The gpio specifier format depends on the gpio controller.

These bindings came up in a discussion IRC today. I think it's rather bad that
we can't agree on a common way to name the properties for mmc. We have
bindings being proposed or already included from Anton, Stephen, Shawn,
Rajendra, Viresh, Lee and Thomas. Almost all of them define GPIO pins
for card detect and write protect, as well properties to define the bus
width and high-speed modes, but we seem to have almost as many different
definitions of these as we have drivers.

Can we please come up with a common binding for these?

	Arnd
Arnd Bergmann March 27, 2012, 4:19 p.m. UTC | #4
On Tuesday 31 January 2012, Thomas Abraham wrote:
> +
> +Optional Board Specific Properties:
> +- samsung,sdhci-bus-width: Number of data lines connected to the controller.
> +  Note: This excludes the clock,command and card detect lines. If this property
> +  is not specified, default value is 1.
> +
> +- samsung,cd-gpio-invert: If 'samsung,sdhci-cd-gpio' card detect method is
> +  selected, this property can be optionally specified to invert the value of
> +  external card detect gpio line.
> +
> +- 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.
> +
> +- gpio-cd: The gpio to be used as card detect line for
> +  'samsung,sdhci-cd-internal' or 'samsung,sdhci-cd-gpio' card detection method.
> +  The gpio specifier format depends on the gpio controller.

These bindings came up in a discussion IRC today. I think it's rather bad that
we can't agree on a common way to name the properties for mmc. We have
bindings being proposed or already included from Anton, Stephen, Shawn,
Rajendra, Viresh, Lee and Thomas. Almost all of them define GPIO pins
for card detect and write protect, as well properties to define the bus
width and high-speed modes, but we seem to have almost as many different
definitions of these as we have drivers.

Can we please come up with a common binding for these?

	Arnd
Viresh Kumar March 30, 2012, 6:33 a.m. UTC | #5
On 3/27/2012 9:49 PM, Arnd Bergmann wrote:
> These bindings came up in a discussion IRC today. I think it's rather bad that
> we can't agree on a common way to name the properties for mmc. We have
> bindings being proposed or already included from Anton, Stephen, Shawn,
> Rajendra, Viresh, Lee and Thomas. Almost all of them define GPIO pins
> for card detect and write protect, as well properties to define the bus
> width and high-speed modes, but we seem to have almost as many different
> definitions of these as we have drivers.
> 
> Can we please come up with a common binding for these?

Is there any progress on this? Sorry i wasn't following all mails.
How should i progress for sdhci-spear?
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
new file mode 100644
index 0000000..8cbdd29
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
@@ -0,0 +1,70 @@ 
+* 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.
+
+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 controller compatible with Exynos4 sdhci
+    controller.
+
+- reg: physical base address of the controller and length of memory mapped
+  region.
+
+- interrupts: The interrupt number to the cpu. The interrupt specifier format
+  depends on the interrupt 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. Note: There is no
+  particular order in which the gpio's have to be listed.
+
+
+Optional Board Specific Properties:
+- samsung,sdhci-bus-width: Number of data lines connected to the controller.
+  Note: This excludes the clock,command and card detect lines. If this property
+  is not specified, default value is 1.
+
+- samsung,cd-gpio-invert: If 'samsung,sdhci-cd-gpio' card detect method is
+  selected, this property can be optionally specified to invert the value of
+  external card detect gpio line.
+
+- 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.
+
+- gpio-cd: The gpio to be used as card detect line for
+  'samsung,sdhci-cd-internal' or 'samsung,sdhci-cd-gpio' card detection method.
+  The gpio specifier format depends on the gpio controller.
+
+Example:
+	sdhci@12530000 {
+		compatible = "samsung,exynos4210-sdhci";
+		reg = <0x12530000 0x100>;
+		interrupts = <139>;
+		samsung,sdhci-bus-width = <4>;
+		samsung,sdhci-cd-internal;
+		gpio-cd = <&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 1760ba8..6159542 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -20,6 +20,8 @@ 
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 
 #include <linux/mmc/host.h>
 
@@ -29,6 +31,8 @@ 
 #include "sdhci.h"
 
 #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
@@ -37,6 +41,7 @@ 
  * @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.
  */
@@ -48,6 +53,7 @@  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];
@@ -415,9 +421,110 @@  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, "samsung,sdhci-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, "gpio-cd", 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; /* invalid gpio number */
+		if (of_get_property(node, "samsung,cd-gpio-invert", 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;
 }
@@ -432,7 +539,7 @@  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;
 	}
@@ -454,21 +561,28 @@  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);
 
@@ -637,6 +751,12 @@  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;
@@ -644,9 +764,9 @@  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)
@@ -673,6 +793,11 @@  static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
 	release_resource(sc->ioarea);
 	kfree(sc->ioarea);
 
+	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);
 
@@ -727,6 +852,16 @@  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),
@@ -734,6 +869,7 @@  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,
 	},
 };