[PATCH] gpio: exynos4: Add device tree support
Kukjin Kim
kgene.kim at samsung.com
Wed Oct 12 09:33:48 EDT 2011
Thomas Abraham wrote:
>
> As gpio chips get registered, a device tree node which represents the
> gpio chip is searched and attached to it. A translate function is also
> provided to convert the gpio specifier into actual platform settings
> for pin function selection, pull up/down and driver strength settings.
>
> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
> ---
> This patch is based on the latest consolidated Samsung GPIO driver
available
> in the following tree:
> https://github.com/kgene/linux-samsung.git branch: for-next
>
> .../devicetree/bindings/gpio/gpio-samsung.txt | 30 +++++++++++
> drivers/gpio/gpio-samsung.c | 53
> ++++++++++++++++++++
> 2 files changed, 83 insertions(+), 0 deletions(-)
> create mode 100644
Documentation/devicetree/bindings/gpio/gpio-samsung.txt
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> new file mode 100644
> index 0000000..883faeb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-samsung.txt
> @@ -0,0 +1,30 @@
> +Samsung Exynos4 GPIO Controller
> +
> +Required properties:
> +- compatible: Format of compatible property value should be
> + "samsung,exynos4-gpio-<controller_name>". Example: For GPA0 controller,
> the
> + compatible property value should be "samsung,exynos4-gpio-gpa0".
> +
> +- reg: Physical base address of the controller and length of memory
mapped
> region.
> +
> +- #gpio-cells: Should be 4. The syntax of the gpio specifier used by
client nodes
> + should be the following with values derived from the SoC user manual.
> + <[phandle of the gpio controller node] <pin number within the gpio
> controller]
> + [mux function] [pull up/down] [drive strength]>
> +
> +- gpio-controller: Specifies that the node is a gpio controller.
> +
> +- #address-cells: should be 1.
> +
> +- #size-cells: should be 1.
> +
> +Example:
> +
> + gpa0: gpio-controller at 11400000 {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "samsung,exynos4-gpio-gpa0";
> + reg = <0x11400000 0x20>;
> + #gpio-cells = <4>;
> + gpio-controller;
> + };
> diff --git a/drivers/gpio/gpio-samsung.c b/drivers/gpio/gpio-samsung.c
> index b6be77a..037d3bb 100644
> --- a/drivers/gpio/gpio-samsung.c
> +++ b/drivers/gpio/gpio-samsung.c
> @@ -24,6 +24,10 @@
> #include <linux/interrupt.h>
> #include <linux/sysdev.h>
> #include <linux/ioport.h>
> +#ifdef CONFIG_OF
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#endif
>
> #include <asm/irq.h>
>
> @@ -2353,6 +2357,52 @@ static struct samsung_gpio_chip exynos4_gpios_3[] =
> {
> #endif
> };
>
> +#if defined(CONFIG_ARCH_EXYNOS4) && defined(CONFIG_OF)
> +int exynos4_gpio_xlate(struct gpio_chip *gc, struct device_node *np,
> + const void *gpio_spec, u32 *flags)
> +{
> + const __be32 *gpio = gpio_spec;
> + const u32 n = be32_to_cpup(gpio);
> + unsigned int pin = gc->base + be32_to_cpu(gpio[0]);
> +
> + if (gc->of_gpio_n_cells < 4) {
> + WARN_ON(1);
> + return -EINVAL;
> + }
> +
> + if (n > gc->ngpio)
> + return -EINVAL;
> +
> + s3c_gpio_cfgpin(pin, S3C_GPIO_SFN(be32_to_cpu(gpio[1])));
> + s3c_gpio_setpull(pin, be32_to_cpu(gpio[2]));
> + s5p_gpio_set_drvstr(pin, be32_to_cpu(gpio[3]));
> + return n;
> +}
> +
> +static __init void exynos4_gpiolib_attach_ofnode(struct gpio_chip *gc)
> +{
> + const char exynos4_gpio_compat_base[] = "samsung,exynos4-gpio-";
> + char *exynos4_gpio_compat;
> +
> + exynos4_gpio_compat = kzalloc(strlen(exynos4_gpio_compat_base) +
> + strlen(gc->label), GFP_KERNEL);
> + if (!exynos4_gpio_compat)
> + return;
> +
> + strcpy(exynos4_gpio_compat, exynos4_gpio_compat_base);
> + strcat(exynos4_gpio_compat, gc->label);
> + gc->of_node = of_find_compatible_node(NULL, NULL,
> exynos4_gpio_compat);
> + gc->of_gpio_n_cells = 4;
> + gc->of_xlate = exynos4_gpio_xlate;
> + kfree(exynos4_gpio_compat);
> +}
> +#else
> +static __init void exynos4_gpiolib_attach_ofnode(struct gpio_chip *chip)
> +{
> + return;
> +}
> +#endif /* defined(CONFIG_ARCH_EXYNOS4) && defined(CONFIG_OF) */
> +
> /* TODO: cleanup soc_is_* */
> static __init int samsung_gpiolib_init(void)
> {
> @@ -2434,6 +2484,7 @@ static __init int samsung_gpiolib_init(void)
> chip->config = &exynos4_gpio_cfg;
> chip->group = group++;
> }
> + exynos4_gpiolib_attach_ofnode(&chip->chip);
> }
> samsung_gpiolib_add_4bit_chips(exynos4_gpios_1, nr_chips,
> S5P_VA_GPIO1);
>
> @@ -2446,6 +2497,7 @@ static __init int samsung_gpiolib_init(void)
> chip->config = &exynos4_gpio_cfg;
> chip->group = group++;
> }
> + exynos4_gpiolib_attach_ofnode(&chip->chip);
> }
> samsung_gpiolib_add_4bit_chips(exynos4_gpios_2, nr_chips,
> S5P_VA_GPIO2);
>
> @@ -2458,6 +2510,7 @@ static __init int samsung_gpiolib_init(void)
> chip->config = &exynos4_gpio_cfg;
> chip->group = group++;
> }
> + exynos4_gpiolib_attach_ofnode(&chip->chip);
> }
> samsung_gpiolib_add_4bit_chips(exynos4_gpios_3, nr_chips,
> S5P_VA_GPIO3);
>
> --
> 1.6.6.rc2
Hi Thomas,
You got some comments from Rob, so could you please address from him?
Others, looks ok to me.
And I need to get the ack from Grant to upstream via Samsung tree for
upcoming merge window.
Grant, is this ok for you?
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.
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