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@xxxxxxxxxx> --- 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@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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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