Thomas, On 10/11/2011 03:16 AM, 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@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". Isn't gpa0 an instance of the h/w, not a version? > + > +- 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]> It would be better to list out the values here. > + > +- 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 Don't need the ifdef here. > > #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, static > + 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); > This code is really ugly, but I guess you inherited it. Converting to a platform driver and using id table would be much cleaner. Rob -- 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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