[PATCH 2/2] gpiolib-of: ad gpio-export support
From: Jean-Christophe PLAGNIOL-VILLARD <hidden>
Date: 2012-11-21 10:14:09
Also in:
linux-devicetree
Subsystem:
gpio subsystem, open firmware and flattened device tree bindings, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
This will allow to export gpios with or without names Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <redacted> --- Documentation/devicetree/bindings/gpio/gpio.txt | 60 ++++++++++++++++++++++ drivers/gpio/gpiolib-of.c | 61 +++++++++++++++++++++++ 2 files changed, 121 insertions(+)
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index a336287..c2a9024 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt@@ -112,3 +112,63 @@ where, The pinctrl node must have "#gpio-range-cells" property to show number of arguments to pass with phandle from gpio controllers node. + +3) gpio-export +-------------- + +gpio-export will allow you to automatically export gpio + +required properties: +- compatible: Should be "gpio-export" + +in each child node will reprensent a gpio or if no name is specified +a list of gpio to export + +required properties: +- gpios: gpio to export + +optional properties: + - gpio-export,name: export name + - gpio-export,output: to set the as output with default value + if no present gpio as input + - pio-export,direction_may_change: boolean to allow the direction to be controllable + +Example: + + +gpio_export { + compatible = "gpio-export"; + #size-cells = <0>; + + in { + gpio-export,name = "in"; + gpios = <&pioC 20 0>; + }; + + out { + gpio-export,name = "out"; + gpio-export,output = <1>; + gpio-export,direction_may_change; + gpios = <&pioC 21 0>; + }; + + in_out { + gpio-export,name = "in_out"; + gpio-export,direction_may_change; + gpios = <&pioC 21 0>; + }; + + gpios_in { + gpios = <&pioB 0 0 + &pioB 3 0 + &pioC 4 0>; + gpio-export,direction_may_change; + }; + + gpios_out { + gpios = <&pioB 1 0 + &pioB 2 0 + &pioC 3 0>; + gpio-export,output = <1>; + }; +};
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index a40cd84..0ab9be4 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c@@ -21,6 +21,8 @@ #include <linux/of_gpio.h> #include <linux/pinctrl/pinctrl.h> #include <linux/slab.h> +#include <linux/init.h> +#include <linux/platform_device.h> /* Private data structure for of_gpiochip_find_and_xlate */ struct gg_data {
@@ -277,3 +279,62 @@ void of_gpiochip_remove(struct gpio_chip *chip) if (chip->of_node) of_node_put(chip->of_node); } + +static struct of_device_id gpio_export_ids[] = { + { .compatible = "gpio-export" }, + { /* sentinel */ } +}; + +static int __init of_gpio_export_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device_node *cnp; + u32 val; + int nb = 0; + + for_each_child_of_node(np, cnp) { + const char *name = NULL; + int gpio; + bool dmc; + int max_gpio = 1; + int i; + + of_property_read_string(cnp, "gpio-export,name", &name); + + if (!name) + max_gpio = of_gpio_count(cnp); + + for (i = 0; i < max_gpio; i++) { + gpio = of_get_gpio(cnp, i); + if (devm_gpio_request(&pdev->dev, gpio, name ? name : of_node_full_name(np))) + continue; + + if (!of_property_read_u32(cnp, "gpio-export,output", &val)) + gpio_direction_output(gpio, val); + else + gpio_direction_input(gpio); + + dmc = of_property_read_bool(np, "gpio-export,direction_may_change"); + gpio_export_with_name(gpio, dmc, name); + nb++; + } + } + + dev_info(&pdev->dev, "%d gpio(s) exported\n", nb); + + return 0; +} + +static struct platform_driver gpio_export_driver = { + .driver = { + .name = "gpio-export", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(gpio_export_ids), + }, +}; + +static int __init of_gpio_export_init(void) +{ + return platform_driver_probe(&gpio_export_driver, of_gpio_export_probe); +} +device_initcall(of_gpio_export_init);
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1.7.10.4