| /* |
| * OF helpers for the GPIO API |
| * |
| * Copyright (c) 2007-2008 MontaVista Software, Inc. |
| * |
| * Author: Anton Vorontsov <avorontsov@ru.mvista.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/errno.h> |
| #include <linux/module.h> |
| #include <linux/io.h> |
| #include <linux/gpio.h> |
| #include <linux/of.h> |
| #include <linux/of_address.h> |
| #include <linux/of_gpio.h> |
| #include <linux/pinctrl/pinctrl.h> |
| #include <linux/slab.h> |
| |
| /* Private data structure for of_gpiochip_find_and_xlate */ |
| struct gg_data { |
| enum of_gpio_flags *flags; |
| struct of_phandle_args gpiospec; |
| |
| int out_gpio; |
| }; |
| |
| /* Private function for resolving node pointer to gpio_chip */ |
| static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data) |
| { |
| struct gg_data *gg_data = data; |
| int ret; |
| |
| if ((gc->of_node != gg_data->gpiospec.np) || |
| (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) || |
| (!gc->of_xlate)) |
| return false; |
| |
| ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags); |
| if (ret < 0) |
| return false; |
| |
| gg_data->out_gpio = ret + gc->base; |
| return true; |
| } |
| |
| /** |
| * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API |
| * @np: device node to get GPIO from |
| * @propname: property name containing gpio specifier(s) |
| * @index: index of the GPIO |
| * @flags: a flags pointer to fill in |
| * |
| * Returns GPIO number to use with Linux generic GPIO API, or one of the errno |
| * value on the error condition. If @flags is not NULL the function also fills |
| * in flags for the GPIO. |
| */ |
| int of_get_named_gpio_flags(struct device_node *np, const char *propname, |
| int index, enum of_gpio_flags *flags) |
| { |
| /* Return -EPROBE_DEFER to support probe() functions to be called |
| * later when the GPIO actually becomes available |
| */ |
| struct gg_data gg_data = { .flags = flags, .out_gpio = -EPROBE_DEFER }; |
| int ret; |
| |
| /* .of_xlate might decide to not fill in the flags, so clear it. */ |
| if (flags) |
| *flags = 0; |
| |
| ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
| &gg_data.gpiospec); |
| if (ret) { |
| pr_debug("%s: can't parse gpios property\n", __func__); |
| return ret; |
| } |
| |
| gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); |
| |
| of_node_put(gg_data.gpiospec.np); |
| pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio); |
| return gg_data.out_gpio; |
| } |
| EXPORT_SYMBOL(of_get_named_gpio_flags); |
| |
| /** |
| * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
| * @gc: pointer to the gpio_chip structure |
| * @np: device node of the GPIO chip |
| * @gpio_spec: gpio specifier as found in the device tree |
| * @flags: a flags pointer to fill in |
| * |
| * This is simple translation function, suitable for the most 1:1 mapped |
| * gpio chips. This function performs only one sanity check: whether gpio |
| * is less than ngpios (that is specified in the gpio_chip). |
| */ |
| int of_gpio_simple_xlate(struct gpio_chip *gc, |
| const struct of_phandle_args *gpiospec, u32 *flags) |
| { |
| /* |
| * We're discouraging gpio_cells < 2, since that way you'll have to |
| * write your own xlate function (that will have to retrive the GPIO |
| * number and the flags from a single gpio cell -- this is possible, |
| * but not recommended). |
| */ |
| if (gc->of_gpio_n_cells < 2) { |
| WARN_ON(1); |
| return -EINVAL; |
| } |
| |
| if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
| return -EINVAL; |
| |
| if (gpiospec->args[0] >= gc->ngpio) |
| return -EINVAL; |
| |
| if (flags) |
| *flags = gpiospec->args[1]; |
| |
| return gpiospec->args[0]; |
| } |
| EXPORT_SYMBOL(of_gpio_simple_xlate); |
| |
| /** |
| * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) |
| * @np: device node of the GPIO chip |
| * @mm_gc: pointer to the of_mm_gpio_chip allocated structure |
| * |
| * To use this function you should allocate and fill mm_gc with: |
| * |
| * 1) In the gpio_chip structure: |
| * - all the callbacks |
| * - of_gpio_n_cells |
| * - of_xlate callback (optional) |
| * |
| * 3) In the of_mm_gpio_chip structure: |
| * - save_regs callback (optional) |
| * |
| * If succeeded, this function will map bank's memory and will |
| * do all necessary work for you. Then you'll able to use .regs |
| * to manage GPIOs from the callbacks. |
| */ |
| int of_mm_gpiochip_add(struct device_node *np, |
| struct of_mm_gpio_chip *mm_gc) |
| { |
| int ret = -ENOMEM; |
| struct gpio_chip *gc = &mm_gc->gc; |
| |
| gc->label = kstrdup(np->full_name, GFP_KERNEL); |
| if (!gc->label) |
| goto err0; |
| |
| mm_gc->regs = of_iomap(np, 0); |
| if (!mm_gc->regs) |
| goto err1; |
| |
| gc->base = -1; |
| |
| if (mm_gc->save_regs) |
| mm_gc->save_regs(mm_gc); |
| |
| mm_gc->gc.of_node = np; |
| |
| ret = gpiochip_add(gc); |
| if (ret) |
| goto err2; |
| |
| return 0; |
| err2: |
| iounmap(mm_gc->regs); |
| err1: |
| kfree(gc->label); |
| err0: |
| pr_err("%s: GPIO chip registration failed with status %d\n", |
| np->full_name, ret); |
| return ret; |
| } |
| EXPORT_SYMBOL(of_mm_gpiochip_add); |
| |
| #ifdef CONFIG_PINCTRL |
| static void of_gpiochip_add_pin_range(struct gpio_chip *chip) |
| { |
| struct device_node *np = chip->of_node; |
| struct of_phandle_args pinspec; |
| struct pinctrl_dev *pctldev; |
| int index = 0, ret; |
| |
| if (!np) |
| return; |
| |
| for (;; index++) { |
| ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, |
| index, &pinspec); |
| if (ret) |
| break; |
| |
| pctldev = of_pinctrl_get(pinspec.np); |
| if (!pctldev) |
| break; |
| |
| ret = gpiochip_add_pin_range(chip, |
| pinctrl_dev_get_devname(pctldev), |
| pinspec.args[0], |
| pinspec.args[1], |
| pinspec.args[2]); |
| |
| if (ret) |
| break; |
| } |
| } |
| |
| #else |
| static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} |
| #endif |
| |
| void of_gpiochip_add(struct gpio_chip *chip) |
| { |
| if ((!chip->of_node) && (chip->dev)) |
| chip->of_node = chip->dev->of_node; |
| |
| if (!chip->of_node) |
| return; |
| |
| if (!chip->of_xlate) { |
| chip->of_gpio_n_cells = 2; |
| chip->of_xlate = of_gpio_simple_xlate; |
| } |
| |
| of_gpiochip_add_pin_range(chip); |
| of_node_get(chip->of_node); |
| } |
| |
| void of_gpiochip_remove(struct gpio_chip *chip) |
| { |
| gpiochip_remove_pin_ranges(chip); |
| |
| if (chip->of_node) |
| of_node_put(chip->of_node); |
| } |