1f141ed65SGrant Likely /* 2f141ed65SGrant Likely * OF helpers for the GPIO API 3f141ed65SGrant Likely * 4f141ed65SGrant Likely * Copyright (c) 2007-2008 MontaVista Software, Inc. 5f141ed65SGrant Likely * 6f141ed65SGrant Likely * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 7f141ed65SGrant Likely * 8f141ed65SGrant Likely * This program is free software; you can redistribute it and/or modify 9f141ed65SGrant Likely * it under the terms of the GNU General Public License as published by 10f141ed65SGrant Likely * the Free Software Foundation; either version 2 of the License, or 11f141ed65SGrant Likely * (at your option) any later version. 12f141ed65SGrant Likely */ 13f141ed65SGrant Likely 14f141ed65SGrant Likely #include <linux/device.h> 15f141ed65SGrant Likely #include <linux/errno.h> 16f141ed65SGrant Likely #include <linux/module.h> 17f141ed65SGrant Likely #include <linux/io.h> 183d0f7cf0SGrant Likely #include <linux/gpio.h> 19f141ed65SGrant Likely #include <linux/of.h> 20f141ed65SGrant Likely #include <linux/of_address.h> 21f141ed65SGrant Likely #include <linux/of_gpio.h> 22f23f1516SShiraz Hashim #include <linux/pinctrl/pinctrl.h> 23f141ed65SGrant Likely #include <linux/slab.h> 24f141ed65SGrant Likely 250df2c999SDong Aisheng /* Private data structure for of_gpiochip_find_and_xlate */ 263d0f7cf0SGrant Likely struct gg_data { 273d0f7cf0SGrant Likely enum of_gpio_flags *flags; 283d0f7cf0SGrant Likely struct of_phandle_args gpiospec; 293d0f7cf0SGrant Likely 303d0f7cf0SGrant Likely int out_gpio; 313d0f7cf0SGrant Likely }; 323d0f7cf0SGrant Likely 333d0f7cf0SGrant Likely /* Private function for resolving node pointer to gpio_chip */ 343d0f7cf0SGrant Likely static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data) 353d0f7cf0SGrant Likely { 363d0f7cf0SGrant Likely struct gg_data *gg_data = data; 373d0f7cf0SGrant Likely int ret; 383d0f7cf0SGrant Likely 393d0f7cf0SGrant Likely if ((gc->of_node != gg_data->gpiospec.np) || 403d0f7cf0SGrant Likely (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) || 413d0f7cf0SGrant Likely (!gc->of_xlate)) 423d0f7cf0SGrant Likely return false; 433d0f7cf0SGrant Likely 443d0f7cf0SGrant Likely ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags); 453d0f7cf0SGrant Likely if (ret < 0) 463d0f7cf0SGrant Likely return false; 473d0f7cf0SGrant Likely 483d0f7cf0SGrant Likely gg_data->out_gpio = ret + gc->base; 493d0f7cf0SGrant Likely return true; 503d0f7cf0SGrant Likely } 513d0f7cf0SGrant Likely 52f141ed65SGrant Likely /** 53f141ed65SGrant Likely * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API 54f141ed65SGrant Likely * @np: device node to get GPIO from 55f141ed65SGrant Likely * @propname: property name containing gpio specifier(s) 56f141ed65SGrant Likely * @index: index of the GPIO 57f141ed65SGrant Likely * @flags: a flags pointer to fill in 58f141ed65SGrant Likely * 59f141ed65SGrant Likely * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 60f141ed65SGrant Likely * value on the error condition. If @flags is not NULL the function also fills 61f141ed65SGrant Likely * in flags for the GPIO. 62f141ed65SGrant Likely */ 63f141ed65SGrant Likely int of_get_named_gpio_flags(struct device_node *np, const char *propname, 64f141ed65SGrant Likely int index, enum of_gpio_flags *flags) 65f141ed65SGrant Likely { 664fbb0022SRoland Stigge /* Return -EPROBE_DEFER to support probe() functions to be called 674fbb0022SRoland Stigge * later when the GPIO actually becomes available 684fbb0022SRoland Stigge */ 694fbb0022SRoland Stigge struct gg_data gg_data = { .flags = flags, .out_gpio = -EPROBE_DEFER }; 70f141ed65SGrant Likely int ret; 71f141ed65SGrant Likely 723d0f7cf0SGrant Likely /* .of_xlate might decide to not fill in the flags, so clear it. */ 73f141ed65SGrant Likely if (flags) 74f141ed65SGrant Likely *flags = 0; 75f141ed65SGrant Likely 763d0f7cf0SGrant Likely ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, 773d0f7cf0SGrant Likely &gg_data.gpiospec); 783d0f7cf0SGrant Likely if (ret) { 793d0f7cf0SGrant Likely pr_debug("%s: can't parse gpios property\n", __func__); 8041920d16SAlexandre Courbot return ret; 813d0f7cf0SGrant Likely } 82f141ed65SGrant Likely 833d0f7cf0SGrant Likely gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); 843d0f7cf0SGrant Likely 853d0f7cf0SGrant Likely of_node_put(gg_data.gpiospec.np); 86c61307a7SThierry Reding pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio); 873d0f7cf0SGrant Likely return gg_data.out_gpio; 88f141ed65SGrant Likely } 89f141ed65SGrant Likely EXPORT_SYMBOL(of_get_named_gpio_flags); 90f141ed65SGrant Likely 91f141ed65SGrant Likely /** 92f141ed65SGrant Likely * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags 93f141ed65SGrant Likely * @gc: pointer to the gpio_chip structure 94f141ed65SGrant Likely * @np: device node of the GPIO chip 95f141ed65SGrant Likely * @gpio_spec: gpio specifier as found in the device tree 96f141ed65SGrant Likely * @flags: a flags pointer to fill in 97f141ed65SGrant Likely * 98f141ed65SGrant Likely * This is simple translation function, suitable for the most 1:1 mapped 99f141ed65SGrant Likely * gpio chips. This function performs only one sanity check: whether gpio 100f141ed65SGrant Likely * is less than ngpios (that is specified in the gpio_chip). 101f141ed65SGrant Likely */ 102f141ed65SGrant Likely int of_gpio_simple_xlate(struct gpio_chip *gc, 103f141ed65SGrant Likely const struct of_phandle_args *gpiospec, u32 *flags) 104f141ed65SGrant Likely { 105f141ed65SGrant Likely /* 106f141ed65SGrant Likely * We're discouraging gpio_cells < 2, since that way you'll have to 107f141ed65SGrant Likely * write your own xlate function (that will have to retrive the GPIO 108f141ed65SGrant Likely * number and the flags from a single gpio cell -- this is possible, 109f141ed65SGrant Likely * but not recommended). 110f141ed65SGrant Likely */ 111f141ed65SGrant Likely if (gc->of_gpio_n_cells < 2) { 112f141ed65SGrant Likely WARN_ON(1); 113f141ed65SGrant Likely return -EINVAL; 114f141ed65SGrant Likely } 115f141ed65SGrant Likely 116f141ed65SGrant Likely if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) 117f141ed65SGrant Likely return -EINVAL; 118f141ed65SGrant Likely 1197b96c686SGrant Likely if (gpiospec->args[0] >= gc->ngpio) 120f141ed65SGrant Likely return -EINVAL; 121f141ed65SGrant Likely 122f141ed65SGrant Likely if (flags) 123f141ed65SGrant Likely *flags = gpiospec->args[1]; 124f141ed65SGrant Likely 125f141ed65SGrant Likely return gpiospec->args[0]; 126f141ed65SGrant Likely } 127f141ed65SGrant Likely EXPORT_SYMBOL(of_gpio_simple_xlate); 128f141ed65SGrant Likely 129f141ed65SGrant Likely /** 130f141ed65SGrant Likely * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) 131f141ed65SGrant Likely * @np: device node of the GPIO chip 132f141ed65SGrant Likely * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 133f141ed65SGrant Likely * 134f141ed65SGrant Likely * To use this function you should allocate and fill mm_gc with: 135f141ed65SGrant Likely * 136f141ed65SGrant Likely * 1) In the gpio_chip structure: 137f141ed65SGrant Likely * - all the callbacks 138f141ed65SGrant Likely * - of_gpio_n_cells 139f141ed65SGrant Likely * - of_xlate callback (optional) 140f141ed65SGrant Likely * 141f141ed65SGrant Likely * 3) In the of_mm_gpio_chip structure: 142f141ed65SGrant Likely * - save_regs callback (optional) 143f141ed65SGrant Likely * 144f141ed65SGrant Likely * If succeeded, this function will map bank's memory and will 145f141ed65SGrant Likely * do all necessary work for you. Then you'll able to use .regs 146f141ed65SGrant Likely * to manage GPIOs from the callbacks. 147f141ed65SGrant Likely */ 148f141ed65SGrant Likely int of_mm_gpiochip_add(struct device_node *np, 149f141ed65SGrant Likely struct of_mm_gpio_chip *mm_gc) 150f141ed65SGrant Likely { 151f141ed65SGrant Likely int ret = -ENOMEM; 152f141ed65SGrant Likely struct gpio_chip *gc = &mm_gc->gc; 153f141ed65SGrant Likely 154f141ed65SGrant Likely gc->label = kstrdup(np->full_name, GFP_KERNEL); 155f141ed65SGrant Likely if (!gc->label) 156f141ed65SGrant Likely goto err0; 157f141ed65SGrant Likely 158f141ed65SGrant Likely mm_gc->regs = of_iomap(np, 0); 159f141ed65SGrant Likely if (!mm_gc->regs) 160f141ed65SGrant Likely goto err1; 161f141ed65SGrant Likely 162f141ed65SGrant Likely gc->base = -1; 163f141ed65SGrant Likely 164f141ed65SGrant Likely if (mm_gc->save_regs) 165f141ed65SGrant Likely mm_gc->save_regs(mm_gc); 166f141ed65SGrant Likely 167f141ed65SGrant Likely mm_gc->gc.of_node = np; 168f141ed65SGrant Likely 169f141ed65SGrant Likely ret = gpiochip_add(gc); 170f141ed65SGrant Likely if (ret) 171f141ed65SGrant Likely goto err2; 172f141ed65SGrant Likely 173f141ed65SGrant Likely return 0; 174f141ed65SGrant Likely err2: 175f141ed65SGrant Likely iounmap(mm_gc->regs); 176f141ed65SGrant Likely err1: 177f141ed65SGrant Likely kfree(gc->label); 178f141ed65SGrant Likely err0: 179f141ed65SGrant Likely pr_err("%s: GPIO chip registration failed with status %d\n", 180f141ed65SGrant Likely np->full_name, ret); 181f141ed65SGrant Likely return ret; 182f141ed65SGrant Likely } 183f141ed65SGrant Likely EXPORT_SYMBOL(of_mm_gpiochip_add); 184f141ed65SGrant Likely 185f23f1516SShiraz Hashim #ifdef CONFIG_PINCTRL 186167c1af9SLinus Walleij static void of_gpiochip_add_pin_range(struct gpio_chip *chip) 187f23f1516SShiraz Hashim { 188f23f1516SShiraz Hashim struct device_node *np = chip->of_node; 189f23f1516SShiraz Hashim struct of_phandle_args pinspec; 1901e63d7b9SLinus Walleij struct pinctrl_dev *pctldev; 191f23f1516SShiraz Hashim int index = 0, ret; 192f23f1516SShiraz Hashim 193f23f1516SShiraz Hashim if (!np) 194f23f1516SShiraz Hashim return; 195f23f1516SShiraz Hashim 196f23f1516SShiraz Hashim do { 197f23f1516SShiraz Hashim ret = of_parse_phandle_with_args(np, "gpio-ranges", 198f23f1516SShiraz Hashim "#gpio-range-cells", index, &pinspec); 199f23f1516SShiraz Hashim if (ret) 200f23f1516SShiraz Hashim break; 201f23f1516SShiraz Hashim 2021e63d7b9SLinus Walleij pctldev = of_pinctrl_get(pinspec.np); 2031e63d7b9SLinus Walleij if (!pctldev) 204f23f1516SShiraz Hashim break; 205f23f1516SShiraz Hashim 2061e63d7b9SLinus Walleij ret = gpiochip_add_pin_range(chip, 207ef5e3eefSHaojian Zhuang pinctrl_dev_get_devname(pctldev), 2081e63d7b9SLinus Walleij pinspec.args[0], 20986853c83SHaojian Zhuang pinspec.args[1], 21086853c83SHaojian Zhuang pinspec.args[2]); 211f23f1516SShiraz Hashim 2121e63d7b9SLinus Walleij if (ret) 2131e63d7b9SLinus Walleij break; 214f23f1516SShiraz Hashim 215f23f1516SShiraz Hashim } while (index++); 216f23f1516SShiraz Hashim } 217f23f1516SShiraz Hashim 218f23f1516SShiraz Hashim #else 219167c1af9SLinus Walleij static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} 220f23f1516SShiraz Hashim #endif 221f23f1516SShiraz Hashim 222f141ed65SGrant Likely void of_gpiochip_add(struct gpio_chip *chip) 223f141ed65SGrant Likely { 224f141ed65SGrant Likely if ((!chip->of_node) && (chip->dev)) 225f141ed65SGrant Likely chip->of_node = chip->dev->of_node; 226f141ed65SGrant Likely 227f141ed65SGrant Likely if (!chip->of_node) 228f141ed65SGrant Likely return; 229f141ed65SGrant Likely 230f141ed65SGrant Likely if (!chip->of_xlate) { 231f141ed65SGrant Likely chip->of_gpio_n_cells = 2; 232f141ed65SGrant Likely chip->of_xlate = of_gpio_simple_xlate; 233f141ed65SGrant Likely } 234f141ed65SGrant Likely 235f23f1516SShiraz Hashim of_gpiochip_add_pin_range(chip); 236f141ed65SGrant Likely of_node_get(chip->of_node); 237f141ed65SGrant Likely } 238f141ed65SGrant Likely 239f141ed65SGrant Likely void of_gpiochip_remove(struct gpio_chip *chip) 240f141ed65SGrant Likely { 241e93fa3f2SLinus Walleij gpiochip_remove_pin_ranges(chip); 242f23f1516SShiraz Hashim 243f141ed65SGrant Likely if (chip->of_node) 244f141ed65SGrant Likely of_node_put(chip->of_node); 245f141ed65SGrant Likely } 246