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) { 79eddf8176SLothar Waßmann pr_debug("%s: can't parse gpios property of node '%s[%d]'\n", 80eddf8176SLothar Waßmann __func__, np->full_name, index); 8141920d16SAlexandre Courbot return ret; 823d0f7cf0SGrant Likely } 83f141ed65SGrant Likely 843d0f7cf0SGrant Likely gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); 853d0f7cf0SGrant Likely 863d0f7cf0SGrant Likely of_node_put(gg_data.gpiospec.np); 87c61307a7SThierry Reding pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio); 883d0f7cf0SGrant Likely return gg_data.out_gpio; 89f141ed65SGrant Likely } 90f141ed65SGrant Likely EXPORT_SYMBOL(of_get_named_gpio_flags); 91f141ed65SGrant Likely 92f141ed65SGrant Likely /** 93f141ed65SGrant Likely * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags 94f141ed65SGrant Likely * @gc: pointer to the gpio_chip structure 95f141ed65SGrant Likely * @np: device node of the GPIO chip 96f141ed65SGrant Likely * @gpio_spec: gpio specifier as found in the device tree 97f141ed65SGrant Likely * @flags: a flags pointer to fill in 98f141ed65SGrant Likely * 99f141ed65SGrant Likely * This is simple translation function, suitable for the most 1:1 mapped 100f141ed65SGrant Likely * gpio chips. This function performs only one sanity check: whether gpio 101f141ed65SGrant Likely * is less than ngpios (that is specified in the gpio_chip). 102f141ed65SGrant Likely */ 103f141ed65SGrant Likely int of_gpio_simple_xlate(struct gpio_chip *gc, 104f141ed65SGrant Likely const struct of_phandle_args *gpiospec, u32 *flags) 105f141ed65SGrant Likely { 106f141ed65SGrant Likely /* 107f141ed65SGrant Likely * We're discouraging gpio_cells < 2, since that way you'll have to 108f141ed65SGrant Likely * write your own xlate function (that will have to retrive the GPIO 109f141ed65SGrant Likely * number and the flags from a single gpio cell -- this is possible, 110f141ed65SGrant Likely * but not recommended). 111f141ed65SGrant Likely */ 112f141ed65SGrant Likely if (gc->of_gpio_n_cells < 2) { 113f141ed65SGrant Likely WARN_ON(1); 114f141ed65SGrant Likely return -EINVAL; 115f141ed65SGrant Likely } 116f141ed65SGrant Likely 117f141ed65SGrant Likely if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) 118f141ed65SGrant Likely return -EINVAL; 119f141ed65SGrant Likely 1207b96c686SGrant Likely if (gpiospec->args[0] >= gc->ngpio) 121f141ed65SGrant Likely return -EINVAL; 122f141ed65SGrant Likely 123f141ed65SGrant Likely if (flags) 124f141ed65SGrant Likely *flags = gpiospec->args[1]; 125f141ed65SGrant Likely 126f141ed65SGrant Likely return gpiospec->args[0]; 127f141ed65SGrant Likely } 128f141ed65SGrant Likely EXPORT_SYMBOL(of_gpio_simple_xlate); 129f141ed65SGrant Likely 130f141ed65SGrant Likely /** 131f141ed65SGrant Likely * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) 132f141ed65SGrant Likely * @np: device node of the GPIO chip 133f141ed65SGrant Likely * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 134f141ed65SGrant Likely * 135f141ed65SGrant Likely * To use this function you should allocate and fill mm_gc with: 136f141ed65SGrant Likely * 137f141ed65SGrant Likely * 1) In the gpio_chip structure: 138f141ed65SGrant Likely * - all the callbacks 139f141ed65SGrant Likely * - of_gpio_n_cells 140f141ed65SGrant Likely * - of_xlate callback (optional) 141f141ed65SGrant Likely * 142f141ed65SGrant Likely * 3) In the of_mm_gpio_chip structure: 143f141ed65SGrant Likely * - save_regs callback (optional) 144f141ed65SGrant Likely * 145f141ed65SGrant Likely * If succeeded, this function will map bank's memory and will 146f141ed65SGrant Likely * do all necessary work for you. Then you'll able to use .regs 147f141ed65SGrant Likely * to manage GPIOs from the callbacks. 148f141ed65SGrant Likely */ 149f141ed65SGrant Likely int of_mm_gpiochip_add(struct device_node *np, 150f141ed65SGrant Likely struct of_mm_gpio_chip *mm_gc) 151f141ed65SGrant Likely { 152f141ed65SGrant Likely int ret = -ENOMEM; 153f141ed65SGrant Likely struct gpio_chip *gc = &mm_gc->gc; 154f141ed65SGrant Likely 155f141ed65SGrant Likely gc->label = kstrdup(np->full_name, GFP_KERNEL); 156f141ed65SGrant Likely if (!gc->label) 157f141ed65SGrant Likely goto err0; 158f141ed65SGrant Likely 159f141ed65SGrant Likely mm_gc->regs = of_iomap(np, 0); 160f141ed65SGrant Likely if (!mm_gc->regs) 161f141ed65SGrant Likely goto err1; 162f141ed65SGrant Likely 163f141ed65SGrant Likely gc->base = -1; 164f141ed65SGrant Likely 165f141ed65SGrant Likely if (mm_gc->save_regs) 166f141ed65SGrant Likely mm_gc->save_regs(mm_gc); 167f141ed65SGrant Likely 168f141ed65SGrant Likely mm_gc->gc.of_node = np; 169f141ed65SGrant Likely 170f141ed65SGrant Likely ret = gpiochip_add(gc); 171f141ed65SGrant Likely if (ret) 172f141ed65SGrant Likely goto err2; 173f141ed65SGrant Likely 174f141ed65SGrant Likely return 0; 175f141ed65SGrant Likely err2: 176f141ed65SGrant Likely iounmap(mm_gc->regs); 177f141ed65SGrant Likely err1: 178f141ed65SGrant Likely kfree(gc->label); 179f141ed65SGrant Likely err0: 180f141ed65SGrant Likely pr_err("%s: GPIO chip registration failed with status %d\n", 181f141ed65SGrant Likely np->full_name, ret); 182f141ed65SGrant Likely return ret; 183f141ed65SGrant Likely } 184f141ed65SGrant Likely EXPORT_SYMBOL(of_mm_gpiochip_add); 185f141ed65SGrant Likely 186f23f1516SShiraz Hashim #ifdef CONFIG_PINCTRL 187167c1af9SLinus Walleij static void of_gpiochip_add_pin_range(struct gpio_chip *chip) 188f23f1516SShiraz Hashim { 189f23f1516SShiraz Hashim struct device_node *np = chip->of_node; 190f23f1516SShiraz Hashim struct of_phandle_args pinspec; 1911e63d7b9SLinus Walleij struct pinctrl_dev *pctldev; 192f23f1516SShiraz Hashim int index = 0, ret; 193586a87e6SChristian Ruppert const char *name; 194586a87e6SChristian Ruppert static const char group_names_propname[] = "gpio-ranges-group-names"; 195586a87e6SChristian Ruppert struct property *group_names; 196f23f1516SShiraz Hashim 197f23f1516SShiraz Hashim if (!np) 198f23f1516SShiraz Hashim return; 199f23f1516SShiraz Hashim 200586a87e6SChristian Ruppert group_names = of_find_property(np, group_names_propname, NULL); 201586a87e6SChristian Ruppert 202ad4e1a7cSHaojian Zhuang for (;; index++) { 203d9fe0039SStephen Warren ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 204d9fe0039SStephen Warren index, &pinspec); 205f23f1516SShiraz Hashim if (ret) 206f23f1516SShiraz Hashim break; 207f23f1516SShiraz Hashim 2081e63d7b9SLinus Walleij pctldev = of_pinctrl_get(pinspec.np); 2091e63d7b9SLinus Walleij if (!pctldev) 210f23f1516SShiraz Hashim break; 211f23f1516SShiraz Hashim 212586a87e6SChristian Ruppert if (pinspec.args[2]) { 213586a87e6SChristian Ruppert if (group_names) { 214586a87e6SChristian Ruppert ret = of_property_read_string_index(np, 215586a87e6SChristian Ruppert group_names_propname, 216586a87e6SChristian Ruppert index, &name); 217586a87e6SChristian Ruppert if (strlen(name)) { 218586a87e6SChristian Ruppert pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", 219586a87e6SChristian Ruppert np->full_name); 220586a87e6SChristian Ruppert break; 221586a87e6SChristian Ruppert } 222586a87e6SChristian Ruppert } 223586a87e6SChristian Ruppert /* npins != 0: linear range */ 2241e63d7b9SLinus Walleij ret = gpiochip_add_pin_range(chip, 225ef5e3eefSHaojian Zhuang pinctrl_dev_get_devname(pctldev), 2261e63d7b9SLinus Walleij pinspec.args[0], 22786853c83SHaojian Zhuang pinspec.args[1], 22886853c83SHaojian Zhuang pinspec.args[2]); 2291e63d7b9SLinus Walleij if (ret) 2301e63d7b9SLinus Walleij break; 231586a87e6SChristian Ruppert } else { 232586a87e6SChristian Ruppert /* npins == 0: special range */ 233586a87e6SChristian Ruppert if (pinspec.args[1]) { 234586a87e6SChristian Ruppert pr_err("%s: Illegal gpio-range format.\n", 235586a87e6SChristian Ruppert np->full_name); 236586a87e6SChristian Ruppert break; 237586a87e6SChristian Ruppert } 238586a87e6SChristian Ruppert 239586a87e6SChristian Ruppert if (!group_names) { 240586a87e6SChristian Ruppert pr_err("%s: GPIO group range requested but no %s property.\n", 241586a87e6SChristian Ruppert np->full_name, group_names_propname); 242586a87e6SChristian Ruppert break; 243586a87e6SChristian Ruppert } 244586a87e6SChristian Ruppert 245586a87e6SChristian Ruppert ret = of_property_read_string_index(np, 246586a87e6SChristian Ruppert group_names_propname, 247586a87e6SChristian Ruppert index, &name); 248586a87e6SChristian Ruppert if (ret) 249586a87e6SChristian Ruppert break; 250586a87e6SChristian Ruppert 251586a87e6SChristian Ruppert if (!strlen(name)) { 252586a87e6SChristian Ruppert pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", 253586a87e6SChristian Ruppert np->full_name); 254586a87e6SChristian Ruppert break; 255586a87e6SChristian Ruppert } 256586a87e6SChristian Ruppert 257586a87e6SChristian Ruppert ret = gpiochip_add_pingroup_range(chip, pctldev, 258586a87e6SChristian Ruppert pinspec.args[0], name); 259586a87e6SChristian Ruppert if (ret) 260586a87e6SChristian Ruppert break; 261586a87e6SChristian Ruppert } 262ad4e1a7cSHaojian Zhuang } 263f23f1516SShiraz Hashim } 264f23f1516SShiraz Hashim 265f23f1516SShiraz Hashim #else 266167c1af9SLinus Walleij static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} 267f23f1516SShiraz Hashim #endif 268f23f1516SShiraz Hashim 269f141ed65SGrant Likely void of_gpiochip_add(struct gpio_chip *chip) 270f141ed65SGrant Likely { 271f141ed65SGrant Likely if ((!chip->of_node) && (chip->dev)) 272f141ed65SGrant Likely chip->of_node = chip->dev->of_node; 273f141ed65SGrant Likely 274f141ed65SGrant Likely if (!chip->of_node) 275f141ed65SGrant Likely return; 276f141ed65SGrant Likely 277f141ed65SGrant Likely if (!chip->of_xlate) { 278f141ed65SGrant Likely chip->of_gpio_n_cells = 2; 279f141ed65SGrant Likely chip->of_xlate = of_gpio_simple_xlate; 280f141ed65SGrant Likely } 281f141ed65SGrant Likely 282f23f1516SShiraz Hashim of_gpiochip_add_pin_range(chip); 283f141ed65SGrant Likely of_node_get(chip->of_node); 284f141ed65SGrant Likely } 285f141ed65SGrant Likely 286f141ed65SGrant Likely void of_gpiochip_remove(struct gpio_chip *chip) 287f141ed65SGrant Likely { 288e93fa3f2SLinus Walleij gpiochip_remove_pin_ranges(chip); 289f23f1516SShiraz Hashim 290f141ed65SGrant Likely if (chip->of_node) 291f141ed65SGrant Likely of_node_put(chip->of_node); 292f141ed65SGrant Likely } 293