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> 18f141ed65SGrant Likely #include <linux/of.h> 19f141ed65SGrant Likely #include <linux/of_address.h> 20f141ed65SGrant Likely #include <linux/of_gpio.h> 21f141ed65SGrant Likely #include <linux/slab.h> 22f141ed65SGrant Likely 23f141ed65SGrant Likely /** 24f141ed65SGrant Likely * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API 25f141ed65SGrant Likely * @np: device node to get GPIO from 26f141ed65SGrant Likely * @propname: property name containing gpio specifier(s) 27f141ed65SGrant Likely * @index: index of the GPIO 28f141ed65SGrant Likely * @flags: a flags pointer to fill in 29f141ed65SGrant Likely * 30f141ed65SGrant Likely * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 31f141ed65SGrant Likely * value on the error condition. If @flags is not NULL the function also fills 32f141ed65SGrant Likely * in flags for the GPIO. 33f141ed65SGrant Likely */ 34f141ed65SGrant Likely int of_get_named_gpio_flags(struct device_node *np, const char *propname, 35f141ed65SGrant Likely int index, enum of_gpio_flags *flags) 36f141ed65SGrant Likely { 37f141ed65SGrant Likely int ret; 38f141ed65SGrant Likely struct gpio_chip *gc; 39f141ed65SGrant Likely struct of_phandle_args gpiospec; 40f141ed65SGrant Likely 41f141ed65SGrant Likely ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, 42f141ed65SGrant Likely &gpiospec); 43f141ed65SGrant Likely if (ret) { 44f141ed65SGrant Likely pr_debug("%s: can't parse gpios property\n", __func__); 45f141ed65SGrant Likely goto err0; 46f141ed65SGrant Likely } 47f141ed65SGrant Likely 48f141ed65SGrant Likely gc = of_node_to_gpiochip(gpiospec.np); 49f141ed65SGrant Likely if (!gc) { 50f141ed65SGrant Likely pr_debug("%s: gpio controller %s isn't registered\n", 51f141ed65SGrant Likely np->full_name, gpiospec.np->full_name); 52f141ed65SGrant Likely ret = -ENODEV; 53f141ed65SGrant Likely goto err1; 54f141ed65SGrant Likely } 55f141ed65SGrant Likely 56f141ed65SGrant Likely if (gpiospec.args_count != gc->of_gpio_n_cells) { 57f141ed65SGrant Likely pr_debug("%s: wrong #gpio-cells for %s\n", 58f141ed65SGrant Likely np->full_name, gpiospec.np->full_name); 59f141ed65SGrant Likely ret = -EINVAL; 60f141ed65SGrant Likely goto err1; 61f141ed65SGrant Likely } 62f141ed65SGrant Likely 63f141ed65SGrant Likely /* .xlate might decide to not fill in the flags, so clear it. */ 64f141ed65SGrant Likely if (flags) 65f141ed65SGrant Likely *flags = 0; 66f141ed65SGrant Likely 67f141ed65SGrant Likely ret = gc->of_xlate(gc, &gpiospec, flags); 68f141ed65SGrant Likely if (ret < 0) 69f141ed65SGrant Likely goto err1; 70f141ed65SGrant Likely 71f141ed65SGrant Likely ret += gc->base; 72f141ed65SGrant Likely err1: 73f141ed65SGrant Likely of_node_put(gpiospec.np); 74f141ed65SGrant Likely err0: 75f141ed65SGrant Likely pr_debug("%s exited with status %d\n", __func__, ret); 76f141ed65SGrant Likely return ret; 77f141ed65SGrant Likely } 78f141ed65SGrant Likely EXPORT_SYMBOL(of_get_named_gpio_flags); 79f141ed65SGrant Likely 80f141ed65SGrant Likely /** 81f141ed65SGrant Likely * of_gpio_named_count - Count GPIOs for a device 82f141ed65SGrant Likely * @np: device node to count GPIOs for 83f141ed65SGrant Likely * @propname: property name containing gpio specifier(s) 84f141ed65SGrant Likely * 85f141ed65SGrant Likely * The function returns the count of GPIOs specified for a node. 86f141ed65SGrant Likely * 87f141ed65SGrant Likely * Note that the empty GPIO specifiers counts too. For example, 88f141ed65SGrant Likely * 89f141ed65SGrant Likely * gpios = <0 90f141ed65SGrant Likely * &pio1 1 2 91f141ed65SGrant Likely * 0 92f141ed65SGrant Likely * &pio2 3 4>; 93f141ed65SGrant Likely * 94f141ed65SGrant Likely * defines four GPIOs (so this function will return 4), two of which 95f141ed65SGrant Likely * are not specified. 96f141ed65SGrant Likely */ 97f141ed65SGrant Likely unsigned int of_gpio_named_count(struct device_node *np, const char* propname) 98f141ed65SGrant Likely { 99f141ed65SGrant Likely unsigned int cnt = 0; 100f141ed65SGrant Likely 101f141ed65SGrant Likely do { 102f141ed65SGrant Likely int ret; 103f141ed65SGrant Likely 104f141ed65SGrant Likely ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", 105f141ed65SGrant Likely cnt, NULL); 106f141ed65SGrant Likely /* A hole in the gpios = <> counts anyway. */ 107f141ed65SGrant Likely if (ret < 0 && ret != -EEXIST) 108f141ed65SGrant Likely break; 109f141ed65SGrant Likely } while (++cnt); 110f141ed65SGrant Likely 111f141ed65SGrant Likely return cnt; 112f141ed65SGrant Likely } 113f141ed65SGrant Likely EXPORT_SYMBOL(of_gpio_named_count); 114f141ed65SGrant Likely 115f141ed65SGrant Likely /** 116f141ed65SGrant Likely * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags 117f141ed65SGrant Likely * @gc: pointer to the gpio_chip structure 118f141ed65SGrant Likely * @np: device node of the GPIO chip 119f141ed65SGrant Likely * @gpio_spec: gpio specifier as found in the device tree 120f141ed65SGrant Likely * @flags: a flags pointer to fill in 121f141ed65SGrant Likely * 122f141ed65SGrant Likely * This is simple translation function, suitable for the most 1:1 mapped 123f141ed65SGrant Likely * gpio chips. This function performs only one sanity check: whether gpio 124f141ed65SGrant Likely * is less than ngpios (that is specified in the gpio_chip). 125f141ed65SGrant Likely */ 126f141ed65SGrant Likely int of_gpio_simple_xlate(struct gpio_chip *gc, 127f141ed65SGrant Likely const struct of_phandle_args *gpiospec, u32 *flags) 128f141ed65SGrant Likely { 129f141ed65SGrant Likely /* 130f141ed65SGrant Likely * We're discouraging gpio_cells < 2, since that way you'll have to 131f141ed65SGrant Likely * write your own xlate function (that will have to retrive the GPIO 132f141ed65SGrant Likely * number and the flags from a single gpio cell -- this is possible, 133f141ed65SGrant Likely * but not recommended). 134f141ed65SGrant Likely */ 135f141ed65SGrant Likely if (gc->of_gpio_n_cells < 2) { 136f141ed65SGrant Likely WARN_ON(1); 137f141ed65SGrant Likely return -EINVAL; 138f141ed65SGrant Likely } 139f141ed65SGrant Likely 140f141ed65SGrant Likely if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) 141f141ed65SGrant Likely return -EINVAL; 142f141ed65SGrant Likely 143f141ed65SGrant Likely if (gpiospec->args[0] > gc->ngpio) 144f141ed65SGrant Likely return -EINVAL; 145f141ed65SGrant Likely 146f141ed65SGrant Likely if (flags) 147f141ed65SGrant Likely *flags = gpiospec->args[1]; 148f141ed65SGrant Likely 149f141ed65SGrant Likely return gpiospec->args[0]; 150f141ed65SGrant Likely } 151f141ed65SGrant Likely EXPORT_SYMBOL(of_gpio_simple_xlate); 152f141ed65SGrant Likely 153f141ed65SGrant Likely /** 154f141ed65SGrant Likely * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) 155f141ed65SGrant Likely * @np: device node of the GPIO chip 156f141ed65SGrant Likely * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 157f141ed65SGrant Likely * 158f141ed65SGrant Likely * To use this function you should allocate and fill mm_gc with: 159f141ed65SGrant Likely * 160f141ed65SGrant Likely * 1) In the gpio_chip structure: 161f141ed65SGrant Likely * - all the callbacks 162f141ed65SGrant Likely * - of_gpio_n_cells 163f141ed65SGrant Likely * - of_xlate callback (optional) 164f141ed65SGrant Likely * 165f141ed65SGrant Likely * 3) In the of_mm_gpio_chip structure: 166f141ed65SGrant Likely * - save_regs callback (optional) 167f141ed65SGrant Likely * 168f141ed65SGrant Likely * If succeeded, this function will map bank's memory and will 169f141ed65SGrant Likely * do all necessary work for you. Then you'll able to use .regs 170f141ed65SGrant Likely * to manage GPIOs from the callbacks. 171f141ed65SGrant Likely */ 172f141ed65SGrant Likely int of_mm_gpiochip_add(struct device_node *np, 173f141ed65SGrant Likely struct of_mm_gpio_chip *mm_gc) 174f141ed65SGrant Likely { 175f141ed65SGrant Likely int ret = -ENOMEM; 176f141ed65SGrant Likely struct gpio_chip *gc = &mm_gc->gc; 177f141ed65SGrant Likely 178f141ed65SGrant Likely gc->label = kstrdup(np->full_name, GFP_KERNEL); 179f141ed65SGrant Likely if (!gc->label) 180f141ed65SGrant Likely goto err0; 181f141ed65SGrant Likely 182f141ed65SGrant Likely mm_gc->regs = of_iomap(np, 0); 183f141ed65SGrant Likely if (!mm_gc->regs) 184f141ed65SGrant Likely goto err1; 185f141ed65SGrant Likely 186f141ed65SGrant Likely gc->base = -1; 187f141ed65SGrant Likely 188f141ed65SGrant Likely if (mm_gc->save_regs) 189f141ed65SGrant Likely mm_gc->save_regs(mm_gc); 190f141ed65SGrant Likely 191f141ed65SGrant Likely mm_gc->gc.of_node = np; 192f141ed65SGrant Likely 193f141ed65SGrant Likely ret = gpiochip_add(gc); 194f141ed65SGrant Likely if (ret) 195f141ed65SGrant Likely goto err2; 196f141ed65SGrant Likely 197f141ed65SGrant Likely return 0; 198f141ed65SGrant Likely err2: 199f141ed65SGrant Likely iounmap(mm_gc->regs); 200f141ed65SGrant Likely err1: 201f141ed65SGrant Likely kfree(gc->label); 202f141ed65SGrant Likely err0: 203f141ed65SGrant Likely pr_err("%s: GPIO chip registration failed with status %d\n", 204f141ed65SGrant Likely np->full_name, ret); 205f141ed65SGrant Likely return ret; 206f141ed65SGrant Likely } 207f141ed65SGrant Likely EXPORT_SYMBOL(of_mm_gpiochip_add); 208f141ed65SGrant Likely 209f141ed65SGrant Likely void of_gpiochip_add(struct gpio_chip *chip) 210f141ed65SGrant Likely { 211f141ed65SGrant Likely if ((!chip->of_node) && (chip->dev)) 212f141ed65SGrant Likely chip->of_node = chip->dev->of_node; 213f141ed65SGrant Likely 214f141ed65SGrant Likely if (!chip->of_node) 215f141ed65SGrant Likely return; 216f141ed65SGrant Likely 217f141ed65SGrant Likely if (!chip->of_xlate) { 218f141ed65SGrant Likely chip->of_gpio_n_cells = 2; 219f141ed65SGrant Likely chip->of_xlate = of_gpio_simple_xlate; 220f141ed65SGrant Likely } 221f141ed65SGrant Likely 222f141ed65SGrant Likely of_node_get(chip->of_node); 223f141ed65SGrant Likely } 224f141ed65SGrant Likely 225f141ed65SGrant Likely void of_gpiochip_remove(struct gpio_chip *chip) 226f141ed65SGrant Likely { 227f141ed65SGrant Likely if (chip->of_node) 228f141ed65SGrant Likely of_node_put(chip->of_node); 229f141ed65SGrant Likely } 230f141ed65SGrant Likely 231f141ed65SGrant Likely /* Private function for resolving node pointer to gpio_chip */ 232f141ed65SGrant Likely static int of_gpiochip_is_match(struct gpio_chip *chip, const void *data) 233f141ed65SGrant Likely { 234f141ed65SGrant Likely return chip->of_node == data; 235f141ed65SGrant Likely } 236f141ed65SGrant Likely 237f141ed65SGrant Likely struct gpio_chip *of_node_to_gpiochip(struct device_node *np) 238f141ed65SGrant Likely { 239f141ed65SGrant Likely return gpiochip_find(np, of_gpiochip_is_match); 240f141ed65SGrant Likely } 241