diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/gpio/gpiolib-of.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/gpio/gpiolib-of.c')
-rw-r--r-- | kernel/drivers/gpio/gpiolib-of.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpiolib-of.c b/kernel/drivers/gpio/gpiolib-of.c new file mode 100644 index 000000000..a6c67c6b4 --- /dev/null +++ b/kernel/drivers/gpio/gpiolib-of.c @@ -0,0 +1,446 @@ +/* + * 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/err.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/gpio/consumer.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_gpio.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/slab.h> +#include <linux/gpio/machine.h> + +#include "gpiolib.h" + +/* Private data structure for of_gpiochip_find_and_xlate */ +struct gg_data { + enum of_gpio_flags *flags; + struct of_phandle_args gpiospec; + + struct gpio_desc *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) { + /* We've found a gpio chip, but the translation failed. + * Store translation error in out_gpio. + * Return false to keep looking, as more than one gpio chip + * could be registered per of-node. + */ + gg_data->out_gpio = ERR_PTR(ret); + return false; + } + + gg_data->out_gpio = gpiochip_get_desc(gc, ret); + return true; +} + +/** + * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for 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 descriptor to use with Linux 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. + */ +struct gpio_desc *of_get_named_gpiod_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 = ERR_PTR(-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 '%s' property of node '%s[%d]'\n", + __func__, propname, np->full_name, index); + return ERR_PTR(ret); + } + + gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); + + of_node_put(gg_data.gpiospec.np); + pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n", + __func__, propname, np->full_name, index, + PTR_ERR_OR_ZERO(gg_data.out_gpio)); + return gg_data.out_gpio; +} + +int of_get_named_gpio_flags(struct device_node *np, const char *list_name, + int index, enum of_gpio_flags *flags) +{ + struct gpio_desc *desc; + + desc = of_get_named_gpiod_flags(np, list_name, index, flags); + + if (IS_ERR(desc)) + return PTR_ERR(desc); + else + return desc_to_gpio(desc); +} +EXPORT_SYMBOL(of_get_named_gpio_flags); + +/** + * of_get_gpio_hog() - Get a GPIO hog descriptor, names and flags for GPIO API + * @np: device node to get GPIO from + * @name: GPIO line name + * @lflags: gpio_lookup_flags - returned from of_find_gpio() or + * of_get_gpio_hog() + * @dflags: gpiod_flags - optional GPIO initialization flags + * + * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno + * value on the error condition. + */ +static struct gpio_desc *of_get_gpio_hog(struct device_node *np, + const char **name, + enum gpio_lookup_flags *lflags, + enum gpiod_flags *dflags) +{ + struct device_node *chip_np; + enum of_gpio_flags xlate_flags; + struct gpio_desc *desc; + struct gg_data gg_data = { + .flags = &xlate_flags, + }; + u32 tmp; + int i, ret; + + chip_np = np->parent; + if (!chip_np) + return ERR_PTR(-EINVAL); + + xlate_flags = 0; + *lflags = 0; + *dflags = 0; + + ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); + if (ret) + return ERR_PTR(ret); + + if (tmp > MAX_PHANDLE_ARGS) + return ERR_PTR(-EINVAL); + + gg_data.gpiospec.args_count = tmp; + gg_data.gpiospec.np = chip_np; + for (i = 0; i < tmp; i++) { + ret = of_property_read_u32_index(np, "gpios", i, + &gg_data.gpiospec.args[i]); + if (ret) + return ERR_PTR(ret); + } + + gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); + if (!gg_data.out_gpio) { + if (np->parent == np) + return ERR_PTR(-ENXIO); + else + return ERR_PTR(-EINVAL); + } + + if (xlate_flags & OF_GPIO_ACTIVE_LOW) + *lflags |= GPIO_ACTIVE_LOW; + + if (of_property_read_bool(np, "input")) + *dflags |= GPIOD_IN; + else if (of_property_read_bool(np, "output-low")) + *dflags |= GPIOD_OUT_LOW; + else if (of_property_read_bool(np, "output-high")) + *dflags |= GPIOD_OUT_HIGH; + else { + pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n", + desc_to_gpio(gg_data.out_gpio), np->name); + return ERR_PTR(-EINVAL); + } + + if (name && of_property_read_string(np, "line-name", name)) + *name = np->name; + + desc = gg_data.out_gpio; + + return desc; +} + +/** + * of_gpiochip_scan_hogs - Scan gpio-controller and apply GPIO hog as requested + * @chip: gpio chip to act on + * + * This is only used by of_gpiochip_add to request/set GPIO initial + * configuration. + */ +static void of_gpiochip_scan_hogs(struct gpio_chip *chip) +{ + struct gpio_desc *desc = NULL; + struct device_node *np; + const char *name; + enum gpio_lookup_flags lflags; + enum gpiod_flags dflags; + + for_each_child_of_node(chip->of_node, np) { + if (!of_property_read_bool(np, "gpio-hog")) + continue; + + desc = of_get_gpio_hog(np, &name, &lflags, &dflags); + if (IS_ERR(desc)) + continue; + + if (gpiod_hog(desc, name, lflags, dflags)) + continue; + } +} + +/** + * 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); + +/** + * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) + * @mm_gc: pointer to the of_mm_gpio_chip allocated structure + */ +void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) +{ + struct gpio_chip *gc = &mm_gc->gc; + + if (!mm_gc) + return; + + gpiochip_remove(gc); + iounmap(mm_gc->regs); + kfree(gc->label); +} +EXPORT_SYMBOL(of_mm_gpiochip_remove); + +#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; + const char *name; + static const char group_names_propname[] = "gpio-ranges-group-names"; + struct property *group_names; + + if (!np) + return; + + group_names = of_find_property(np, group_names_propname, NULL); + + 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; + + if (pinspec.args[2]) { + if (group_names) { + ret = of_property_read_string_index(np, + group_names_propname, + index, &name); + if (strlen(name)) { + pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", + np->full_name); + break; + } + } + /* npins != 0: linear range */ + ret = gpiochip_add_pin_range(chip, + pinctrl_dev_get_devname(pctldev), + pinspec.args[0], + pinspec.args[1], + pinspec.args[2]); + if (ret) + break; + } else { + /* npins == 0: special range */ + if (pinspec.args[1]) { + pr_err("%s: Illegal gpio-range format.\n", + np->full_name); + break; + } + + if (!group_names) { + pr_err("%s: GPIO group range requested but no %s property.\n", + np->full_name, group_names_propname); + break; + } + + ret = of_property_read_string_index(np, + group_names_propname, + index, &name); + if (ret) + break; + + if (!strlen(name)) { + pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", + np->full_name); + break; + } + + ret = gpiochip_add_pingroup_range(chip, pctldev, + pinspec.args[0], name); + 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); + + of_gpiochip_scan_hogs(chip); +} + +void of_gpiochip_remove(struct gpio_chip *chip) +{ + gpiochip_remove_pin_ranges(chip); + of_node_put(chip->of_node); +} |