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-rw-r--r--drivers/gpio/gpiolib-of.c1032
1 files changed, 1032 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
new file mode 100644
index 000000000..0e4e12916
--- /dev/null
+++ b/drivers/gpio/gpiolib-of.c
@@ -0,0 +1,1032 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * OF helpers for the GPIO API
+ *
+ * Copyright (c) 2007-2008 MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ */
+
+#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"
+#include "gpiolib-of.h"
+
+/**
+ * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
+ * @dev: Consuming device
+ * @con_id: Function within the GPIO consumer
+ *
+ * Some elder GPIO controllers need special quirks. Currently we handle
+ * the Freescale and PPC GPIO controller with bindings that doesn't use the
+ * established "cs-gpios" for chip selects but instead rely on
+ * "gpios" for the chip select lines. If we detect this, we redirect
+ * the counting of "cs-gpios" to count "gpios" transparent to the
+ * driver.
+ */
+static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
+{
+ struct device_node *np = dev->of_node;
+
+ if (!IS_ENABLED(CONFIG_SPI_MASTER))
+ return 0;
+ if (!con_id || strcmp(con_id, "cs"))
+ return 0;
+ if (!of_device_is_compatible(np, "fsl,spi") &&
+ !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
+ !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
+ return 0;
+ return of_gpio_named_count(np, "gpios");
+}
+
+/*
+ * This is used by external users of of_gpio_count() from <linux/of_gpio.h>
+ *
+ * FIXME: get rid of those external users by converting them to GPIO
+ * descriptors and let them all use gpiod_count()
+ */
+int of_gpio_get_count(struct device *dev, const char *con_id)
+{
+ int ret;
+ char propname[32];
+ unsigned int i;
+
+ ret = of_gpio_spi_cs_get_count(dev, con_id);
+ if (ret > 0)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+ if (con_id)
+ snprintf(propname, sizeof(propname), "%s-%s",
+ con_id, gpio_suffixes[i]);
+ else
+ snprintf(propname, sizeof(propname), "%s",
+ gpio_suffixes[i]);
+
+ ret = of_gpio_named_count(dev->of_node, propname);
+ if (ret > 0)
+ break;
+ }
+ return ret ? ret : -ENOENT;
+}
+
+static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
+{
+ struct of_phandle_args *gpiospec = data;
+
+ return chip->gpiodev->dev.of_node == gpiospec->np &&
+ chip->of_xlate &&
+ chip->of_xlate(chip, gpiospec, NULL) >= 0;
+}
+
+static struct gpio_chip *of_find_gpiochip_by_xlate(
+ struct of_phandle_args *gpiospec)
+{
+ return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
+}
+
+static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
+ struct of_phandle_args *gpiospec,
+ enum of_gpio_flags *flags)
+{
+ int ret;
+
+ if (chip->of_gpio_n_cells != gpiospec->args_count)
+ return ERR_PTR(-EINVAL);
+
+ ret = chip->of_xlate(chip, gpiospec, flags);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ return gpiochip_get_desc(chip, ret);
+}
+
+/**
+ * of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs
+ * to set the .valid_mask
+ * @gc: the target gpio_chip
+ *
+ * Return: true if the valid mask needs to be set
+ */
+bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
+{
+ int size;
+ const struct device_node *np = gc->of_node;
+
+ size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
+ if (size > 0 && size % 2 == 0)
+ return true;
+ return false;
+}
+
+static void of_gpio_flags_quirks(const struct device_node *np,
+ const char *propname,
+ enum of_gpio_flags *flags,
+ int index)
+{
+ /*
+ * Some GPIO fixed regulator quirks.
+ * Note that active low is the default.
+ */
+ if (IS_ENABLED(CONFIG_REGULATOR) &&
+ (of_device_is_compatible(np, "regulator-fixed") ||
+ of_device_is_compatible(np, "reg-fixed-voltage") ||
+ (!(strcmp(propname, "enable-gpio") &&
+ strcmp(propname, "enable-gpios")) &&
+ of_device_is_compatible(np, "regulator-gpio")))) {
+ bool active_low = !of_property_read_bool(np,
+ "enable-active-high");
+ /*
+ * The regulator GPIO handles are specified such that the
+ * presence or absence of "enable-active-high" solely controls
+ * the polarity of the GPIO line. Any phandle flags must
+ * be actively ignored.
+ */
+ if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) {
+ pr_warn("%s GPIO handle specifies active low - ignored\n",
+ of_node_full_name(np));
+ *flags &= ~OF_GPIO_ACTIVE_LOW;
+ }
+ if (active_low)
+ *flags |= OF_GPIO_ACTIVE_LOW;
+ }
+ /*
+ * Legacy open drain handling for fixed voltage regulators.
+ */
+ if (IS_ENABLED(CONFIG_REGULATOR) &&
+ of_device_is_compatible(np, "reg-fixed-voltage") &&
+ of_property_read_bool(np, "gpio-open-drain")) {
+ *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
+ pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
+ of_node_full_name(np));
+ }
+
+ /*
+ * Legacy handling of SPI active high chip select. If we have a
+ * property named "cs-gpios" we need to inspect the child node
+ * to determine if the flags should have inverted semantics.
+ */
+ if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
+ of_property_read_bool(np, "cs-gpios")) {
+ struct device_node *child;
+ u32 cs;
+ int ret;
+
+ for_each_child_of_node(np, child) {
+ ret = of_property_read_u32(child, "reg", &cs);
+ if (ret)
+ continue;
+ if (cs == index) {
+ /*
+ * SPI children have active low chip selects
+ * by default. This can be specified negatively
+ * by just omitting "spi-cs-high" in the
+ * device node, or actively by tagging on
+ * GPIO_ACTIVE_LOW as flag in the device
+ * tree. If the line is simultaneously
+ * tagged as active low in the device tree
+ * and has the "spi-cs-high" set, we get a
+ * conflict and the "spi-cs-high" flag will
+ * take precedence.
+ */
+ if (of_property_read_bool(child, "spi-cs-high")) {
+ if (*flags & OF_GPIO_ACTIVE_LOW) {
+ pr_warn("%s GPIO handle specifies active low - ignored\n",
+ of_node_full_name(child));
+ *flags &= ~OF_GPIO_ACTIVE_LOW;
+ }
+ } else {
+ if (!(*flags & OF_GPIO_ACTIVE_LOW))
+ pr_info("%s enforce active low on chipselect handle\n",
+ of_node_full_name(child));
+ *flags |= OF_GPIO_ACTIVE_LOW;
+ }
+ of_node_put(child);
+ break;
+ }
+ }
+ }
+
+ /* Legacy handling of stmmac's active-low PHY reset line */
+ if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
+ !strcmp(propname, "snps,reset-gpio") &&
+ of_property_read_bool(np, "snps,reset-active-low"))
+ *flags |= OF_GPIO_ACTIVE_LOW;
+}
+
+/**
+ * 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.
+ */
+static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np,
+ const char *propname, int index, enum of_gpio_flags *flags)
+{
+ struct of_phandle_args gpiospec;
+ struct gpio_chip *chip;
+ struct gpio_desc *desc;
+ int ret;
+
+ ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
+ &gpiospec);
+ if (ret) {
+ pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
+ __func__, propname, np, index);
+ return ERR_PTR(ret);
+ }
+
+ chip = of_find_gpiochip_by_xlate(&gpiospec);
+ if (!chip) {
+ desc = ERR_PTR(-EPROBE_DEFER);
+ goto out;
+ }
+
+ desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
+ if (IS_ERR(desc))
+ goto out;
+
+ if (flags)
+ of_gpio_flags_quirks(np, propname, flags, index);
+
+ pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
+ __func__, propname, np, index,
+ PTR_ERR_OR_ZERO(desc));
+
+out:
+ of_node_put(gpiospec.np);
+
+ return desc;
+}
+
+int of_get_named_gpio_flags(const 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_GPL(of_get_named_gpio_flags);
+
+/* Converts gpio_lookup_flags into bitmask of GPIO_* values */
+static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags)
+{
+ unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
+
+ if (flags & OF_GPIO_ACTIVE_LOW)
+ lflags |= GPIO_ACTIVE_LOW;
+
+ if (flags & OF_GPIO_SINGLE_ENDED) {
+ if (flags & OF_GPIO_OPEN_DRAIN)
+ lflags |= GPIO_OPEN_DRAIN;
+ else
+ lflags |= GPIO_OPEN_SOURCE;
+ }
+
+ if (flags & OF_GPIO_TRANSITORY)
+ lflags |= GPIO_TRANSITORY;
+
+ if (flags & OF_GPIO_PULL_UP)
+ lflags |= GPIO_PULL_UP;
+
+ if (flags & OF_GPIO_PULL_DOWN)
+ lflags |= GPIO_PULL_DOWN;
+
+ if (flags & OF_GPIO_PULL_DISABLE)
+ lflags |= GPIO_PULL_DISABLE;
+
+ return lflags;
+}
+
+/**
+ * gpiod_get_from_of_node() - obtain a GPIO from an OF node
+ * @node: handle of the OF node
+ * @propname: name of the DT property representing the GPIO
+ * @index: index of the GPIO to obtain for the consumer
+ * @dflags: GPIO initialization flags
+ * @label: label to attach to the requested GPIO
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @dflags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *gpiod_get_from_of_node(const struct device_node *node,
+ const char *propname, int index,
+ enum gpiod_flags dflags,
+ const char *label)
+{
+ unsigned long lflags;
+ struct gpio_desc *desc;
+ enum of_gpio_flags of_flags;
+ int ret;
+
+ desc = of_get_named_gpiod_flags(node, propname, index, &of_flags);
+ if (!desc || IS_ERR(desc))
+ return desc;
+
+ ret = gpiod_request(desc, label);
+ if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
+ return desc;
+ if (ret)
+ return ERR_PTR(ret);
+
+ lflags = of_convert_gpio_flags(of_flags);
+
+ ret = gpiod_configure_flags(desc, propname, lflags, dflags);
+ if (ret < 0) {
+ gpiod_put(desc);
+ return ERR_PTR(ret);
+ }
+
+ return desc;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
+
+/*
+ * The SPI GPIO bindings happened before we managed to establish that GPIO
+ * properties should be named "foo-gpios" so we have this special kludge for
+ * them.
+ */
+static struct gpio_desc *of_find_spi_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ char prop_name[32]; /* 32 is max size of property name */
+
+ /*
+ * Hopefully the compiler stubs the rest of the function if this
+ * is false.
+ */
+ if (!IS_ENABLED(CONFIG_SPI_MASTER))
+ return ERR_PTR(-ENOENT);
+
+ /* Allow this specifically for "spi-gpio" devices */
+ if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
+ return ERR_PTR(-ENOENT);
+
+ /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
+ snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
+
+ return of_get_named_gpiod_flags(np, prop_name, idx, of_flags);
+}
+
+/*
+ * The old Freescale bindings use simply "gpios" as name for the chip select
+ * lines rather than "cs-gpios" like all other SPI hardware. Account for this
+ * with a special quirk.
+ */
+static struct gpio_desc *of_find_spi_cs_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ if (!IS_ENABLED(CONFIG_SPI_MASTER))
+ return ERR_PTR(-ENOENT);
+
+ /* Allow this specifically for Freescale and PPC devices */
+ if (!of_device_is_compatible(np, "fsl,spi") &&
+ !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
+ !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
+ return ERR_PTR(-ENOENT);
+ /* Allow only if asking for "cs-gpios" */
+ if (!con_id || strcmp(con_id, "cs"))
+ return ERR_PTR(-ENOENT);
+
+ /*
+ * While all other SPI controllers use "cs-gpios" the Freescale
+ * uses just "gpios" so translate to that when "cs-gpios" is
+ * requested.
+ */
+ return of_get_named_gpiod_flags(np, "gpios", idx, of_flags);
+}
+
+/*
+ * Some regulator bindings happened before we managed to establish that GPIO
+ * properties should be named "foo-gpios" so we have this special kludge for
+ * them.
+ */
+static struct gpio_desc *of_find_regulator_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ /* These are the connection IDs we accept as legacy GPIO phandles */
+ const char *whitelist[] = {
+ "wlf,ldoena", /* Arizona */
+ "wlf,ldo1ena", /* WM8994 */
+ "wlf,ldo2ena", /* WM8994 */
+ };
+ int i;
+
+ if (!IS_ENABLED(CONFIG_REGULATOR))
+ return ERR_PTR(-ENOENT);
+
+ if (!con_id)
+ return ERR_PTR(-ENOENT);
+
+ i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
+ if (i < 0)
+ return ERR_PTR(-ENOENT);
+
+ return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
+}
+
+static struct gpio_desc *of_find_arizona_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
+ return ERR_PTR(-ENOENT);
+
+ if (!con_id || strcmp(con_id, "wlf,reset"))
+ return ERR_PTR(-ENOENT);
+
+ return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
+}
+
+static struct gpio_desc *of_find_usb_gpio(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags)
+{
+ /*
+ * Currently this USB quirk is only for the Fairchild FUSB302 host
+ * which is using an undocumented DT GPIO line named "fcs,int_n"
+ * without the compulsory "-gpios" suffix.
+ */
+ if (!IS_ENABLED(CONFIG_TYPEC_FUSB302))
+ return ERR_PTR(-ENOENT);
+
+ if (!con_id || strcmp(con_id, "fcs,int_n"))
+ return ERR_PTR(-ENOENT);
+
+ return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
+}
+
+typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
+ const char *con_id,
+ unsigned int idx,
+ enum of_gpio_flags *of_flags);
+static const of_find_gpio_quirk of_find_gpio_quirks[] = {
+ of_find_spi_gpio,
+ of_find_spi_cs_gpio,
+ of_find_regulator_gpio,
+ of_find_arizona_gpio,
+ of_find_usb_gpio,
+ NULL
+};
+
+struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx, unsigned long *flags)
+{
+ char prop_name[32]; /* 32 is max size of property name */
+ enum of_gpio_flags of_flags;
+ const of_find_gpio_quirk *q;
+ struct gpio_desc *desc;
+ unsigned int i;
+
+ /* Try GPIO property "foo-gpios" and "foo-gpio" */
+ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+ if (con_id)
+ snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
+ gpio_suffixes[i]);
+ else
+ snprintf(prop_name, sizeof(prop_name), "%s",
+ gpio_suffixes[i]);
+
+ desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
+ &of_flags);
+
+ if (!gpiod_not_found(desc))
+ break;
+ }
+
+ /* Properly named GPIO was not found, try workarounds */
+ for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++)
+ desc = (*q)(dev->of_node, con_id, idx, &of_flags);
+
+ if (IS_ERR(desc))
+ return desc;
+
+ *flags = of_convert_gpio_flags(of_flags);
+
+ return desc;
+}
+
+/**
+ * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
+ * @np: device node to get GPIO from
+ * @chip: GPIO chip whose hog is parsed
+ * @idx: Index of the GPIO to parse
+ * @name: GPIO line name
+ * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
+ * of_find_gpio() or of_parse_own_gpio()
+ * @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_parse_own_gpio(struct device_node *np,
+ struct gpio_chip *chip,
+ unsigned int idx, const char **name,
+ unsigned long *lflags,
+ enum gpiod_flags *dflags)
+{
+ struct device_node *chip_np;
+ enum of_gpio_flags xlate_flags;
+ struct of_phandle_args gpiospec;
+ struct gpio_desc *desc;
+ unsigned int i;
+ u32 tmp;
+ int ret;
+
+ chip_np = chip->of_node;
+ if (!chip_np)
+ return ERR_PTR(-EINVAL);
+
+ xlate_flags = 0;
+ *lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
+ *dflags = GPIOD_ASIS;
+
+ ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
+ if (ret)
+ return ERR_PTR(ret);
+
+ gpiospec.np = chip_np;
+ gpiospec.args_count = tmp;
+
+ for (i = 0; i < tmp; i++) {
+ ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
+ &gpiospec.args[i]);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
+ if (IS_ERR(desc))
+ return desc;
+
+ *lflags = of_convert_gpio_flags(xlate_flags);
+
+ 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 (%pOFn): no hogging state specified, bailing out\n",
+ desc_to_gpio(desc), np);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (name && of_property_read_string(np, "line-name", name))
+ *name = np->name;
+
+ return desc;
+}
+
+/**
+ * of_gpiochip_add_hog - Add all hogs in a hog device node
+ * @chip: gpio chip to act on
+ * @hog: device node describing the hogs
+ *
+ * Returns error if it fails otherwise 0 on success.
+ */
+static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
+{
+ enum gpiod_flags dflags;
+ struct gpio_desc *desc;
+ unsigned long lflags;
+ const char *name;
+ unsigned int i;
+ int ret;
+
+ for (i = 0;; i++) {
+ desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);
+ if (IS_ERR(desc))
+ break;
+
+ ret = gpiod_hog(desc, name, lflags, dflags);
+ if (ret < 0)
+ return ret;
+
+#ifdef CONFIG_OF_DYNAMIC
+ desc->hog = hog;
+#endif
+ }
+
+ return 0;
+}
+
+/**
+ * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
+ * @chip: gpio chip to act on
+ *
+ * This is only used by of_gpiochip_add to request/set GPIO initial
+ * configuration.
+ * It returns error if it fails otherwise 0 on success.
+ */
+static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
+{
+ struct device_node *np;
+ int ret;
+
+ for_each_available_child_of_node(chip->of_node, np) {
+ if (!of_property_read_bool(np, "gpio-hog"))
+ continue;
+
+ ret = of_gpiochip_add_hog(chip, np);
+ if (ret < 0) {
+ of_node_put(np);
+ return ret;
+ }
+
+ of_node_set_flag(np, OF_POPULATED);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_OF_DYNAMIC
+/**
+ * of_gpiochip_remove_hog - Remove all hogs in a hog device node
+ * @chip: gpio chip to act on
+ * @hog: device node describing the hogs
+ */
+static void of_gpiochip_remove_hog(struct gpio_chip *chip,
+ struct device_node *hog)
+{
+ struct gpio_desc *desc;
+
+ for_each_gpio_desc_with_flag(chip, desc, FLAG_IS_HOGGED)
+ if (desc->hog == hog)
+ gpiochip_free_own_desc(desc);
+}
+
+static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
+{
+ return device_match_of_node(&chip->gpiodev->dev, data);
+}
+
+static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
+{
+ return gpiochip_find(np, of_gpiochip_match_node);
+}
+
+static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
+ void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct gpio_chip *chip;
+ int ret;
+
+ /*
+ * This only supports adding and removing complete gpio-hog nodes.
+ * Modifying an existing gpio-hog node is not supported (except for
+ * changing its "status" property, which is treated the same as
+ * addition/removal).
+ */
+ switch (of_reconfig_get_state_change(action, arg)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ if (!of_property_read_bool(rd->dn, "gpio-hog"))
+ return NOTIFY_OK; /* not for us */
+
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ chip = of_find_gpiochip_by_node(rd->dn->parent);
+ if (chip == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ ret = of_gpiochip_add_hog(chip, rd->dn);
+ if (ret < 0) {
+ pr_err("%s: failed to add hogs for %pOF\n", __func__,
+ rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ return notifier_from_errno(ret);
+ }
+ break;
+
+ case OF_RECONFIG_CHANGE_REMOVE:
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK; /* already depopulated */
+
+ chip = of_find_gpiochip_by_node(rd->dn->parent);
+ if (chip == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ of_gpiochip_remove_hog(chip, rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+struct notifier_block gpio_of_notifier = {
+ .notifier_call = of_gpio_notify,
+};
+#endif /* CONFIG_OF_DYNAMIC */
+
+/**
+ * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
+ * @gc: pointer to the gpio_chip structure
+ * @gpiospec: 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).
+ */
+static 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 retrieve 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];
+}
+
+/**
+ * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
+ * @np: device node of the GPIO chip
+ * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
+ * @data: driver data to store in the struct gpio_chip
+ *
+ * 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_data(struct device_node *np,
+ struct of_mm_gpio_chip *mm_gc,
+ void *data)
+{
+ int ret = -ENOMEM;
+ struct gpio_chip *gc = &mm_gc->gc;
+
+ gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
+ 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);
+
+ of_node_put(mm_gc->gc.of_node);
+ mm_gc->gc.of_node = of_node_get(np);
+
+ ret = gpiochip_add_data(gc, data);
+ if (ret)
+ goto err2;
+
+ return 0;
+err2:
+ of_node_put(np);
+ iounmap(mm_gc->regs);
+err1:
+ kfree(gc->label);
+err0:
+ pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data);
+
+/**
+ * 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_GPL(of_mm_gpiochip_remove);
+
+static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
+{
+ int len, i;
+ u32 start, count;
+ struct device_node *np = chip->of_node;
+
+ len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
+ if (len < 0 || len % 2 != 0)
+ return;
+
+ for (i = 0; i < len; i += 2) {
+ of_property_read_u32_index(np, "gpio-reserved-ranges",
+ i, &start);
+ of_property_read_u32_index(np, "gpio-reserved-ranges",
+ i + 1, &count);
+ if (start >= chip->ngpio || start + count > chip->ngpio)
+ continue;
+
+ bitmap_clear(chip->valid_mask, start, count);
+ }
+};
+
+#ifdef CONFIG_PINCTRL
+static int 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 0;
+
+ if (!of_property_read_bool(np, "gpio-ranges") &&
+ chip->of_gpio_ranges_fallback) {
+ return chip->of_gpio_ranges_fallback(chip, np);
+ }
+
+ 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);
+ of_node_put(pinspec.np);
+ if (!pctldev)
+ return -EPROBE_DEFER;
+
+ if (pinspec.args[2]) {
+ if (group_names) {
+ of_property_read_string_index(np,
+ group_names_propname,
+ index, &name);
+ if (strlen(name)) {
+ pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
+ np);
+ 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)
+ return ret;
+ } else {
+ /* npins == 0: special range */
+ if (pinspec.args[1]) {
+ pr_err("%pOF: Illegal gpio-range format.\n",
+ np);
+ break;
+ }
+
+ if (!group_names) {
+ pr_err("%pOF: GPIO group range requested but no %s property.\n",
+ np, group_names_propname);
+ break;
+ }
+
+ ret = of_property_read_string_index(np,
+ group_names_propname,
+ index, &name);
+ if (ret)
+ break;
+
+ if (!strlen(name)) {
+ pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
+ np);
+ break;
+ }
+
+ ret = gpiochip_add_pingroup_range(chip, pctldev,
+ pinspec.args[0], name);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+#else
+static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
+#endif
+
+int of_gpiochip_add(struct gpio_chip *chip)
+{
+ int ret;
+
+ if (!chip->of_node)
+ return 0;
+
+ if (!chip->of_xlate) {
+ chip->of_gpio_n_cells = 2;
+ chip->of_xlate = of_gpio_simple_xlate;
+ }
+
+ if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
+ return -EINVAL;
+
+ of_gpiochip_init_valid_mask(chip);
+
+ ret = of_gpiochip_add_pin_range(chip);
+ if (ret)
+ return ret;
+
+ of_node_get(chip->of_node);
+
+ ret = of_gpiochip_scan_gpios(chip);
+ if (ret)
+ of_node_put(chip->of_node);
+
+ return ret;
+}
+
+void of_gpiochip_remove(struct gpio_chip *chip)
+{
+ of_node_put(chip->of_node);
+}
+
+void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
+{
+ /* Set default OF node to parent's one if present */
+ if (gc->parent)
+ gdev->dev.of_node = gc->parent->of_node;
+
+ if (gc->fwnode)
+ gc->of_node = to_of_node(gc->fwnode);
+
+ /* If the gpiochip has an assigned OF node this takes precedence */
+ if (gc->of_node)
+ gdev->dev.of_node = gc->of_node;
+ else
+ gc->of_node = gdev->dev.of_node;
+}