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kernel/drivers/gpio/gpiolib-of.c

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// 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/io.h>
#include <linux/module.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/string.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include "gpiolib.h"
#include "gpiolib-of.h"
/*
* This is Linux-specific flags. By default controllers' and Linux' mapping
* match, but GPIO controllers are free to translate their own flags to
* Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
*/
enum of_gpio_flags {
OF_GPIO_ACTIVE_LOW = 0x1,
OF_GPIO_SINGLE_ENDED = 0x2,
OF_GPIO_OPEN_DRAIN = 0x4,
OF_GPIO_TRANSITORY = 0x8,
OF_GPIO_PULL_UP = 0x10,
OF_GPIO_PULL_DOWN = 0x20,
OF_GPIO_PULL_DISABLE = 0x40,
};
/**
* of_gpio_named_count() - Count GPIOs for a device
* @np: device node to count GPIOs for
* @propname: property name containing gpio specifier(s)
*
* The function returns the count of GPIOs specified for a node.
* Note that the empty GPIO specifiers count too. Returns either
* Number of gpios defined in property,
* -EINVAL for an incorrectly formed gpios property, or
* -ENOENT for a missing gpios property
*
* Example:
* gpios = <0
* &gpio1 1 2
* 0
* &gpio2 3 4>;
*
* The above example defines four GPIOs, two of which are not specified.
* This function will return '4'
*/
static int of_gpio_named_count(const struct device_node *np,
const char *propname)
{
return of_count_phandle_with_args(np, propname, "#gpio-cells");
}
/**
* 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");
}
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 < gpio_suffix_count; 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 device_match_of_node(&chip->gpiodev->dev, 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);
}
/*
* Overrides stated polarity of a gpio line and warns when there is a
* discrepancy.
*/
static void of_gpio_quirk_polarity(const struct device_node *np,
bool active_high,
enum of_gpio_flags *flags)
{
if (active_high) {
if (*flags & OF_GPIO_ACTIVE_LOW) {
pr_warn("%s GPIO handle specifies active low - ignored\n",
of_node_full_name(np));
*flags &= ~OF_GPIO_ACTIVE_LOW;
}
} else {
if (!(*flags & OF_GPIO_ACTIVE_LOW))
pr_info("%s enforce active low on GPIO handle\n",
of_node_full_name(np));
*flags |= OF_GPIO_ACTIVE_LOW;
}
}
/*
* This quirk does static polarity overrides in cases where existing
* DTS specified incorrect polarity.
*/
static void of_gpio_try_fixup_polarity(const struct device_node *np,
const char *propname,
enum of_gpio_flags *flags)
{
static const struct {
const char *compatible;
const char *propname;
bool active_high;
} gpios[] = {
#if !IS_ENABLED(CONFIG_LCD_HX8357)
/*
* Himax LCD controllers used incorrectly named
* "gpios-reset" property and also specified wrong
* polarity.
*/
{ "himax,hx8357", "gpios-reset", false },
{ "himax,hx8369", "gpios-reset", false },
#endif
};
unsigned int i;
for (i = 0; i < ARRAY_SIZE(gpios); i++) {
if (of_device_is_compatible(np, gpios[i].compatible) &&
!strcmp(propname, gpios[i].propname)) {
of_gpio_quirk_polarity(np, gpios[i].active_high, flags);
break;
}
}
}
static void of_gpio_set_polarity_by_property(const struct device_node *np,
const char *propname,
enum of_gpio_flags *flags)
{
const struct device_node *np_compat = np;
const struct device_node *np_propname = np;
static const struct {
const char *compatible;
const char *gpio_propname;
const char *polarity_propname;
} gpios[] = {
#if IS_ENABLED(CONFIG_FEC)
/* Freescale Fast Ethernet Controller */
{ "fsl,imx25-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx27-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx28-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx6q-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,mvf600-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx6sx-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx6ul-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx8mq-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,imx8qm-fec", "phy-reset-gpios", "phy-reset-active-high" },
{ "fsl,s32v234-fec", "phy-reset-gpios", "phy-reset-active-high" },
#endif
#if IS_ENABLED(CONFIG_PCI_IMX6)
{ "fsl,imx6q-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx6sx-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx6qp-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx7d-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx8mq-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx8mm-pcie", "reset-gpio", "reset-gpio-active-high" },
{ "fsl,imx8mp-pcie", "reset-gpio", "reset-gpio-active-high" },
#endif
/*
* 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 IS_ENABLED(CONFIG_REGULATOR_FIXED_VOLTAGE)
{ "regulator-fixed", "gpios", "enable-active-high" },
{ "regulator-fixed", "gpio", "enable-active-high" },
{ "reg-fixed-voltage", "gpios", "enable-active-high" },
{ "reg-fixed-voltage", "gpio", "enable-active-high" },
#endif
#if IS_ENABLED(CONFIG_REGULATOR_GPIO)
{ "regulator-gpio", "enable-gpio", "enable-active-high" },
{ "regulator-gpio", "enable-gpios", "enable-active-high" },
#endif
#if IS_ENABLED(CONFIG_MMC_ATMELMCI)
{ "atmel,hsmci", "cd-gpios", "cd-inverted" },
#endif
};
unsigned int i;
bool active_high;
#if IS_ENABLED(CONFIG_MMC_ATMELMCI)
/*
* The Atmel HSMCI has compatible property in the parent node and
* gpio property in a child node
*/
if (of_device_is_compatible(np->parent, "atmel,hsmci")) {
np_compat = np->parent;
np_propname = np;
}
#endif
for (i = 0; i < ARRAY_SIZE(gpios); i++) {
if (of_device_is_compatible(np_compat, gpios[i].compatible) &&
!strcmp(propname, gpios[i].gpio_propname)) {
active_high = of_property_read_bool(np_propname,
gpios[i].polarity_propname);
of_gpio_quirk_polarity(np, active_high, flags);
break;
}
}
}
static void of_gpio_flags_quirks(const struct device_node *np,
const char *propname,
enum of_gpio_flags *flags,
int index)
{
of_gpio_try_fixup_polarity(np, propname, flags);
of_gpio_set_polarity_by_property(np, propname, flags);
/*
* 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.
*/
bool active_high = of_property_read_bool(child,
"spi-cs-high");
of_gpio_quirk_polarity(child, active_high,
flags);
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;
}
/**
* of_get_named_gpio() - Get a GPIO number to use with GPIO API
* @np: device node to get GPIO from
* @propname: Name of property containing gpio specifier(s)
* @index: index of the GPIO
*
* Returns GPIO number to use with Linux generic GPIO API, or one of the errno
* value on the error condition.
*/
int of_get_named_gpio(const struct device_node *np, const char *propname,
int index)
{
struct gpio_desc *desc;
desc = of_get_named_gpiod_flags(np, propname, index, NULL);
if (IS_ERR(desc))
return PTR_ERR(desc);
else
return desc_to_gpio(desc);
}
EXPORT_SYMBOL_GPL(of_get_named_gpio);
/* 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;
}
static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
const char *con_id,
unsigned int idx,
enum of_gpio_flags *of_flags)
{
static const struct of_rename_gpio {
const char *con_id;
const char *legacy_id; /* NULL - same as con_id */
/*
* Compatible string can be set to NULL in case where
* matching to a particular compatible is not practical,
* but it should only be done for gpio names that have
* vendor prefix to reduce risk of false positives.
* Addition of such entries is strongly discouraged.
*/
const char *compatible;
} gpios[] = {
#if !IS_ENABLED(CONFIG_LCD_HX8357)
/* Himax LCD controllers used "gpios-reset" */
{ "reset", "gpios-reset", "himax,hx8357" },
{ "reset", "gpios-reset", "himax,hx8369" },
#endif
#if IS_ENABLED(CONFIG_MFD_ARIZONA)
{ "wlf,reset", NULL, NULL },
#endif
#if IS_ENABLED(CONFIG_RTC_DRV_MOXART)
{ "rtc-data", "gpio-rtc-data", "moxa,moxart-rtc" },
{ "rtc-sclk", "gpio-rtc-sclk", "moxa,moxart-rtc" },
{ "rtc-reset", "gpio-rtc-reset", "moxa,moxart-rtc" },
#endif
#if IS_ENABLED(CONFIG_NFC_MRVL_I2C)
{ "reset", "reset-n-io", "marvell,nfc-i2c" },
#endif
#if IS_ENABLED(CONFIG_NFC_MRVL_SPI)
{ "reset", "reset-n-io", "marvell,nfc-spi" },
#endif
#if IS_ENABLED(CONFIG_NFC_MRVL_UART)
{ "reset", "reset-n-io", "marvell,nfc-uart" },
{ "reset", "reset-n-io", "mrvl,nfc-uart" },
#endif
#if !IS_ENABLED(CONFIG_PCI_LANTIQ)
/* MIPS Lantiq PCI */
{ "reset", "gpios-reset", "lantiq,pci-xway" },
#endif
/*
* 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.
*/
#if IS_ENABLED(CONFIG_REGULATOR_ARIZONA_LDO1)
{ "wlf,ldoena", NULL, NULL }, /* Arizona */
#endif
#if IS_ENABLED(CONFIG_REGULATOR_WM8994)
{ "wlf,ldo1ena", NULL, NULL }, /* WM8994 */
{ "wlf,ldo2ena", NULL, NULL }, /* WM8994 */
#endif
#if IS_ENABLED(CONFIG_SND_SOC_CS42L56)
{ "reset", "cirrus,gpio-nreset", "cirrus,cs42l56" },
#endif
#if IS_ENABLED(CONFIG_SND_SOC_TLV320AIC3X)
{ "reset", "gpio-reset", "ti,tlv320aic3x" },
{ "reset", "gpio-reset", "ti,tlv320aic33" },
{ "reset", "gpio-reset", "ti,tlv320aic3007" },
{ "reset", "gpio-reset", "ti,tlv320aic3104" },
{ "reset", "gpio-reset", "ti,tlv320aic3106" },
#endif
#if IS_ENABLED(CONFIG_SPI_GPIO)
/*
* 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.
*/
{ "miso", "gpio-miso", "spi-gpio" },
{ "mosi", "gpio-mosi", "spi-gpio" },
{ "sck", "gpio-sck", "spi-gpio" },
#endif
/*
* The old Freescale bindings use simply "gpios" as name
* for the chip select lines rather than "cs-gpios" like
* all other SPI hardware. Allow this specifically for
* Freescale and PPC devices.
*/
#if IS_ENABLED(CONFIG_SPI_FSL_SPI)
{ "cs", "gpios", "fsl,spi" },
{ "cs", "gpios", "aeroflexgaisler,spictrl" },
#endif
#if IS_ENABLED(CONFIG_SPI_PPC4xx)
{ "cs", "gpios", "ibm,ppc4xx-spi" },
#endif
#if IS_ENABLED(CONFIG_TYPEC_FUSB302)
/*
* Fairchild FUSB302 host is using undocumented "fcs,int_n"
* property without the compulsory "-gpios" suffix.
*/
{ "fcs,int_n", NULL, "fcs,fusb302" },
#endif
};
struct gpio_desc *desc;
const char *legacy_id;
unsigned int i;
if (!con_id)
return ERR_PTR(-ENOENT);
for (i = 0; i < ARRAY_SIZE(gpios); i++) {
if (strcmp(con_id, gpios[i].con_id))
continue;
if (gpios[i].compatible &&
!of_device_is_compatible(np, gpios[i].compatible))
continue;
legacy_id = gpios[i].legacy_id ?: gpios[i].con_id;
desc = of_get_named_gpiod_flags(np, legacy_id, idx, of_flags);
if (!gpiod_not_found(desc)) {
pr_info("%s uses legacy gpio name '%s' instead of '%s-gpios'\n",
of_node_full_name(np), legacy_id, con_id);
return desc;
}
}
return ERR_PTR(-ENOENT);
}
static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np,
const char *con_id,
unsigned int idx,
enum of_gpio_flags *of_flags)
{
struct gpio_desc *desc;
const char *legacy_id;
if (!IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448))
return ERR_PTR(-ENOENT);
if (!of_device_is_compatible(np, "mediatek,mt2701-cs42448-machine"))
return ERR_PTR(-ENOENT);
if (!con_id || strcmp(con_id, "i2s1-in-sel"))
return ERR_PTR(-ENOENT);
if (idx == 0)
legacy_id = "i2s1-in-sel-gpio1";
else if (idx == 1)
legacy_id = "i2s1-in-sel-gpio2";
else
return ERR_PTR(-ENOENT);
desc = of_get_named_gpiod_flags(np, legacy_id, 0, of_flags);
if (!gpiod_not_found(desc))
pr_info("%s is using legacy gpio name '%s' instead of '%s-gpios'\n",
of_node_full_name(np), legacy_id, con_id);
return desc;
}
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_gpio_rename,
of_find_mt2701_gpio,
NULL
};
struct gpio_desc *of_find_gpio(struct device_node *np, 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 < gpio_suffix_count; 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(np, 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)(np, 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 = dev_of_node(&chip->gpiodev->dev);
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(dev_of_node(&chip->gpiodev->dev), 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];
}
#if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP)
#include <linux/gpio/legacy-of-mm-gpiochip.h>
/**
* 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);
fwnode_handle_put(mm_gc->gc.fwnode);
mm_gc->gc.fwnode = fwnode_handle_get(of_fwnode_handle(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;
gpiochip_remove(gc);
iounmap(mm_gc->regs);
kfree(gc->label);
}
EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
#endif
#ifdef CONFIG_PINCTRL
static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
{
struct of_phandle_args pinspec;
struct pinctrl_dev *pctldev;
struct device_node *np;
int index = 0, ret;
const char *name;
static const char group_names_propname[] = "gpio-ranges-group-names";
struct property *group_names;
np = dev_of_node(&chip->gpiodev->dev);
if (!np)
return 0;
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)
{
struct device_node *np;
int ret;
np = dev_of_node(&chip->gpiodev->dev);
if (!np)
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;
ret = of_gpiochip_add_pin_range(chip);
if (ret)
return ret;
fwnode_handle_get(chip->fwnode);
ret = of_gpiochip_scan_gpios(chip);
if (ret)
fwnode_handle_put(chip->fwnode);
return ret;
}
void of_gpiochip_remove(struct gpio_chip *chip)
{
fwnode_handle_put(chip->fwnode);
}
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