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![Saravana Kannan](/assets/img/avatar_default.png)
There are multiple instances of GPIO device tree nodes of the form:
foo {
compatible = "acme,foo";
...
gpio0: gpio0@xxxxxxxx {
compatible = "acme,bar";
...
gpio-controller;
};
gpio1: gpio1@xxxxxxxx {
compatible = "acme,bar";
...
gpio-controller;
};
...
}
bazz {
my-gpios = <&gpio0 ...>;
}
Case 1: The driver for "foo" populates struct device for these gpio*
nodes and then probes them using a driver that binds with "acme,bar".
This driver for "acme,bar" then registers the gpio* nodes with gpiolib.
This lines up with how DT nodes with the "compatible" property are
typically converted to struct devices and then registered with driver
core to probe them. This also allows the gpio* devices to hook into all
the driver core capabilities like runtime PM, probe deferral,
suspend/resume ordering, device links, etc.
Case 2: The driver for "foo" doesn't populate struct devices for these
gpio* nodes before registering them with gpiolib. Instead it just loops
through its child nodes and directly registers the gpio* nodes with
gpiolib.
Drivers that follow case 2 cause problems with fw_devlink=on. This is
because fw_devlink will prevent bazz from probing until there's a struct
device that has gpio0 as its fwnode (because bazz lists gpio0 as a GPIO
supplier). Once the struct device is available, fw_devlink will create a
device link with gpio0 device as the supplier and bazz device as the
consumer. After this point, since the gpio0 device will never bind to a
driver, the device link will prevent bazz device from ever probing.
Finding and refactoring all the instances of drivers that follow case 2
will cause a lot of code churn and it is not something that can be done
in one shot. In some instances it might not even be possible to refactor
them cleanly. Examples of such instances are [1] [2].
This patch works around this problem and avoids all the code churn by
simply setting the fwnode of the gpio_device and creating a stub driver
to bind to the gpio_device. This allows all the consumers to continue
probing when the driver follows case 2.
[1] - https://lore.kernel.org/lkml/20201014191235.7f71fcb4@xhacker.debian/
[2] - https://lore.kernel.org/lkml/e28e1f38d87c12a3c714a6573beba6e1@kernel.org/
Fixes: e590474768
("driver core: Set fw_devlink=on by default")
Cc: Marc Zyngier <maz@kernel.org>
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210122193600.1415639-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1052 lines
26 KiB
C
1052 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* OF helpers for the GPIO API
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*
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* Copyright (c) 2007-2008 MontaVista Software, Inc.
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*
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* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
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*/
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <linux/gpio/consumer.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_gpio.h>
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#include <linux/pinctrl/pinctrl.h>
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#include <linux/slab.h>
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#include <linux/gpio/machine.h>
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#include "gpiolib.h"
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#include "gpiolib-of.h"
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/**
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* of_gpio_spi_cs_get_count() - special GPIO counting for SPI
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* @dev: Consuming device
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* @con_id: Function within the GPIO consumer
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*
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* Some elder GPIO controllers need special quirks. Currently we handle
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* the Freescale and PPC GPIO controller with bindings that doesn't use the
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* established "cs-gpios" for chip selects but instead rely on
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* "gpios" for the chip select lines. If we detect this, we redirect
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* the counting of "cs-gpios" to count "gpios" transparent to the
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* driver.
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*/
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static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
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{
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struct device_node *np = dev->of_node;
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if (!IS_ENABLED(CONFIG_SPI_MASTER))
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return 0;
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if (!con_id || strcmp(con_id, "cs"))
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return 0;
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if (!of_device_is_compatible(np, "fsl,spi") &&
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!of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
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!of_device_is_compatible(np, "ibm,ppc4xx-spi"))
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return 0;
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return of_gpio_named_count(np, "gpios");
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}
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/*
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* This is used by external users of of_gpio_count() from <linux/of_gpio.h>
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*
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* FIXME: get rid of those external users by converting them to GPIO
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* descriptors and let them all use gpiod_count()
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*/
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int of_gpio_get_count(struct device *dev, const char *con_id)
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{
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int ret;
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char propname[32];
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unsigned int i;
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ret = of_gpio_spi_cs_get_count(dev, con_id);
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if (ret > 0)
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return ret;
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for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
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if (con_id)
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snprintf(propname, sizeof(propname), "%s-%s",
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con_id, gpio_suffixes[i]);
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else
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snprintf(propname, sizeof(propname), "%s",
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gpio_suffixes[i]);
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ret = of_gpio_named_count(dev->of_node, propname);
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if (ret > 0)
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break;
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}
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return ret ? ret : -ENOENT;
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}
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static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
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{
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struct of_phandle_args *gpiospec = data;
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return chip->gpiodev->dev.of_node == gpiospec->np &&
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chip->of_xlate &&
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chip->of_xlate(chip, gpiospec, NULL) >= 0;
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}
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static struct gpio_chip *of_find_gpiochip_by_xlate(
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struct of_phandle_args *gpiospec)
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{
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return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
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}
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static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
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struct of_phandle_args *gpiospec,
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enum of_gpio_flags *flags)
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{
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int ret;
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if (chip->of_gpio_n_cells != gpiospec->args_count)
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return ERR_PTR(-EINVAL);
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ret = chip->of_xlate(chip, gpiospec, flags);
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if (ret < 0)
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return ERR_PTR(ret);
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return gpiochip_get_desc(chip, ret);
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}
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/**
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* of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs
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* to set the .valid_mask
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* @gc: the target gpio_chip
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*
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* Return: true if the valid mask needs to be set
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*/
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bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
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{
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int size;
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struct device_node *np = gc->of_node;
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size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
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if (size > 0 && size % 2 == 0)
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return true;
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return false;
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}
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static void of_gpio_flags_quirks(struct device_node *np,
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const char *propname,
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enum of_gpio_flags *flags,
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int index)
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{
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/*
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* Some GPIO fixed regulator quirks.
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* Note that active low is the default.
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*/
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if (IS_ENABLED(CONFIG_REGULATOR) &&
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(of_device_is_compatible(np, "regulator-fixed") ||
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of_device_is_compatible(np, "reg-fixed-voltage") ||
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(!(strcmp(propname, "enable-gpio") &&
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strcmp(propname, "enable-gpios")) &&
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of_device_is_compatible(np, "regulator-gpio")))) {
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bool active_low = !of_property_read_bool(np,
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"enable-active-high");
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/*
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* The regulator GPIO handles are specified such that the
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* presence or absence of "enable-active-high" solely controls
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* the polarity of the GPIO line. Any phandle flags must
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* be actively ignored.
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*/
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if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) {
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pr_warn("%s GPIO handle specifies active low - ignored\n",
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of_node_full_name(np));
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*flags &= ~OF_GPIO_ACTIVE_LOW;
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}
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if (active_low)
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*flags |= OF_GPIO_ACTIVE_LOW;
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}
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/*
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* Legacy open drain handling for fixed voltage regulators.
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*/
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if (IS_ENABLED(CONFIG_REGULATOR) &&
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of_device_is_compatible(np, "reg-fixed-voltage") &&
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of_property_read_bool(np, "gpio-open-drain")) {
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*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
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pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
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of_node_full_name(np));
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}
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/*
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* Legacy handling of SPI active high chip select. If we have a
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* property named "cs-gpios" we need to inspect the child node
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* to determine if the flags should have inverted semantics.
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*/
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if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
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of_property_read_bool(np, "cs-gpios")) {
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struct device_node *child;
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u32 cs;
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int ret;
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for_each_child_of_node(np, child) {
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ret = of_property_read_u32(child, "reg", &cs);
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if (ret)
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continue;
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if (cs == index) {
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/*
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* SPI children have active low chip selects
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* by default. This can be specified negatively
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* by just omitting "spi-cs-high" in the
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* device node, or actively by tagging on
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* GPIO_ACTIVE_LOW as flag in the device
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* tree. If the line is simultaneously
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* tagged as active low in the device tree
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* and has the "spi-cs-high" set, we get a
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* conflict and the "spi-cs-high" flag will
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* take precedence.
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*/
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if (of_property_read_bool(child, "spi-cs-high")) {
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if (*flags & OF_GPIO_ACTIVE_LOW) {
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pr_warn("%s GPIO handle specifies active low - ignored\n",
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of_node_full_name(child));
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*flags &= ~OF_GPIO_ACTIVE_LOW;
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}
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} else {
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if (!(*flags & OF_GPIO_ACTIVE_LOW))
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pr_info("%s enforce active low on chipselect handle\n",
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of_node_full_name(child));
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*flags |= OF_GPIO_ACTIVE_LOW;
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}
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of_node_put(child);
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break;
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}
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}
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}
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/* Legacy handling of stmmac's active-low PHY reset line */
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if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
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!strcmp(propname, "snps,reset-gpio") &&
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of_property_read_bool(np, "snps,reset-active-low"))
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*flags |= OF_GPIO_ACTIVE_LOW;
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}
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/**
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* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
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* @np: device node to get GPIO from
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* @propname: property name containing gpio specifier(s)
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* @index: index of the GPIO
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* @flags: a flags pointer to fill in
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*
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* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
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* value on the error condition. If @flags is not NULL the function also fills
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* in flags for the GPIO.
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*/
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static struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
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const char *propname, int index, enum of_gpio_flags *flags)
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{
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struct of_phandle_args gpiospec;
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struct gpio_chip *chip;
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struct gpio_desc *desc;
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int ret;
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ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
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&gpiospec);
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if (ret) {
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pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
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__func__, propname, np, index);
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return ERR_PTR(ret);
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}
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chip = of_find_gpiochip_by_xlate(&gpiospec);
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if (!chip) {
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desc = ERR_PTR(-EPROBE_DEFER);
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goto out;
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}
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desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
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if (IS_ERR(desc))
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goto out;
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if (flags)
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of_gpio_flags_quirks(np, propname, flags, index);
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pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
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__func__, propname, np, index,
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PTR_ERR_OR_ZERO(desc));
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out:
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of_node_put(gpiospec.np);
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return desc;
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}
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int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
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int index, enum of_gpio_flags *flags)
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{
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struct gpio_desc *desc;
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desc = of_get_named_gpiod_flags(np, list_name, index, flags);
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if (IS_ERR(desc))
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return PTR_ERR(desc);
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else
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return desc_to_gpio(desc);
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}
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EXPORT_SYMBOL_GPL(of_get_named_gpio_flags);
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/**
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* gpiod_get_from_of_node() - obtain a GPIO from an OF node
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* @node: handle of the OF node
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* @propname: name of the DT property representing the GPIO
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* @index: index of the GPIO to obtain for the consumer
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* @dflags: GPIO initialization flags
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* @label: label to attach to the requested GPIO
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*
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* Returns:
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* On successful request the GPIO pin is configured in accordance with
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* provided @dflags.
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*
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* In case of error an ERR_PTR() is returned.
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*/
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struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
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const char *propname, int index,
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enum gpiod_flags dflags,
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const char *label)
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{
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unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
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struct gpio_desc *desc;
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enum of_gpio_flags flags;
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bool active_low = false;
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bool single_ended = false;
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bool open_drain = false;
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bool transitory = false;
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int ret;
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desc = of_get_named_gpiod_flags(node, propname,
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index, &flags);
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if (!desc || IS_ERR(desc)) {
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return desc;
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}
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active_low = flags & OF_GPIO_ACTIVE_LOW;
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single_ended = flags & OF_GPIO_SINGLE_ENDED;
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open_drain = flags & OF_GPIO_OPEN_DRAIN;
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transitory = flags & OF_GPIO_TRANSITORY;
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ret = gpiod_request(desc, label);
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if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
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return desc;
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if (ret)
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return ERR_PTR(ret);
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if (active_low)
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lflags |= GPIO_ACTIVE_LOW;
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if (single_ended) {
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if (open_drain)
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lflags |= GPIO_OPEN_DRAIN;
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else
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lflags |= GPIO_OPEN_SOURCE;
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}
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if (transitory)
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lflags |= GPIO_TRANSITORY;
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if (flags & OF_GPIO_PULL_UP)
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lflags |= GPIO_PULL_UP;
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if (flags & OF_GPIO_PULL_DOWN)
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lflags |= GPIO_PULL_DOWN;
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ret = gpiod_configure_flags(desc, propname, lflags, dflags);
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if (ret < 0) {
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gpiod_put(desc);
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return ERR_PTR(ret);
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}
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return desc;
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}
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EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
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/*
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* The SPI GPIO bindings happened before we managed to establish that GPIO
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* properties should be named "foo-gpios" so we have this special kludge for
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* them.
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*/
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static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
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enum of_gpio_flags *of_flags)
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{
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char prop_name[32]; /* 32 is max size of property name */
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struct device_node *np = dev->of_node;
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struct gpio_desc *desc;
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/*
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* Hopefully the compiler stubs the rest of the function if this
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* is false.
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*/
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if (!IS_ENABLED(CONFIG_SPI_MASTER))
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return ERR_PTR(-ENOENT);
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|
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/* Allow this specifically for "spi-gpio" devices */
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if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
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return ERR_PTR(-ENOENT);
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/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
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snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
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desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
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return desc;
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}
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/*
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* The old Freescale bindings use simply "gpios" as name for the chip select
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* lines rather than "cs-gpios" like all other SPI hardware. Account for this
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* with a special quirk.
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*/
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static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
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const char *con_id,
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unsigned int idx,
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unsigned long *flags)
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{
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struct device_node *np = dev->of_node;
|
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|
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if (!IS_ENABLED(CONFIG_SPI_MASTER))
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return ERR_PTR(-ENOENT);
|
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|
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/* Allow this specifically for Freescale and PPC devices */
|
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if (!of_device_is_compatible(np, "fsl,spi") &&
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!of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
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!of_device_is_compatible(np, "ibm,ppc4xx-spi"))
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return ERR_PTR(-ENOENT);
|
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/* Allow only if asking for "cs-gpios" */
|
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if (!con_id || strcmp(con_id, "cs"))
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return ERR_PTR(-ENOENT);
|
|
|
|
/*
|
|
* While all other SPI controllers use "cs-gpios" the Freescale
|
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* uses just "gpios" so translate to that when "cs-gpios" is
|
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* requested.
|
|
*/
|
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return of_find_gpio(dev, NULL, idx, flags);
|
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}
|
|
|
|
/*
|
|
* 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 *dev, const char *con_id,
|
|
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 */
|
|
};
|
|
struct device_node *np = dev->of_node;
|
|
struct gpio_desc *desc;
|
|
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);
|
|
|
|
desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
|
|
return desc;
|
|
}
|
|
|
|
static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
|
|
const char *con_id,
|
|
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(dev->of_node, con_id, 0, of_flags);
|
|
}
|
|
|
|
static struct gpio_desc *of_find_usb_gpio(struct device *dev,
|
|
const char *con_id,
|
|
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(dev->of_node, con_id, 0, of_flags);
|
|
}
|
|
|
|
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;
|
|
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;
|
|
}
|
|
|
|
if (gpiod_not_found(desc)) {
|
|
/* Special handling for SPI GPIOs if used */
|
|
desc = of_find_spi_gpio(dev, con_id, &of_flags);
|
|
}
|
|
|
|
if (gpiod_not_found(desc)) {
|
|
/* This quirk looks up flags and all */
|
|
desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
|
|
if (!IS_ERR(desc))
|
|
return desc;
|
|
}
|
|
|
|
if (gpiod_not_found(desc)) {
|
|
/* Special handling for regulator GPIOs if used */
|
|
desc = of_find_regulator_gpio(dev, con_id, &of_flags);
|
|
}
|
|
|
|
if (gpiod_not_found(desc))
|
|
desc = of_find_arizona_gpio(dev, con_id, &of_flags);
|
|
|
|
if (gpiod_not_found(desc))
|
|
desc = of_find_usb_gpio(dev, con_id, &of_flags);
|
|
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
if (of_flags & OF_GPIO_ACTIVE_LOW)
|
|
*flags |= GPIO_ACTIVE_LOW;
|
|
|
|
if (of_flags & OF_GPIO_SINGLE_ENDED) {
|
|
if (of_flags & OF_GPIO_OPEN_DRAIN)
|
|
*flags |= GPIO_OPEN_DRAIN;
|
|
else
|
|
*flags |= GPIO_OPEN_SOURCE;
|
|
}
|
|
|
|
if (of_flags & OF_GPIO_TRANSITORY)
|
|
*flags |= GPIO_TRANSITORY;
|
|
|
|
if (of_flags & OF_GPIO_PULL_UP)
|
|
*flags |= GPIO_PULL_UP;
|
|
if (of_flags & OF_GPIO_PULL_DOWN)
|
|
*flags |= GPIO_PULL_DOWN;
|
|
|
|
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;
|
|
|
|
if (xlate_flags & OF_GPIO_ACTIVE_LOW)
|
|
*lflags |= GPIO_ACTIVE_LOW;
|
|
if (xlate_flags & OF_GPIO_TRANSITORY)
|
|
*lflags |= GPIO_TRANSITORY;
|
|
if (xlate_flags & OF_GPIO_PULL_UP)
|
|
*lflags |= GPIO_PULL_UP;
|
|
if (xlate_flags & OF_GPIO_PULL_DOWN)
|
|
*lflags |= GPIO_PULL_DOWN;
|
|
|
|
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 *descs = chip->gpiodev->descs;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < chip->ngpio; i++) {
|
|
if (test_bit(FLAG_IS_HOGGED, &descs[i].flags) &&
|
|
descs[i].hog == hog)
|
|
gpiochip_free_own_desc(&descs[i]);
|
|
}
|
|
}
|
|
|
|
static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
|
|
{
|
|
return chip->gpiodev->dev.of_node == 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);
|
|
|
|
mm_gc->gc.of_node = np;
|
|
|
|
ret = gpiochip_add_data(gc, data);
|
|
if (ret)
|
|
goto err2;
|
|
|
|
return 0;
|
|
err2:
|
|
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;
|
|
|
|
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)
|
|
{
|
|
/* 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;
|
|
if (gdev->dev.of_node)
|
|
gdev->dev.fwnode = of_fwnode_handle(gdev->dev.of_node);
|
|
}
|