openwrt-mirror/target/linux/generic/hack-6.1/800-GPIO-add-named-gpio-exports.patch

From cc809a441d8f2924f785eb863dfa6aef47a25b0b Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Tue, 12 Aug 2014 20:49:27 +0200
Subject: [PATCH 30/36] GPIO: add named gpio exports

Signed-off-by: John Crispin <blogic@openwrt.org>
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -19,6 +19,8 @@
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/slab.h>
 #include <linux/gpio/machine.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
 
 #include "gpiolib.h"
 #include "gpiolib-of.h"
@@ -1030,3 +1032,100 @@ void of_gpio_dev_init(struct gpio_chip *
 	else
 		gc->of_node = gdev->dev.of_node;
 }
+
+#ifdef CONFIG_GPIO_SYSFS
+
+static struct of_device_id gpio_export_ids[] = {
+	{ .compatible = "gpio-export" },
+	{ /* sentinel */ }
+};
+
+static int of_gpio_export_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *cnp;
+	u32 val;
+	int nb = 0;
+
+	for_each_child_of_node(np, cnp) {
+		const char *name = NULL;
+		int gpio;
+		bool dmc;
+		int max_gpio = 1;
+		int i;
+
+		of_property_read_string(cnp, "gpio-export,name", &name);
+
+		if (!name)
+			max_gpio = of_gpio_count(cnp);
+
+		for (i = 0; i < max_gpio; i++) {
+			struct gpio_desc *desc;
+			unsigned flags = 0;
+			enum of_gpio_flags of_flags;
+
+			gpio = of_get_gpio_flags(cnp, i, &of_flags);
+			if (!gpio_is_valid(gpio))
+				return gpio;
+
+			if (of_flags & OF_GPIO_ACTIVE_LOW)
+				flags |= GPIOF_ACTIVE_LOW;
+
+			if (!of_property_read_u32(cnp, "gpio-export,output", &val)) {
+				if (of_flags & OF_GPIO_SINGLE_ENDED) {
+					/*
+					 * As gpiod_direction_output_raw() is used, we
+					 * need to emulate open drain or open source here.
+					 */
+					if (of_flags & OF_GPIO_OPEN_DRAIN) {
+						flags |= GPIOF_OPEN_DRAIN;
+						flags |= val ? GPIOF_IN : GPIOF_OUT_INIT_LOW;
+					} else {
+						flags |= GPIOF_OPEN_SOURCE;
+						flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_IN;
+					}
+				} else {
+					flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+				}
+			} else {
+				flags |= GPIOF_IN;
+			}
+
+			if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np)))
+				continue;
+
+			/*
+			 * When emulating open-source or open-drain functionalities by not
+			 * actively driving the line (setting mode to input) we still need to
+			 * set the IS_OUT flag or otherwise we won't be able to set the line
+			 * value anymore.
+			 */
+			if ((flags & GPIOF_IN) &&
+			    ((flags & GPIOF_OPEN_DRAIN) || (flags & GPIOF_OPEN_SOURCE))) {
+				desc = gpio_to_desc(gpio);
+				set_bit(FLAG_IS_OUT, &desc->flags);
+			}
+
+			dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
+			gpio_export_with_name(gpio, dmc, name);
+			nb++;
+		}
+	}
+
+	dev_info(&pdev->dev, "%d gpio(s) exported\n", nb);
+
+	return 0;
+}
+
+static struct platform_driver gpio_export_driver = {
+	.driver		= {
+		.name		= "gpio-export",
+		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(gpio_export_ids),
+	},
+	.probe		= of_gpio_export_probe,
+};
+
+module_platform_driver(gpio_export_driver);
+
+#endif
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -125,6 +125,12 @@ static inline int gpio_export(unsigned g
 	return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 }
 
+int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name);
+static inline int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name)
+{
+	return __gpiod_export(gpio_to_desc(gpio), direction_may_change, name);
+}
+
 static inline int gpio_export_link(struct device *dev, const char *name,
 				   unsigned gpio)
 {
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -715,6 +715,7 @@ static inline struct gpio_desc *acpi_get
 
 #if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS)
 
+int _gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name);
 int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
 int gpiod_export_link(struct device *dev, const char *name,
 		      struct gpio_desc *desc);
@@ -722,6 +723,13 @@ void gpiod_unexport(struct gpio_desc *de
 
 #else  /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */
 
+static inline int _gpiod_export(struct gpio_desc *desc,
+			       bool direction_may_change,
+			       const char *name)
+{
+	return -ENOSYS;
+}
+
 static inline int gpiod_export(struct gpio_desc *desc,
 			       bool direction_may_change)
 {
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -544,7 +544,7 @@ static struct class gpio_class = {
  *
  * Returns zero on success, else an error.
  */
-int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name)
 {
 	struct gpio_chip	*chip;
 	struct gpio_device	*gdev;
@@ -606,6 +606,8 @@ int gpiod_export(struct gpio_desc *desc,
 	offset = gpio_chip_hwgpio(desc);
 	if (chip->names && chip->names[offset])
 		ioname = chip->names[offset];
+	if (name)
+		ioname = name;
 
 	dev = device_create_with_groups(&gpio_class, &gdev->dev,
 					MKDEV(0, 0), data, gpio_groups,
@@ -627,6 +629,12 @@ err_unlock:
 	gpiod_dbg(desc, "%s: status %d\n", __func__, status);
 	return status;
 }
+EXPORT_SYMBOL_GPL(__gpiod_export);
+
+int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+{
+	return __gpiod_export(desc, direction_may_change, NULL);
+}
 EXPORT_SYMBOL_GPL(gpiod_export);
 
 static int match_export(struct device *dev, const void *desc)