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
@@ -21,6 +21,8 @@
 
 #include <linux/gpio/consumer.h>
 #include <linux/gpio/machine.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
 
 #include "gpiolib.h"
 #include "gpiolib-of.h"
@@ -1129,3 +1131,74 @@ void of_gpiochip_remove(struct gpio_chip
 {
 	of_node_put(dev_of_node(&chip->gpiodev->dev));
 }
+
+#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_named_count(cnp, "gpios");
+
+		for (i = 0; i < max_gpio; i++) {
+			struct gpio_desc *desc;
+			unsigned flags = 0;
+			enum of_gpio_flags of_flags;
+
+			desc = of_get_named_gpiod_flags(cnp, "gpios", i, &of_flags);
+			if (IS_ERR(desc))
+				return PTR_ERR(desc);
+			gpio = desc_to_gpio(desc);
+
+			if (of_flags & OF_GPIO_ACTIVE_LOW)
+				flags |= GPIOF_ACTIVE_LOW;
+
+			if (!of_property_read_u32(cnp, "gpio-export,output", &val))
+				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;
+
+			dmc = of_property_read_bool(cnp, "gpio-export,direction_may_change");
+			gpio_export_with_name(gpio_to_desc(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/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -644,7 +644,10 @@ 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 gpio_export_with_name(struct gpio_desc *desc, bool direction_may_change,
+			  const char *name);
 int gpiod_export_link(struct device *dev, const char *name,
 		      struct gpio_desc *desc);
 void gpiod_unexport(struct gpio_desc *desc);
@@ -653,11 +656,25 @@ void gpiod_unexport(struct gpio_desc *de
 
 #include <asm/errno.h>
 
+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)
 {
 	return -ENOSYS;
 }
+
+static inline int gpio_export_with_name(struct gpio_desc *desc,
+					bool direction_may_change,
+					const char *name)
+{
+	return -ENOSYS;
+}
 
 static inline int gpiod_export_link(struct device *dev, const char *name,
 				    struct gpio_desc *desc)
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -558,7 +558,7 @@ 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;
@@ -620,6 +620,8 @@ 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,
@@ -641,8 +643,21 @@ 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);
 
+int gpio_export_with_name(struct gpio_desc *desc, bool direction_may_change,
+			  const char *name)
+{
+	return __gpiod_export(desc, direction_may_change, name);
+}
+EXPORT_SYMBOL_GPL(gpio_export_with_name);
+
 static int match_export(struct device *dev, const void *desc)
 {
 	struct gpiod_data *data = dev_get_drvdata(dev);