From 13949fa9daa91a60c7cfef40755f7611cc2cf653 Mon Sep 17 00:00:00 2001
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Thu, 12 Sep 2019 20:22:39 -0700
Subject: gpiolib: introduce fwnode_gpiod_get_index()
Git-commit: 13949fa9daa91a60c7cfef40755f7611cc2cf653
Patch-mainline: v5.5-rc1
References: bsc#1152489

This introduces fwnode_gpiod_get_index() that iterates through common gpio
suffixes when trying to locate a GPIO within a given firmware node.

We also switch devm_fwnode_gpiod_get_index() to call
fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
its own.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20190913032240.50333-3-dmitry.torokhov@gmail.com
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpio/gpiolib.c        |   48 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/gpio/consumer.h |   13 +++++++++++
 2 files changed, 61 insertions(+)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4350,6 +4350,54 @@ static int platform_gpio_count(struct de
 }
 
 /**
+ * fwnode_gpiod_get_index - obtain a GPIO from firmware node
+ * @fwnode:	handle of the firmware node
+ * @con_id:	function within the GPIO consumer
+ * @index:	index of the GPIO to obtain for the consumer
+ * @flags:	GPIO initialization flags
+ * @label:	label to attach to the requested GPIO
+ *
+ * This function can be used for drivers that get their configuration
+ * from opaque firmware.
+ *
+ * The function properly finds the corresponding GPIO using whatever is the
+ * underlying firmware interface and then makes sure that the GPIO
+ * descriptor is requested before it is returned to the caller.
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @flags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label)
+{
+	struct gpio_desc *desc;
+	char prop_name[32]; /* 32 is max size of property name */
+	unsigned int i;
+
+	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 = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
+					      label);
+		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+			break;
+	}
+
+	return desc;
+}
+EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
+
+/**
  * gpiod_count - return the number of GPIOs associated with a device / function
  *		or -ENOENT if no GPIO has been assigned to the requested function
  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -176,6 +176,10 @@ struct gpio_desc *fwnode_get_named_gpiod
 					 const char *propname, int index,
 					 enum gpiod_flags dflags,
 					 const char *label);
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label);
 struct gpio_desc *devm_fwnode_get_index_gpiod_from_child(struct device *dev,
 						const char *con_id, int index,
 						struct fwnode_handle *child,
@@ -529,6 +533,15 @@ struct gpio_desc *fwnode_get_named_gpiod
 					 const char *label)
 {
 	return ERR_PTR(-ENOSYS);
+}
+
+static inline
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+					 const char *con_id, int index,
+					 enum gpiod_flags flags,
+					 const char *label)
+{
+	return ERR_PTR(-ENOSYS);
 }
 
 static inline