gpio: Rework of_gpiochip_set_names() to use device property accessors

In order to use "gpio-line-names" property in systems not having DT as
their boot firmware, rework of_gpiochip_set_names() to use device property
accessors. This reworked function is placed in a separate file making it
clear it deals with universal device properties.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 145847a..bd51ad8 100644 (file)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO)    += -DDEBUG
 obj-$(CONFIG_GPIO_DEVRES)      += devres.o
 obj-$(CONFIG_GPIOLIB)          += gpiolib.o
 obj-$(CONFIG_GPIOLIB)          += gpiolib-legacy.o
+obj-$(CONFIG_GPIOLIB)          += gpiolib-devprop.o
 obj-$(CONFIG_OF_GPIO)          += gpiolib-of.o
 obj-$(CONFIG_GPIO_SYSFS)       += gpiolib-sysfs.o
 obj-$(CONFIG_GPIO_ACPI)                += gpiolib-acpi.o

diff --git a/drivers/gpio/gpiolib-devprop.c b/drivers/gpio/gpiolib-devprop.c
new file mode 100644 (file)
index 0000000..17bfc41
--- /dev/null
+++ b/drivers/gpio/gpiolib-devprop.c
@@ -0,0 +1,62 @@
+/*
+ * Device property helpers for GPIO chips.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+
+#include "gpiolib.h"
+
+/**
+ * devprop_gpiochip_set_names - Set GPIO line names using device properties
+ * @chip: GPIO chip whose lines should be named, if possible
+ *
+ * Looks for device property "gpio-line-names" and if it exists assigns
+ * GPIO line names for the chip. The memory allocated for the assigned
+ * names belong to the underlying firmware node and should not be released
+ * by the caller.
+ */
+void devprop_gpiochip_set_names(struct gpio_chip *chip)
+{
+       struct gpio_device *gdev = chip->gpiodev;
+       const char **names;
+       int ret, i;
+
+       ret = device_property_read_string_array(chip->parent, "gpio-line-names",
+                                               NULL, 0);
+       if (ret < 0)
+               return;
+
+       if (ret != gdev->ngpio) {
+               dev_warn(chip->parent,
+                        "names %d do not match number of GPIOs %d\n", ret,
+                        gdev->ngpio);
+               return;
+       }
+
+       names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
+       if (!names)
+               return;
+
+       ret = device_property_read_string_array(chip->parent, "gpio-line-names",
+                                               names, gdev->ngpio);
+       if (ret < 0) {
+               dev_warn(chip->parent, "failed to read GPIO line names\n");
+               kfree(names);
+               return;
+       }
+
+       for (i = 0; i < gdev->ngpio; i++)
+               gdev->descs[i].name = names[i];
+
+       kfree(names);
+}

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index ecad3f0..3fa4e84 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -222,51 +222,6 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
 }
 
 /**
- * of_gpiochip_set_names() - set up the names of the lines
- * @chip: GPIO chip whose lines should be named, if possible
- */
-static void of_gpiochip_set_names(struct gpio_chip *gc)
-{
-       struct gpio_device *gdev = gc->gpiodev;
-       struct device_node *np = gc->of_node;
-       int i;
-       int nstrings;
-
-       nstrings = of_property_count_strings(np, "gpio-line-names");
-       if (nstrings <= 0)
-               /* Lines names not present */
-               return;
-
-       /* This is normally not what you want */
-       if (gdev->ngpio != nstrings)
-               dev_info(&gdev->dev, "gpio-line-names specifies %d line "
-                        "names but there are %d lines on the chip\n",
-                        nstrings, gdev->ngpio);
-
-       /*
-        * Make sure to not index beyond the end of the number of descriptors
-        * of the GPIO device.
-        */
-       for (i = 0; i < gdev->ngpio; i++) {
-               const char *name;
-               int ret;
-
-               ret = of_property_read_string_index(np,
-                                                   "gpio-line-names",
-                                                   i,
-                                                   &name);
-               if (ret) {
-                       if (ret != -ENODATA)
-                                dev_err(&gdev->dev,
-                                        "unable to name line %d: %d\n",
-                                        i, ret);
-                       break;
-               }
-               gdev->descs[i].name = name;
-       }
-}
-
-/**
  * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
  * @chip:      gpio chip to act on
  *
@@ -522,7 +477,7 @@ int of_gpiochip_add(struct gpio_chip *chip)
 
        /* If the chip defines names itself, these take precedence */
        if (!chip->names)
-               of_gpiochip_set_names(chip);
+               devprop_gpiochip_set_names(chip);
 
        of_node_get(chip->of_node);
 

diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 346fbda..d10eaf5 100644 (file)
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -209,6 +209,8 @@ static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
        return desc - &desc->gdev->descs[0];
 }
 
+void devprop_gpiochip_set_names(struct gpio_chip *chip);
+
 /* With descriptor prefix */
 
 #define gpiod_emerg(desc, fmt, ...)                                           \