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path: root/drivers/gpio/gpiolib-devprop.c
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Diffstat (limited to 'drivers/gpio/gpiolib-devprop.c')
-rw-r--r--drivers/gpio/gpiolib-devprop.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-devprop.c b/drivers/gpio/gpiolib-devprop.c
new file mode 100644
index 000000000000..27f383bda7d9
--- /dev/null
+++ b/drivers/gpio/gpiolib-devprop.c
@@ -0,0 +1,67 @@
+/*
+ * 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;
+
+ if (!chip->parent) {
+ dev_warn(&gdev->dev, "GPIO chip parent is NULL\n");
+ return;
+ }
+
+ 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);
+}