[media] media: rc: gpio-ir-recv: add support for device tree parsing

This patch adds device tree parsing for gpio_ir_recv platform_data and
the mandatory binding documentation. It basically follows what we already
have for e.g. gpio_keys. All required device tree properties are OS
independent but an optional property allows linux specific support for rc
maps.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 68 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
new file mode 100644
index 000000000000..56e726ef4bf2
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
@@ -0,0 +1,16 @@
+Device-Tree bindings for GPIO IR receiver
+
+Required properties:
+        - compatible: should be "gpio-ir-receiver".
+        - gpios: specifies GPIO used for IR signal reception.
+
+Optional properties:
+        - linux,rc-map-name: Linux specific remote control map name.
+
+Example node:
+
+        ir: ir-receiver {
+                compatible = "gpio-ir-receiver";
+                gpios = <&gpio0 19 1>;
+                linux,rc-map-name = "rc-rc6-mce";
+        };
diff --git a/drivers/media/rc/gpio-ir-recv.c b/drivers/media/rc/gpio-ir-recv.c
index 382f362b69af..8b82ae9bd686 100644
--- a/drivers/media/rc/gpio-ir-recv.c
+++ b/drivers/media/rc/gpio-ir-recv.c
@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
+#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/irq.h>
 #include <media/rc-core.h>
@@ -30,6 +31,45 @@ struct gpio_rc_dev {
         bool active_low;
 };
 
+#ifdef CONFIG_OF
+/*
+ * Translate OpenFirmware node properties into platform_data
+ */
+static int gpio_ir_recv_get_devtree_pdata(struct device *dev,
+                                  struct gpio_ir_recv_platform_data *pdata)
+{
+        struct device_node *np = dev->of_node;
+        enum of_gpio_flags flags;
+        int gpio;
+
+        gpio = of_get_gpio_flags(np, 0, &flags);
+        if (gpio < 0) {
+                if (gpio != -EPROBE_DEFER)
+                        dev_err(dev, "Failed to get gpio flags (%d)\n", gpio);
+                return gpio;
+        }
+
+        pdata->gpio_nr = gpio;
+        pdata->active_low = (flags & OF_GPIO_ACTIVE_LOW);
+        /* probe() takes care of map_name == NULL or allowed_protos == 0 */
+        pdata->map_name = of_get_property(np, "linux,rc-map-name", NULL);
+        pdata->allowed_protos = 0;
+
+        return 0;
+}
+
+static struct of_device_id gpio_ir_recv_of_match[] = {
+        { .compatible = "gpio-ir-receiver", },
+        { },
+};
+MODULE_DEVICE_TABLE(of, gpio_ir_recv_of_match);
+
+#else /* !CONFIG_OF */
+
+#define gpio_ir_recv_get_devtree_pdata(dev, pdata)      (-ENOSYS)
+
+#endif
+
 static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
 {
         struct gpio_rc_dev *gpio_dev = dev_id;
@@ -66,6 +106,17 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
                                         pdev->dev.platform_data;
         int rc;
 
+        if (pdev->dev.of_node) {
+                struct gpio_ir_recv_platform_data *dtpdata =
+                        devm_kzalloc(&pdev->dev, sizeof(*dtpdata), GFP_KERNEL);
+                if (!dtpdata)
+                        return -ENOMEM;
+                rc = gpio_ir_recv_get_devtree_pdata(&pdev->dev, dtpdata);
+                if (rc)
+                        return rc;
+                pdata = dtpdata;
+        }
+
         if (!pdata)
                 return -EINVAL;
 
@@ -191,6 +242,7 @@ static struct platform_driver gpio_ir_recv_driver = {
         .driver = {
                 .name   = GPIO_IR_DRIVER_NAME,
                 .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(gpio_ir_recv_of_match),
 #ifdef CONFIG_PM
                 .pm     = &gpio_ir_recv_pm_ops,
 #endif