mfd: max8925: Support dt for backlight

Add device tree support in max8925 backlight.

Signed-off-by: Qing Xu <qingx@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 30 insertions, 1 deletions

diff --git a/drivers/video/backlight/max8925_bl.c b/drivers/video/backlight/max8925_bl.c
index 2c9bce050aa9..5ca11b066b7e 100644
--- a/drivers/video/backlight/max8925_bl.c
+++ b/drivers/video/backlight/max8925_bl.c
@@ -101,6 +101,29 @@ static const struct backlight_ops max8925_backlight_ops = {
         .get_brightness = max8925_backlight_get_brightness,
 };
 
+#ifdef CONFIG_OF
+static int max8925_backlight_dt_init(struct platform_device *pdev,
+                              struct max8925_backlight_pdata *pdata)
+{
+        struct device_node *nproot = pdev->dev.parent->of_node, *np;
+        int dual_string;
+
+        if (!nproot)
+                return -ENODEV;
+        np = of_find_node_by_name(nproot, "backlight");
+        if (!np) {
+                dev_err(&pdev->dev, "failed to find backlight node\n");
+                return -ENODEV;
+        }
+
+        of_property_read_u32(np, "maxim,max8925-dual-string", &dual_string);
+        pdata->dual_string = dual_string;
+        return 0;
+}
+#else
+#define max8925_backlight_dt_init(x, y) (-1)
+#endif
+
 static int max8925_backlight_probe(struct platform_device *pdev)
 {
         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
@@ -147,6 +170,13 @@ static int max8925_backlight_probe(struct platform_device *pdev)
         platform_set_drvdata(pdev, bl);
 
         value = 0;
+        if (pdev->dev.parent->of_node && !pdata) {
+                pdata = devm_kzalloc(&pdev->dev,
+                                     sizeof(struct max8925_backlight_pdata),
+                                     GFP_KERNEL);
+                max8925_backlight_dt_init(pdev, pdata);
+        }
+
         if (pdata) {
                 if (pdata->lxw_scl)
                         value |= (1 << 7);
@@ -158,7 +188,6 @@ static int max8925_backlight_probe(struct platform_device *pdev)
         ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value);
         if (ret < 0)
                 goto out_brt;
-
         backlight_update_status(bl);
         return 0;
 out_brt: