leds: lp55xx: add support for Device Tree bindings

This patch allows the lp5521 driver to be successfully probed and
initialised when Device Tree support is enabled.

Based on a patch by Gabriel Fernandez, rewritten in accordance
with review feedback.

Cc: Gabriel Fernandez <gabriel.fernandez@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

4 files changed, 87 insertions, 10 deletions

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 19752c928aa2..d461e2664b09 100644
--- a/drivers/leds/leds-lp5521.c
+++ b/drivers/leds/leds-lp5521.c
@@ -31,6 +31,7 @@
 #include <linux/mutex.h>
 #include <linux/platform_data/leds-lp55xx.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #include "leds-lp55xx-common.h"
 
@@ -416,12 +417,20 @@ static int lp5521_probe(struct i2c_client *client,
         int ret;
         struct lp55xx_chip *chip;
         struct lp55xx_led *led;
-        struct lp55xx_platform_data *pdata = client->dev.platform_data;
-
-        if (!pdata) {
-                dev_err(&client->dev, "no platform data\n");
-                return -EINVAL;
+        struct lp55xx_platform_data *pdata;
+        struct device_node *np = client->dev.of_node;
+
+        if (!client->dev.platform_data) {
+                if (np) {
+                        ret = lp55xx_of_populate_pdata(&client->dev, np);
+                        if (ret < 0)
+                                return ret;
+                } else {
+                        dev_err(&client->dev, "no platform data\n");
+                        return -EINVAL;
+                }
         }
+        pdata = client->dev.platform_data;
 
         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
         if (!chip)
@@ -481,6 +490,7 @@ static int lp5521_remove(struct i2c_client *client)
 
 static const struct i2c_device_id lp5521_id[] = {
         { "lp5521", 0 }, /* Three channel chip */
+        { "national,lp5521", 0 }, /* OF compatible */
         { }
 };
 MODULE_DEVICE_TABLE(i2c, lp5521_id);
diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
index 229f734040af..365e9148e5e8 100644
--- a/drivers/leds/leds-lp5523.c
+++ b/drivers/leds/leds-lp5523.c
@@ -429,12 +429,20 @@ static int lp5523_probe(struct i2c_client *client,
         int ret;
         struct lp55xx_chip *chip;
         struct lp55xx_led *led;
-        struct lp55xx_platform_data *pdata = client->dev.platform_data;
-
-        if (!pdata) {
-                dev_err(&client->dev, "no platform data\n");
-                return -EINVAL;
+        struct lp55xx_platform_data *pdata;
+        struct device_node *np = client->dev.of_node;
+
+        if (!client->dev.platform_data) {
+                if (np) {
+                        ret = lp55xx_of_populate_pdata(&client->dev, np);
+                        if (ret < 0)
+                                return ret;
+                } else {
+                        dev_err(&client->dev, "no platform data\n");
+                        return -EINVAL;
+                }
         }
+        pdata = client->dev.platform_data;
 
         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
         if (!chip)
@@ -495,6 +503,7 @@ static int lp5523_remove(struct i2c_client *client)
 static const struct i2c_device_id lp5523_id[] = {
         { "lp5523",  LP5523 },
         { "lp55231", LP55231 },
+        { "national,lp5523", 0 }, /* OF compatible */
         { }
 };
 
diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
index ba34199dc3d9..a0d2bd2fa23c 100644
--- a/drivers/leds/leds-lp55xx-common.c
+++ b/drivers/leds/leds-lp55xx-common.c
@@ -19,6 +19,7 @@
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/platform_data/leds-lp55xx.h>
+#include <linux/slab.h>
 
 #include "leds-lp55xx-common.h"
 
@@ -554,6 +555,59 @@ void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
 }
 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
 
+int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
+{
+        struct lp55xx_platform_data *pdata;
+        u8 led_cur[3];
+        u8 max_cur[3];
+        u8 clock_mode;
+        u8 num_channel;
+        const char *label;
+        struct lp55xx_led_config *led_config;
+        int ret;
+        int i;
+
+        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        ret = of_property_read_u8(np, "num-channel", &num_channel);
+        if (ret < 0)
+                return ret;
+        ret = of_property_read_u8_array(np, "led-cur", led_cur, num_channel);
+        if (ret < 0)
+                return ret;
+        ret = of_property_read_u8_array(np, "max-cur", max_cur, num_channel);
+        if (ret < 0)
+                return ret;
+        ret = of_property_read_string(np, "label", &label);
+        if (ret < 0)
+                return ret;
+        ret = of_property_read_u8_array(np, "clock-mode", &clock_mode, 1);
+        if (ret < 0)
+                return ret;
+
+        led_config = devm_kzalloc(dev, sizeof(*led_config) * num_channel,
+                                  GFP_KERNEL);
+        if (!led_config)
+                return -ENOMEM;
+
+        for (i = 0; i < num_channel; i++) {
+                led_config[i].chan_nr = i;
+                led_config[i].led_current = led_cur[i];
+                led_config[i].max_current = max_cur[i];
+        }
+        pdata->label = kzalloc(sizeof(char) * 32, GFP_KERNEL);
+        strcpy((char *)pdata->label, (char *) label);
+        pdata->led_config = &led_config[0];
+        pdata->num_channels = num_channel;
+        pdata->clock_mode = clock_mode;
+        dev->platform_data = pdata;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
+
 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 MODULE_DESCRIPTION("LP55xx Common Driver");
 MODULE_LICENSE("GPL");
diff --git a/drivers/leds/leds-lp55xx-common.h b/drivers/leds/leds-lp55xx-common.h
index fa6a078bf547..dbbf86df0f1f 100644
--- a/drivers/leds/leds-lp55xx-common.h
+++ b/drivers/leds/leds-lp55xx-common.h
@@ -135,4 +135,8 @@ extern void lp55xx_unregister_leds(struct lp55xx_led *led,
 extern int lp55xx_register_sysfs(struct lp55xx_chip *chip);
 extern void lp55xx_unregister_sysfs(struct lp55xx_chip *chip);
 
+/* common device tree population function */
+extern int lp55xx_of_populate_pdata(struct device *dev,
+                                    struct device_node *np);
+
 #endif /* _LEDS_LP55XX_COMMON_H */