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Date: Fri, 19 Apr 2013 06:28:40 +0000
From: "Kim, Milo" <Milo.Kim@...com>
To: "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>
CC: Richard Purdie <rpurdie@...ys.net>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH 5/5] backlight: lp855x: add a device tree structure
This patch enables supporting the DT structure of LP855x family devices.
If the platform data is NULL, the driver tries to parse a DT structure.
Then, the platform data is copied from the DT.
Documentation is added as well.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@...com>
---
.../devicetree/bindings/video/backlight/lp855x.txt | 41 +++++++++++
drivers/video/backlight/lp855x_bl.c | 73 +++++++++++++++++++-
2 files changed, 112 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/video/backlight/lp855x.txt
diff --git a/Documentation/devicetree/bindings/video/backlight/lp855x.txt b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
new file mode 100644
index 0000000..1482103
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
@@ -0,0 +1,41 @@
+lp855x bindings
+
+Required properties:
+ - compatible: "ti,lp8550", "ti,lp8551", "ti,lp8552", "ti,lp8553",
+ "ti,lp8556", "ti,lp8557"
+ - reg: I2C slave address (u8)
+ - dev-ctrl: Value of DEVICE CONTROL register (u8). It depends on the device.
+
+Optional properties:
+ - bl-name: Backlight device name (string)
+ - init-brt: Initial value of backlight brightness (u8)
+ - pwm-period: PWM period value. Set only PWM input mode used (u32)
+ - rom-addr: Register address of ROM area to be updated (u8)
+ - rom-val: Register value to be updated (u8)
+
+Example:
+
+ /* LP8556 */
+ backlight@2c {
+ compatible = "ti,lp8556";
+ reg = <0x2c>;
+
+ bl-name = "lcd-bl";
+ dev-ctrl = /bits/ 8 <0x85>;
+ init-brt = /bits/ 8 <0x10>;
+ };
+
+ /* LP8557 */
+ backlight@2c {
+ compatible = "ti,lp8557";
+ reg = <0x2c>;
+
+ dev-ctrl = /bits/ 8 <0x41>;
+ init-brt = /bits/ 8 <0x0a>;
+
+ /* 4V OV, 4 output LED string enabled */
+ rom_14h {
+ rom-addr = /bits/ 8 <0x14>;
+ rom-val = /bits/ 8 <0xcf>;
+ };
+ };
diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index f558f8f..a0e1e02 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -14,6 +14,7 @@
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/err.h>
+#include <linux/of.h>
#include <linux/platform_data/lp855x.h>
#include <linux/pwm.h>
@@ -338,15 +339,71 @@ static const struct attribute_group lp855x_attr_group = {
.attrs = lp855x_attributes,
};
+#ifdef CONFIG_OF
+static int lp855x_parse_dt(struct device *dev, struct device_node *node)
+{
+ struct lp855x_platform_data *pdata;
+ int rom_length;
+
+ if (!node) {
+ dev_err(dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ of_property_read_string(node, "bl-name", &pdata->name);
+ of_property_read_u8(node, "dev-ctrl", &pdata->device_control);
+ of_property_read_u8(node, "init-brt", &pdata->initial_brightness);
+ of_property_read_u32(node, "pwm-period", &pdata->period_ns);
+
+ /* Fill ROM platform data if defined */
+ rom_length = of_get_child_count(node);
+ if (rom_length > 0) {
+ struct lp855x_rom_data *rom;
+ struct device_node *child;
+ int i = 0;
+
+ rom = devm_kzalloc(dev, sizeof(*rom) * rom_length, GFP_KERNEL);
+ if (!rom)
+ return -ENOMEM;
+
+ for_each_child_of_node(node, child) {
+ of_property_read_u8(child, "rom-addr", &rom[i].addr);
+ of_property_read_u8(child, "rom-val", &rom[i].val);
+ i++;
+ }
+
+ pdata->size_program = rom_length;
+ pdata->rom_data = &rom[0];
+ }
+
+ dev->platform_data = pdata;
+
+ return 0;
+}
+#else
+static int lp855x_parse_dt(struct device *dev, struct device_node *node)
+{
+ return -EINVAL;
+}
+#endif
+
static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
struct lp855x *lp;
struct lp855x_platform_data *pdata = cl->dev.platform_data;
+ struct device_node *node = cl->dev.of_node;
int ret;
if (!pdata) {
- dev_err(&cl->dev, "no platform data supplied\n");
- return -EINVAL;
+ ret = lp855x_parse_dt(&cl->dev, node);
+ if (ret < 0)
+ return ret;
+
+ pdata = cl->dev.platform_data;
}
if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
@@ -408,6 +465,17 @@ static int lp855x_remove(struct i2c_client *cl)
return 0;
}
+static const struct of_device_id lp855x_dt_ids[] = {
+ { .compatible = "ti,lp8550", },
+ { .compatible = "ti,lp8551", },
+ { .compatible = "ti,lp8552", },
+ { .compatible = "ti,lp8553", },
+ { .compatible = "ti,lp8556", },
+ { .compatible = "ti,lp8557", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lp855x_dt_ids);
+
static const struct i2c_device_id lp855x_ids[] = {
{"lp8550", LP8550},
{"lp8551", LP8551},
@@ -422,6 +490,7 @@ MODULE_DEVICE_TABLE(i2c, lp855x_ids);
static struct i2c_driver lp855x_driver = {
.driver = {
.name = "lp855x",
+ .of_match_table = of_match_ptr(lp855x_dt_ids),
},
.probe = lp855x_probe,
.remove = lp855x_remove,
--
1.7.9.5
Best Regards,
Milo
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