Commit 4add0664 authored by Kim, Milo's avatar Kim, Milo Committed by Linus Torvalds

backlight: lp855x: add a device tree structure

Enable 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: default avatarMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c365e59d
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>;
};
};
......@@ -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,
......
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