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path: root/drivers/video/backlight/lp855x_bl.c
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-rw-r--r--drivers/video/backlight/lp855x_bl.c134
1 files changed, 90 insertions, 44 deletions
diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index e94932c69f54..2b9e2bbbb03e 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -5,6 +5,7 @@
* Copyright (C) 2011 Texas Instruments
*/
+#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
@@ -170,22 +171,6 @@ static int lp855x_configure(struct lp855x *lp)
int i, ret;
struct lp855x_platform_data *pd = lp->pdata;
- switch (lp->chip_id) {
- case LP8550:
- case LP8551:
- case LP8552:
- case LP8553:
- case LP8556:
- lp->cfg = &lp855x_dev_cfg;
- break;
- case LP8555:
- case LP8557:
- lp->cfg = &lp8557_dev_cfg;
- break;
- default:
- return -EINVAL;
- }
-
if (lp->cfg->pre_init_device) {
ret = lp->cfg->pre_init_device(lp);
if (ret) {
@@ -346,7 +331,7 @@ static int lp855x_parse_dt(struct lp855x *lp)
{
struct device *dev = lp->dev;
struct device_node *node = dev->of_node;
- struct lp855x_platform_data *pdata;
+ struct lp855x_platform_data *pdata = lp->pdata;
int rom_length;
if (!node) {
@@ -354,10 +339,6 @@ static int lp855x_parse_dt(struct lp855x *lp)
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);
@@ -384,8 +365,6 @@ static int lp855x_parse_dt(struct lp855x *lp)
pdata->rom_data = &rom[0];
}
- lp->pdata = pdata;
-
return 0;
}
#else
@@ -395,28 +374,89 @@ static int lp855x_parse_dt(struct lp855x *lp)
}
#endif
+static int lp855x_parse_acpi(struct lp855x *lp)
+{
+ int ret;
+
+ /*
+ * On ACPI the device has already been initialized by the firmware
+ * and is in register mode, so we can read back the settings from
+ * the registers.
+ */
+ ret = i2c_smbus_read_byte_data(lp->client, lp->cfg->reg_brightness);
+ if (ret < 0)
+ return ret;
+
+ lp->pdata->initial_brightness = ret;
+
+ ret = i2c_smbus_read_byte_data(lp->client, lp->cfg->reg_devicectrl);
+ if (ret < 0)
+ return ret;
+
+ lp->pdata->device_control = ret;
+ return 0;
+}
+
static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
+ const struct acpi_device_id *acpi_id = NULL;
+ struct device *dev = &cl->dev;
struct lp855x *lp;
int ret;
if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
return -EIO;
- lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
+ lp = devm_kzalloc(dev, sizeof(struct lp855x), GFP_KERNEL);
if (!lp)
return -ENOMEM;
lp->client = cl;
- lp->dev = &cl->dev;
- lp->chipname = id->name;
- lp->chip_id = id->driver_data;
- lp->pdata = dev_get_platdata(&cl->dev);
+ lp->dev = dev;
+ lp->pdata = dev_get_platdata(dev);
+
+ if (id) {
+ lp->chipname = id->name;
+ lp->chip_id = id->driver_data;
+ } else {
+ acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
+ if (!acpi_id)
+ return -ENODEV;
+
+ lp->chipname = acpi_id->id;
+ lp->chip_id = acpi_id->driver_data;
+ }
+
+ switch (lp->chip_id) {
+ case LP8550:
+ case LP8551:
+ case LP8552:
+ case LP8553:
+ case LP8556:
+ lp->cfg = &lp855x_dev_cfg;
+ break;
+ case LP8555:
+ case LP8557:
+ lp->cfg = &lp8557_dev_cfg;
+ break;
+ default:
+ return -EINVAL;
+ }
if (!lp->pdata) {
- ret = lp855x_parse_dt(lp);
- if (ret < 0)
- return ret;
+ lp->pdata = devm_kzalloc(dev, sizeof(*lp->pdata), GFP_KERNEL);
+ if (!lp->pdata)
+ return -ENOMEM;
+
+ if (id) {
+ ret = lp855x_parse_dt(lp);
+ if (ret < 0)
+ return ret;
+ } else {
+ ret = lp855x_parse_acpi(lp);
+ if (ret < 0)
+ return ret;
+ }
}
if (lp->pdata->period_ns > 0)
@@ -424,30 +464,27 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
else
lp->mode = REGISTER_BASED;
- lp->supply = devm_regulator_get(lp->dev, "power");
+ lp->supply = devm_regulator_get(dev, "power");
if (IS_ERR(lp->supply)) {
if (PTR_ERR(lp->supply) == -EPROBE_DEFER)
return -EPROBE_DEFER;
lp->supply = NULL;
}
- lp->enable = devm_regulator_get_optional(lp->dev, "enable");
+ lp->enable = devm_regulator_get_optional(dev, "enable");
if (IS_ERR(lp->enable)) {
ret = PTR_ERR(lp->enable);
if (ret == -ENODEV) {
lp->enable = NULL;
} else {
- if (ret != -EPROBE_DEFER)
- dev_err(lp->dev, "error getting enable regulator: %d\n",
- ret);
- return ret;
+ return dev_err_probe(dev, ret, "getting enable regulator\n");
}
}
if (lp->supply) {
ret = regulator_enable(lp->supply);
if (ret < 0) {
- dev_err(&cl->dev, "failed to enable supply: %d\n", ret);
+ dev_err(dev, "failed to enable supply: %d\n", ret);
return ret;
}
}
@@ -455,7 +492,7 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
if (lp->enable) {
ret = regulator_enable(lp->enable);
if (ret < 0) {
- dev_err(lp->dev, "failed to enable vddio: %d\n", ret);
+ dev_err(dev, "failed to enable vddio: %d\n", ret);
goto disable_supply;
}
@@ -470,20 +507,19 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
ret = lp855x_configure(lp);
if (ret) {
- dev_err(lp->dev, "device config err: %d", ret);
+ dev_err(dev, "device config err: %d", ret);
goto disable_vddio;
}
ret = lp855x_backlight_register(lp);
if (ret) {
- dev_err(lp->dev,
- "failed to register backlight. err: %d\n", ret);
+ dev_err(dev, "failed to register backlight. err: %d\n", ret);
goto disable_vddio;
}
- ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
+ ret = sysfs_create_group(&dev->kobj, &lp855x_attr_group);
if (ret) {
- dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
+ dev_err(dev, "failed to register sysfs. err: %d\n", ret);
goto disable_vddio;
}
@@ -540,10 +576,20 @@ static const struct i2c_device_id lp855x_ids[] = {
};
MODULE_DEVICE_TABLE(i2c, lp855x_ids);
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id lp855x_acpi_match[] = {
+ /* Xiaomi specific HID used for the LP8556 on the Mi Pad 2 */
+ { "XMCC0001", LP8556 },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, lp855x_acpi_match);
+#endif
+
static struct i2c_driver lp855x_driver = {
.driver = {
.name = "lp855x",
.of_match_table = of_match_ptr(lp855x_dt_ids),
+ .acpi_match_table = ACPI_PTR(lp855x_acpi_match),
},
.probe = lp855x_probe,
.remove = lp855x_remove,
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