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path: root/drivers/video/backlight/lp855x_bl.c
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Diffstat (limited to 'drivers/video/backlight/lp855x_bl.c')
-rw-r--r--drivers/video/backlight/lp855x_bl.c247
1 files changed, 153 insertions, 94 deletions
diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index 73612485ed07..d191560ce285 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -1,14 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* TI LP855x Backlight Driver
*
* Copyright (C) 2011 Texas Instruments
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
*/
+#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
@@ -25,7 +22,7 @@
#define LP855X_DEVICE_CTRL 0x01
#define LP855X_EEPROM_START 0xA0
#define LP855X_EEPROM_END 0xA7
-#define LP8556_EPROM_START 0xA0
+#define LP8556_EPROM_START 0x98
#define LP8556_EPROM_END 0xAF
/* LP8555/7 Registers */
@@ -74,6 +71,7 @@ struct lp855x {
struct device *dev;
struct lp855x_platform_data *pdata;
struct pwm_device *pwm;
+ bool needs_pwm_init;
struct regulator *supply; /* regulator for VDD input */
struct regulator *enable; /* regulator for EN/VDDIO input */
};
@@ -174,22 +172,6 @@ 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) {
@@ -235,32 +217,24 @@ err:
return ret;
}
-static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
+static int lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
{
- unsigned int period = lp->pdata->period_ns;
- unsigned int duty = br * period / max_br;
- struct pwm_device *pwm;
-
- /* request pwm device with the consumer name */
- if (!lp->pwm) {
- pwm = devm_pwm_get(lp->dev, lp->chipname);
- if (IS_ERR(pwm))
- return;
-
- lp->pwm = pwm;
-
- /*
- * FIXME: pwm_apply_args() should be removed when switching to
- * the atomic PWM API.
- */
- pwm_apply_args(pwm);
+ struct pwm_state state;
+
+ if (lp->needs_pwm_init) {
+ pwm_init_state(lp->pwm, &state);
+ /* Legacy platform data compatibility */
+ if (lp->pdata->period_ns > 0)
+ state.period = lp->pdata->period_ns;
+ lp->needs_pwm_init = false;
+ } else {
+ pwm_get_state(lp->pwm, &state);
}
- pwm_config(lp->pwm, duty, period);
- if (duty)
- pwm_enable(lp->pwm);
- else
- pwm_disable(lp->pwm);
+ state.duty_cycle = div_u64(br * state.period, max_br);
+ state.enabled = state.duty_cycle;
+
+ return pwm_apply_might_sleep(lp->pwm, &state);
}
static int lp855x_bl_update_status(struct backlight_device *bl)
@@ -272,11 +246,12 @@ static int lp855x_bl_update_status(struct backlight_device *bl)
brightness = 0;
if (lp->mode == PWM_BASED)
- lp855x_pwm_ctrl(lp, brightness, bl->props.max_brightness);
+ return lp855x_pwm_ctrl(lp, brightness,
+ bl->props.max_brightness);
else if (lp->mode == REGISTER_BASED)
- lp855x_write_byte(lp, lp->cfg->reg_brightness, (u8)brightness);
-
- return 0;
+ return lp855x_write_byte(lp, lp->cfg->reg_brightness,
+ (u8)brightness);
+ return -EINVAL;
}
static const struct backlight_ops lp855x_bl_ops = {
@@ -350,7 +325,7 @@ 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) {
@@ -358,13 +333,10 @@ 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);
+ /* Deprecated, specify period in pwms property instead */
of_property_read_u32(node, "pwm-period", &pdata->period_ns);
/* Fill ROM platform data if defined */
@@ -388,8 +360,6 @@ static int lp855x_parse_dt(struct lp855x *lp)
pdata->rom_data = &rom[0];
}
- lp->pdata = pdata;
-
return 0;
}
#else
@@ -399,59 +369,129 @@ static int lp855x_parse_dt(struct lp855x *lp)
}
#endif
-static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
+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 = i2c_client_get_device_id(cl);
+ 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;
+ }
- if (!lp->pdata) {
- ret = lp855x_parse_dt(lp);
- if (ret < 0)
- return ret;
+ 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->period_ns > 0)
- lp->mode = PWM_BASED;
- else
- lp->mode = REGISTER_BASED;
+ if (!lp->pdata) {
+ lp->pdata = devm_kzalloc(dev, sizeof(*lp->pdata), GFP_KERNEL);
+ if (!lp->pdata)
+ return -ENOMEM;
- lp->supply = devm_regulator_get(lp->dev, "power");
+ if (id) {
+ ret = lp855x_parse_dt(lp);
+ if (ret < 0)
+ return ret;
+ } else {
+ ret = lp855x_parse_acpi(lp);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ 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) {
+ if (ret == -ENODEV)
lp->enable = NULL;
- } else {
- if (ret != -EPROBE_DEFER)
- dev_err(lp->dev, "error getting enable regulator: %d\n",
- ret);
- return ret;
- }
+ else
+ return dev_err_probe(dev, ret, "getting enable regulator\n");
+ }
+
+ lp->pwm = devm_pwm_get(lp->dev, lp->chipname);
+ if (IS_ERR(lp->pwm)) {
+ ret = PTR_ERR(lp->pwm);
+ if (ret == -ENODEV || ret == -EINVAL)
+ lp->pwm = NULL;
+ else
+ return dev_err_probe(dev, ret, "getting PWM\n");
+
+ lp->needs_pwm_init = false;
+ lp->mode = REGISTER_BASED;
+ dev_dbg(dev, "mode: register based\n");
+ } else {
+ lp->needs_pwm_init = true;
+ lp->mode = PWM_BASED;
+ dev_dbg(dev, "mode: PWM based\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;
}
}
@@ -459,8 +499,8 @@ 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);
- return ret;
+ dev_err(dev, "failed to enable vddio: %d\n", ret);
+ goto disable_supply;
}
/*
@@ -474,41 +514,50 @@ 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);
- return 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);
- return 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);
- return ret;
+ dev_err(dev, "failed to register sysfs. err: %d\n", ret);
+ goto disable_vddio;
}
backlight_update_status(lp->bl);
+
return 0;
+
+disable_vddio:
+ if (lp->enable)
+ regulator_disable(lp->enable);
+disable_supply:
+ if (lp->supply)
+ regulator_disable(lp->supply);
+
+ return ret;
}
-static int lp855x_remove(struct i2c_client *cl)
+static void lp855x_remove(struct i2c_client *cl)
{
struct lp855x *lp = i2c_get_clientdata(cl);
lp->bl->props.brightness = 0;
backlight_update_status(lp->bl);
+ if (lp->enable)
+ regulator_disable(lp->enable);
if (lp->supply)
regulator_disable(lp->supply);
sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
-
- return 0;
}
-static const struct of_device_id lp855x_dt_ids[] = {
+static const struct of_device_id lp855x_dt_ids[] __maybe_unused = {
{ .compatible = "ti,lp8550", },
{ .compatible = "ti,lp8551", },
{ .compatible = "ti,lp8552", },
@@ -532,10 +581,20 @@ 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,
generated by cgit (git 2.34.1) at 2025-12-25 15:39:24 +0000