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linux/drivers/leds/leds-lm3530.c
Uwe Kleine-König ed5c2f5fd1 i2c: Make remove callback return void 
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00

501 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 ST-Ericsson SA.
* Copyright (C) 2009 Motorola, Inc.
*
* Simple driver for National Semiconductor LM3530 Backlight driver chip
*
* Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
* based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
*/
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/led-lm3530.h>
#include <linux/types.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#define LM3530_LED_DEV "lcd-backlight"
#define LM3530_NAME "lm3530-led"
#define LM3530_GEN_CONFIG 0x10
#define LM3530_ALS_CONFIG 0x20
#define LM3530_BRT_RAMP_RATE 0x30
#define LM3530_ALS_IMP_SELECT 0x41
#define LM3530_BRT_CTRL_REG 0xA0
#define LM3530_ALS_ZB0_REG 0x60
#define LM3530_ALS_ZB1_REG 0x61
#define LM3530_ALS_ZB2_REG 0x62
#define LM3530_ALS_ZB3_REG 0x63
#define LM3530_ALS_Z0T_REG 0x70
#define LM3530_ALS_Z1T_REG 0x71
#define LM3530_ALS_Z2T_REG 0x72
#define LM3530_ALS_Z3T_REG 0x73
#define LM3530_ALS_Z4T_REG 0x74
#define LM3530_REG_MAX 14
/* General Control Register */
#define LM3530_EN_I2C_SHIFT (0)
#define LM3530_RAMP_LAW_SHIFT (1)
#define LM3530_MAX_CURR_SHIFT (2)
#define LM3530_EN_PWM_SHIFT (5)
#define LM3530_PWM_POL_SHIFT (6)
#define LM3530_EN_PWM_SIMPLE_SHIFT (7)
#define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
#define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
#define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
#define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
/* ALS Config Register Options */
#define LM3530_ALS_AVG_TIME_SHIFT (0)
#define LM3530_EN_ALS_SHIFT (3)
#define LM3530_ALS_SEL_SHIFT (5)
#define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
/* Brightness Ramp Rate Register */
#define LM3530_BRT_RAMP_FALL_SHIFT (0)
#define LM3530_BRT_RAMP_RISE_SHIFT (3)
/* ALS Resistor Select */
#define LM3530_ALS1_IMP_SHIFT (0)
#define LM3530_ALS2_IMP_SHIFT (4)
/* Zone Boundary Register defaults */
#define LM3530_ALS_ZB_MAX (4)
#define LM3530_ALS_WINDOW_mV (1000)
#define LM3530_ALS_OFFSET_mV (4)
/* Zone Target Register defaults */
#define LM3530_DEF_ZT_0 (0x7F)
#define LM3530_DEF_ZT_1 (0x66)
#define LM3530_DEF_ZT_2 (0x4C)
#define LM3530_DEF_ZT_3 (0x33)
#define LM3530_DEF_ZT_4 (0x19)
/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
#define MAX_BRIGHTNESS (127)
struct lm3530_mode_map {
const char *mode;
enum lm3530_mode mode_val;
};
static struct lm3530_mode_map mode_map[] = {
{ "man", LM3530_BL_MODE_MANUAL },
{ "als", LM3530_BL_MODE_ALS },
{ "pwm", LM3530_BL_MODE_PWM },
};
/**
* struct lm3530_data
* @led_dev: led class device
* @client: i2c client
* @pdata: LM3530 platform data
* @mode: mode of operation - manual, ALS, PWM
* @regulator: regulator
* @brightness: previous brightness value
* @enable: regulator is enabled
*/
struct lm3530_data {
struct led_classdev led_dev;
struct i2c_client *client;
struct lm3530_platform_data *pdata;
enum lm3530_mode mode;
struct regulator *regulator;
enum led_brightness brightness;
bool enable;
};
/*
* struct lm3530_als_data
* @config : value of ALS configuration register
* @imp_sel : value of ALS resistor select register
* @zone : values of ALS ZB(Zone Boundary) registers
*/
struct lm3530_als_data {
u8 config;
u8 imp_sel;
u8 zones[LM3530_ALS_ZB_MAX];
};
static const u8 lm3530_reg[LM3530_REG_MAX] = {
LM3530_GEN_CONFIG,
LM3530_ALS_CONFIG,
LM3530_BRT_RAMP_RATE,
LM3530_ALS_IMP_SELECT,
LM3530_BRT_CTRL_REG,
LM3530_ALS_ZB0_REG,
LM3530_ALS_ZB1_REG,
LM3530_ALS_ZB2_REG,
LM3530_ALS_ZB3_REG,
LM3530_ALS_Z0T_REG,
LM3530_ALS_Z1T_REG,
LM3530_ALS_Z2T_REG,
LM3530_ALS_Z3T_REG,
LM3530_ALS_Z4T_REG,
};
static int lm3530_get_mode_from_str(const char *str)
{
int i;
for (i = 0; i < ARRAY_SIZE(mode_map); i++)
if (sysfs_streq(str, mode_map[i].mode))
return mode_map[i].mode_val;
return -EINVAL;
}
static void lm3530_als_configure(struct lm3530_platform_data *pdata,
struct lm3530_als_data *als)
{
int i;
u32 als_vmin, als_vmax, als_vstep;
if (pdata->als_vmax == 0) {
pdata->als_vmin = 0;
pdata->als_vmax = LM3530_ALS_WINDOW_mV;
}
als_vmin = pdata->als_vmin;
als_vmax = pdata->als_vmax;
if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
/* n zone boundary makes n+1 zones */
als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
als->config =
(pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
(LM3530_ENABLE_ALS) |
(pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
als->imp_sel =
(pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
(pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
}
static int lm3530_led_enable(struct lm3530_data *drvdata)
{
int ret;
if (drvdata->enable)
return 0;
ret = regulator_enable(drvdata->regulator);
if (ret) {
dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret);
return ret;
}
drvdata->enable = true;
return 0;
}
static void lm3530_led_disable(struct lm3530_data *drvdata)
{
int ret;
if (!drvdata->enable)
return;
ret = regulator_disable(drvdata->regulator);
if (ret) {
dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n",
ret);
return;
}
drvdata->enable = false;
}
static int lm3530_init_registers(struct lm3530_data *drvdata)
{
int ret = 0;
int i;
u8 gen_config;
u8 brt_ramp;
u8 brightness;
u8 reg_val[LM3530_REG_MAX];
struct lm3530_platform_data *pdata = drvdata->pdata;
struct i2c_client *client = drvdata->client;
struct lm3530_pwm_data *pwm = &pdata->pwm_data;
struct lm3530_als_data als;
memset(&als, 0, sizeof(struct lm3530_als_data));
gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
switch (drvdata->mode) {
case LM3530_BL_MODE_MANUAL:
gen_config |= LM3530_ENABLE_I2C;
break;
case LM3530_BL_MODE_ALS:
gen_config |= LM3530_ENABLE_I2C;
lm3530_als_configure(pdata, &als);
break;
case LM3530_BL_MODE_PWM:
gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
(pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
break;
}
brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
(pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
if (drvdata->brightness)
brightness = drvdata->brightness;
else
brightness = drvdata->brightness = pdata->brt_val;
if (brightness > drvdata->led_dev.max_brightness)
brightness = drvdata->led_dev.max_brightness;
reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
reg_val[1] = als.config; /* LM3530_ALS_CONFIG */
reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
reg_val[3] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */
reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */
reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */
reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */
reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */
reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */
reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
ret = lm3530_led_enable(drvdata);
if (ret)
return ret;
for (i = 0; i < LM3530_REG_MAX; i++) {
/* do not update brightness register when pwm mode */
if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
drvdata->mode == LM3530_BL_MODE_PWM) {
if (pwm->pwm_set_intensity)
pwm->pwm_set_intensity(reg_val[i],
drvdata->led_dev.max_brightness);
continue;
}
ret = i2c_smbus_write_byte_data(client,
lm3530_reg[i], reg_val[i]);
if (ret)
break;
}
return ret;
}
static void lm3530_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brt_val)
{
int err;
struct lm3530_data *drvdata =
container_of(led_cdev, struct lm3530_data, led_dev);
struct lm3530_platform_data *pdata = drvdata->pdata;
struct lm3530_pwm_data *pwm = &pdata->pwm_data;
u8 max_brightness = led_cdev->max_brightness;
switch (drvdata->mode) {
case LM3530_BL_MODE_MANUAL:
if (!drvdata->enable) {
err = lm3530_init_registers(drvdata);
if (err) {
dev_err(&drvdata->client->dev,
"Register Init failed: %d\n", err);
break;
}
}
/* set the brightness in brightness control register*/
err = i2c_smbus_write_byte_data(drvdata->client,
LM3530_BRT_CTRL_REG, brt_val);
if (err)
dev_err(&drvdata->client->dev,
"Unable to set brightness: %d\n", err);
else
drvdata->brightness = brt_val;
if (brt_val == 0)
lm3530_led_disable(drvdata);
break;
case LM3530_BL_MODE_ALS:
break;
case LM3530_BL_MODE_PWM:
if (pwm->pwm_set_intensity)
pwm->pwm_set_intensity(brt_val, max_brightness);
break;
default:
break;
}
}
static ssize_t mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct lm3530_data *drvdata;
int i, len = 0;
drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
for (i = 0; i < ARRAY_SIZE(mode_map); i++)
if (drvdata->mode == mode_map[i].mode_val)
len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
else
len += sprintf(buf + len, "%s ", mode_map[i].mode);
len += sprintf(buf + len, "\n");
return len;
}
static ssize_t mode_store(struct device *dev, struct device_attribute
*attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct lm3530_data *drvdata;
struct lm3530_pwm_data *pwm;
u8 max_brightness;
int mode, err;
drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
pwm = &drvdata->pdata->pwm_data;
max_brightness = led_cdev->max_brightness;
mode = lm3530_get_mode_from_str(buf);
if (mode < 0) {
dev_err(dev, "Invalid mode\n");
return mode;
}
drvdata->mode = mode;
/* set pwm to low if unnecessary */
if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
pwm->pwm_set_intensity(0, max_brightness);
err = lm3530_init_registers(drvdata);
if (err) {
dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
return err;
}
return sizeof(drvdata->mode);
}
static DEVICE_ATTR_RW(mode);
static struct attribute *lm3530_attrs[] = {
&dev_attr_mode.attr,
NULL
};
ATTRIBUTE_GROUPS(lm3530);
static int lm3530_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lm3530_platform_data *pdata = dev_get_platdata(&client->dev);
struct lm3530_data *drvdata;
int err = 0;
if (pdata == NULL) {
dev_err(&client->dev, "platform data required\n");
return -ENODEV;
}
/* BL mode */
if (pdata->mode > LM3530_BL_MODE_PWM) {
dev_err(&client->dev, "Illegal Mode request\n");
return -EINVAL;
}
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
return -EIO;
}
drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
drvdata->mode = pdata->mode;
drvdata->client = client;
drvdata->pdata = pdata;
drvdata->brightness = LED_OFF;
drvdata->enable = false;
drvdata->led_dev.name = LM3530_LED_DEV;
drvdata->led_dev.brightness_set = lm3530_brightness_set;
drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
drvdata->led_dev.groups = lm3530_groups;
i2c_set_clientdata(client, drvdata);
drvdata->regulator = devm_regulator_get(&client->dev, "vin");
if (IS_ERR(drvdata->regulator)) {
dev_err(&client->dev, "regulator get failed\n");
err = PTR_ERR(drvdata->regulator);
drvdata->regulator = NULL;
return err;
}
if (drvdata->pdata->brt_val) {
err = lm3530_init_registers(drvdata);
if (err < 0) {
dev_err(&client->dev,
"Register Init failed: %d\n", err);
return err;
}
}
err = led_classdev_register(&client->dev, &drvdata->led_dev);
if (err < 0) {
dev_err(&client->dev, "Register led class failed: %d\n", err);
return err;
}
return 0;
}
static void lm3530_remove(struct i2c_client *client)
{
struct lm3530_data *drvdata = i2c_get_clientdata(client);
lm3530_led_disable(drvdata);
led_classdev_unregister(&drvdata->led_dev);
}
static const struct i2c_device_id lm3530_id[] = {
{LM3530_NAME, 0},
{}
};
MODULE_DEVICE_TABLE(i2c, lm3530_id);
static struct i2c_driver lm3530_i2c_driver = {
.probe = lm3530_probe,
.remove = lm3530_remove,
.id_table = lm3530_id,
.driver = {
.name = LM3530_NAME,
},
};
module_i2c_driver(lm3530_i2c_driver);
MODULE_DESCRIPTION("Back Light driver for LM3530");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
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