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linux/drivers/leds/leds-lm3692x.c
Uwe Kleine-König cf642faef7 leds: lm3692x: Return 0 from remove callback 
The only difference between returning zero or a non-zero value is that
for the non-zero case the i2c will print a generic error message
("remove failed (-ESOMETHING), will be ignored").

In this case however the driver itself already emitted a more helpful
error message, so the additional error message isn't helpful at all.

The long-term goal is to make the i2c remove callback return void, making
all implementations return 0 is preparatory work for this change.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
2022-02-12 13:02:50 +01:00

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13 KiB
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// SPDX-License-Identifier: GPL-2.0
// TI LM3692x LED chip family driver
// Copyright (C) 2017-18 Texas Instruments Incorporated - https://www.ti.com/
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/leds.h>
#include <linux/log2.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#define LM36922_MODEL 0
#define LM36923_MODEL 1
#define LM3692X_REV 0x0
#define LM3692X_RESET 0x1
#define LM3692X_EN 0x10
#define LM3692X_BRT_CTRL 0x11
#define LM3692X_PWM_CTRL 0x12
#define LM3692X_BOOST_CTRL 0x13
#define LM3692X_AUTO_FREQ_HI 0x15
#define LM3692X_AUTO_FREQ_LO 0x16
#define LM3692X_BL_ADJ_THRESH 0x17
#define LM3692X_BRT_LSB 0x18
#define LM3692X_BRT_MSB 0x19
#define LM3692X_FAULT_CTRL 0x1e
#define LM3692X_FAULT_FLAGS 0x1f
#define LM3692X_SW_RESET BIT(0)
#define LM3692X_DEVICE_EN BIT(0)
#define LM3692X_LED1_EN BIT(1)
#define LM3692X_LED2_EN BIT(2)
#define LM36923_LED3_EN BIT(3)
#define LM3692X_ENABLE_MASK (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
LM3692X_LED2_EN | LM36923_LED3_EN)
/* Brightness Control Bits */
#define LM3692X_BL_ADJ_POL BIT(0)
#define LM3692X_RAMP_RATE_125us 0x00
#define LM3692X_RAMP_RATE_250us BIT(1)
#define LM3692X_RAMP_RATE_500us BIT(2)
#define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2))
#define LM3692X_RAMP_RATE_2ms BIT(3)
#define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1))
#define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3))
#define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3))
#define LM3692X_RAMP_EN BIT(4)
#define LM3692X_BRHT_MODE_REG 0x00
#define LM3692X_BRHT_MODE_PWM BIT(5)
#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
#define LM3692X_MAP_MODE_EXP BIT(7)
/* PWM Register Bits */
#define LM3692X_PWM_FILTER_100 BIT(0)
#define LM3692X_PWM_FILTER_150 BIT(1)
#define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1))
#define LM3692X_PWM_HYSTER_1LSB BIT(2)
#define LM3692X_PWM_HYSTER_2LSB BIT(3)
#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
#define LM3692X_PWM_HYSTER_4LSB BIT(4)
#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
#define LM3692X_PWM_POLARITY BIT(5)
#define LM3692X_PWM_SAMP_4MHZ BIT(6)
#define LM3692X_PWM_SAMP_24MHZ BIT(7)
/* Boost Control Bits */
#define LM3692X_OCP_PROT_1A BIT(0)
#define LM3692X_OCP_PROT_1_25A BIT(1)
#define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1))
#define LM3692X_OVP_21V BIT(2)
#define LM3692X_OVP_25V BIT(3)
#define LM3692X_OVP_29V (BIT(2) | BIT(3))
#define LM3692X_MIN_IND_22UH BIT(4)
#define LM3692X_BOOST_SW_1MHZ BIT(5)
#define LM3692X_BOOST_SW_NO_SHIFT BIT(6)
/* Fault Control Bits */
#define LM3692X_FAULT_CTRL_OVP BIT(0)
#define LM3692X_FAULT_CTRL_OCP BIT(1)
#define LM3692X_FAULT_CTRL_TSD BIT(2)
#define LM3692X_FAULT_CTRL_OPEN BIT(3)
/* Fault Flag Bits */
#define LM3692X_FAULT_FLAG_OVP BIT(0)
#define LM3692X_FAULT_FLAG_OCP BIT(1)
#define LM3692X_FAULT_FLAG_TSD BIT(2)
#define LM3692X_FAULT_FLAG_SHRT BIT(3)
#define LM3692X_FAULT_FLAG_OPEN BIT(4)
/**
* struct lm3692x_led
* @lock: Lock for reading/writing the device
* @client: Pointer to the I2C client
* @led_dev: LED class device pointer
* @regmap: Devices register map
* @enable_gpio: VDDIO/EN gpio to enable communication interface
* @regulator: LED supply regulator pointer
* @led_enable: LED sync to be enabled
* @model_id: Current device model ID enumerated
*/
struct lm3692x_led {
struct mutex lock;
struct i2c_client *client;
struct led_classdev led_dev;
struct regmap *regmap;
struct gpio_desc *enable_gpio;
struct regulator *regulator;
int led_enable;
int model_id;
u8 boost_ctrl, brightness_ctrl;
bool enabled;
};
static const struct reg_default lm3692x_reg_defs[] = {
{LM3692X_EN, 0xf},
{LM3692X_BRT_CTRL, 0x61},
{LM3692X_PWM_CTRL, 0x73},
{LM3692X_BOOST_CTRL, 0x6f},
{LM3692X_AUTO_FREQ_HI, 0x0},
{LM3692X_AUTO_FREQ_LO, 0x0},
{LM3692X_BL_ADJ_THRESH, 0x0},
{LM3692X_BRT_LSB, 0x7},
{LM3692X_BRT_MSB, 0xff},
{LM3692X_FAULT_CTRL, 0x7},
};
static const struct regmap_config lm3692x_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = LM3692X_FAULT_FLAGS,
.reg_defaults = lm3692x_reg_defs,
.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
.cache_type = REGCACHE_RBTREE,
};
static int lm3692x_fault_check(struct lm3692x_led *led)
{
int ret;
unsigned int read_buf;
ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
if (ret)
return ret;
if (read_buf)
dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
/* The first read may clear the fault. Check again to see if the fault
* still exits and return that value.
*/
regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
if (read_buf)
dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
read_buf);
return read_buf;
}
static int lm3692x_leds_enable(struct lm3692x_led *led)
{
int enable_state;
int ret, reg_ret;
if (led->enabled)
return 0;
if (led->regulator) {
ret = regulator_enable(led->regulator);
if (ret) {
dev_err(&led->client->dev,
"Failed to enable regulator: %d\n", ret);
return ret;
}
}
if (led->enable_gpio)
gpiod_direction_output(led->enable_gpio, 1);
ret = lm3692x_fault_check(led);
if (ret) {
dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
ret);
goto out;
}
ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
if (ret)
goto out;
/*
* For glitch free operation, the following data should
* only be written while LEDx enable bits are 0 and the device enable
* bit is set to 1.
* per Section 7.5.14 of the data sheet
*/
ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
if (ret)
goto out;
/* Set the brightness to 0 so when enabled the LEDs do not come
* on with full brightness.
*/
ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
if (ret)
goto out;
ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
if (ret)
goto out;
switch (led->led_enable) {
case 0:
default:
if (led->model_id == LM36923_MODEL)
enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
LM36923_LED3_EN;
else
enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
break;
case 1:
enable_state = LM3692X_LED1_EN;
break;
case 2:
enable_state = LM3692X_LED2_EN;
break;
case 3:
if (led->model_id == LM36923_MODEL) {
enable_state = LM36923_LED3_EN;
break;
}
ret = -EINVAL;
dev_err(&led->client->dev,
"LED3 sync not available on this device\n");
goto out;
}
ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
enable_state | LM3692X_DEVICE_EN);
led->enabled = true;
return ret;
out:
dev_err(&led->client->dev, "Fail writing initialization values\n");
if (led->enable_gpio)
gpiod_direction_output(led->enable_gpio, 0);
if (led->regulator) {
reg_ret = regulator_disable(led->regulator);
if (reg_ret)
dev_err(&led->client->dev,
"Failed to disable regulator: %d\n", reg_ret);
}
return ret;
}
static int lm3692x_leds_disable(struct lm3692x_led *led)
{
int ret;
if (!led->enabled)
return 0;
ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
if (ret) {
dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
ret);
return ret;
}
if (led->enable_gpio)
gpiod_direction_output(led->enable_gpio, 0);
if (led->regulator) {
ret = regulator_disable(led->regulator);
if (ret)
dev_err(&led->client->dev,
"Failed to disable regulator: %d\n", ret);
}
led->enabled = false;
return ret;
}
static int lm3692x_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brt_val)
{
struct lm3692x_led *led =
container_of(led_cdev, struct lm3692x_led, led_dev);
int ret;
int led_brightness_lsb = (brt_val >> 5);
mutex_lock(&led->lock);
if (brt_val == 0) {
ret = lm3692x_leds_disable(led);
goto out;
} else {
lm3692x_leds_enable(led);
}
ret = lm3692x_fault_check(led);
if (ret) {
dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
ret);
goto out;
}
ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
if (ret) {
dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
goto out;
}
ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
if (ret) {
dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
goto out;
}
out:
mutex_unlock(&led->lock);
return ret;
}
static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
u32 max_cur)
{
u32 max_code;
/* see p.12 of LM36922 data sheet for brightness formula */
max_code = ((max_cur * 1000) - 37806) / 12195;
if (max_code > 0x7FF)
max_code = 0x7FF;
return max_code >> 3;
}
static int lm3692x_probe_dt(struct lm3692x_led *led)
{
struct fwnode_handle *child = NULL;
struct led_init_data init_data = {};
u32 ovp, max_cur;
int ret;
led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
"enable", GPIOD_OUT_LOW);
if (IS_ERR(led->enable_gpio)) {
ret = PTR_ERR(led->enable_gpio);
dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
ret);
return ret;
}
led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
if (IS_ERR(led->regulator)) {
ret = PTR_ERR(led->regulator);
if (ret != -ENODEV)
return dev_err_probe(&led->client->dev, ret,
"Failed to get vled regulator\n");
led->regulator = NULL;
}
led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
LM3692X_BOOST_SW_NO_SHIFT |
LM3692X_OCP_PROT_1_5A;
ret = device_property_read_u32(&led->client->dev,
"ti,ovp-microvolt", &ovp);
if (ret) {
led->boost_ctrl |= LM3692X_OVP_29V;
} else {
switch (ovp) {
case 17000000:
break;
case 21000000:
led->boost_ctrl |= LM3692X_OVP_21V;
break;
case 25000000:
led->boost_ctrl |= LM3692X_OVP_25V;
break;
case 29000000:
led->boost_ctrl |= LM3692X_OVP_29V;
break;
default:
dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
return -EINVAL;
}
}
child = device_get_next_child_node(&led->client->dev, child);
if (!child) {
dev_err(&led->client->dev, "No LED Child node\n");
return -ENODEV;
}
ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
if (ret) {
fwnode_handle_put(child);
dev_err(&led->client->dev, "reg DT property missing\n");
return ret;
}
ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur);
led->led_dev.max_brightness = ret ? LED_FULL :
lm3692x_max_brightness(led, max_cur);
init_data.fwnode = child;
init_data.devicename = led->client->name;
init_data.default_label = ":";
ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
&init_data);
if (ret)
dev_err(&led->client->dev, "led register err: %d\n", ret);
fwnode_handle_put(init_data.fwnode);
return ret;
}
static int lm3692x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lm3692x_led *led;
int ret;
led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;
mutex_init(&led->lock);
led->client = client;
led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
led->model_id = id->driver_data;
i2c_set_clientdata(client, led);
led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
if (IS_ERR(led->regmap)) {
ret = PTR_ERR(led->regmap);
dev_err(&client->dev, "Failed to allocate register map: %d\n",
ret);
return ret;
}
ret = lm3692x_probe_dt(led);
if (ret)
return ret;
ret = lm3692x_leds_enable(led);
if (ret)
return ret;
return 0;
}
static int lm3692x_remove(struct i2c_client *client)
{
struct lm3692x_led *led = i2c_get_clientdata(client);
lm3692x_leds_disable(led);
mutex_destroy(&led->lock);
return 0;
}
static const struct i2c_device_id lm3692x_id[] = {
{ "lm36922", LM36922_MODEL },
{ "lm36923", LM36923_MODEL },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm3692x_id);
static const struct of_device_id of_lm3692x_leds_match[] = {
{ .compatible = "ti,lm36922", },
{ .compatible = "ti,lm36923", },
{},
};
MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
static struct i2c_driver lm3692x_driver = {
.driver = {
.name = "lm3692x",
.of_match_table = of_lm3692x_leds_match,
},
.probe = lm3692x_probe,
.remove = lm3692x_remove,
.id_table = lm3692x_id,
};
module_i2c_driver(lm3692x_driver);
MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");
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