linux/drivers/video/backlight/lm3630a_bl.c
Lee Jones 3e799ccda3 backlight: lm3630a_bl: Remove invalid checks for unsigned int < 0
unsigned ints 'sources' and 'bank' cannot be less than LM3630A_SINK_0 (0)
and LM3630A_BANK_0 (0) respecitively, so change the logic to only check
for thier two possible valid values.

Fixes W=1 warnings:

 drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_led_sources’:
 drivers/video/backlight/lm3630a_bl.c:394:18: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
 394 | if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
 | ^
 drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_bank’:
 drivers/video/backlight/lm3630a_bl.c:415:11: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
 415 | if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
 | ^

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Jeong <gshark.jeong@gmail.com>
Cc: LDD MLP <ldd-mlp@list.ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-07-06 08:11:43 +01:00

635 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Simple driver for Texas Instruments LM3630A Backlight driver chip
* Copyright (C) 2012 Texas Instruments
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/gpio/consumer.h>
#include <linux/pwm.h>
#include <linux/platform_data/lm3630a_bl.h>
#define REG_CTRL 0x00
#define REG_BOOST 0x02
#define REG_CONFIG 0x01
#define REG_BRT_A 0x03
#define REG_BRT_B 0x04
#define REG_I_A 0x05
#define REG_I_B 0x06
#define REG_INT_STATUS 0x09
#define REG_INT_EN 0x0A
#define REG_FAULT 0x0B
#define REG_PWM_OUTLOW 0x12
#define REG_PWM_OUTHIGH 0x13
#define REG_FILTER_STRENGTH 0x50
#define REG_MAX 0x50
#define INT_DEBOUNCE_MSEC 10
#define LM3630A_BANK_0 0
#define LM3630A_BANK_1 1
#define LM3630A_NUM_SINKS 2
#define LM3630A_SINK_0 0
#define LM3630A_SINK_1 1
struct lm3630a_chip {
struct device *dev;
struct delayed_work work;
int irq;
struct workqueue_struct *irqthread;
struct lm3630a_platform_data *pdata;
struct backlight_device *bleda;
struct backlight_device *bledb;
struct gpio_desc *enable_gpio;
struct regmap *regmap;
struct pwm_device *pwmd;
};
/* i2c access */
static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
{
int rval;
unsigned int reg_val;
rval = regmap_read(pchip->regmap, reg, &reg_val);
if (rval < 0)
return rval;
return reg_val & 0xFF;
}
static int lm3630a_write(struct lm3630a_chip *pchip,
unsigned int reg, unsigned int data)
{
return regmap_write(pchip->regmap, reg, data);
}
static int lm3630a_update(struct lm3630a_chip *pchip,
unsigned int reg, unsigned int mask,
unsigned int data)
{
return regmap_update_bits(pchip->regmap, reg, mask, data);
}
/* initialize chip */
static int lm3630a_chip_init(struct lm3630a_chip *pchip)
{
int rval;
struct lm3630a_platform_data *pdata = pchip->pdata;
usleep_range(1000, 2000);
/* set Filter Strength Register */
rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03);
/* set Cofig. register */
rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
/* set boost control */
rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
/* set current A */
rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
/* set current B */
rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
/* set control */
rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
usleep_range(1000, 2000);
/* set brightness A and B */
rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);
if (rval < 0)
dev_err(pchip->dev, "i2c failed to access register\n");
return rval;
}
/* interrupt handling */
static void lm3630a_delayed_func(struct work_struct *work)
{
int rval;
struct lm3630a_chip *pchip;
pchip = container_of(work, struct lm3630a_chip, work.work);
rval = lm3630a_read(pchip, REG_INT_STATUS);
if (rval < 0) {
dev_err(pchip->dev,
"i2c failed to access REG_INT_STATUS Register\n");
return;
}
dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
}
static irqreturn_t lm3630a_isr_func(int irq, void *chip)
{
int rval;
struct lm3630a_chip *pchip = chip;
unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);
queue_delayed_work(pchip->irqthread, &pchip->work, delay);
rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
if (rval < 0) {
dev_err(pchip->dev, "i2c failed to access register\n");
return IRQ_NONE;
}
return IRQ_HANDLED;
}
static int lm3630a_intr_config(struct lm3630a_chip *pchip)
{
int rval;
rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
if (rval < 0)
return rval;
INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
if (!pchip->irqthread) {
dev_err(pchip->dev, "create irq thread fail\n");
return -ENOMEM;
}
if (request_threaded_irq
(pchip->irq, NULL, lm3630a_isr_func,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
dev_err(pchip->dev, "request threaded irq fail\n");
destroy_workqueue(pchip->irqthread);
return -ENOMEM;
}
return rval;
}
static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
{
unsigned int period = pchip->pdata->pwm_period;
unsigned int duty = br * period / br_max;
pwm_config(pchip->pwmd, duty, period);
if (duty)
pwm_enable(pchip->pwmd);
else
pwm_disable(pchip->pwmd);
}
/* update and get brightness */
static int lm3630a_bank_a_update_status(struct backlight_device *bl)
{
int ret;
struct lm3630a_chip *pchip = bl_get_data(bl);
enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
/* pwm control */
if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
lm3630a_pwm_ctrl(pchip, bl->props.brightness,
bl->props.max_brightness);
return bl->props.brightness;
}
/* disable sleep */
ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
if (ret < 0)
goto out_i2c_err;
usleep_range(1000, 2000);
/* minimum brightness is 0x04 */
ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
if (bl->props.brightness < 0x4)
ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
else
ret |= lm3630a_update(pchip, REG_CTRL,
LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
if (ret < 0)
goto out_i2c_err;
return 0;
out_i2c_err:
dev_err(pchip->dev, "i2c failed to access\n");
return bl->props.brightness;
}
static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
{
int brightness, rval;
struct lm3630a_chip *pchip = bl_get_data(bl);
enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
if (rval < 0)
goto out_i2c_err;
brightness = (rval & 0x01) << 8;
rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
if (rval < 0)
goto out_i2c_err;
brightness |= rval;
goto out;
}
/* disable sleep */
rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
if (rval < 0)
goto out_i2c_err;
usleep_range(1000, 2000);
rval = lm3630a_read(pchip, REG_BRT_A);
if (rval < 0)
goto out_i2c_err;
brightness = rval;
out:
bl->props.brightness = brightness;
return bl->props.brightness;
out_i2c_err:
dev_err(pchip->dev, "i2c failed to access register\n");
return 0;
}
static const struct backlight_ops lm3630a_bank_a_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = lm3630a_bank_a_update_status,
.get_brightness = lm3630a_bank_a_get_brightness,
};
/* update and get brightness */
static int lm3630a_bank_b_update_status(struct backlight_device *bl)
{
int ret;
struct lm3630a_chip *pchip = bl_get_data(bl);
enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
/* pwm control */
if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
lm3630a_pwm_ctrl(pchip, bl->props.brightness,
bl->props.max_brightness);
return bl->props.brightness;
}
/* disable sleep */
ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
if (ret < 0)
goto out_i2c_err;
usleep_range(1000, 2000);
/* minimum brightness is 0x04 */
ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
if (bl->props.brightness < 0x4)
ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
else
ret |= lm3630a_update(pchip, REG_CTRL,
LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
if (ret < 0)
goto out_i2c_err;
return 0;
out_i2c_err:
dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
return bl->props.brightness;
}
static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
{
int brightness, rval;
struct lm3630a_chip *pchip = bl_get_data(bl);
enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
if (rval < 0)
goto out_i2c_err;
brightness = (rval & 0x01) << 8;
rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
if (rval < 0)
goto out_i2c_err;
brightness |= rval;
goto out;
}
/* disable sleep */
rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
if (rval < 0)
goto out_i2c_err;
usleep_range(1000, 2000);
rval = lm3630a_read(pchip, REG_BRT_B);
if (rval < 0)
goto out_i2c_err;
brightness = rval;
out:
bl->props.brightness = brightness;
return bl->props.brightness;
out_i2c_err:
dev_err(pchip->dev, "i2c failed to access register\n");
return 0;
}
static const struct backlight_ops lm3630a_bank_b_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = lm3630a_bank_b_update_status,
.get_brightness = lm3630a_bank_b_get_brightness,
};
static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
{
struct lm3630a_platform_data *pdata = pchip->pdata;
struct backlight_properties props;
const char *label;
props.type = BACKLIGHT_RAW;
if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
props.brightness = pdata->leda_init_brt;
props.max_brightness = pdata->leda_max_brt;
label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda";
pchip->bleda =
devm_backlight_device_register(pchip->dev, label,
pchip->dev, pchip,
&lm3630a_bank_a_ops, &props);
if (IS_ERR(pchip->bleda))
return PTR_ERR(pchip->bleda);
}
if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
(pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
props.brightness = pdata->ledb_init_brt;
props.max_brightness = pdata->ledb_max_brt;
label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb";
pchip->bledb =
devm_backlight_device_register(pchip->dev, label,
pchip->dev, pchip,
&lm3630a_bank_b_ops, &props);
if (IS_ERR(pchip->bledb))
return PTR_ERR(pchip->bledb);
}
return 0;
}
static const struct regmap_config lm3630a_regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = REG_MAX,
};
static int lm3630a_parse_led_sources(struct fwnode_handle *node,
int default_led_sources)
{
u32 sources[LM3630A_NUM_SINKS];
int ret, num_sources, i;
num_sources = fwnode_property_count_u32(node, "led-sources");
if (num_sources < 0)
return default_led_sources;
else if (num_sources > ARRAY_SIZE(sources))
return -EINVAL;
ret = fwnode_property_read_u32_array(node, "led-sources", sources,
num_sources);
if (ret)
return ret;
for (i = 0; i < num_sources; i++) {
if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
return -EINVAL;
ret |= BIT(sources[i]);
}
return ret;
}
static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
struct fwnode_handle *node, int *seen_led_sources)
{
int led_sources, ret;
const char *label;
u32 bank, val;
bool linear;
ret = fwnode_property_read_u32(node, "reg", &bank);
if (ret)
return ret;
if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
return -EINVAL;
led_sources = lm3630a_parse_led_sources(node, BIT(bank));
if (led_sources < 0)
return led_sources;
if (*seen_led_sources & led_sources)
return -EINVAL;
*seen_led_sources |= led_sources;
linear = fwnode_property_read_bool(node,
"ti,linear-mapping-mode");
if (bank) {
if (led_sources & BIT(LM3630A_SINK_0) ||
!(led_sources & BIT(LM3630A_SINK_1)))
return -EINVAL;
pdata->ledb_ctrl = linear ?
LM3630A_LEDB_ENABLE_LINEAR :
LM3630A_LEDB_ENABLE;
} else {
if (!(led_sources & BIT(LM3630A_SINK_0)))
return -EINVAL;
pdata->leda_ctrl = linear ?
LM3630A_LEDA_ENABLE_LINEAR :
LM3630A_LEDA_ENABLE;
if (led_sources & BIT(LM3630A_SINK_1))
pdata->ledb_ctrl = LM3630A_LEDB_ON_A;
}
ret = fwnode_property_read_string(node, "label", &label);
if (!ret) {
if (bank)
pdata->ledb_label = label;
else
pdata->leda_label = label;
}
ret = fwnode_property_read_u32(node, "default-brightness",
&val);
if (!ret) {
if (bank)
pdata->ledb_init_brt = val;
else
pdata->leda_init_brt = val;
}
ret = fwnode_property_read_u32(node, "max-brightness", &val);
if (!ret) {
if (bank)
pdata->ledb_max_brt = val;
else
pdata->leda_max_brt = val;
}
return 0;
}
static int lm3630a_parse_node(struct lm3630a_chip *pchip,
struct lm3630a_platform_data *pdata)
{
int ret = -ENODEV, seen_led_sources = 0;
struct fwnode_handle *node;
device_for_each_child_node(pchip->dev, node) {
ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
if (ret)
return ret;
}
return ret;
}
static int lm3630a_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
struct lm3630a_chip *pchip;
int rval;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "fail : i2c functionality check\n");
return -EOPNOTSUPP;
}
pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
GFP_KERNEL);
if (!pchip)
return -ENOMEM;
pchip->dev = &client->dev;
pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
if (IS_ERR(pchip->regmap)) {
rval = PTR_ERR(pchip->regmap);
dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
return rval;
}
i2c_set_clientdata(client, pchip);
if (pdata == NULL) {
pdata = devm_kzalloc(pchip->dev,
sizeof(struct lm3630a_platform_data),
GFP_KERNEL);
if (pdata == NULL)
return -ENOMEM;
/* default values */
pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
rval = lm3630a_parse_node(pchip, pdata);
if (rval) {
dev_err(&client->dev, "fail : parse node\n");
return rval;
}
}
pchip->pdata = pdata;
pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
GPIOD_OUT_HIGH);
if (IS_ERR(pchip->enable_gpio)) {
rval = PTR_ERR(pchip->enable_gpio);
return rval;
}
/* chip initialize */
rval = lm3630a_chip_init(pchip);
if (rval < 0) {
dev_err(&client->dev, "fail : init chip\n");
return rval;
}
/* backlight register */
rval = lm3630a_backlight_register(pchip);
if (rval < 0) {
dev_err(&client->dev, "fail : backlight register.\n");
return rval;
}
/* pwm */
if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
if (IS_ERR(pchip->pwmd)) {
dev_err(&client->dev, "fail : get pwm device\n");
return PTR_ERR(pchip->pwmd);
}
/*
* FIXME: pwm_apply_args() should be removed when switching to
* the atomic PWM API.
*/
pwm_apply_args(pchip->pwmd);
}
/* interrupt enable : irq 0 is not allowed */
pchip->irq = client->irq;
if (pchip->irq) {
rval = lm3630a_intr_config(pchip);
if (rval < 0)
return rval;
}
dev_info(&client->dev, "LM3630A backlight register OK.\n");
return 0;
}
static int lm3630a_remove(struct i2c_client *client)
{
int rval;
struct lm3630a_chip *pchip = i2c_get_clientdata(client);
rval = lm3630a_write(pchip, REG_BRT_A, 0);
if (rval < 0)
dev_err(pchip->dev, "i2c failed to access register\n");
rval = lm3630a_write(pchip, REG_BRT_B, 0);
if (rval < 0)
dev_err(pchip->dev, "i2c failed to access register\n");
if (pchip->irq) {
free_irq(pchip->irq, pchip);
flush_workqueue(pchip->irqthread);
destroy_workqueue(pchip->irqthread);
}
return 0;
}
static const struct i2c_device_id lm3630a_id[] = {
{LM3630A_NAME, 0},
{}
};
MODULE_DEVICE_TABLE(i2c, lm3630a_id);
static const struct of_device_id lm3630a_match_table[] = {
{ .compatible = "ti,lm3630a", },
{ },
};
MODULE_DEVICE_TABLE(of, lm3630a_match_table);
static struct i2c_driver lm3630a_i2c_driver = {
.driver = {
.name = LM3630A_NAME,
.of_match_table = lm3630a_match_table,
},
.probe = lm3630a_probe,
.remove = lm3630a_remove,
.id_table = lm3630a_id,
};
module_i2c_driver(lm3630a_i2c_driver);
MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
MODULE_LICENSE("GPL v2");