linux/drivers/leds/leds-aw200xx.c
Javier Carrasco a361af3c16 leds: aw200xx: Switch to device_for_each_child_node_scoped()
Switch to device_for_each_child_node_scoped() to simplify the code by
removing the need for calls to fwnode_handle_put() in the error paths.

This also prevents possible memory leaks if new error paths are added
without the required call to fwnode_handle_put().

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240927-leds_device_for_each_child_node_scoped-v1-4-95c0614b38c8@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-10-09 15:16:42 +01:00

670 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Awinic AW20036/AW20054/AW20072/AW20108 LED driver
*
* Copyright (c) 2023, SberDevices. All Rights Reserved.
*
* Author: Martin Kurbanov <mmkurbanov@sberdevices.ru>
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/container_of.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/time.h>
#include <linux/units.h>
#define AW200XX_DIM_MAX (BIT(6) - 1)
#define AW200XX_FADE_MAX (BIT(8) - 1)
#define AW200XX_IMAX_DEFAULT_uA 60000
#define AW200XX_IMAX_MAX_uA 160000
#define AW200XX_IMAX_MIN_uA 3300
/* Page 0 */
#define AW200XX_REG_PAGE0_BASE 0xc000
/* Select page register */
#define AW200XX_REG_PAGE 0xF0
#define AW200XX_PAGE_MASK (GENMASK(7, 6) | GENMASK(2, 0))
#define AW200XX_PAGE_SHIFT 0
#define AW200XX_NUM_PAGES 6
#define AW200XX_PAGE_SIZE 256
#define AW200XX_REG(page, reg) \
(AW200XX_REG_PAGE0_BASE + (page) * AW200XX_PAGE_SIZE + (reg))
#define AW200XX_REG_MAX \
AW200XX_REG(AW200XX_NUM_PAGES - 1, AW200XX_PAGE_SIZE - 1)
#define AW200XX_PAGE0 0
#define AW200XX_PAGE1 1
#define AW200XX_PAGE2 2
#define AW200XX_PAGE3 3
#define AW200XX_PAGE4 4
#define AW200XX_PAGE5 5
/* Chip ID register */
#define AW200XX_REG_IDR AW200XX_REG(AW200XX_PAGE0, 0x00)
#define AW200XX_IDR_CHIPID 0x18
/* Sleep mode register */
#define AW200XX_REG_SLPCR AW200XX_REG(AW200XX_PAGE0, 0x01)
#define AW200XX_SLPCR_ACTIVE 0x00
/* Reset register */
#define AW200XX_REG_RSTR AW200XX_REG(AW200XX_PAGE0, 0x02)
#define AW200XX_RSTR_RESET 0x01
/* Global current configuration register */
#define AW200XX_REG_GCCR AW200XX_REG(AW200XX_PAGE0, 0x03)
#define AW200XX_GCCR_IMAX_MASK GENMASK(7, 4)
#define AW200XX_GCCR_IMAX(x) ((x) << 4)
#define AW200XX_GCCR_ALLON BIT(3)
/* Fast clear display control register */
#define AW200XX_REG_FCD AW200XX_REG(AW200XX_PAGE0, 0x04)
#define AW200XX_FCD_CLEAR 0x01
/* Display size configuration */
#define AW200XX_REG_DSIZE AW200XX_REG(AW200XX_PAGE0, 0x80)
#define AW200XX_DSIZE_COLUMNS_MAX 12
#define AW200XX_LED2REG(x, columns) \
((x) + (((x) / (columns)) * (AW200XX_DSIZE_COLUMNS_MAX - (columns))))
/* DIM current configuration register on page 1 */
#define AW200XX_REG_DIM_PAGE1(x, columns) \
AW200XX_REG(AW200XX_PAGE1, AW200XX_LED2REG(x, columns))
/*
* DIM current configuration register (page 4).
* The even address for current DIM configuration.
* The odd address for current FADE configuration
*/
#define AW200XX_REG_DIM(x, columns) \
AW200XX_REG(AW200XX_PAGE4, AW200XX_LED2REG(x, columns) * 2)
#define AW200XX_REG_DIM2FADE(x) ((x) + 1)
#define AW200XX_REG_FADE2DIM(fade) \
DIV_ROUND_UP((fade) * AW200XX_DIM_MAX, AW200XX_FADE_MAX)
/*
* Duty ratio of display scan (see p.15 of datasheet for formula):
* duty = (592us / 600.5us) * (1 / (display_rows + 1))
*
* Multiply to 1000 (MILLI) to improve the accuracy of calculations.
*/
#define AW200XX_DUTY_RATIO(rows) \
(((592UL * USEC_PER_SEC) / 600500UL) * (MILLI / (rows)) / MILLI)
struct aw200xx_chipdef {
u32 channels;
u32 display_size_rows_max;
u32 display_size_columns;
};
struct aw200xx_led {
struct led_classdev cdev;
struct aw200xx *chip;
int dim;
u32 num;
};
struct aw200xx {
const struct aw200xx_chipdef *cdef;
struct i2c_client *client;
struct regmap *regmap;
struct mutex mutex;
u32 num_leds;
u32 display_rows;
struct gpio_desc *hwen;
struct aw200xx_led leds[] __counted_by(num_leds);
};
static ssize_t dim_show(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct led_classdev *cdev = dev_get_drvdata(dev);
struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
int dim = led->dim;
if (dim < 0)
return sysfs_emit(buf, "auto\n");
return sysfs_emit(buf, "%d\n", dim);
}
static ssize_t dim_store(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct led_classdev *cdev = dev_get_drvdata(dev);
struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
struct aw200xx *chip = led->chip;
u32 columns = chip->cdef->display_size_columns;
int dim;
ssize_t ret;
if (sysfs_streq(buf, "auto")) {
dim = -1;
} else {
ret = kstrtoint(buf, 0, &dim);
if (ret)
return ret;
if (dim > AW200XX_DIM_MAX)
return -EINVAL;
}
mutex_lock(&chip->mutex);
if (dim >= 0) {
ret = regmap_write(chip->regmap,
AW200XX_REG_DIM_PAGE1(led->num, columns),
dim);
if (ret)
goto out_unlock;
}
led->dim = dim;
ret = count;
out_unlock:
mutex_unlock(&chip->mutex);
return ret;
}
static DEVICE_ATTR_RW(dim);
static struct attribute *dim_attrs[] = {
&dev_attr_dim.attr,
NULL
};
ATTRIBUTE_GROUPS(dim);
static int aw200xx_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
struct aw200xx *chip = led->chip;
int dim;
u32 reg;
int ret;
mutex_lock(&chip->mutex);
reg = AW200XX_REG_DIM(led->num, chip->cdef->display_size_columns);
dim = led->dim;
if (dim < 0)
dim = AW200XX_REG_FADE2DIM(brightness);
ret = regmap_write(chip->regmap, reg, dim);
if (ret)
goto out_unlock;
ret = regmap_write(chip->regmap,
AW200XX_REG_DIM2FADE(reg), brightness);
out_unlock:
mutex_unlock(&chip->mutex);
return ret;
}
static u32 aw200xx_imax_from_global(const struct aw200xx *const chip,
u32 global_imax_uA)
{
u64 led_imax_uA;
/*
* The output current of each LED (see p.14 of datasheet for formula):
* Iled = Imax * (dim / 63) * ((fade + 1) / 256) * duty
*
* The value of duty is determined by the following formula:
* duty = (592us / 600.5us) * (1 / (display_rows + 1))
*
* Calculated for the maximum values of fade and dim.
* We divide by 1000 because we earlier multiplied by 1000 to improve
* accuracy when calculating the duty.
*/
led_imax_uA = global_imax_uA * AW200XX_DUTY_RATIO(chip->display_rows);
do_div(led_imax_uA, MILLI);
return led_imax_uA;
}
static u32 aw200xx_imax_to_global(const struct aw200xx *const chip,
u32 led_imax_uA)
{
u32 duty = AW200XX_DUTY_RATIO(chip->display_rows);
/* The output current of each LED (see p.14 of datasheet for formula) */
return (led_imax_uA * 1000U) / duty;
}
#define AW200XX_IMAX_MULTIPLIER1 10000
#define AW200XX_IMAX_MULTIPLIER2 3333
#define AW200XX_IMAX_BASE_VAL1 0
#define AW200XX_IMAX_BASE_VAL2 8
/*
* The AW200XX has a 4-bit register (GCCR) to configure the global current,
* which ranges from 3.3mA to 160mA. The following table indicates the values
* of the global current, divided into two parts:
*
* +-----------+-----------------+-----------+-----------------+
* | reg value | global max (mA) | reg value | global max (mA) |
* +-----------+-----------------+-----------+-----------------+
* | 0 | 10 | 8 | 3.3 |
* | 1 | 20 | 9 | 6.7 |
* | 2 | 30 | 10 | 10 |
* | 3 | 40 | 11 | 13.3 |
* | 4 | 60 | 12 | 20 |
* | 5 | 80 | 13 | 26.7 |
* | 6 | 120 | 14 | 40 |
* | 7 | 160 | 15 | 53.3 |
* +-----------+-----------------+-----------+-----------------+
*
* The left part with a multiplier of 10, and the right part with a multiplier
* of 3.3.
* So we have two formulas to calculate the global current:
* for the left part of the table:
* imax = coefficient * 10
*
* for the right part of the table:
* imax = coefficient * 3.3
*
* The coefficient table consists of the following values:
* 1, 2, 3, 4, 6, 8, 12, 16.
*/
static int aw200xx_set_imax(const struct aw200xx *const chip,
u32 led_imax_uA)
{
u32 g_imax_uA = aw200xx_imax_to_global(chip, led_imax_uA);
static const u32 coeff_table[] = {1, 2, 3, 4, 6, 8, 12, 16};
u32 gccr_imax = UINT_MAX;
u32 cur_imax = 0;
int i;
for (i = 0; i < ARRAY_SIZE(coeff_table); i++) {
u32 imax;
/* select closest ones */
imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER1;
if (g_imax_uA >= imax && imax > cur_imax) {
cur_imax = imax;
gccr_imax = i + AW200XX_IMAX_BASE_VAL1;
}
imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER2;
imax = DIV_ROUND_CLOSEST(imax, 100) * 100;
if (g_imax_uA >= imax && imax > cur_imax) {
cur_imax = imax;
gccr_imax = i + AW200XX_IMAX_BASE_VAL2;
}
}
if (gccr_imax == UINT_MAX)
return -EINVAL;
return regmap_update_bits(chip->regmap, AW200XX_REG_GCCR,
AW200XX_GCCR_IMAX_MASK,
AW200XX_GCCR_IMAX(gccr_imax));
}
static int aw200xx_chip_reset(const struct aw200xx *const chip)
{
int ret;
ret = regmap_write(chip->regmap, AW200XX_REG_RSTR, AW200XX_RSTR_RESET);
if (ret)
return ret;
/* According to the datasheet software reset takes at least 1ms */
fsleep(1000);
regcache_mark_dirty(chip->regmap);
return regmap_write(chip->regmap, AW200XX_REG_FCD, AW200XX_FCD_CLEAR);
}
static int aw200xx_chip_init(const struct aw200xx *const chip)
{
int ret;
ret = regmap_write(chip->regmap, AW200XX_REG_DSIZE,
chip->display_rows - 1);
if (ret)
return ret;
ret = regmap_write(chip->regmap, AW200XX_REG_SLPCR,
AW200XX_SLPCR_ACTIVE);
if (ret)
return ret;
return regmap_update_bits(chip->regmap, AW200XX_REG_GCCR,
AW200XX_GCCR_ALLON, AW200XX_GCCR_ALLON);
}
static int aw200xx_chip_check(const struct aw200xx *const chip)
{
struct device *dev = &chip->client->dev;
u32 chipid;
int ret;
ret = regmap_read(chip->regmap, AW200XX_REG_IDR, &chipid);
if (ret)
return dev_err_probe(dev, ret, "Failed to read chip ID\n");
if (chipid != AW200XX_IDR_CHIPID)
return dev_err_probe(dev, -ENODEV,
"Chip reported wrong ID: %x\n", chipid);
return 0;
}
static void aw200xx_enable(const struct aw200xx *const chip)
{
gpiod_set_value_cansleep(chip->hwen, 1);
/*
* After HWEN pin set high the chip begins to load the OTP information,
* which takes 200us to complete. About 200us wait time is needed for
* internal oscillator startup and display SRAM initialization. After
* display SRAM initialization, the registers in page1 to page5 can be
* configured via i2c interface.
*/
fsleep(400);
}
static void aw200xx_disable(const struct aw200xx *const chip)
{
return gpiod_set_value_cansleep(chip->hwen, 0);
}
static int aw200xx_probe_get_display_rows(struct device *dev,
struct aw200xx *chip)
{
struct fwnode_handle *child;
u32 max_source = 0;
device_for_each_child_node(dev, child) {
u32 source;
int ret;
ret = fwnode_property_read_u32(child, "reg", &source);
if (ret || source >= chip->cdef->channels)
continue;
max_source = max(max_source, source);
}
if (max_source == 0)
return -EINVAL;
chip->display_rows = max_source / chip->cdef->display_size_columns + 1;
return 0;
}
static int aw200xx_probe_fw(struct device *dev, struct aw200xx *chip)
{
u32 current_min, current_max, min_uA;
int ret;
int i;
ret = aw200xx_probe_get_display_rows(dev, chip);
if (ret)
return dev_err_probe(dev, ret,
"No valid led definitions found\n");
current_max = aw200xx_imax_from_global(chip, AW200XX_IMAX_MAX_uA);
current_min = aw200xx_imax_from_global(chip, AW200XX_IMAX_MIN_uA);
min_uA = UINT_MAX;
i = 0;
device_for_each_child_node_scoped(dev, child) {
struct led_init_data init_data = {};
struct aw200xx_led *led;
u32 source, imax;
ret = fwnode_property_read_u32(child, "reg", &source);
if (ret) {
dev_err(dev, "Missing reg property\n");
chip->num_leds--;
continue;
}
if (source >= chip->cdef->channels) {
dev_err(dev, "LED reg %u out of range (max %u)\n",
source, chip->cdef->channels);
chip->num_leds--;
continue;
}
ret = fwnode_property_read_u32(child, "led-max-microamp",
&imax);
if (ret) {
dev_info(&chip->client->dev,
"DT property led-max-microamp is missing\n");
} else if (imax < current_min || imax > current_max) {
dev_err(dev, "Invalid value %u for led-max-microamp\n",
imax);
chip->num_leds--;
continue;
} else {
min_uA = min(min_uA, imax);
}
led = &chip->leds[i];
led->dim = -1;
led->num = source;
led->chip = chip;
led->cdev.brightness_set_blocking = aw200xx_brightness_set;
led->cdev.max_brightness = AW200XX_FADE_MAX;
led->cdev.groups = dim_groups;
init_data.fwnode = child;
ret = devm_led_classdev_register_ext(dev, &led->cdev,
&init_data);
if (ret)
break;
i++;
}
if (!chip->num_leds)
return -EINVAL;
if (min_uA == UINT_MAX) {
min_uA = aw200xx_imax_from_global(chip,
AW200XX_IMAX_DEFAULT_uA);
}
return aw200xx_set_imax(chip, min_uA);
}
static const struct regmap_range_cfg aw200xx_ranges[] = {
{
.name = "aw200xx",
.range_min = 0,
.range_max = AW200XX_REG_MAX,
.selector_reg = AW200XX_REG_PAGE,
.selector_mask = AW200XX_PAGE_MASK,
.selector_shift = AW200XX_PAGE_SHIFT,
.window_start = 0,
.window_len = AW200XX_PAGE_SIZE,
},
};
static const struct regmap_range aw200xx_writeonly_ranges[] = {
regmap_reg_range(AW200XX_REG(AW200XX_PAGE1, 0x00), AW200XX_REG_MAX),
};
static const struct regmap_access_table aw200xx_readable_table = {
.no_ranges = aw200xx_writeonly_ranges,
.n_no_ranges = ARRAY_SIZE(aw200xx_writeonly_ranges),
};
static const struct regmap_range aw200xx_readonly_ranges[] = {
regmap_reg_range(AW200XX_REG_IDR, AW200XX_REG_IDR),
};
static const struct regmap_access_table aw200xx_writeable_table = {
.no_ranges = aw200xx_readonly_ranges,
.n_no_ranges = ARRAY_SIZE(aw200xx_readonly_ranges),
};
static const struct regmap_config aw200xx_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = AW200XX_REG_MAX,
.ranges = aw200xx_ranges,
.num_ranges = ARRAY_SIZE(aw200xx_ranges),
.rd_table = &aw200xx_readable_table,
.wr_table = &aw200xx_writeable_table,
.cache_type = REGCACHE_MAPLE,
.disable_locking = true,
};
static void aw200xx_chip_reset_action(void *data)
{
aw200xx_chip_reset(data);
}
static void aw200xx_disable_action(void *data)
{
aw200xx_disable(data);
}
static int aw200xx_probe(struct i2c_client *client)
{
const struct aw200xx_chipdef *cdef;
struct aw200xx *chip;
int count;
int ret;
cdef = device_get_match_data(&client->dev);
if (!cdef)
return -ENODEV;
count = device_get_child_node_count(&client->dev);
if (!count || count > cdef->channels)
return dev_err_probe(&client->dev, -EINVAL,
"Incorrect number of leds (%d)", count);
chip = devm_kzalloc(&client->dev, struct_size(chip, leds, count),
GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->cdef = cdef;
chip->num_leds = count;
chip->client = client;
i2c_set_clientdata(client, chip);
chip->regmap = devm_regmap_init_i2c(client, &aw200xx_regmap_config);
if (IS_ERR(chip->regmap))
return PTR_ERR(chip->regmap);
chip->hwen = devm_gpiod_get_optional(&client->dev, "enable",
GPIOD_OUT_HIGH);
if (IS_ERR(chip->hwen))
return dev_err_probe(&client->dev, PTR_ERR(chip->hwen),
"Cannot get enable GPIO");
aw200xx_enable(chip);
ret = devm_add_action(&client->dev, aw200xx_disable_action, chip);
if (ret)
return ret;
ret = aw200xx_chip_check(chip);
if (ret)
return ret;
ret = devm_mutex_init(&client->dev, &chip->mutex);
if (ret)
return ret;
/* Need a lock now since after call aw200xx_probe_fw, sysfs nodes created */
mutex_lock(&chip->mutex);
ret = aw200xx_chip_reset(chip);
if (ret)
goto out_unlock;
ret = devm_add_action(&client->dev, aw200xx_chip_reset_action, chip);
if (ret)
goto out_unlock;
ret = aw200xx_probe_fw(&client->dev, chip);
if (ret)
goto out_unlock;
ret = aw200xx_chip_init(chip);
out_unlock:
if (ret)
aw200xx_disable(chip);
mutex_unlock(&chip->mutex);
return ret;
}
static const struct aw200xx_chipdef aw20036_cdef = {
.channels = 36,
.display_size_rows_max = 3,
.display_size_columns = 12,
};
static const struct aw200xx_chipdef aw20054_cdef = {
.channels = 54,
.display_size_rows_max = 6,
.display_size_columns = 9,
};
static const struct aw200xx_chipdef aw20072_cdef = {
.channels = 72,
.display_size_rows_max = 6,
.display_size_columns = 12,
};
static const struct aw200xx_chipdef aw20108_cdef = {
.channels = 108,
.display_size_rows_max = 9,
.display_size_columns = 12,
};
static const struct i2c_device_id aw200xx_id[] = {
{ "aw20036" },
{ "aw20054" },
{ "aw20072" },
{ "aw20108" },
{}
};
MODULE_DEVICE_TABLE(i2c, aw200xx_id);
static const struct of_device_id aw200xx_match_table[] = {
{ .compatible = "awinic,aw20036", .data = &aw20036_cdef, },
{ .compatible = "awinic,aw20054", .data = &aw20054_cdef, },
{ .compatible = "awinic,aw20072", .data = &aw20072_cdef, },
{ .compatible = "awinic,aw20108", .data = &aw20108_cdef, },
{}
};
MODULE_DEVICE_TABLE(of, aw200xx_match_table);
static struct i2c_driver aw200xx_driver = {
.driver = {
.name = "aw200xx",
.of_match_table = aw200xx_match_table,
},
.probe = aw200xx_probe,
.id_table = aw200xx_id,
};
module_i2c_driver(aw200xx_driver);
MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
MODULE_DESCRIPTION("AW200XX LED driver");
MODULE_LICENSE("GPL");