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linux/drivers/leds/leds-is31fl319x.c
Javier Carrasco 10cc487692 leds: is31fl319x: Use device_for_each_child_node_scoped() to access child nodes 
The iterated nodes are direct children of the device node, and the
`device_for_each_child_node()` macro accounts for child node
availability.

`fwnode_for_each_available_child_node()` is meant to access the child
nodes of an fwnode, and therefore not direct child nodes of the device
node.

In this case, the child nodes are not required outside the loop, and
the scoped version of the macro can be used to remove the repetitive
`goto put` pattern.

Use `device_for_each_child_node_scoped_scoped()` to indicate device's
direct child nodes.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240721-device_for_each_child_node-available-v2-4-f33748fd8b2d@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-08-01 13:40:08 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2015-16 Golden Delicious Computers
*
* Author: Nikolaus Schaller <hns@goldelico.com>
*
* LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
* effect LEDs.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
/* register numbers */
#define IS31FL319X_SHUTDOWN 0x00
/* registers for 3190, 3191 and 3193 */
#define IS31FL3190_BREATHING 0x01
#define IS31FL3190_LEDMODE 0x02
#define IS31FL3190_CURRENT 0x03
#define IS31FL3190_PWM(channel) (0x04 + channel)
#define IS31FL3190_DATA_UPDATE 0x07
#define IS31FL3190_T0(channel) (0x0a + channel)
#define IS31FL3190_T1T2(channel) (0x10 + channel)
#define IS31FL3190_T3T4(channel) (0x16 + channel)
#define IS31FL3190_TIME_UPDATE 0x1c
#define IS31FL3190_LEDCONTROL 0x1d
#define IS31FL3190_RESET 0x2f
#define IS31FL3190_CURRENT_uA_MIN 5000
#define IS31FL3190_CURRENT_uA_DEFAULT 42000
#define IS31FL3190_CURRENT_uA_MAX 42000
#define IS31FL3190_CURRENT_SHIFT 2
#define IS31FL3190_CURRENT_MASK GENMASK(4, 2)
#define IS31FL3190_CURRENT_5_mA 0x02
#define IS31FL3190_CURRENT_10_mA 0x01
#define IS31FL3190_CURRENT_17dot5_mA 0x04
#define IS31FL3190_CURRENT_30_mA 0x03
#define IS31FL3190_CURRENT_42_mA 0x00
/* registers for 3196 and 3199 */
#define IS31FL3196_CTRL1 0x01
#define IS31FL3196_CTRL2 0x02
#define IS31FL3196_CONFIG1 0x03
#define IS31FL3196_CONFIG2 0x04
#define IS31FL3196_RAMP_MODE 0x05
#define IS31FL3196_BREATH_MARK 0x06
#define IS31FL3196_PWM(channel) (0x07 + channel)
#define IS31FL3196_DATA_UPDATE 0x10
#define IS31FL3196_T0(channel) (0x11 + channel)
#define IS31FL3196_T123_1 0x1a
#define IS31FL3196_T123_2 0x1b
#define IS31FL3196_T123_3 0x1c
#define IS31FL3196_T4(channel) (0x1d + channel)
#define IS31FL3196_TIME_UPDATE 0x26
#define IS31FL3196_RESET 0xff
#define IS31FL3196_REG_CNT (IS31FL3196_RESET + 1)
#define IS31FL319X_MAX_LEDS 9
/* CS (Current Setting) in CONFIG2 register */
#define IS31FL3196_CONFIG2_CS_SHIFT 4
#define IS31FL3196_CONFIG2_CS_MASK GENMASK(2, 0)
#define IS31FL3196_CONFIG2_CS_STEP_REF 12
#define IS31FL3196_CURRENT_uA_MIN 5000
#define IS31FL3196_CURRENT_uA_MAX 40000
#define IS31FL3196_CURRENT_uA_STEP 5000
#define IS31FL3196_CURRENT_uA_DEFAULT 20000
/* Audio gain in CONFIG2 register */
#define IS31FL3196_AUDIO_GAIN_DB_MAX ((u32)21)
#define IS31FL3196_AUDIO_GAIN_DB_STEP 3
/*
* regmap is used as a cache of chip's register space,
* to avoid reading back brightness values from chip,
* which is known to hang.
*/
struct is31fl319x_chip {
const struct is31fl319x_chipdef *cdef;
struct i2c_client *client;
struct gpio_desc *shutdown_gpio;
struct regmap *regmap;
struct mutex lock;
u32 audio_gain_db;
struct is31fl319x_led {
struct is31fl319x_chip *chip;
struct led_classdev cdev;
u32 max_microamp;
bool configured;
} leds[IS31FL319X_MAX_LEDS];
};
struct is31fl319x_chipdef {
int num_leds;
u8 reset_reg;
const struct regmap_config *is31fl319x_regmap_config;
int (*brightness_set)(struct led_classdev *cdev, enum led_brightness brightness);
u32 current_default;
u32 current_min;
u32 current_max;
bool is_3196or3199;
};
static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
{
/* we have no readable registers */
return false;
}
static bool is31fl3190_volatile_reg(struct device *dev, unsigned int reg)
{
/* volatile registers are not cached */
switch (reg) {
case IS31FL3190_DATA_UPDATE:
case IS31FL3190_TIME_UPDATE:
case IS31FL3190_RESET:
return true; /* always write-through */
default:
return false;
}
}
static const struct reg_default is31fl3190_reg_defaults[] = {
{ IS31FL3190_LEDMODE, 0x00 },
{ IS31FL3190_CURRENT, 0x00 },
{ IS31FL3190_PWM(0), 0x00 },
{ IS31FL3190_PWM(1), 0x00 },
{ IS31FL3190_PWM(2), 0x00 },
};
static const struct regmap_config is31fl3190_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = IS31FL3190_RESET,
.cache_type = REGCACHE_FLAT,
.readable_reg = is31fl319x_readable_reg,
.volatile_reg = is31fl3190_volatile_reg,
.reg_defaults = is31fl3190_reg_defaults,
.num_reg_defaults = ARRAY_SIZE(is31fl3190_reg_defaults),
};
static bool is31fl3196_volatile_reg(struct device *dev, unsigned int reg)
{
/* volatile registers are not cached */
switch (reg) {
case IS31FL3196_DATA_UPDATE:
case IS31FL3196_TIME_UPDATE:
case IS31FL3196_RESET:
return true; /* always write-through */
default:
return false;
}
}
static const struct reg_default is31fl3196_reg_defaults[] = {
{ IS31FL3196_CONFIG1, 0x00 },
{ IS31FL3196_CONFIG2, 0x00 },
{ IS31FL3196_PWM(0), 0x00 },
{ IS31FL3196_PWM(1), 0x00 },
{ IS31FL3196_PWM(2), 0x00 },
{ IS31FL3196_PWM(3), 0x00 },
{ IS31FL3196_PWM(4), 0x00 },
{ IS31FL3196_PWM(5), 0x00 },
{ IS31FL3196_PWM(6), 0x00 },
{ IS31FL3196_PWM(7), 0x00 },
{ IS31FL3196_PWM(8), 0x00 },
};
static const struct regmap_config is31fl3196_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = IS31FL3196_REG_CNT,
.cache_type = REGCACHE_FLAT,
.readable_reg = is31fl319x_readable_reg,
.volatile_reg = is31fl3196_volatile_reg,
.reg_defaults = is31fl3196_reg_defaults,
.num_reg_defaults = ARRAY_SIZE(is31fl3196_reg_defaults),
};
static int is31fl3190_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, cdev);
struct is31fl319x_chip *is31 = led->chip;
int chan = led - is31->leds;
int ret;
int i;
u8 ctrl = 0;
dev_dbg(&is31->client->dev, "channel %d: %d\n", chan, brightness);
mutex_lock(&is31->lock);
/* update PWM register */
ret = regmap_write(is31->regmap, IS31FL3190_PWM(chan), brightness);
if (ret < 0)
goto out;
/* read current brightness of all PWM channels */
for (i = 0; i < is31->cdef->num_leds; i++) {
unsigned int pwm_value;
bool on;
/*
* since neither cdev nor the chip can provide
* the current setting, we read from the regmap cache
*/
ret = regmap_read(is31->regmap, IS31FL3190_PWM(i), &pwm_value);
on = ret >= 0 && pwm_value > LED_OFF;
ctrl |= on << i;
}
if (ctrl > 0) {
dev_dbg(&is31->client->dev, "power up %02x\n", ctrl);
regmap_write(is31->regmap, IS31FL3190_LEDCONTROL, ctrl);
/* update PWMs */
regmap_write(is31->regmap, IS31FL3190_DATA_UPDATE, 0x00);
/* enable chip from shut down and enable all channels */
ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x20);
} else {
dev_dbg(&is31->client->dev, "power down\n");
/* shut down (no need to clear LEDCONTROL) */
ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
}
out:
mutex_unlock(&is31->lock);
return ret;
}
static int is31fl3196_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, cdev);
struct is31fl319x_chip *is31 = led->chip;
int chan = led - is31->leds;
int ret;
int i;
u8 ctrl1 = 0, ctrl2 = 0;
dev_dbg(&is31->client->dev, "channel %d: %d\n", chan, brightness);
mutex_lock(&is31->lock);
/* update PWM register */
ret = regmap_write(is31->regmap, IS31FL3196_PWM(chan), brightness);
if (ret < 0)
goto out;
/* read current brightness of all PWM channels */
for (i = 0; i < is31->cdef->num_leds; i++) {
unsigned int pwm_value;
bool on;
/*
* since neither cdev nor the chip can provide
* the current setting, we read from the regmap cache
*/
ret = regmap_read(is31->regmap, IS31FL3196_PWM(i), &pwm_value);
on = ret >= 0 && pwm_value > LED_OFF;
if (i < 3)
ctrl1 |= on << i; /* 0..2 => bit 0..2 */
else if (i < 6)
ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
else
ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
}
if (ctrl1 > 0 || ctrl2 > 0) {
dev_dbg(&is31->client->dev, "power up %02x %02x\n",
ctrl1, ctrl2);
regmap_write(is31->regmap, IS31FL3196_CTRL1, ctrl1);
regmap_write(is31->regmap, IS31FL3196_CTRL2, ctrl2);
/* update PWMs */
regmap_write(is31->regmap, IS31FL3196_DATA_UPDATE, 0x00);
/* enable chip from shut down */
ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
} else {
dev_dbg(&is31->client->dev, "power down\n");
/* shut down (no need to clear CTRL1/2) */
ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
}
out:
mutex_unlock(&is31->lock);
return ret;
}
static const struct is31fl319x_chipdef is31fl3190_cdef = {
.num_leds = 1,
.reset_reg = IS31FL3190_RESET,
.is31fl319x_regmap_config = &is31fl3190_regmap_config,
.brightness_set = is31fl3190_brightness_set,
.current_default = IS31FL3190_CURRENT_uA_DEFAULT,
.current_min = IS31FL3190_CURRENT_uA_MIN,
.current_max = IS31FL3190_CURRENT_uA_MAX,
.is_3196or3199 = false,
};
static const struct is31fl319x_chipdef is31fl3193_cdef = {
.num_leds = 3,
.reset_reg = IS31FL3190_RESET,
.is31fl319x_regmap_config = &is31fl3190_regmap_config,
.brightness_set = is31fl3190_brightness_set,
.current_default = IS31FL3190_CURRENT_uA_DEFAULT,
.current_min = IS31FL3190_CURRENT_uA_MIN,
.current_max = IS31FL3190_CURRENT_uA_MAX,
.is_3196or3199 = false,
};
static const struct is31fl319x_chipdef is31fl3196_cdef = {
.num_leds = 6,
.reset_reg = IS31FL3196_RESET,
.is31fl319x_regmap_config = &is31fl3196_regmap_config,
.brightness_set = is31fl3196_brightness_set,
.current_default = IS31FL3196_CURRENT_uA_DEFAULT,
.current_min = IS31FL3196_CURRENT_uA_MIN,
.current_max = IS31FL3196_CURRENT_uA_MAX,
.is_3196or3199 = true,
};
static const struct is31fl319x_chipdef is31fl3199_cdef = {
.num_leds = 9,
.reset_reg = IS31FL3196_RESET,
.is31fl319x_regmap_config = &is31fl3196_regmap_config,
.brightness_set = is31fl3196_brightness_set,
.current_default = IS31FL3196_CURRENT_uA_DEFAULT,
.current_min = IS31FL3196_CURRENT_uA_MIN,
.current_max = IS31FL3196_CURRENT_uA_MAX,
.is_3196or3199 = true,
};
static const struct of_device_id of_is31fl319x_match[] = {
{ .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
{ .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
{ .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
{ .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
{ .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
{ .compatible = "si-en,sn3190", .data = &is31fl3190_cdef, },
{ .compatible = "si-en,sn3191", .data = &is31fl3190_cdef, },
{ .compatible = "si-en,sn3193", .data = &is31fl3193_cdef, },
{ .compatible = "si-en,sn3196", .data = &is31fl3196_cdef, },
{ .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, },
{ }
};
MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
static int is31fl319x_parse_child_fw(const struct device *dev,
const struct fwnode_handle *child,
struct is31fl319x_led *led,
struct is31fl319x_chip *is31)
{
struct led_classdev *cdev = &led->cdev;
int ret;
if (fwnode_property_read_string(child, "label", &cdev->name))
cdev->name = fwnode_get_name(child);
ret = fwnode_property_read_string(child, "linux,default-trigger", &cdev->default_trigger);
if (ret < 0 && ret != -EINVAL) /* is optional */
return ret;
led->max_microamp = is31->cdef->current_default;
ret = fwnode_property_read_u32(child, "led-max-microamp", &led->max_microamp);
if (!ret) {
if (led->max_microamp < is31->cdef->current_min)
return -EINVAL; /* not supported */
led->max_microamp = min(led->max_microamp,
is31->cdef->current_max);
}
return 0;
}
static int is31fl319x_parse_fw(struct device *dev, struct is31fl319x_chip *is31)
{
struct fwnode_handle *fwnode = dev_fwnode(dev);
int count;
int ret;
is31->shutdown_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
if (IS_ERR(is31->shutdown_gpio))
return dev_err_probe(dev, PTR_ERR(is31->shutdown_gpio),
"Failed to get shutdown gpio\n");
is31->cdef = device_get_match_data(dev);
count = 0;
device_for_each_child_node_scoped(dev, child)
count++;
dev_dbg(dev, "probing with %d leds defined in DT\n", count);
if (!count || count > is31->cdef->num_leds)
return dev_err_probe(dev, -ENODEV,
"Number of leds defined must be between 1 and %u\n",
is31->cdef->num_leds);
device_for_each_child_node_scoped(dev, child) {
struct is31fl319x_led *led;
u32 reg;
ret = fwnode_property_read_u32(child, "reg", &reg);
if (ret)
return dev_err_probe(dev, ret, "Failed to read led 'reg' property\n");
if (reg < 1 || reg > is31->cdef->num_leds)
return dev_err_probe(dev, -EINVAL, "invalid led reg %u\n", reg);
led = &is31->leds[reg - 1];
if (led->configured)
return dev_err_probe(dev, -EINVAL, "led %u is already configured\n", reg);
ret = is31fl319x_parse_child_fw(dev, child, led, is31);
if (ret)
return dev_err_probe(dev, ret, "led %u DT parsing failed\n", reg);
led->configured = true;
}
is31->audio_gain_db = 0;
if (is31->cdef->is_3196or3199) {
ret = fwnode_property_read_u32(fwnode, "audio-gain-db", &is31->audio_gain_db);
if (!ret)
is31->audio_gain_db = min(is31->audio_gain_db,
IS31FL3196_AUDIO_GAIN_DB_MAX);
}
return 0;
}
static inline int is31fl3190_microamp_to_cs(struct device *dev, u32 microamp)
{
switch (microamp) {
case 5000:
return IS31FL3190_CURRENT_5_mA;
case 10000:
return IS31FL3190_CURRENT_10_mA;
case 17500:
return IS31FL3190_CURRENT_17dot5_mA;
case 30000:
return IS31FL3190_CURRENT_30_mA;
case 42000:
return IS31FL3190_CURRENT_42_mA;
default:
dev_warn(dev, "Unsupported current value: %d, using 5000 µA!\n", microamp);
return IS31FL3190_CURRENT_5_mA;
}
}
static inline int is31fl3196_microamp_to_cs(struct device *dev, u32 microamp)
{
/* round down to nearest supported value (range check done by caller) */
u32 step = microamp / IS31FL3196_CURRENT_uA_STEP;
return ((IS31FL3196_CONFIG2_CS_STEP_REF - step) &
IS31FL3196_CONFIG2_CS_MASK) <<
IS31FL3196_CONFIG2_CS_SHIFT; /* CS encoding */
}
static inline int is31fl3196_db_to_gain(u32 dezibel)
{
/* round down to nearest supported value (range check done by caller) */
return dezibel / IS31FL3196_AUDIO_GAIN_DB_STEP;
}
static void is31f1319x_mutex_destroy(void *lock)
{
mutex_destroy(lock);
}
static int is31fl319x_probe(struct i2c_client *client)
{
struct is31fl319x_chip *is31;
struct device *dev = &client->dev;
int err;
int i = 0;
u32 aggregated_led_microamp;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -EIO;
is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
if (!is31)
return -ENOMEM;
mutex_init(&is31->lock);
err = devm_add_action_or_reset(dev, is31f1319x_mutex_destroy, &is31->lock);
if (err)
return err;
err = is31fl319x_parse_fw(&client->dev, is31);
if (err)
return err;
if (is31->shutdown_gpio) {
gpiod_direction_output(is31->shutdown_gpio, 0);
mdelay(5);
gpiod_direction_output(is31->shutdown_gpio, 1);
}
is31->client = client;
is31->regmap = devm_regmap_init_i2c(client, is31->cdef->is31fl319x_regmap_config);
if (IS_ERR(is31->regmap))
return dev_err_probe(dev, PTR_ERR(is31->regmap), "failed to allocate register map\n");
i2c_set_clientdata(client, is31);
/* check for write-reply from chip (we can't read any registers) */
err = regmap_write(is31->regmap, is31->cdef->reset_reg, 0x00);
if (err < 0)
return dev_err_probe(dev, err, "no response from chip write\n");
/*
* Kernel conventions require per-LED led-max-microamp property.
* But the chip does not allow to limit individual LEDs.
* So we take minimum from all subnodes for safety of hardware.
*/
aggregated_led_microamp = is31->cdef->current_max;
for (i = 0; i < is31->cdef->num_leds; i++)
if (is31->leds[i].configured &&
is31->leds[i].max_microamp < aggregated_led_microamp)
aggregated_led_microamp = is31->leds[i].max_microamp;
if (is31->cdef->is_3196or3199)
regmap_write(is31->regmap, IS31FL3196_CONFIG2,
is31fl3196_microamp_to_cs(dev, aggregated_led_microamp) |
is31fl3196_db_to_gain(is31->audio_gain_db));
else
regmap_update_bits(is31->regmap, IS31FL3190_CURRENT, IS31FL3190_CURRENT_MASK,
is31fl3190_microamp_to_cs(dev, aggregated_led_microamp) << IS31FL3190_CURRENT_SHIFT);
for (i = 0; i < is31->cdef->num_leds; i++) {
struct is31fl319x_led *led = &is31->leds[i];
if (!led->configured)
continue;
led->chip = is31;
led->cdev.brightness_set_blocking = is31->cdef->brightness_set;
err = devm_led_classdev_register(&client->dev, &led->cdev);
if (err < 0)
return err;
}
return 0;
}
/*
* i2c-core (and modalias) requires that id_table be properly filled,
* even though it is not used for DeviceTree based instantiation.
*/
static const struct i2c_device_id is31fl319x_id[] = {
{ "is31fl3190" },
{ "is31fl3191" },
{ "is31fl3193" },
{ "is31fl3196" },
{ "is31fl3199" },
{ "sn3190" },
{ "sn3191" },
{ "sn3193" },
{ "sn3196" },
{ "sn3199" },
{},
};
MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
static struct i2c_driver is31fl319x_driver = {
.driver = {
.name = "leds-is31fl319x",
.of_match_table = of_is31fl319x_match,
},
.probe = is31fl319x_probe,
.id_table = is31fl319x_id,
};
module_i2c_driver(is31fl319x_driver);
MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
MODULE_DESCRIPTION("IS31FL319X LED driver");
MODULE_LICENSE("GPL v2");
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