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kernel/drivers/leds/leds-is31fl319x.c

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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/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
/* register numbers */
#define IS31FL319X_SHUTDOWN 0x00
#define IS31FL319X_CTRL1 0x01
#define IS31FL319X_CTRL2 0x02
#define IS31FL319X_CONFIG1 0x03
#define IS31FL319X_CONFIG2 0x04
#define IS31FL319X_RAMP_MODE 0x05
#define IS31FL319X_BREATH_MASK 0x06
#define IS31FL319X_PWM(channel) (0x07 + channel)
#define IS31FL319X_DATA_UPDATE 0x10
#define IS31FL319X_T0(channel) (0x11 + channel)
#define IS31FL319X_T123_1 0x1a
#define IS31FL319X_T123_2 0x1b
#define IS31FL319X_T123_3 0x1c
#define IS31FL319X_T4(channel) (0x1d + channel)
#define IS31FL319X_TIME_UPDATE 0x26
#define IS31FL319X_RESET 0xff
#define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1)
#define IS31FL319X_MAX_LEDS 9
/* CS (Current Setting) in CONFIG2 register */
#define IS31FL319X_CONFIG2_CS_SHIFT 4
#define IS31FL319X_CONFIG2_CS_MASK 0x7
#define IS31FL319X_CONFIG2_CS_STEP_REF 12
#define IS31FL319X_CURRENT_MIN ((u32)5000)
#define IS31FL319X_CURRENT_MAX ((u32)40000)
#define IS31FL319X_CURRENT_STEP ((u32)5000)
#define IS31FL319X_CURRENT_DEFAULT ((u32)20000)
/* Audio gain in CONFIG2 register */
#define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21)
#define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)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;
};
static const struct is31fl319x_chipdef is31fl3190_cdef = {
.num_leds = 1,
};
static const struct is31fl319x_chipdef is31fl3193_cdef = {
.num_leds = 3,
};
static const struct is31fl319x_chipdef is31fl3196_cdef = {
.num_leds = 6,
};
static const struct is31fl319x_chipdef is31fl3199_cdef = {
.num_leds = 9,
};
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,sn3199", .data = &is31fl3199_cdef, },
{ }
};
MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
static int is31fl319x_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, "%s %d: %d\n", __func__, chan, brightness);
mutex_lock(&is31->lock);
/* update PWM register */
ret = regmap_write(is31->regmap, IS31FL319X_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, IS31FL319X_PWM(i), &pwm_value);
dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
__func__, i, ret, 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, IS31FL319X_CTRL1, ctrl1);
regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
/* update PWMs */
regmap_write(is31->regmap, IS31FL319X_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 int is31fl319x_parse_child_dt(const struct device *dev,
const struct device_node *child,
struct is31fl319x_led *led)
{
struct led_classdev *cdev = &led->cdev;
int ret;
if (of_property_read_string(child, "label", &cdev->name))
cdev->name = child->name;
ret = of_property_read_string(child, "linux,default-trigger",
&cdev->default_trigger);
if (ret < 0 && ret != -EINVAL) /* is optional */
return ret;
led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
ret = of_property_read_u32(child, "led-max-microamp",
&led->max_microamp);
if (!ret) {
if (led->max_microamp < IS31FL319X_CURRENT_MIN)
return -EINVAL; /* not supported */
led->max_microamp = min(led->max_microamp,
IS31FL319X_CURRENT_MAX);
}
return 0;
}
static int is31fl319x_parse_dt(struct device *dev,
struct is31fl319x_chip *is31)
{
struct device_node *np = dev_of_node(dev), *child;
int count;
int ret;
if (!np)
return -ENODEV;
is31->shutdown_gpio = devm_gpiod_get_optional(dev,
"shutdown",
GPIOD_OUT_HIGH);
if (IS_ERR(is31->shutdown_gpio)) {
ret = PTR_ERR(is31->shutdown_gpio);
dev_err(dev, "Failed to get shutdown gpio: %d\n", ret);
return ret;
}
is31->cdef = device_get_match_data(dev);
count = of_get_available_child_count(np);
dev_dbg(dev, "probing with %d leds defined in DT\n", count);
if (!count || count > is31->cdef->num_leds) {
dev_err(dev, "Number of leds defined must be between 1 and %u\n",
is31->cdef->num_leds);
return -ENODEV;
}
for_each_available_child_of_node(np, child) {
struct is31fl319x_led *led;
u32 reg;
ret = of_property_read_u32(child, "reg", &reg);
if (ret) {
dev_err(dev, "Failed to read led 'reg' property\n");
goto put_child_node;
}
if (reg < 1 || reg > is31->cdef->num_leds) {
dev_err(dev, "invalid led reg %u\n", reg);
ret = -EINVAL;
goto put_child_node;
}
led = &is31->leds[reg - 1];
if (led->configured) {
dev_err(dev, "led %u is already configured\n", reg);
ret = -EINVAL;
goto put_child_node;
}
ret = is31fl319x_parse_child_dt(dev, child, led);
if (ret) {
dev_err(dev, "led %u DT parsing failed\n", reg);
goto put_child_node;
}
led->configured = true;
}
is31->audio_gain_db = 0;
ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
if (!ret)
is31->audio_gain_db = min(is31->audio_gain_db,
IS31FL319X_AUDIO_GAIN_DB_MAX);
return 0;
put_child_node:
of_node_put(child);
return ret;
}
static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
{ /* we have no readable registers */
return false;
}
static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
{ /* volatile registers are not cached */
switch (reg) {
case IS31FL319X_DATA_UPDATE:
case IS31FL319X_TIME_UPDATE:
case IS31FL319X_RESET:
return true; /* always write-through */
default:
return false;
}
}
static const struct reg_default is31fl319x_reg_defaults[] = {
{ IS31FL319X_CONFIG1, 0x00},
{ IS31FL319X_CONFIG2, 0x00},
{ IS31FL319X_PWM(0), 0x00},
{ IS31FL319X_PWM(1), 0x00},
{ IS31FL319X_PWM(2), 0x00},
{ IS31FL319X_PWM(3), 0x00},
{ IS31FL319X_PWM(4), 0x00},
{ IS31FL319X_PWM(5), 0x00},
{ IS31FL319X_PWM(6), 0x00},
{ IS31FL319X_PWM(7), 0x00},
{ IS31FL319X_PWM(8), 0x00},
};
static struct regmap_config regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = IS31FL319X_REG_CNT,
.cache_type = REGCACHE_FLAT,
.readable_reg = is31fl319x_readable_reg,
.volatile_reg = is31fl319x_volatile_reg,
.reg_defaults = is31fl319x_reg_defaults,
.num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
};
static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
{ /* round down to nearest supported value (range check done by caller) */
u32 step = microamp / IS31FL319X_CURRENT_STEP;
return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
IS31FL319X_CONFIG2_CS_MASK) <<
IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
}
static inline int is31fl319x_db_to_gain(u32 dezibel)
{ /* round down to nearest supported value (range check done by caller) */
return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
}
static int is31fl319x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct is31fl319x_chip *is31;
struct device *dev = &client->dev;
int err;
int i = 0;
u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
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 = is31fl319x_parse_dt(&client->dev, is31);
if (err)
goto free_mutex;
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, &regmap_config);
if (IS_ERR(is31->regmap)) {
dev_err(&client->dev, "failed to allocate register map\n");
err = PTR_ERR(is31->regmap);
goto free_mutex;
}
i2c_set_clientdata(client, is31);
/* check for write-reply from chip (we can't read any registers) */
err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
if (err < 0) {
dev_err(&client->dev, "no response from chip write: err = %d\n",
err);
err = -EIO; /* does not answer */
goto free_mutex;
}
/*
* 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.
*/
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;
regmap_write(is31->regmap, IS31FL319X_CONFIG2,
is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
is31fl319x_db_to_gain(is31->audio_gain_db));
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 = is31fl319x_brightness_set;
err = devm_led_classdev_register(&client->dev, &led->cdev);
if (err < 0)
goto free_mutex;
}
return 0;
free_mutex:
mutex_destroy(&is31->lock);
return err;
}
static int is31fl319x_remove(struct i2c_client *client)
{
struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
mutex_destroy(&is31->lock);
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" },
{ "sn3199" },
{},
};
MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
static struct i2c_driver is31fl319x_driver = {
.driver = {
.name = "leds-is31fl319x",
.of_match_table = of_match_ptr(of_is31fl319x_match),
},
.probe = is31fl319x_probe,
.remove = is31fl319x_remove,
.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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