AN30259A is a 3-channel LED driver which uses I2C. It supports timed operation via an internal PWM clock, and variable brightness. This driver offers support for basic hardware-based blinking and brightness control. The datasheet is freely available: https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf Signed-off-by: Simon Shields <simon@xxxxxxxxxxxxx> --- drivers/leds/Kconfig | 11 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-an30259a.c | 391 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 403 insertions(+) create mode 100644 drivers/leds/leds-an30259a.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 3e763d2a0cb3..369bfb1227f8 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -57,6 +57,17 @@ config LEDS_AAT1290 depends on PINCTRL help This option enables support for the LEDs on the AAT1290. + +config LEDS_AN30259A + tristate "LED support for Panasonic AN30259A" + depends on LEDS_CLASS && I2C && OF + help + This option enables support for the AN30259A 3-channel + LED driver. + + To compile this driver as a module, choose M here: the module + will be called leds-an30259a. + config LEDS_APU tristate "Front panel LED support for PC Engines APU/APU2 boards" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 987884a5b9a5..44f9b42d1600 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o obj-$(CONFIG_LEDS_AAT1290) += leds-aat1290.o obj-$(CONFIG_LEDS_APU) += leds-apu.o obj-$(CONFIG_LEDS_AS3645A) += leds-as3645a.o +obj-$(CONFIG_LEDS_AN30259A) += leds-an30259a.o obj-$(CONFIG_LEDS_BCM6328) += leds-bcm6328.o obj-$(CONFIG_LEDS_BCM6358) += leds-bcm6358.o obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o diff --git a/drivers/leds/leds-an30259a.c b/drivers/leds/leds-an30259a.c new file mode 100644 index 000000000000..61275eb8106d --- /dev/null +++ b/drivers/leds/leds-an30259a.c @@ -0,0 +1,391 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Driver for Panasonic AN30259A 3-channel LED driver +// +// Copyright (c) 2018 Simon Shields <simon@xxxxxxxxxxxxx> +// +// Datasheet: +// https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf + +#include <linux/i2c.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <uapi/linux/uleds.h> + +#define MAX_LEDS 3 + +#define REG_SRESET 0x00 +#define LED_SRESET BIT(0) + +/* LED power registers */ +#define REG_LED_ON 0x01 +#define LED_EN(x) BIT(x - 1) +#define LED_SLOPE(x) BIT((x - 1) + 4) + +#define REG_LEDCC(x) (0x03 + (x - 1)) + +/* slope control registers */ +#define REG_SLOPE(x) (0x06 + (x - 1)) +#define LED_SLOPETIME1(x) (x) +#define LED_SLOPETIME2(x) ((x) << 4) + +#define REG_LEDCNT1(x) (0x09 + (4 * (x - 1))) +#define LED_DUTYMAX(x) ((x) << 4) +#define LED_DUTYMID(x) (x) + +#define REG_LEDCNT2(x) (0x0A + (4 * (x - 1))) +#define LED_DELAY(x) ((x) << 4) +#define LED_DUTYMIN(x) (x) + +/* detention time control (length of each slope step) */ +#define REG_LEDCNT3(x) (0x0B + (4 * (x - 1))) +#define LED_DT1(x) (x) +#define LED_DT2(x) ((x) << 4) + +#define REG_LEDCNT4(x) (0x0C + (4 * (x - 1))) +#define LED_DT3(x) (x) +#define LED_DT4(x) ((x) << 4) + +#define REG_MAX 0x14 + +#define BLINK_MAX_TIME 7500 /* ms */ +#define SLOPE_RESOLUTION 500 /* ms */ + +#define STATE_OFF 0 +#define STATE_KEEP 1 +#define STATE_ON 2 + +struct an30259a; + +struct an30259a_led { + struct an30259a *chip; + struct led_classdev cdev; + u32 num; + u32 default_state; + char label[LED_MAX_NAME_SIZE]; +}; + +struct an30259a { + struct mutex mutex; /* held when writing to registers */ + struct i2c_client *client; + struct an30259a_led leds[MAX_LEDS]; + struct regmap *regmap; + int num_leds; +}; + +/* + * When doing sloping, AN30259A only allows us + * to set the first four bits of a 7-bit brightness + * value, as opposed to the full 8-bit range + * allowed in constant output mode. + * + * This function returns the best approximation + * of the 8-bit brightness value in the 7-bit range + * we have available. + */ +static u8 an30259a_get_dutymax(u8 brightness) +{ + u8 duty_max, floor, ceil; + + /* squash 8 bit number into 7-bit PWM range. */ + duty_max = brightness >> 1; + + /* + * Bottom 3 bits are always set for DUTYMAX, + * so figure out the closest value. + */ + ceil = duty_max | 0x7; + floor = ceil - 0x8; + + if ((duty_max - floor) < (ceil - duty_max)) + duty_max = floor >> 3; + else + duty_max = ceil >> 3; + + return duty_max; +} + +static int an30259a_brightness_set(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct an30259a_led *led; + int ret; + unsigned int led_on; + u8 dutymax; + + led = container_of(cdev, struct an30259a_led, cdev); + mutex_lock(&led->chip->mutex); + + ret = regmap_read(led->chip->regmap, REG_LED_ON, &led_on); + if (ret) + goto error; + + switch (brightness) { + case LED_OFF: + led_on &= ~LED_EN(led->num); + led_on &= ~LED_SLOPE(led->num); + break; + default: + led_on |= LED_EN(led->num); + dutymax = an30259a_get_dutymax(brightness & 0xff); + ret = regmap_write(led->chip->regmap, REG_LEDCNT1(led->num), + LED_DUTYMAX(dutymax) | LED_DUTYMID(dutymax)); + if (ret) + goto error; + break; + } + ret = regmap_write(led->chip->regmap, REG_LED_ON, led_on); + if (ret) + goto error; + + ret = regmap_write(led->chip->regmap, REG_LEDCC(led->num), + brightness & 0xff); + +error: + mutex_unlock(&led->chip->mutex); + + return ret; +} + +static int an30259a_blink_set(struct led_classdev *cdev, + unsigned long *delay_off, unsigned long *delay_on) +{ + struct an30259a_led *led; + int ret, num; + unsigned int led_on; + unsigned long off = *delay_off, on = *delay_on; + + led = container_of(cdev, struct an30259a_led, cdev); + + mutex_lock(&led->chip->mutex); + num = led->num; + + /* slope time - multiples of 500ms only, floored */ + off -= off % SLOPE_RESOLUTION; + /* don't floor off time to zero if a non-zero time was requested */ + if (!off && *delay_off) + off += SLOPE_RESOLUTION; + else if (off > BLINK_MAX_TIME) + off = BLINK_MAX_TIME; + *delay_off = off; + + on -= on % SLOPE_RESOLUTION; + /* don't floor on time to zero if a non-zero time was requested */ + if (!on && *delay_on) + on += SLOPE_RESOLUTION; + else if (on > BLINK_MAX_TIME) + on = BLINK_MAX_TIME; + *delay_on = on; + + /* convert into values the HW will understand */ + off /= SLOPE_RESOLUTION; + on /= SLOPE_RESOLUTION; + + /* duty min should be zero (=off), delay should be zero */ + ret = regmap_write(led->chip->regmap, REG_LEDCNT2(num), + LED_DELAY(0) | LED_DUTYMIN(0)); + if (ret) + goto error; + + /* reset detention time (no "breathing" effect) */ + ret = regmap_write(led->chip->regmap, REG_LEDCNT3(num), + LED_DT1(0) | LED_DT2(0)); + if (ret) + goto error; + ret = regmap_write(led->chip->regmap, REG_LEDCNT4(num), + LED_DT3(0) | LED_DT4(0)); + if (ret) + goto error; + + /* slope time controls on/off cycle length */ + ret = regmap_write(led->chip->regmap, REG_SLOPE(num), + LED_SLOPETIME1(off) | LED_SLOPETIME2(on)); + if (ret) + goto error; + + /* Finally, enable slope mode. */ + ret = regmap_read(led->chip->regmap, REG_LED_ON, &led_on); + if (ret) + goto error; + + led_on |= LED_SLOPE(num); + + ret = regmap_write(led->chip->regmap, REG_LED_ON, led_on); + +error: + mutex_unlock(&led->chip->mutex); + + return ret; +} + +static int an30259a_dt_init(struct i2c_client *client, + struct an30259a *chip) +{ + struct device_node *np = client->dev.of_node, *child; + int count, ret; + int i = 0; + const char *str; + struct an30259a_led *led; + + count = of_get_child_count(np); + if (!count || count > MAX_LEDS) + return -EINVAL; + + for_each_available_child_of_node(np, child) { + u32 source; + + ret = of_property_read_u32(child, "reg", &source); + if (ret != 0 || !source || source > MAX_LEDS) { + dev_err(&client->dev, "Couldn't read LED address: %d\n", + ret); + count--; + continue; + } + + led = &chip->leds[i]; + + led->num = source; + led->chip = chip; + + if (of_property_read_string(child, "label", &str)) + snprintf(led->label, sizeof(led->label), "an30259a::"); + else + snprintf(led->label, sizeof(led->label), "an30259a:%s", + str); + + led->cdev.name = led->label; + + if (!of_property_read_string(child, "default-state", &str)) { + if (!strcmp(str, "on")) + led->default_state = STATE_ON; + else if (!strcmp(str, "keep")) + led->default_state = STATE_KEEP; + else + led->default_state = STATE_OFF; + } + + of_property_read_string(child, "linux,default-trigger", + &led->cdev.default_trigger); + + i++; + } + + if (!count) + return -EINVAL; + + chip->num_leds = i; + + return 0; +} + +static const struct regmap_config an30259a_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = REG_MAX, +}; + +static void an30259a_init_default_state(struct an30259a_led *led) +{ + struct an30259a *chip = led->chip; + int led_on, err; + + switch (led->default_state) { + case STATE_ON: + led->cdev.brightness = LED_FULL; + break; + case STATE_KEEP: + err = regmap_read(chip->regmap, REG_LED_ON, &led_on); + if (err) + break; + + if (!(led_on & LED_EN(led->num))) { + led->cdev.brightness = LED_OFF; + break; + } + regmap_read(chip->regmap, REG_LEDCC(led->num), + &led->cdev.brightness); + break; + default: + led->cdev.brightness = LED_OFF; + } + + an30259a_brightness_set(&led->cdev, led->cdev.brightness); +} + +static int an30259a_probe(struct i2c_client *client) +{ + struct an30259a *chip; + int i, err; + + chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + err = an30259a_dt_init(client, chip); + if (err < 0) + return err; + + mutex_init(&chip->mutex); + chip->client = client; + i2c_set_clientdata(client, chip); + + chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config); + + for (i = 0; i < chip->num_leds; i++) { + an30259a_init_default_state(&chip->leds[i]); + chip->leds[i].cdev.brightness_set_blocking = + an30259a_brightness_set; + chip->leds[i].cdev.blink_set = an30259a_blink_set; + + err = devm_led_classdev_register(&client->dev, + &chip->leds[i].cdev); + if (err < 0) + goto exit; + } + return 0; + +exit: + mutex_destroy(&chip->mutex); + return err; +} + +static int an30259a_remove(struct i2c_client *client) +{ + struct an30259a *chip = i2c_get_clientdata(client); + + mutex_destroy(&chip->mutex); + + return 0; +} + +static const struct of_device_id an30259a_match_table[] = { + { .compatible = "panasonic,an30259a", }, + { /* sentinel */ }, +}; + +MODULE_DEVICE_TABLE(of, an30259a_match_table); + +static const struct i2c_device_id an30259a_id[] = { + { "an30259a", 0 }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(i2c, an30259a_id); + +static struct i2c_driver an30259a_driver = { + .driver = { + .name = "leds-an32059a", + .of_match_table = of_match_ptr(an30259a_match_table), + }, + .probe_new = an30259a_probe, + .remove = an30259a_remove, + .id_table = an30259a_id, +}; + +module_i2c_driver(an30259a_driver); + +MODULE_AUTHOR("Simon Shields <simon@xxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("AN32059A LED driver"); +MODULE_LICENSE("GPL v2"); -- 2.16.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
