Hi Simon, Thanks for the update. I'd like to clarify some details about brightness setting range and blink setting. Please refer to my comments in the code. On 03/19/2018 02:59 PM, Simon Shields wrote: > 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; You should set max_brightness accordingly if the device doesn't support 255 brightness levels. Otherwise, if you leave it initialized to 0, the LED core will adjust it to LED_FULL, which will give misleading information to the userspace. > + > + /* > + * 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; Please keep in mind that blink_set should return -EINVAL in case the device can't handle given delay_on/off constraints. LED core will employ software blink fallback then. > + > + 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"); In case of SPDX GPL-2.0+ at the top we should have MODULE_LICENSE("GPL") here. -- Best regards, Jacek Anaszewski -- 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
