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SubjectRe: [PATCH v3 2/2] leds: add Panasonic AN30259A support
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Hi Simon,

Thank you for the updated patch. It looks good in general, with
one reservation, please refer below.

On 07/21/2018 04:12 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@lineageos.org>
> ---
> drivers/leds/Kconfig | 11 ++
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-an30259a.c | 365 +++++++++++++++++++++++++++++++++++
> 3 files changed, 377 insertions(+)
> create mode 100644 drivers/leds/leds-an30259a.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 6e3a998f3370..1567882fd039 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 420b5d2cfa62..4c1b0054f379 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..c7b900b388ac
> --- /dev/null
> +++ b/drivers/leds/leds-an30259a.c
> @@ -0,0 +1,365 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +//
> +// Driver for Panasonic AN30259A 3-channel LED driver
> +//
> +// Copyright (c) 2018 Simon Shields <simon@lineageos.org>
> +//
> +// 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

Please add AN30259A_ namespacing prefix to all the above macro
definitions.

> +
> +struct an30259a;
> +
> +struct an30259a_led {
> + struct an30259a *chip;
> + struct led_classdev cdev;
> + u32 num;
> + u32 default_state;
> + bool sloping;
> + 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;
> +};
> +
> +static int an30259a_brightness_set(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct an30259a_led *led;
> + int ret;
> + unsigned int led_on;
> +
> + 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);
> + led->sloping = false;
> + break;
> + default:
> + led_on |= LED_EN(led->num);
> + if (led->sloping)
> + led_on |= LED_SLOPE(led->num);
> + ret = regmap_write(led->chip->regmap, REG_LEDCNT1(led->num),
> + LED_DUTYMAX(0xf) | LED_DUTYMID(0xf));
> + 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);
> +
> +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, duty;
> + 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 can only be a multiple of 500ms. */
> + if (off % SLOPE_RESOLUTION || on % SLOPE_RESOLUTION) {
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + /* up to a maximum of 7500ms. */
> + if (off > BLINK_MAX_TIME || on > BLINK_MAX_TIME) {
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + /* if no blink specified, default to 1 Hz. */
> + if (!off && !on) {
> + *delay_off = off = 500;
> + *delay_on = on = 500;
> + }
> +
> + /* 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) | LED_EN(led->num);
> +
> + ret = regmap_write(led->chip->regmap, REG_LED_ON, led_on);
> +
> + if (!ret)
> + led->sloping = true;
> +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@lineageos.org>");
> +MODULE_DESCRIPTION("AN32059A LED driver");
> +MODULE_LICENSE("GPL v2");
>

--
Best regards,
Jacek Anaszewski

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