leds: add Panasonic AN30259A support

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>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

3 files changed, 379 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 44097a3e0fcc..a72f97fca57b 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -58,6 +58,16 @@ config LEDS_AAT1290
         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/APU3 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..1c1f0c8c56f4
--- /dev/null
+++ b/drivers/leds/leds-an30259a.c
@@ -0,0 +1,368 @@
+// 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 AN30259A_MAX_LEDS 3
+
+#define AN30259A_REG_SRESET 0x00
+#define AN30259A_LED_SRESET BIT(0)
+
+/* LED power registers */
+#define AN30259A_REG_LED_ON 0x01
+#define AN30259A_LED_EN(x) BIT((x) - 1)
+#define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
+
+#define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
+
+/* slope control registers */
+#define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
+#define AN30259A_LED_SLOPETIME1(x) (x)
+#define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
+
+#define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
+#define AN30259A_LED_DUTYMAX(x) ((x) << 4)
+#define AN30259A_LED_DUTYMID(x) (x)
+
+#define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
+#define AN30259A_LED_DELAY(x) ((x) << 4)
+#define AN30259A_LED_DUTYMIN(x) (x)
+
+/* detention time control (length of each slope step) */
+#define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
+#define AN30259A_LED_DT1(x) (x)
+#define AN30259A_LED_DT2(x) ((x) << 4)
+
+#define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
+#define AN30259A_LED_DT3(x) (x)
+#define AN30259A_LED_DT4(x) ((x) << 4)
+
+#define AN30259A_REG_MAX 0x14
+
+#define AN30259A_BLINK_MAX_TIME 7500 /* ms */
+#define AN30259A_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;
+        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[AN30259A_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, AN30259A_REG_LED_ON, &led_on);
+        if (ret)
+                goto error;
+
+        switch (brightness) {
+        case LED_OFF:
+                led_on &= ~AN30259A_LED_EN(led->num);
+                led_on &= ~AN30259A_LED_SLOPE(led->num);
+                led->sloping = false;
+                break;
+        default:
+                led_on |= AN30259A_LED_EN(led->num);
+                if (led->sloping)
+                        led_on |= AN30259A_LED_SLOPE(led->num);
+                ret = regmap_write(led->chip->regmap,
+                                   AN30259A_REG_LEDCNT1(led->num),
+                                   AN30259A_LED_DUTYMAX(0xf) |
+                                   AN30259A_LED_DUTYMID(0xf));
+                if (ret)
+                        goto error;
+                break;
+        }
+
+        ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
+        if (ret)
+                goto error;
+
+        ret = regmap_write(led->chip->regmap, AN30259A_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;
+        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 % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
+                ret = -EINVAL;
+                goto error;
+        }
+
+        /* up to a maximum of 7500ms. */
+        if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_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 /= AN30259A_SLOPE_RESOLUTION;
+        on /= AN30259A_SLOPE_RESOLUTION;
+
+        /* duty min should be zero (=off), delay should be zero. */
+        ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
+                           AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
+        if (ret)
+                goto error;
+
+        /* reset detention time (no "breathing" effect). */
+        ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
+                           AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
+        if (ret)
+                goto error;
+        ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
+                           AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
+        if (ret)
+                goto error;
+
+        /* slope time controls on/off cycle length. */
+        ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
+                           AN30259A_LED_SLOPETIME1(off) |
+                           AN30259A_LED_SLOPETIME2(on));
+        if (ret)
+                goto error;
+
+        /* Finally, enable slope mode. */
+        ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
+        if (ret)
+                goto error;
+
+        led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
+
+        ret = regmap_write(led->chip->regmap, AN30259A_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 > AN30259A_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 > AN30259A_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 = AN30259A_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, AN30259A_REG_LED_ON, &led_on);
+                if (err)
+                        break;
+
+                if (!(led_on & AN30259A_LED_EN(led->num))) {
+                        led->cdev.brightness = LED_OFF;
+                        break;
+                }
+                regmap_read(chip->regmap, AN30259A_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");