--- /dev/null
+// 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");
projects / platform / kernel / linux-starfive.git / commitdiff