drivers/leds/leds-an30259a.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 //
0003 // Driver for Panasonic AN30259A 3-channel LED driver
0004 //
0005 // Copyright (c) 2018 Simon Shields <simon@lineageos.org>
0006 //
0007 // Datasheet:
0008 // https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf
0009
0010 #include <linux/i2c.h>
0011 #include <linux/leds.h>
0012 #include <linux/module.h>
0013 #include <linux/mutex.h>
0014 #include <linux/of.h>
0015 #include <linux/regmap.h>
0016
0017 #define AN30259A_MAX_LEDS 3
0018
0019 #define AN30259A_REG_SRESET 0x00
0020 #define AN30259A_LED_SRESET BIT(0)
0021
0022 /* LED power registers */
0023 #define AN30259A_REG_LED_ON 0x01
0024 #define AN30259A_LED_EN(x) BIT((x) - 1)
0025 #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
0026
0027 #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
0028
0029 /* slope control registers */
0030 #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
0031 #define AN30259A_LED_SLOPETIME1(x) (x)
0032 #define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
0033
0034 #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
0035 #define AN30259A_LED_DUTYMAX(x) ((x) << 4)
0036 #define AN30259A_LED_DUTYMID(x) (x)
0037
0038 #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
0039 #define AN30259A_LED_DELAY(x) ((x) << 4)
0040 #define AN30259A_LED_DUTYMIN(x) (x)
0041
0042 /* detention time control (length of each slope step) */
0043 #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
0044 #define AN30259A_LED_DT1(x) (x)
0045 #define AN30259A_LED_DT2(x) ((x) << 4)
0046
0047 #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
0048 #define AN30259A_LED_DT3(x) (x)
0049 #define AN30259A_LED_DT4(x) ((x) << 4)
0050
0051 #define AN30259A_REG_MAX 0x14
0052
0053 #define AN30259A_BLINK_MAX_TIME 7500 /* ms */
0054 #define AN30259A_SLOPE_RESOLUTION 500 /* ms */
0055
0056 #define AN30259A_NAME "an30259a"
0057
0058 #define STATE_OFF 0
0059 #define STATE_KEEP 1
0060 #define STATE_ON 2
0061
0062 struct an30259a;
0063
0064 struct an30259a_led {
0065     struct an30259a *chip;
0066     struct fwnode_handle *fwnode;
0067     struct led_classdev cdev;
0068     u32 num;
0069     u32 default_state;
0070     bool sloping;
0071 };
0072
0073 struct an30259a {
0074     struct mutex mutex; /* held when writing to registers */
0075     struct i2c_client *client;
0076     struct an30259a_led leds[AN30259A_MAX_LEDS];
0077     struct regmap *regmap;
0078     int num_leds;
0079 };
0080
0081 static int an30259a_brightness_set(struct led_classdev *cdev,
0082                    enum led_brightness brightness)
0083 {
0084     struct an30259a_led *led;
0085     int ret;
0086     unsigned int led_on;
0087
0088     led = container_of(cdev, struct an30259a_led, cdev);
0089     mutex_lock(&led->chip->mutex);
0090
0091     ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
0092     if (ret)
0093         goto error;
0094
0095     switch (brightness) {
0096     case LED_OFF:
0097         led_on &= ~AN30259A_LED_EN(led->num);
0098         led_on &= ~AN30259A_LED_SLOPE(led->num);
0099         led->sloping = false;
0100         break;
0101     default:
0102         led_on |= AN30259A_LED_EN(led->num);
0103         if (led->sloping)
0104             led_on |= AN30259A_LED_SLOPE(led->num);
0105         ret = regmap_write(led->chip->regmap,
0106                    AN30259A_REG_LEDCNT1(led->num),
0107                    AN30259A_LED_DUTYMAX(0xf) |
0108                    AN30259A_LED_DUTYMID(0xf));
0109         if (ret)
0110             goto error;
0111         break;
0112     }
0113
0114     ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
0115     if (ret)
0116         goto error;
0117
0118     ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num),
0119                brightness);
0120
0121 error:
0122     mutex_unlock(&led->chip->mutex);
0123
0124     return ret;
0125 }
0126
0127 static int an30259a_blink_set(struct led_classdev *cdev,
0128                   unsigned long *delay_off, unsigned long *delay_on)
0129 {
0130     struct an30259a_led *led;
0131     int ret, num;
0132     unsigned int led_on;
0133     unsigned long off = *delay_off, on = *delay_on;
0134
0135     led = container_of(cdev, struct an30259a_led, cdev);
0136
0137     mutex_lock(&led->chip->mutex);
0138     num = led->num;
0139
0140     /* slope time can only be a multiple of 500ms. */
0141     if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
0142         ret = -EINVAL;
0143         goto error;
0144     }
0145
0146     /* up to a maximum of 7500ms. */
0147     if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) {
0148         ret = -EINVAL;
0149         goto error;
0150     }
0151
0152     /* if no blink specified, default to 1 Hz. */
0153     if (!off && !on) {
0154         *delay_off = off = 500;
0155         *delay_on = on = 500;
0156     }
0157
0158     /* convert into values the HW will understand. */
0159     off /= AN30259A_SLOPE_RESOLUTION;
0160     on /= AN30259A_SLOPE_RESOLUTION;
0161
0162     /* duty min should be zero (=off), delay should be zero. */
0163     ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
0164                AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
0165     if (ret)
0166         goto error;
0167
0168     /* reset detention time (no "breathing" effect). */
0169     ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
0170                AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
0171     if (ret)
0172         goto error;
0173     ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
0174                AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
0175     if (ret)
0176         goto error;
0177
0178     /* slope time controls on/off cycle length. */
0179     ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
0180                AN30259A_LED_SLOPETIME1(off) |
0181                AN30259A_LED_SLOPETIME2(on));
0182     if (ret)
0183         goto error;
0184
0185     /* Finally, enable slope mode. */
0186     ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
0187     if (ret)
0188         goto error;
0189
0190     led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
0191
0192     ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
0193
0194     if (!ret)
0195         led->sloping = true;
0196 error:
0197     mutex_unlock(&led->chip->mutex);
0198
0199     return ret;
0200 }
0201
0202 static int an30259a_dt_init(struct i2c_client *client,
0203                 struct an30259a *chip)
0204 {
0205     struct device_node *np = dev_of_node(&client->dev), *child;
0206     int count, ret;
0207     int i = 0;
0208     const char *str;
0209     struct an30259a_led *led;
0210
0211     count = of_get_available_child_count(np);
0212     if (!count || count > AN30259A_MAX_LEDS)
0213         return -EINVAL;
0214
0215     for_each_available_child_of_node(np, child) {
0216         u32 source;
0217
0218         ret = of_property_read_u32(child, "reg", &source);
0219         if (ret != 0 || !source || source > AN30259A_MAX_LEDS) {
0220             dev_err(&client->dev, "Couldn't read LED address: %d\n",
0221                 ret);
0222             count--;
0223             continue;
0224         }
0225
0226         led = &chip->leds[i];
0227
0228         led->num = source;
0229         led->chip = chip;
0230         led->fwnode = of_fwnode_handle(child);
0231
0232         if (!of_property_read_string(child, "default-state", &str)) {
0233             if (!strcmp(str, "on"))
0234                 led->default_state = STATE_ON;
0235             else if (!strcmp(str, "keep"))
0236                 led->default_state = STATE_KEEP;
0237             else
0238                 led->default_state = STATE_OFF;
0239         }
0240
0241         i++;
0242     }
0243
0244     if (!count)
0245         return -EINVAL;
0246
0247     chip->num_leds = i;
0248
0249     return 0;
0250 }
0251
0252 static const struct regmap_config an30259a_regmap_config = {
0253     .reg_bits = 8,
0254     .val_bits = 8,
0255     .max_register = AN30259A_REG_MAX,
0256 };
0257
0258 static void an30259a_init_default_state(struct an30259a_led *led)
0259 {
0260     struct an30259a *chip = led->chip;
0261     int led_on, err;
0262
0263     switch (led->default_state) {
0264     case STATE_ON:
0265         led->cdev.brightness = LED_FULL;
0266         break;
0267     case STATE_KEEP:
0268         err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on);
0269         if (err)
0270             break;
0271
0272         if (!(led_on & AN30259A_LED_EN(led->num))) {
0273             led->cdev.brightness = LED_OFF;
0274             break;
0275         }
0276         regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num),
0277                 &led->cdev.brightness);
0278         break;
0279     default:
0280         led->cdev.brightness = LED_OFF;
0281     }
0282
0283     an30259a_brightness_set(&led->cdev, led->cdev.brightness);
0284 }
0285
0286 static int an30259a_probe(struct i2c_client *client)
0287 {
0288     struct an30259a *chip;
0289     int i, err;
0290
0291     chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
0292     if (!chip)
0293         return -ENOMEM;
0294
0295     err = an30259a_dt_init(client, chip);
0296     if (err < 0)
0297         return err;
0298
0299     mutex_init(&chip->mutex);
0300     chip->client = client;
0301     i2c_set_clientdata(client, chip);
0302
0303     chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config);
0304
0305     if (IS_ERR(chip->regmap)) {
0306         err = PTR_ERR(chip->regmap);
0307         dev_err(&client->dev, "Failed to allocate register map: %d\n",
0308             err);
0309         goto exit;
0310     }
0311
0312     for (i = 0; i < chip->num_leds; i++) {
0313         struct led_init_data init_data = {};
0314
0315         an30259a_init_default_state(&chip->leds[i]);
0316         chip->leds[i].cdev.brightness_set_blocking =
0317             an30259a_brightness_set;
0318         chip->leds[i].cdev.blink_set = an30259a_blink_set;
0319
0320         init_data.fwnode = chip->leds[i].fwnode;
0321         init_data.devicename = AN30259A_NAME;
0322         init_data.default_label = ":";
0323
0324         err = devm_led_classdev_register_ext(&client->dev,
0325                          &chip->leds[i].cdev,
0326                          &init_data);
0327         if (err < 0)
0328             goto exit;
0329     }
0330     return 0;
0331
0332 exit:
0333     mutex_destroy(&chip->mutex);
0334     return err;
0335 }
0336
0337 static int an30259a_remove(struct i2c_client *client)
0338 {
0339     struct an30259a *chip = i2c_get_clientdata(client);
0340
0341     mutex_destroy(&chip->mutex);
0342
0343     return 0;
0344 }
0345
0346 static const struct of_device_id an30259a_match_table[] = {
0347     { .compatible = "panasonic,an30259a", },
0348     { /* sentinel */ },
0349 };
0350
0351 MODULE_DEVICE_TABLE(of, an30259a_match_table);
0352
0353 static const struct i2c_device_id an30259a_id[] = {
0354     { "an30259a", 0 },
0355     { /* sentinel */ },
0356 };
0357 MODULE_DEVICE_TABLE(i2c, an30259a_id);
0358
0359 static struct i2c_driver an30259a_driver = {
0360     .driver = {
0361         .name = "leds-an30259a",
0362         .of_match_table = of_match_ptr(an30259a_match_table),
0363     },
0364     .probe_new = an30259a_probe,
0365     .remove = an30259a_remove,
0366     .id_table = an30259a_id,
0367 };
0368
0369 module_i2c_driver(an30259a_driver);
0370
0371 MODULE_AUTHOR("Simon Shields <simon@lineageos.org>");
0372 MODULE_DESCRIPTION("AN30259A LED driver");
0373 MODULE_LICENSE("GPL v2");