drivers/leds/leds-pca963x.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright 2011 bct electronic GmbH
0004  * Copyright 2013 Qtechnology/AS
0005  *
0006  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
0007  * Author: Ricardo Ribalda <ribalda@kernel.org>
0008  *
0009  * Based on leds-pca955x.c
0010  *
0011  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
0012  * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
0013  *
0014  * Note that hardware blinking violates the leds infrastructure driver
0015  * interface since the hardware only supports blinking all LEDs with the
0016  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
0017  * blink will actually blink but all LEDs that are set to blink will blink
0018  * in identical fashion.  The delay_on/delay_off values of the last LED
0019  * that is set to blink will be used for all of the blinking LEDs.
0020  * Hardware blinking is disabled by default but can be enabled by setting
0021  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
0022  * or by adding the 'nxp,hw-blink' property to the DTS.
0023  */
0024
0025 #include <linux/module.h>
0026 #include <linux/delay.h>
0027 #include <linux/string.h>
0028 #include <linux/ctype.h>
0029 #include <linux/leds.h>
0030 #include <linux/err.h>
0031 #include <linux/i2c.h>
0032 #include <linux/property.h>
0033 #include <linux/slab.h>
0034 #include <linux/of.h>
0035
0036 /* LED select registers determine the source that drives LED outputs */
0037 #define PCA963X_LED_OFF     0x0 /* LED driver off */
0038 #define PCA963X_LED_ON      0x1 /* LED driver on */
0039 #define PCA963X_LED_PWM     0x2 /* Controlled through PWM */
0040 #define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
0041
0042 #define PCA963X_MODE2_OUTDRV    0x04    /* Open-drain or totem pole */
0043 #define PCA963X_MODE2_INVRT 0x10    /* Normal or inverted direction */
0044 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
0045
0046 #define PCA963X_MODE1       0x00
0047 #define PCA963X_MODE2       0x01
0048 #define PCA963X_PWM_BASE    0x02
0049
0050 enum pca963x_type {
0051     pca9633,
0052     pca9634,
0053     pca9635,
0054 };
0055
0056 struct pca963x_chipdef {
0057     u8          grppwm;
0058     u8          grpfreq;
0059     u8          ledout_base;
0060     int         n_leds;
0061     unsigned int        scaling;
0062 };
0063
0064 static struct pca963x_chipdef pca963x_chipdefs[] = {
0065     [pca9633] = {
0066         .grppwm     = 0x6,
0067         .grpfreq    = 0x7,
0068         .ledout_base    = 0x8,
0069         .n_leds     = 4,
0070     },
0071     [pca9634] = {
0072         .grppwm     = 0xa,
0073         .grpfreq    = 0xb,
0074         .ledout_base    = 0xc,
0075         .n_leds     = 8,
0076     },
0077     [pca9635] = {
0078         .grppwm     = 0x12,
0079         .grpfreq    = 0x13,
0080         .ledout_base    = 0x14,
0081         .n_leds     = 16,
0082     },
0083 };
0084
0085 /* Total blink period in milliseconds */
0086 #define PCA963X_BLINK_PERIOD_MIN    42
0087 #define PCA963X_BLINK_PERIOD_MAX    10667
0088
0089 static const struct i2c_device_id pca963x_id[] = {
0090     { "pca9632", pca9633 },
0091     { "pca9633", pca9633 },
0092     { "pca9634", pca9634 },
0093     { "pca9635", pca9635 },
0094     { }
0095 };
0096 MODULE_DEVICE_TABLE(i2c, pca963x_id);
0097
0098 struct pca963x;
0099
0100 struct pca963x_led {
0101     struct pca963x *chip;
0102     struct led_classdev led_cdev;
0103     int led_num; /* 0 .. 15 potentially */
0104     u8 gdc;
0105     u8 gfrq;
0106 };
0107
0108 struct pca963x {
0109     struct pca963x_chipdef *chipdef;
0110     struct mutex mutex;
0111     struct i2c_client *client;
0112     unsigned long leds_on;
0113     struct pca963x_led leds[];
0114 };
0115
0116 static int pca963x_brightness(struct pca963x_led *led,
0117                   enum led_brightness brightness)
0118 {
0119     struct i2c_client *client = led->chip->client;
0120     struct pca963x_chipdef *chipdef = led->chip->chipdef;
0121     u8 ledout_addr, ledout, mask, val;
0122     int shift;
0123     int ret;
0124
0125     ledout_addr = chipdef->ledout_base + (led->led_num / 4);
0126     shift = 2 * (led->led_num % 4);
0127     mask = 0x3 << shift;
0128     ledout = i2c_smbus_read_byte_data(client, ledout_addr);
0129
0130     switch (brightness) {
0131     case LED_FULL:
0132         val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
0133         ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
0134         break;
0135     case LED_OFF:
0136         val = ledout & ~mask;
0137         ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
0138         break;
0139     default:
0140         ret = i2c_smbus_write_byte_data(client,
0141                         PCA963X_PWM_BASE +
0142                         led->led_num,
0143                         brightness);
0144         if (ret < 0)
0145             return ret;
0146
0147         val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
0148         ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
0149         break;
0150     }
0151
0152     return ret;
0153 }
0154
0155 static void pca963x_blink(struct pca963x_led *led)
0156 {
0157     struct i2c_client *client = led->chip->client;
0158     struct pca963x_chipdef *chipdef = led->chip->chipdef;
0159     u8 ledout_addr, ledout, mask, val, mode2;
0160     int shift;
0161
0162     ledout_addr = chipdef->ledout_base + (led->led_num / 4);
0163     shift = 2 * (led->led_num % 4);
0164     mask = 0x3 << shift;
0165     mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
0166
0167     i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
0168
0169     i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
0170
0171     if (!(mode2 & PCA963X_MODE2_DMBLNK))
0172         i2c_smbus_write_byte_data(client, PCA963X_MODE2,
0173                       mode2 | PCA963X_MODE2_DMBLNK);
0174
0175     mutex_lock(&led->chip->mutex);
0176
0177     ledout = i2c_smbus_read_byte_data(client, ledout_addr);
0178     if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
0179         val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
0180         i2c_smbus_write_byte_data(client, ledout_addr, val);
0181     }
0182
0183     mutex_unlock(&led->chip->mutex);
0184 }
0185
0186 static int pca963x_power_state(struct pca963x_led *led)
0187 {
0188     struct i2c_client *client = led->chip->client;
0189     unsigned long *leds_on = &led->chip->leds_on;
0190     unsigned long cached_leds = *leds_on;
0191
0192     if (led->led_cdev.brightness)
0193         set_bit(led->led_num, leds_on);
0194     else
0195         clear_bit(led->led_num, leds_on);
0196
0197     if (!(*leds_on) != !cached_leds)
0198         return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
0199                          *leds_on ? 0 : BIT(4));
0200
0201     return 0;
0202 }
0203
0204 static int pca963x_led_set(struct led_classdev *led_cdev,
0205                enum led_brightness value)
0206 {
0207     struct pca963x_led *led;
0208     int ret;
0209
0210     led = container_of(led_cdev, struct pca963x_led, led_cdev);
0211
0212     mutex_lock(&led->chip->mutex);
0213
0214     ret = pca963x_brightness(led, value);
0215     if (ret < 0)
0216         goto unlock;
0217     ret = pca963x_power_state(led);
0218
0219 unlock:
0220     mutex_unlock(&led->chip->mutex);
0221     return ret;
0222 }
0223
0224 static unsigned int pca963x_period_scale(struct pca963x_led *led,
0225                      unsigned int val)
0226 {
0227     unsigned int scaling = led->chip->chipdef->scaling;
0228
0229     return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
0230 }
0231
0232 static int pca963x_blink_set(struct led_classdev *led_cdev,
0233                  unsigned long *delay_on, unsigned long *delay_off)
0234 {
0235     unsigned long time_on, time_off, period;
0236     struct pca963x_led *led;
0237     u8 gdc, gfrq;
0238
0239     led = container_of(led_cdev, struct pca963x_led, led_cdev);
0240
0241     time_on = *delay_on;
0242     time_off = *delay_off;
0243
0244     /* If both zero, pick reasonable defaults of 500ms each */
0245     if (!time_on && !time_off) {
0246         time_on = 500;
0247         time_off = 500;
0248     }
0249
0250     period = pca963x_period_scale(led, time_on + time_off);
0251
0252     /* If period not supported by hardware, default to someting sane. */
0253     if ((period < PCA963X_BLINK_PERIOD_MIN) ||
0254         (period > PCA963X_BLINK_PERIOD_MAX)) {
0255         time_on = 500;
0256         time_off = 500;
0257         period = pca963x_period_scale(led, 1000);
0258     }
0259
0260     /*
0261      * From manual: duty cycle = (GDC / 256) ->
0262      *  (time_on / period) = (GDC / 256) ->
0263      *      GDC = ((time_on * 256) / period)
0264      */
0265     gdc = (pca963x_period_scale(led, time_on) * 256) / period;
0266
0267     /*
0268      * From manual: period = ((GFRQ + 1) / 24) in seconds.
0269      * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
0270      *      GFRQ = ((period * 24 / 1000) - 1)
0271      */
0272     gfrq = (period * 24 / 1000) - 1;
0273
0274     led->gdc = gdc;
0275     led->gfrq = gfrq;
0276
0277     pca963x_blink(led);
0278
0279     *delay_on = time_on;
0280     *delay_off = time_off;
0281
0282     return 0;
0283 }
0284
0285 static int pca963x_register_leds(struct i2c_client *client,
0286                  struct pca963x *chip)
0287 {
0288     struct pca963x_chipdef *chipdef = chip->chipdef;
0289     struct pca963x_led *led = chip->leds;
0290     struct device *dev = &client->dev;
0291     struct fwnode_handle *child;
0292     bool hw_blink;
0293     s32 mode2;
0294     u32 reg;
0295     int ret;
0296
0297     if (device_property_read_u32(dev, "nxp,period-scale",
0298                      &chipdef->scaling))
0299         chipdef->scaling = 1000;
0300
0301     hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
0302
0303     mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
0304     if (mode2 < 0)
0305         return mode2;
0306
0307     /* default to open-drain unless totem pole (push-pull) is specified */
0308     if (device_property_read_bool(dev, "nxp,totem-pole"))
0309         mode2 |= PCA963X_MODE2_OUTDRV;
0310     else
0311         mode2 &= ~PCA963X_MODE2_OUTDRV;
0312
0313     /* default to non-inverted output, unless inverted is specified */
0314     if (device_property_read_bool(dev, "nxp,inverted-out"))
0315         mode2 |= PCA963X_MODE2_INVRT;
0316     else
0317         mode2 &= ~PCA963X_MODE2_INVRT;
0318
0319     ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
0320     if (ret < 0)
0321         return ret;
0322
0323     device_for_each_child_node(dev, child) {
0324         struct led_init_data init_data = {};
0325         char default_label[32];
0326
0327         ret = fwnode_property_read_u32(child, "reg", &reg);
0328         if (ret || reg >= chipdef->n_leds) {
0329             dev_err(dev, "Invalid 'reg' property for node %pfw\n",
0330                 child);
0331             ret = -EINVAL;
0332             goto err;
0333         }
0334
0335         led->led_num = reg;
0336         led->chip = chip;
0337         led->led_cdev.brightness_set_blocking = pca963x_led_set;
0338         if (hw_blink)
0339             led->led_cdev.blink_set = pca963x_blink_set;
0340
0341         init_data.fwnode = child;
0342         /* for backwards compatibility */
0343         init_data.devicename = "pca963x";
0344         snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
0345              client->adapter->nr, client->addr, reg);
0346         init_data.default_label = default_label;
0347
0348         ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
0349                              &init_data);
0350         if (ret) {
0351             dev_err(dev, "Failed to register LED for node %pfw\n",
0352                 child);
0353             goto err;
0354         }
0355
0356         ++led;
0357     }
0358
0359     return 0;
0360 err:
0361     fwnode_handle_put(child);
0362     return ret;
0363 }
0364
0365 static const struct of_device_id of_pca963x_match[] = {
0366     { .compatible = "nxp,pca9632", },
0367     { .compatible = "nxp,pca9633", },
0368     { .compatible = "nxp,pca9634", },
0369     { .compatible = "nxp,pca9635", },
0370     {},
0371 };
0372 MODULE_DEVICE_TABLE(of, of_pca963x_match);
0373
0374 static int pca963x_probe(struct i2c_client *client,
0375              const struct i2c_device_id *id)
0376 {
0377     struct device *dev = &client->dev;
0378     struct pca963x_chipdef *chipdef;
0379     struct pca963x *chip;
0380     int i, count;
0381
0382     chipdef = &pca963x_chipdefs[id->driver_data];
0383
0384     count = device_get_child_node_count(dev);
0385     if (!count || count > chipdef->n_leds) {
0386         dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
0387             dev_fwnode(dev), chipdef->n_leds);
0388         return -EINVAL;
0389     }
0390
0391     chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
0392     if (!chip)
0393         return -ENOMEM;
0394
0395     i2c_set_clientdata(client, chip);
0396
0397     mutex_init(&chip->mutex);
0398     chip->chipdef = chipdef;
0399     chip->client = client;
0400
0401     /* Turn off LEDs by default*/
0402     for (i = 0; i < chipdef->n_leds / 4; i++)
0403         i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
0404
0405     /* Disable LED all-call address, and power down initially */
0406     i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
0407
0408     return pca963x_register_leds(client, chip);
0409 }
0410
0411 static struct i2c_driver pca963x_driver = {
0412     .driver = {
0413         .name   = "leds-pca963x",
0414         .of_match_table = of_pca963x_match,
0415     },
0416     .probe  = pca963x_probe,
0417     .id_table = pca963x_id,
0418 };
0419
0420 module_i2c_driver(pca963x_driver);
0421
0422 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
0423 MODULE_DESCRIPTION("PCA963X LED driver");
0424 MODULE_LICENSE("GPL v2");