drivers/pwm/pwm-twl-led.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
   4  *
   5  * Copyright (C) 2012 Texas Instruments
   6  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   7  *
   8  * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
   9  * Hemanth V <hemanthv@ti.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pwm.h>
  16 #include <linux/mfd/twl.h>
  17 #include <linux/slab.h>
  18
  19 /*
  20  * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
  21  * To generate the signal on TWL4030:
  22  *  - LEDA uses PWMA
  23  *  - LEDB uses PWMB
  24  * TWL6030 has one LED pin with dedicated LEDPWM
  25  */
  26
  27 #define TWL4030_LED_MAX         0x7f
  28 #define TWL6030_LED_MAX         0xff
  29
  30 /* Registers, bits and macro for TWL4030 */
  31 #define TWL4030_LEDEN_REG       0x00
  32 #define TWL4030_PWMA_REG        0x01
  33
  34 #define TWL4030_LEDXON          (1 << 0)
  35 #define TWL4030_LEDXPWM         (1 << 4)
  36 #define TWL4030_LED_PINS        (TWL4030_LEDXON | TWL4030_LEDXPWM)
  37 #define TWL4030_LED_TOGGLE(led, x)      ((x) << (led))
  38
  39 /* Register, bits and macro for TWL6030 */
  40 #define TWL6030_LED_PWM_CTRL1   0xf4
  41 #define TWL6030_LED_PWM_CTRL2   0xf5
  42
  43 #define TWL6040_LED_MODE_HW     0x00
  44 #define TWL6040_LED_MODE_ON     0x01
  45 #define TWL6040_LED_MODE_OFF    0x02
  46 #define TWL6040_LED_MODE_MASK   0x03
  47
  48 struct twl_pwmled_chip {
  49         struct pwm_chip chip;
  50         struct mutex mutex;
  51 };
  52
  53 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
  54 {
  55         return container_of(chip, struct twl_pwmled_chip, chip);
  56 }
  57
  58 static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
  59                               int duty_ns, int period_ns)
  60 {
  61         int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
  62         u8 pwm_config[2] = { 1, 0 };
  63         int base, ret;
  64
  65         /*
  66          * To configure the duty period:
  67          * On-cycle is set to 1 (the minimum allowed value)
  68          * The off time of 0 is not configurable, so the mapping is:
  69          * 0 -> off cycle = 2,
  70          * 1 -> off cycle = 2,
  71          * 2 -> off cycle = 3,
  72          * 126 - > off cycle 127,
  73          * 127 - > off cycle 1
  74          * When on cycle == off cycle the PWM will be always on
  75          */
  76         if (duty_cycle == 1)
  77                 duty_cycle = 2;
  78         else if (duty_cycle > TWL4030_LED_MAX)
  79                 duty_cycle = 1;
  80
  81         base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
  82
  83         pwm_config[1] = duty_cycle;
  84
  85         ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
  86         if (ret < 0)
  87                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
  88
  89         return ret;
  90 }
  91
  92 static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  93 {
  94         struct twl_pwmled_chip *twl = to_twl(chip);
  95         int ret;
  96         u8 val;
  97
  98         mutex_lock(&twl->mutex);
  99         ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 100         if (ret < 0) {
 101                 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 102                 goto out;
 103         }
 104
 105         val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 106
 107         ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 108         if (ret < 0)
 109                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 110
 111 out:
 112         mutex_unlock(&twl->mutex);
 113         return ret;
 114 }
 115
 116 static void twl4030_pwmled_disable(struct pwm_chip *chip,
 117                                    struct pwm_device *pwm)
 118 {
 119         struct twl_pwmled_chip *twl = to_twl(chip);
 120         int ret;
 121         u8 val;
 122
 123         mutex_lock(&twl->mutex);
 124         ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 125         if (ret < 0) {
 126                 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 127                 goto out;
 128         }
 129
 130         val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 131
 132         ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 133         if (ret < 0)
 134                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 135
 136 out:
 137         mutex_unlock(&twl->mutex);
 138 }
 139
 140 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 141                               int duty_ns, int period_ns)
 142 {
 143         int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
 144         u8 on_time;
 145         int ret;
 146
 147         on_time = duty_cycle & 0xff;
 148
 149         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
 150                                TWL6030_LED_PWM_CTRL1);
 151         if (ret < 0)
 152                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 153
 154         return ret;
 155 }
 156
 157 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 158 {
 159         struct twl_pwmled_chip *twl = to_twl(chip);
 160         int ret;
 161         u8 val;
 162
 163         mutex_lock(&twl->mutex);
 164         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 165         if (ret < 0) {
 166                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 167                         pwm->label);
 168                 goto out;
 169         }
 170
 171         val &= ~TWL6040_LED_MODE_MASK;
 172         val |= TWL6040_LED_MODE_ON;
 173
 174         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 175         if (ret < 0)
 176                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 177
 178 out:
 179         mutex_unlock(&twl->mutex);
 180         return ret;
 181 }
 182
 183 static void twl6030_pwmled_disable(struct pwm_chip *chip,
 184                                    struct pwm_device *pwm)
 185 {
 186         struct twl_pwmled_chip *twl = to_twl(chip);
 187         int ret;
 188         u8 val;
 189
 190         mutex_lock(&twl->mutex);
 191         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 192         if (ret < 0) {
 193                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 194                         pwm->label);
 195                 goto out;
 196         }
 197
 198         val &= ~TWL6040_LED_MODE_MASK;
 199         val |= TWL6040_LED_MODE_OFF;
 200
 201         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 202         if (ret < 0)
 203                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 204
 205 out:
 206         mutex_unlock(&twl->mutex);
 207 }
 208
 209 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
 210 {
 211         struct twl_pwmled_chip *twl = to_twl(chip);
 212         int ret;
 213         u8 val;
 214
 215         mutex_lock(&twl->mutex);
 216         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 217         if (ret < 0) {
 218                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 219                         pwm->label);
 220                 goto out;
 221         }
 222
 223         val &= ~TWL6040_LED_MODE_MASK;
 224         val |= TWL6040_LED_MODE_OFF;
 225
 226         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 227         if (ret < 0)
 228                 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 229
 230 out:
 231         mutex_unlock(&twl->mutex);
 232         return ret;
 233 }
 234
 235 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
 236 {
 237         struct twl_pwmled_chip *twl = to_twl(chip);
 238         int ret;
 239         u8 val;
 240
 241         mutex_lock(&twl->mutex);
 242         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 243         if (ret < 0) {
 244                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 245                         pwm->label);
 246                 goto out;
 247         }
 248
 249         val &= ~TWL6040_LED_MODE_MASK;
 250         val |= TWL6040_LED_MODE_HW;
 251
 252         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 253         if (ret < 0)
 254                 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 255
 256 out:
 257         mutex_unlock(&twl->mutex);
 258 }
 259
 260 static const struct pwm_ops twl4030_pwmled_ops = {
 261         .enable = twl4030_pwmled_enable,
 262         .disable = twl4030_pwmled_disable,
 263         .config = twl4030_pwmled_config,
 264         .owner = THIS_MODULE,
 265 };
 266
 267 static const struct pwm_ops twl6030_pwmled_ops = {
 268         .enable = twl6030_pwmled_enable,
 269         .disable = twl6030_pwmled_disable,
 270         .config = twl6030_pwmled_config,
 271         .request = twl6030_pwmled_request,
 272         .free = twl6030_pwmled_free,
 273         .owner = THIS_MODULE,
 274 };
 275
 276 static int twl_pwmled_probe(struct platform_device *pdev)
 277 {
 278         struct twl_pwmled_chip *twl;
 279
 280         twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 281         if (!twl)
 282                 return -ENOMEM;
 283
 284         if (twl_class_is_4030()) {
 285                 twl->chip.ops = &twl4030_pwmled_ops;
 286                 twl->chip.npwm = 2;
 287         } else {
 288                 twl->chip.ops = &twl6030_pwmled_ops;
 289                 twl->chip.npwm = 1;
 290         }
 291
 292         twl->chip.dev = &pdev->dev;
 293
 294         mutex_init(&twl->mutex);
 295
 296         return devm_pwmchip_add(&pdev->dev, &twl->chip);
 297 }
 298
 299 #ifdef CONFIG_OF
 300 static const struct of_device_id twl_pwmled_of_match[] = {
 301         { .compatible = "ti,twl4030-pwmled" },
 302         { .compatible = "ti,twl6030-pwmled" },
 303         { },
 304 };
 305 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 306 #endif
 307
 308 static struct platform_driver twl_pwmled_driver = {
 309         .driver = {
 310                 .name = "twl-pwmled",
 311                 .of_match_table = of_match_ptr(twl_pwmled_of_match),
 312         },
 313         .probe = twl_pwmled_probe,
 314 };
 315 module_platform_driver(twl_pwmled_driver);
 316
 317 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 318 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 319 MODULE_ALIAS("platform:twl-pwmled");
 320 MODULE_LICENSE("GPL");