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 twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 141                                 const struct pwm_state *state)
 142 {
 143         int ret;
 144
 145         if (state->polarity != PWM_POLARITY_NORMAL)
 146                 return -EINVAL;
 147
 148         if (!state->enabled) {
 149                 if (pwm->state.enabled)
 150                         twl4030_pwmled_disable(chip, pwm);
 151
 152                 return 0;
 153         }
 154
 155         /*
 156          * We cannot skip calling ->config even if state->period ==
 157          * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
 158          * because we might have exited early in the last call to
 159          * pwm_apply_state because of !state->enabled and so the two values in
 160          * pwm->state might not be configured in hardware.
 161          */
 162         ret = twl4030_pwmled_config(pwm->chip, pwm,
 163                                     state->duty_cycle, state->period);
 164         if (ret)
 165                 return ret;
 166
 167         if (!pwm->state.enabled)
 168                 ret = twl4030_pwmled_enable(chip, pwm);
 169
 170         return ret;
 171 }
 172
 173
 174 static const struct pwm_ops twl4030_pwmled_ops = {
 175         .apply = twl4030_pwmled_apply,
 176         .owner = THIS_MODULE,
 177 };
 178
 179 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 180                               int duty_ns, int period_ns)
 181 {
 182         int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
 183         u8 on_time;
 184         int ret;
 185
 186         on_time = duty_cycle & 0xff;
 187
 188         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
 189                                TWL6030_LED_PWM_CTRL1);
 190         if (ret < 0)
 191                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 192
 193         return ret;
 194 }
 195
 196 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 197 {
 198         struct twl_pwmled_chip *twl = to_twl(chip);
 199         int ret;
 200         u8 val;
 201
 202         mutex_lock(&twl->mutex);
 203         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 204         if (ret < 0) {
 205                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 206                         pwm->label);
 207                 goto out;
 208         }
 209
 210         val &= ~TWL6040_LED_MODE_MASK;
 211         val |= TWL6040_LED_MODE_ON;
 212
 213         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 214         if (ret < 0)
 215                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 216
 217 out:
 218         mutex_unlock(&twl->mutex);
 219         return ret;
 220 }
 221
 222 static void twl6030_pwmled_disable(struct pwm_chip *chip,
 223                                    struct pwm_device *pwm)
 224 {
 225         struct twl_pwmled_chip *twl = to_twl(chip);
 226         int ret;
 227         u8 val;
 228
 229         mutex_lock(&twl->mutex);
 230         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 231         if (ret < 0) {
 232                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 233                         pwm->label);
 234                 goto out;
 235         }
 236
 237         val &= ~TWL6040_LED_MODE_MASK;
 238         val |= TWL6040_LED_MODE_OFF;
 239
 240         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 241         if (ret < 0)
 242                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 243
 244 out:
 245         mutex_unlock(&twl->mutex);
 246 }
 247
 248 static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 249                                 const struct pwm_state *state)
 250 {
 251         int err;
 252
 253         if (state->polarity != pwm->state.polarity)
 254                 return -EINVAL;
 255
 256         if (!state->enabled) {
 257                 if (pwm->state.enabled)
 258                         twl6030_pwmled_disable(chip, pwm);
 259
 260                 return 0;
 261         }
 262
 263         err = twl6030_pwmled_config(pwm->chip, pwm,
 264                                     state->duty_cycle, state->period);
 265         if (err)
 266                 return err;
 267
 268         if (!pwm->state.enabled)
 269                 err = twl6030_pwmled_enable(chip, pwm);
 270
 271         return err;
 272 }
 273
 274 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
 275 {
 276         struct twl_pwmled_chip *twl = to_twl(chip);
 277         int ret;
 278         u8 val;
 279
 280         mutex_lock(&twl->mutex);
 281         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 282         if (ret < 0) {
 283                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 284                         pwm->label);
 285                 goto out;
 286         }
 287
 288         val &= ~TWL6040_LED_MODE_MASK;
 289         val |= TWL6040_LED_MODE_OFF;
 290
 291         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 292         if (ret < 0)
 293                 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 294
 295 out:
 296         mutex_unlock(&twl->mutex);
 297         return ret;
 298 }
 299
 300 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
 301 {
 302         struct twl_pwmled_chip *twl = to_twl(chip);
 303         int ret;
 304         u8 val;
 305
 306         mutex_lock(&twl->mutex);
 307         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 308         if (ret < 0) {
 309                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 310                         pwm->label);
 311                 goto out;
 312         }
 313
 314         val &= ~TWL6040_LED_MODE_MASK;
 315         val |= TWL6040_LED_MODE_HW;
 316
 317         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 318         if (ret < 0)
 319                 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 320
 321 out:
 322         mutex_unlock(&twl->mutex);
 323 }
 324
 325 static const struct pwm_ops twl6030_pwmled_ops = {
 326         .apply = twl6030_pwmled_apply,
 327         .request = twl6030_pwmled_request,
 328         .free = twl6030_pwmled_free,
 329         .owner = THIS_MODULE,
 330 };
 331
 332 static int twl_pwmled_probe(struct platform_device *pdev)
 333 {
 334         struct twl_pwmled_chip *twl;
 335
 336         twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 337         if (!twl)
 338                 return -ENOMEM;
 339
 340         if (twl_class_is_4030()) {
 341                 twl->chip.ops = &twl4030_pwmled_ops;
 342                 twl->chip.npwm = 2;
 343         } else {
 344                 twl->chip.ops = &twl6030_pwmled_ops;
 345                 twl->chip.npwm = 1;
 346         }
 347
 348         twl->chip.dev = &pdev->dev;
 349
 350         mutex_init(&twl->mutex);
 351
 352         return devm_pwmchip_add(&pdev->dev, &twl->chip);
 353 }
 354
 355 #ifdef CONFIG_OF
 356 static const struct of_device_id twl_pwmled_of_match[] = {
 357         { .compatible = "ti,twl4030-pwmled" },
 358         { .compatible = "ti,twl6030-pwmled" },
 359         { },
 360 };
 361 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 362 #endif
 363
 364 static struct platform_driver twl_pwmled_driver = {
 365         .driver = {
 366                 .name = "twl-pwmled",
 367                 .of_match_table = of_match_ptr(twl_pwmled_of_match),
 368         },
 369         .probe = twl_pwmled_probe,
 370 };
 371 module_platform_driver(twl_pwmled_driver);
 372
 373 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 374 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 375 MODULE_ALIAS("platform:twl-pwmled");
 376 MODULE_LICENSE("GPL");