drivers/pwm/pwm-twl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for TWL4030/6030 Generic Pulse Width Modulator
   4  *
   5  * Copyright (C) 2012 Texas Instruments
   6  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pwm.h>
  13 #include <linux/mfd/twl.h>
  14 #include <linux/slab.h>
  15
  16 /*
  17  * This driver handles the PWMs of TWL4030 and TWL6030.
  18  * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
  19  * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
  20  */
  21
  22 #define TWL_PWM_MAX             0x7f
  23
  24 /* Registers, bits and macro for TWL4030 */
  25 #define TWL4030_GPBR1_REG       0x0c
  26 #define TWL4030_PMBR1_REG       0x0d
  27
  28 /* GPBR1 register bits */
  29 #define TWL4030_PWMXCLK_ENABLE  (1 << 0)
  30 #define TWL4030_PWMX_ENABLE     (1 << 2)
  31 #define TWL4030_PWMX_BITS       (TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
  32 #define TWL4030_PWM_TOGGLE(pwm, x)      ((x) << (pwm))
  33
  34 /* PMBR1 register bits */
  35 #define TWL4030_GPIO6_PWM0_MUTE_MASK            (0x03 << 2)
  36 #define TWL4030_GPIO6_PWM0_MUTE_PWM0            (0x01 << 2)
  37 #define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK       (0x03 << 4)
  38 #define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1       (0x03 << 4)
  39
  40 /* Register, bits and macro for TWL6030 */
  41 #define TWL6030_TOGGLE3_REG     0x92
  42
  43 #define TWL6030_PWMXR           (1 << 0)
  44 #define TWL6030_PWMXS           (1 << 1)
  45 #define TWL6030_PWMXEN          (1 << 2)
  46 #define TWL6030_PWM_TOGGLE(pwm, x)      ((x) << (pwm * 3))
  47
  48 struct twl_pwm_chip {
  49         struct pwm_chip chip;
  50         struct mutex mutex;
  51         u8 twl6030_toggle3;
  52         u8 twl4030_pwm_mux;
  53 };
  54
  55 static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
  56 {
  57         return container_of(chip, struct twl_pwm_chip, chip);
  58 }
  59
  60 static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  61                           u64 duty_ns, u64 period_ns)
  62 {
  63         int duty_cycle = DIV64_U64_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
  64         u8 pwm_config[2] = { 1, 0 };
  65         int base, ret;
  66
  67         /*
  68          * To configure the duty period:
  69          * On-cycle is set to 1 (the minimum allowed value)
  70          * The off time of 0 is not configurable, so the mapping is:
  71          * 0 -> off cycle = 2,
  72          * 1 -> off cycle = 2,
  73          * 2 -> off cycle = 3,
  74          * 126 - > off cycle 127,
  75          * 127 - > off cycle 1
  76          * When on cycle == off cycle the PWM will be always on
  77          */
  78         if (duty_cycle == 1)
  79                 duty_cycle = 2;
  80         else if (duty_cycle > TWL_PWM_MAX)
  81                 duty_cycle = 1;
  82
  83         base = pwm->hwpwm * 3;
  84
  85         pwm_config[1] = duty_cycle;
  86
  87         ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
  88         if (ret < 0)
  89                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
  90
  91         return ret;
  92 }
  93
  94 static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  95 {
  96         struct twl_pwm_chip *twl = to_twl(chip);
  97         int ret;
  98         u8 val;
  99
 100         mutex_lock(&twl->mutex);
 101         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
 102         if (ret < 0) {
 103                 dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
 104                 goto out;
 105         }
 106
 107         val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
 108
 109         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 110         if (ret < 0)
 111                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 112
 113         val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
 114
 115         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 116         if (ret < 0)
 117                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 118
 119 out:
 120         mutex_unlock(&twl->mutex);
 121         return ret;
 122 }
 123
 124 static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 125 {
 126         struct twl_pwm_chip *twl = to_twl(chip);
 127         int ret;
 128         u8 val;
 129
 130         mutex_lock(&twl->mutex);
 131         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
 132         if (ret < 0) {
 133                 dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
 134                 goto out;
 135         }
 136
 137         val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
 138
 139         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 140         if (ret < 0)
 141                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 142
 143         val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
 144
 145         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 146         if (ret < 0)
 147                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 148
 149 out:
 150         mutex_unlock(&twl->mutex);
 151 }
 152
 153 static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 154 {
 155         struct twl_pwm_chip *twl = to_twl(chip);
 156         int ret;
 157         u8 val, mask, bits;
 158
 159         if (pwm->hwpwm == 1) {
 160                 mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
 161                 bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
 162         } else {
 163                 mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
 164                 bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
 165         }
 166
 167         mutex_lock(&twl->mutex);
 168         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
 169         if (ret < 0) {
 170                 dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
 171                 goto out;
 172         }
 173
 174         /* Save the current MUX configuration for the PWM */
 175         twl->twl4030_pwm_mux &= ~mask;
 176         twl->twl4030_pwm_mux |= (val & mask);
 177
 178         /* Select PWM functionality */
 179         val &= ~mask;
 180         val |= bits;
 181
 182         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
 183         if (ret < 0)
 184                 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 185
 186 out:
 187         mutex_unlock(&twl->mutex);
 188         return ret;
 189 }
 190
 191 static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 192 {
 193         struct twl_pwm_chip *twl = to_twl(chip);
 194         int ret;
 195         u8 val, mask;
 196
 197         if (pwm->hwpwm == 1)
 198                 mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
 199         else
 200                 mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
 201
 202         mutex_lock(&twl->mutex);
 203         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
 204         if (ret < 0) {
 205                 dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
 206                 goto out;
 207         }
 208
 209         /* Restore the MUX configuration for the PWM */
 210         val &= ~mask;
 211         val |= (twl->twl4030_pwm_mux & mask);
 212
 213         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
 214         if (ret < 0)
 215                 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 216
 217 out:
 218         mutex_unlock(&twl->mutex);
 219 }
 220
 221 static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 222 {
 223         struct twl_pwm_chip *twl = to_twl(chip);
 224         int ret;
 225         u8 val;
 226
 227         mutex_lock(&twl->mutex);
 228         val = twl->twl6030_toggle3;
 229         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
 230         val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
 231
 232         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 233         if (ret < 0) {
 234                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 235                 goto out;
 236         }
 237
 238         twl->twl6030_toggle3 = val;
 239 out:
 240         mutex_unlock(&twl->mutex);
 241         return ret;
 242 }
 243
 244 static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 245 {
 246         struct twl_pwm_chip *twl = to_twl(chip);
 247         int ret;
 248         u8 val;
 249
 250         mutex_lock(&twl->mutex);
 251         val = twl->twl6030_toggle3;
 252         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
 253         val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
 254
 255         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 256         if (ret < 0) {
 257                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 258                 goto out;
 259         }
 260
 261         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
 262
 263         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 264         if (ret < 0) {
 265                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 266                 goto out;
 267         }
 268
 269         val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
 270
 271         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 272         if (ret < 0) {
 273                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 274                 goto out;
 275         }
 276
 277         twl->twl6030_toggle3 = val;
 278 out:
 279         mutex_unlock(&twl->mutex);
 280 }
 281
 282 static int twl4030_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 283                              const struct pwm_state *state)
 284 {
 285         int err;
 286
 287         if (state->polarity != PWM_POLARITY_NORMAL)
 288                 return -EINVAL;
 289
 290         if (!state->enabled) {
 291                 if (pwm->state.enabled)
 292                         twl4030_pwm_disable(chip, pwm);
 293
 294                 return 0;
 295         }
 296
 297         err = twl_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
 298         if (err)
 299                 return err;
 300
 301         if (!pwm->state.enabled)
 302                 err = twl4030_pwm_enable(chip, pwm);
 303
 304         return err;
 305 }
 306
 307 static int twl6030_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 308                              const struct pwm_state *state)
 309 {
 310         int err;
 311
 312         if (state->polarity != PWM_POLARITY_NORMAL)
 313                 return -EINVAL;
 314
 315         if (!state->enabled) {
 316                 if (pwm->state.enabled)
 317                         twl6030_pwm_disable(chip, pwm);
 318
 319                 return 0;
 320         }
 321
 322         err = twl_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
 323         if (err)
 324                 return err;
 325
 326         if (!pwm->state.enabled)
 327                 err = twl6030_pwm_enable(chip, pwm);
 328
 329         return err;
 330 }
 331
 332 static const struct pwm_ops twl4030_pwm_ops = {
 333         .apply = twl4030_pwm_apply,
 334         .request = twl4030_pwm_request,
 335         .free = twl4030_pwm_free,
 336         .owner = THIS_MODULE,
 337 };
 338
 339 static const struct pwm_ops twl6030_pwm_ops = {
 340         .apply = twl6030_pwm_apply,
 341         .owner = THIS_MODULE,
 342 };
 343
 344 static int twl_pwm_probe(struct platform_device *pdev)
 345 {
 346         struct twl_pwm_chip *twl;
 347
 348         twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 349         if (!twl)
 350                 return -ENOMEM;
 351
 352         if (twl_class_is_4030())
 353                 twl->chip.ops = &twl4030_pwm_ops;
 354         else
 355                 twl->chip.ops = &twl6030_pwm_ops;
 356
 357         twl->chip.dev = &pdev->dev;
 358         twl->chip.npwm = 2;
 359
 360         mutex_init(&twl->mutex);
 361
 362         return devm_pwmchip_add(&pdev->dev, &twl->chip);
 363 }
 364
 365 #ifdef CONFIG_OF
 366 static const struct of_device_id twl_pwm_of_match[] = {
 367         { .compatible = "ti,twl4030-pwm" },
 368         { .compatible = "ti,twl6030-pwm" },
 369         { },
 370 };
 371 MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
 372 #endif
 373
 374 static struct platform_driver twl_pwm_driver = {
 375         .driver = {
 376                 .name = "twl-pwm",
 377                 .of_match_table = of_match_ptr(twl_pwm_of_match),
 378         },
 379         .probe = twl_pwm_probe,
 380 };
 381 module_platform_driver(twl_pwm_driver);
 382
 383 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 384 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
 385 MODULE_ALIAS("platform:twl-pwm");
 386 MODULE_LICENSE("GPL");