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