drivers/pwm/pwm-twl.c

   1 /*
   2  * Driver for TWL4030/6030 Generic Pulse Width Modulator
   3  *
   4  * Copyright (C) 2012 Texas Instruments
   5  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/pwm.h>
  23 #include <linux/i2c/twl.h>
  24 #include <linux/slab.h>
  25
  26 /*
  27  * This driver handles the PWMs of TWL4030 and TWL6030.
  28  * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
  29  * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
  30  */
  31
  32 #define TWL_PWM_MAX             0x7f
  33
  34 /* Registers, bits and macro for TWL4030 */
  35 #define TWL4030_GPBR1_REG       0x0c
  36 #define TWL4030_PMBR1_REG       0x0d
  37
  38 /* GPBR1 register bits */
  39 #define TWL4030_PWMXCLK_ENABLE  (1 << 0)
  40 #define TWL4030_PWMX_ENABLE     (1 << 2)
  41 #define TWL4030_PWMX_BITS       (TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
  42 #define TWL4030_PWM_TOGGLE(pwm, x)      ((x) << (pwm))
  43
  44 /* PMBR1 register bits */
  45 #define TWL4030_GPIO6_PWM0_MUTE_MASK            (0x03 << 2)
  46 #define TWL4030_GPIO6_PWM0_MUTE_PWM0            (0x01 << 2)
  47 #define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK       (0x03 << 4)
  48 #define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1       (0x03 << 4)
  49
  50 /* Register, bits and macro for TWL6030 */
  51 #define TWL6030_TOGGLE3_REG     0x92
  52
  53 #define TWL6030_PWMXR           (1 << 0)
  54 #define TWL6030_PWMXS           (1 << 1)
  55 #define TWL6030_PWMXEN          (1 << 2)
  56 #define TWL6030_PWM_TOGGLE(pwm, x)      ((x) << (pwm * 3))
  57
  58 struct twl_pwm_chip {
  59         struct pwm_chip chip;
  60         struct mutex mutex;
  61         u8 twl6030_toggle3;
  62         u8 twl4030_pwm_mux;
  63 };
  64
  65 static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
  66 {
  67         return container_of(chip, struct twl_pwm_chip, chip);
  68 }
  69
  70 static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  71                               int duty_ns, int period_ns)
  72 {
  73         int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
  74         u8 pwm_config[2] = { 1, 0 };
  75         int base, ret;
  76
  77         /*
  78          * To configure the duty period:
  79          * On-cycle is set to 1 (the minimum allowed value)
  80          * The off time of 0 is not configurable, so the mapping is:
  81          * 0 -> off cycle = 2,
  82          * 1 -> off cycle = 2,
  83          * 2 -> off cycle = 3,
  84          * 126 - > off cycle 127,
  85          * 127 - > off cycle 1
  86          * When on cycle == off cycle the PWM will be always on
  87          */
  88         if (duty_cycle == 1)
  89                 duty_cycle = 2;
  90         else if (duty_cycle > TWL_PWM_MAX)
  91                 duty_cycle = 1;
  92
  93         base = pwm->hwpwm * 3;
  94
  95         pwm_config[1] = duty_cycle;
  96
  97         ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
  98         if (ret < 0)
  99                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 100
 101         return ret;
 102 }
 103
 104 static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 105 {
 106         struct twl_pwm_chip *twl = to_twl(chip);
 107         int ret;
 108         u8 val;
 109
 110         mutex_lock(&twl->mutex);
 111         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
 112         if (ret < 0) {
 113                 dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
 114                 goto out;
 115         }
 116
 117         val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
 118
 119         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 120         if (ret < 0)
 121                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 122
 123         val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
 124
 125         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 126         if (ret < 0)
 127                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 128
 129 out:
 130         mutex_unlock(&twl->mutex);
 131         return ret;
 132 }
 133
 134 static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 135 {
 136         struct twl_pwm_chip *twl = to_twl(chip);
 137         int ret;
 138         u8 val;
 139
 140         mutex_lock(&twl->mutex);
 141         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
 142         if (ret < 0) {
 143                 dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
 144                 goto out;
 145         }
 146
 147         val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
 148
 149         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 150         if (ret < 0)
 151                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 152
 153         val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
 154
 155         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
 156         if (ret < 0)
 157                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 158
 159 out:
 160         mutex_unlock(&twl->mutex);
 161 }
 162
 163 static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 164 {
 165         struct twl_pwm_chip *twl = to_twl(chip);
 166         int ret;
 167         u8 val, mask, bits;
 168
 169         if (pwm->hwpwm == 1) {
 170                 mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
 171                 bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
 172         } else {
 173                 mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
 174                 bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
 175         }
 176
 177         mutex_lock(&twl->mutex);
 178         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
 179         if (ret < 0) {
 180                 dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
 181                 goto out;
 182         }
 183
 184         /* Save the current MUX configuration for the PWM */
 185         twl->twl4030_pwm_mux &= ~mask;
 186         twl->twl4030_pwm_mux |= (val & mask);
 187
 188         /* Select PWM functionality */
 189         val &= ~mask;
 190         val |= bits;
 191
 192         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
 193         if (ret < 0)
 194                 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 195
 196 out:
 197         mutex_unlock(&twl->mutex);
 198         return ret;
 199 }
 200
 201 static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 202 {
 203         struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
 204                                                 chip);
 205         int ret;
 206         u8 val, mask;
 207
 208         if (pwm->hwpwm == 1)
 209                 mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
 210         else
 211                 mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
 212
 213         mutex_lock(&twl->mutex);
 214         ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
 215         if (ret < 0) {
 216                 dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
 217                 goto out;
 218         }
 219
 220         /* Restore the MUX configuration for the PWM */
 221         val &= ~mask;
 222         val |= (twl->twl4030_pwm_mux & mask);
 223
 224         ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
 225         if (ret < 0)
 226                 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 227
 228 out:
 229         mutex_unlock(&twl->mutex);
 230 }
 231
 232 static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 233 {
 234         struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
 235                                                 chip);
 236         int ret;
 237         u8 val;
 238
 239         mutex_lock(&twl->mutex);
 240         val = twl->twl6030_toggle3;
 241         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
 242         val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
 243
 244         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 245         if (ret < 0) {
 246                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 247                 goto out;
 248         }
 249
 250         twl->twl6030_toggle3 = val;
 251 out:
 252         mutex_unlock(&twl->mutex);
 253         return 0;
 254 }
 255
 256 static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 257 {
 258         struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
 259                                                 chip);
 260         int ret;
 261         u8 val;
 262
 263         mutex_lock(&twl->mutex);
 264         val = twl->twl6030_toggle3;
 265         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
 266         val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
 267
 268         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 269         if (ret < 0) {
 270                 dev_err(chip->dev, "%s: Failed to read TOGGLE3\n", pwm->label);
 271                 goto out;
 272         }
 273
 274         val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
 275
 276         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
 277         if (ret < 0) {
 278                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 279                 goto out;
 280         }
 281
 282         twl->twl6030_toggle3 = val;
 283 out:
 284         mutex_unlock(&twl->mutex);
 285 }
 286
 287 static const struct pwm_ops twl4030_pwm_ops = {
 288         .config = twl_pwm_config,
 289         .enable = twl4030_pwm_enable,
 290         .disable = twl4030_pwm_disable,
 291         .request = twl4030_pwm_request,
 292         .free = twl4030_pwm_free,
 293 };
 294
 295 static const struct pwm_ops twl6030_pwm_ops = {
 296         .config = twl_pwm_config,
 297         .enable = twl6030_pwm_enable,
 298         .disable = twl6030_pwm_disable,
 299 };
 300
 301 static int twl_pwm_probe(struct platform_device *pdev)
 302 {
 303         struct twl_pwm_chip *twl;
 304         int ret;
 305
 306         twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 307         if (!twl)
 308                 return -ENOMEM;
 309
 310         if (twl_class_is_4030())
 311                 twl->chip.ops = &twl4030_pwm_ops;
 312         else
 313                 twl->chip.ops = &twl6030_pwm_ops;
 314
 315         twl->chip.dev = &pdev->dev;
 316         twl->chip.base = -1;
 317         twl->chip.npwm = 2;
 318
 319         mutex_init(&twl->mutex);
 320
 321         ret = pwmchip_add(&twl->chip);
 322         if (ret < 0)
 323                 return ret;
 324
 325         platform_set_drvdata(pdev, twl);
 326
 327         return 0;
 328 }
 329
 330 static int twl_pwm_remove(struct platform_device *pdev)
 331 {
 332         struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
 333
 334         return pwmchip_remove(&twl->chip);
 335 }
 336
 337 #ifdef CONFIG_OF
 338 static struct of_device_id twl_pwm_of_match[] = {
 339         { .compatible = "ti,twl4030-pwm" },
 340         { .compatible = "ti,twl6030-pwm" },
 341         { },
 342 };
 343 MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
 344 #endif
 345
 346 static struct platform_driver twl_pwm_driver = {
 347         .driver = {
 348                 .name = "twl-pwm",
 349                 .of_match_table = of_match_ptr(twl_pwm_of_match),
 350         },
 351         .probe = twl_pwm_probe,
 352         .remove = twl_pwm_remove,
 353 };
 354 module_platform_driver(twl_pwm_driver);
 355
 356 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 357 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
 358 MODULE_ALIAS("platform:twl-pwm");
 359 MODULE_LICENSE("GPL");