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