LXR linux/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
  59struct twl_pwm_chip {
  60        struct pwm_chip chip;
  61        struct mutex mutex;
  62        u8 twl6030_toggle3;
  63        u8 twl4030_pwm_mux;
  64};
  65
  66static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
  67{
  68        return container_of(chip, struct twl_pwm_chip, chip);
  69}
  70
  71static 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
 105static 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
 130out:
 131        mutex_unlock(&twl->mutex);
 132        return ret;
 133}
 134
 135static 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
 160out:
 161        mutex_unlock(&twl->mutex);
 162}
 163
 164static 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
 197out:
 198        mutex_unlock(&twl->mutex);
 199        return ret;
 200}
 201
 202static 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
 228out:
 229        mutex_unlock(&twl->mutex);
 230}
 231
 232static 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;
 250out:
 251        mutex_unlock(&twl->mutex);
 252        return ret;
 253}
 254
 255static 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;
 273out:
 274        mutex_unlock(&twl->mutex);
 275}
 276
 277static 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
 286static 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
 293static 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
 323static 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
 331static const struct of_device_id twl_pwm_of_match[] = {
 332        { .compatible = "ti,twl4030-pwm" },
 333        { .compatible = "ti,twl6030-pwm" },
 334        { },
 335};
 336MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
 337#endif
 338
 339static 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};
 347module_platform_driver(twl_pwm_driver);
 348
 349MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 350MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
 351MODULE_ALIAS("platform:twl-pwm");
 352MODULE_LICENSE("GPL");
 353