linux/drivers/pwm/pwm-twl-led.c
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   1/*
   2 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
   3 *
   4 * Copyright (C) 2012 Texas Instruments
   5 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   6 *
   7 * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
   8 * Hemanth V <hemanthv@ti.com>
   9 *
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms of the GNU General Public License version 2 as published by
  12 * the Free Software Foundation.
  13 *
  14 * This program is distributed in the hope that it will be useful, but WITHOUT
  15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17 * more details.
  18 *
  19 * You should have received a copy of the GNU General Public License along with
  20 * this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23#include <linux/module.h>
  24#include <linux/platform_device.h>
  25#include <linux/pwm.h>
  26#include <linux/i2c/twl.h>
  27#include <linux/slab.h>
  28
  29/*
  30 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
  31 * To generate the signal on TWL4030:
  32 *  - LEDA uses PWMA
  33 *  - LEDB uses PWMB
  34 * TWL6030 has one LED pin with dedicated LEDPWM
  35 */
  36
  37#define TWL4030_LED_MAX         0x7f
  38#define TWL6030_LED_MAX         0xff
  39
  40/* Registers, bits and macro for TWL4030 */
  41#define TWL4030_LEDEN_REG       0x00
  42#define TWL4030_PWMA_REG        0x01
  43
  44#define TWL4030_LEDXON          (1 << 0)
  45#define TWL4030_LEDXPWM         (1 << 4)
  46#define TWL4030_LED_PINS        (TWL4030_LEDXON | TWL4030_LEDXPWM)
  47#define TWL4030_LED_TOGGLE(led, x)      ((x) << (led))
  48
  49/* Register, bits and macro for TWL6030 */
  50#define TWL6030_LED_PWM_CTRL1   0xf4
  51#define TWL6030_LED_PWM_CTRL2   0xf5
  52
  53#define TWL6040_LED_MODE_HW     0x00
  54#define TWL6040_LED_MODE_ON     0x01
  55#define TWL6040_LED_MODE_OFF    0x02
  56#define TWL6040_LED_MODE_MASK   0x03
  57
  58struct twl_pwmled_chip {
  59        struct pwm_chip chip;
  60        struct mutex mutex;
  61};
  62
  63static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
  64{
  65        return container_of(chip, struct twl_pwmled_chip, chip);
  66}
  67
  68static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
  69                              int duty_ns, int period_ns)
  70{
  71        int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
  72        u8 pwm_config[2] = { 1, 0 };
  73        int base, ret;
  74
  75        /*
  76         * To configure the duty period:
  77         * On-cycle is set to 1 (the minimum allowed value)
  78         * The off time of 0 is not configurable, so the mapping is:
  79         * 0 -> off cycle = 2,
  80         * 1 -> off cycle = 2,
  81         * 2 -> off cycle = 3,
  82         * 126 - > off cycle 127,
  83         * 127 - > off cycle 1
  84         * When on cycle == off cycle the PWM will be always on
  85         */
  86        if (duty_cycle == 1)
  87                duty_cycle = 2;
  88        else if (duty_cycle > TWL4030_LED_MAX)
  89                duty_cycle = 1;
  90
  91        base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
  92
  93        pwm_config[1] = duty_cycle;
  94
  95        ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
  96        if (ret < 0)
  97                dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
  98
  99        return ret;
 100}
 101
 102static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 103{
 104        struct twl_pwmled_chip *twl = to_twl(chip);
 105        int ret;
 106        u8 val;
 107
 108        mutex_lock(&twl->mutex);
 109        ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 110        if (ret < 0) {
 111                dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 112                goto out;
 113        }
 114
 115        val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 116
 117        ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 118        if (ret < 0)
 119                dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 120
 121out:
 122        mutex_unlock(&twl->mutex);
 123        return ret;
 124}
 125
 126static void twl4030_pwmled_disable(struct pwm_chip *chip,
 127                                   struct pwm_device *pwm)
 128{
 129        struct twl_pwmled_chip *twl = to_twl(chip);
 130        int ret;
 131        u8 val;
 132
 133        mutex_lock(&twl->mutex);
 134        ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 135        if (ret < 0) {
 136                dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 137                goto out;
 138        }
 139
 140        val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 141
 142        ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 143        if (ret < 0)
 144                dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 145
 146out:
 147        mutex_unlock(&twl->mutex);
 148}
 149
 150static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 151                              int duty_ns, int period_ns)
 152{
 153        int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
 154        u8 on_time;
 155        int ret;
 156
 157        on_time = duty_cycle & 0xff;
 158
 159        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
 160                               TWL6030_LED_PWM_CTRL1);
 161        if (ret < 0)
 162                dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 163
 164        return ret;
 165}
 166
 167static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 168{
 169        struct twl_pwmled_chip *twl = to_twl(chip);
 170        int ret;
 171        u8 val;
 172
 173        mutex_lock(&twl->mutex);
 174        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 175        if (ret < 0) {
 176                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 177                        pwm->label);
 178                goto out;
 179        }
 180
 181        val &= ~TWL6040_LED_MODE_MASK;
 182        val |= TWL6040_LED_MODE_ON;
 183
 184        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 185        if (ret < 0)
 186                dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 187
 188out:
 189        mutex_unlock(&twl->mutex);
 190        return ret;
 191}
 192
 193static void twl6030_pwmled_disable(struct pwm_chip *chip,
 194                                   struct pwm_device *pwm)
 195{
 196        struct twl_pwmled_chip *twl = to_twl(chip);
 197        int ret;
 198        u8 val;
 199
 200        mutex_lock(&twl->mutex);
 201        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 202        if (ret < 0) {
 203                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 204                        pwm->label);
 205                goto out;
 206        }
 207
 208        val &= ~TWL6040_LED_MODE_MASK;
 209        val |= TWL6040_LED_MODE_OFF;
 210
 211        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 212        if (ret < 0)
 213                dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 214
 215out:
 216        mutex_unlock(&twl->mutex);
 217}
 218
 219static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
 220{
 221        struct twl_pwmled_chip *twl = to_twl(chip);
 222        int ret;
 223        u8 val;
 224
 225        mutex_lock(&twl->mutex);
 226        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 227        if (ret < 0) {
 228                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 229                        pwm->label);
 230                goto out;
 231        }
 232
 233        val &= ~TWL6040_LED_MODE_MASK;
 234        val |= TWL6040_LED_MODE_OFF;
 235
 236        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 237        if (ret < 0)
 238                dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 239
 240out:
 241        mutex_unlock(&twl->mutex);
 242        return ret;
 243}
 244
 245static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
 246{
 247        struct twl_pwmled_chip *twl = to_twl(chip);
 248        int ret;
 249        u8 val;
 250
 251        mutex_lock(&twl->mutex);
 252        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 253        if (ret < 0) {
 254                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 255                        pwm->label);
 256                goto out;
 257        }
 258
 259        val &= ~TWL6040_LED_MODE_MASK;
 260        val |= TWL6040_LED_MODE_HW;
 261
 262        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 263        if (ret < 0)
 264                dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 265
 266out:
 267        mutex_unlock(&twl->mutex);
 268}
 269
 270static const struct pwm_ops twl4030_pwmled_ops = {
 271        .enable = twl4030_pwmled_enable,
 272        .disable = twl4030_pwmled_disable,
 273        .config = twl4030_pwmled_config,
 274};
 275
 276static const struct pwm_ops twl6030_pwmled_ops = {
 277        .enable = twl6030_pwmled_enable,
 278        .disable = twl6030_pwmled_disable,
 279        .config = twl6030_pwmled_config,
 280        .request = twl6030_pwmled_request,
 281        .free = twl6030_pwmled_free,
 282};
 283
 284static int twl_pwmled_probe(struct platform_device *pdev)
 285{
 286        struct twl_pwmled_chip *twl;
 287        int ret;
 288
 289        twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 290        if (!twl)
 291                return -ENOMEM;
 292
 293        if (twl_class_is_4030()) {
 294                twl->chip.ops = &twl4030_pwmled_ops;
 295                twl->chip.npwm = 2;
 296        } else {
 297                twl->chip.ops = &twl6030_pwmled_ops;
 298                twl->chip.npwm = 1;
 299        }
 300
 301        twl->chip.dev = &pdev->dev;
 302        twl->chip.base = -1;
 303
 304        mutex_init(&twl->mutex);
 305
 306        ret = pwmchip_add(&twl->chip);
 307        if (ret < 0)
 308                return ret;
 309
 310        platform_set_drvdata(pdev, twl);
 311
 312        return 0;
 313}
 314
 315static int twl_pwmled_remove(struct platform_device *pdev)
 316{
 317        struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);
 318
 319        return pwmchip_remove(&twl->chip);
 320}
 321
 322#ifdef CONFIG_OF
 323static struct of_device_id twl_pwmled_of_match[] = {
 324        { .compatible = "ti,twl4030-pwmled" },
 325        { .compatible = "ti,twl6030-pwmled" },
 326        { },
 327};
 328MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 329#endif
 330
 331static struct platform_driver twl_pwmled_driver = {
 332        .driver = {
 333                .name = "twl-pwmled",
 334                .of_match_table = of_match_ptr(twl_pwmled_of_match),
 335        },
 336        .probe = twl_pwmled_probe,
 337        .remove = twl_pwmled_remove,
 338};
 339module_platform_driver(twl_pwmled_driver);
 340
 341MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 342MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 343MODULE_ALIAS("platform:twl-pwmled");
 344MODULE_LICENSE("GPL");
 345
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