linux/drivers/pwm/pwm-twl-led.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
   4 *
   5 * Copyright (C) 2012 Texas Instruments
   6 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   7 *
   8 * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
   9 * Hemanth V <hemanthv@ti.com>
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/of.h>
  14#include <linux/platform_device.h>
  15#include <linux/pwm.h>
  16#include <linux/mfd/twl.h>
  17#include <linux/slab.h>
  18
  19/*
  20 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
  21 * To generate the signal on TWL4030:
  22 *  - LEDA uses PWMA
  23 *  - LEDB uses PWMB
  24 * TWL6030 has one LED pin with dedicated LEDPWM
  25 */
  26
  27#define TWL4030_LED_MAX         0x7f
  28#define TWL6030_LED_MAX         0xff
  29
  30/* Registers, bits and macro for TWL4030 */
  31#define TWL4030_LEDEN_REG       0x00
  32#define TWL4030_PWMA_REG        0x01
  33
  34#define TWL4030_LEDXON          (1 << 0)
  35#define TWL4030_LEDXPWM         (1 << 4)
  36#define TWL4030_LED_PINS        (TWL4030_LEDXON | TWL4030_LEDXPWM)
  37#define TWL4030_LED_TOGGLE(led, x)      ((x) << (led))
  38
  39/* Register, bits and macro for TWL6030 */
  40#define TWL6030_LED_PWM_CTRL1   0xf4
  41#define TWL6030_LED_PWM_CTRL2   0xf5
  42
  43#define TWL6040_LED_MODE_HW     0x00
  44#define TWL6040_LED_MODE_ON     0x01
  45#define TWL6040_LED_MODE_OFF    0x02
  46#define TWL6040_LED_MODE_MASK   0x03
  47
  48struct twl_pwmled_chip {
  49        struct pwm_chip chip;
  50        struct mutex mutex;
  51};
  52
  53static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
  54{
  55        return container_of(chip, struct twl_pwmled_chip, chip);
  56}
  57
  58static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
  59                              int duty_ns, int period_ns)
  60{
  61        int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
  62        u8 pwm_config[2] = { 1, 0 };
  63        int base, ret;
  64
  65        /*
  66         * To configure the duty period:
  67         * On-cycle is set to 1 (the minimum allowed value)
  68         * The off time of 0 is not configurable, so the mapping is:
  69         * 0 -> off cycle = 2,
  70         * 1 -> off cycle = 2,
  71         * 2 -> off cycle = 3,
  72         * 126 - > off cycle 127,
  73         * 127 - > off cycle 1
  74         * When on cycle == off cycle the PWM will be always on
  75         */
  76        if (duty_cycle == 1)
  77                duty_cycle = 2;
  78        else if (duty_cycle > TWL4030_LED_MAX)
  79                duty_cycle = 1;
  80
  81        base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
  82
  83        pwm_config[1] = duty_cycle;
  84
  85        ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
  86        if (ret < 0)
  87                dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
  88
  89        return ret;
  90}
  91
  92static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  93{
  94        struct twl_pwmled_chip *twl = to_twl(chip);
  95        int ret;
  96        u8 val;
  97
  98        mutex_lock(&twl->mutex);
  99        ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 100        if (ret < 0) {
 101                dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 102                goto out;
 103        }
 104
 105        val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 106
 107        ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 108        if (ret < 0)
 109                dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 110
 111out:
 112        mutex_unlock(&twl->mutex);
 113        return ret;
 114}
 115
 116static void twl4030_pwmled_disable(struct pwm_chip *chip,
 117                                   struct pwm_device *pwm)
 118{
 119        struct twl_pwmled_chip *twl = to_twl(chip);
 120        int ret;
 121        u8 val;
 122
 123        mutex_lock(&twl->mutex);
 124        ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
 125        if (ret < 0) {
 126                dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
 127                goto out;
 128        }
 129
 130        val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
 131
 132        ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
 133        if (ret < 0)
 134                dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 135
 136out:
 137        mutex_unlock(&twl->mutex);
 138}
 139
 140static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 141                              int duty_ns, int period_ns)
 142{
 143        int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
 144        u8 on_time;
 145        int ret;
 146
 147        on_time = duty_cycle & 0xff;
 148
 149        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
 150                               TWL6030_LED_PWM_CTRL1);
 151        if (ret < 0)
 152                dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 153
 154        return ret;
 155}
 156
 157static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 158{
 159        struct twl_pwmled_chip *twl = to_twl(chip);
 160        int ret;
 161        u8 val;
 162
 163        mutex_lock(&twl->mutex);
 164        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 165        if (ret < 0) {
 166                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 167                        pwm->label);
 168                goto out;
 169        }
 170
 171        val &= ~TWL6040_LED_MODE_MASK;
 172        val |= TWL6040_LED_MODE_ON;
 173
 174        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 175        if (ret < 0)
 176                dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
 177
 178out:
 179        mutex_unlock(&twl->mutex);
 180        return ret;
 181}
 182
 183static void twl6030_pwmled_disable(struct pwm_chip *chip,
 184                                   struct pwm_device *pwm)
 185{
 186        struct twl_pwmled_chip *twl = to_twl(chip);
 187        int ret;
 188        u8 val;
 189
 190        mutex_lock(&twl->mutex);
 191        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 192        if (ret < 0) {
 193                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 194                        pwm->label);
 195                goto out;
 196        }
 197
 198        val &= ~TWL6040_LED_MODE_MASK;
 199        val |= TWL6040_LED_MODE_OFF;
 200
 201        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 202        if (ret < 0)
 203                dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
 204
 205out:
 206        mutex_unlock(&twl->mutex);
 207}
 208
 209static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
 210{
 211        struct twl_pwmled_chip *twl = to_twl(chip);
 212        int ret;
 213        u8 val;
 214
 215        mutex_lock(&twl->mutex);
 216        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 217        if (ret < 0) {
 218                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 219                        pwm->label);
 220                goto out;
 221        }
 222
 223        val &= ~TWL6040_LED_MODE_MASK;
 224        val |= TWL6040_LED_MODE_OFF;
 225
 226        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 227        if (ret < 0)
 228                dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
 229
 230out:
 231        mutex_unlock(&twl->mutex);
 232        return ret;
 233}
 234
 235static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
 236{
 237        struct twl_pwmled_chip *twl = to_twl(chip);
 238        int ret;
 239        u8 val;
 240
 241        mutex_lock(&twl->mutex);
 242        ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
 243        if (ret < 0) {
 244                dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
 245                        pwm->label);
 246                goto out;
 247        }
 248
 249        val &= ~TWL6040_LED_MODE_MASK;
 250        val |= TWL6040_LED_MODE_HW;
 251
 252        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
 253        if (ret < 0)
 254                dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
 255
 256out:
 257        mutex_unlock(&twl->mutex);
 258}
 259
 260static const struct pwm_ops twl4030_pwmled_ops = {
 261        .enable = twl4030_pwmled_enable,
 262        .disable = twl4030_pwmled_disable,
 263        .config = twl4030_pwmled_config,
 264        .owner = THIS_MODULE,
 265};
 266
 267static const struct pwm_ops twl6030_pwmled_ops = {
 268        .enable = twl6030_pwmled_enable,
 269        .disable = twl6030_pwmled_disable,
 270        .config = twl6030_pwmled_config,
 271        .request = twl6030_pwmled_request,
 272        .free = twl6030_pwmled_free,
 273        .owner = THIS_MODULE,
 274};
 275
 276static int twl_pwmled_probe(struct platform_device *pdev)
 277{
 278        struct twl_pwmled_chip *twl;
 279
 280        twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
 281        if (!twl)
 282                return -ENOMEM;
 283
 284        if (twl_class_is_4030()) {
 285                twl->chip.ops = &twl4030_pwmled_ops;
 286                twl->chip.npwm = 2;
 287        } else {
 288                twl->chip.ops = &twl6030_pwmled_ops;
 289                twl->chip.npwm = 1;
 290        }
 291
 292        twl->chip.dev = &pdev->dev;
 293
 294        mutex_init(&twl->mutex);
 295
 296        return devm_pwmchip_add(&pdev->dev, &twl->chip);
 297}
 298
 299#ifdef CONFIG_OF
 300static const struct of_device_id twl_pwmled_of_match[] = {
 301        { .compatible = "ti,twl4030-pwmled" },
 302        { .compatible = "ti,twl6030-pwmled" },
 303        { },
 304};
 305MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 306#endif
 307
 308static struct platform_driver twl_pwmled_driver = {
 309        .driver = {
 310                .name = "twl-pwmled",
 311                .of_match_table = of_match_ptr(twl_pwmled_of_match),
 312        },
 313        .probe = twl_pwmled_probe,
 314};
 315module_platform_driver(twl_pwmled_driver);
 316
 317MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 318MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 319MODULE_ALIAS("platform:twl-pwmled");
 320MODULE_LICENSE("GPL");
 321