drivers/pwm/pwm-twl-led.c

   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
  58 struct twl_pwmled_chip {
  59         struct pwm_chip chip;
  60         struct mutex mutex;
  61 };
  62
  63 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
  64 {
  65         return container_of(chip, struct twl_pwmled_chip, chip);
  66 }
  67
  68 static 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
 102 static 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
 121 out:
 122         mutex_unlock(&twl->mutex);
 123         return ret;
 124 }
 125
 126 static 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
 146 out:
 147         mutex_unlock(&twl->mutex);
 148 }
 149
 150 static 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
 167 static 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
 188 out:
 189         mutex_unlock(&twl->mutex);
 190         return ret;
 191 }
 192
 193 static 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
 215 out:
 216         mutex_unlock(&twl->mutex);
 217 }
 218
 219 static 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
 240 out:
 241         mutex_unlock(&twl->mutex);
 242         return ret;
 243 }
 244
 245 static 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
 266 out:
 267         mutex_unlock(&twl->mutex);
 268 }
 269
 270 static const struct pwm_ops twl4030_pwmled_ops = {
 271         .enable = twl4030_pwmled_enable,
 272         .disable = twl4030_pwmled_disable,
 273         .config = twl4030_pwmled_config,
 274 };
 275
 276 static 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
 284 static 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
 315 static 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
 323 static struct of_device_id twl_pwmled_of_match[] = {
 324         { .compatible = "ti,twl4030-pwmled" },
 325         { .compatible = "ti,twl6030-pwmled" },
 326         { },
 327 };
 328 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
 329 #endif
 330
 331 static 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 };
 339 module_platform_driver(twl_pwmled_driver);
 340
 341 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 342 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
 343 MODULE_ALIAS("platform:twl-pwmled");
 344 MODULE_LICENSE("GPL");