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 48 struct twl_pwmled_chip { 49 struct pwm_chip chip; 50 struct mutex mutex; 51 }; 52 53 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip) 54 { 55 return container_of(chip, struct twl_pwmled_chip, chip); 56 } 57 58 static 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 92 static 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); 110 111 out: 112 mutex_unlock(&twl->mutex); 113 return ret; 114 } 115 116 static 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); 135 136 out: 137 mutex_unlock(&twl->mutex); 138 } 139 140 static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, 141 const struct pwm_state *state) 142 { 143 int ret; 144 145 if (state->polarity != PWM_POLARITY_NORMAL) 146 return -EINVAL; 147 148 if (!state->enabled) { 149 if (pwm->state.enabled) 150 twl4030_pwmled_disable(chip, pwm); 151 152 return 0; 153 } 154 155 /* 156 * We cannot skip calling ->config even if state->period == 157 * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle 158 * because we might have exited early in the last call to 159 * pwm_apply_state because of !state->enabled and so the two values in 160 * pwm->state might not be configured in hardware. 161 */ 162 ret = twl4030_pwmled_config(pwm->chip, pwm, 163 state->duty_cycle, state->period); 164 if (ret) 165 return ret; 166 167 if (!pwm->state.enabled) 168 ret = twl4030_pwmled_enable(chip, pwm); 169 170 return ret; 171 } 172 173 174 static const struct pwm_ops twl4030_pwmled_ops = { 175 .apply = twl4030_pwmled_apply, 176 .owner = THIS_MODULE, 177 }; 178 179 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm, 180 int duty_ns, int period_ns) 181 { 182 int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns; 183 u8 on_time; 184 int ret; 185 186 on_time = duty_cycle & 0xff; 187 188 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time, 189 TWL6030_LED_PWM_CTRL1); 190 if (ret < 0) 191 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label); 192 193 return ret; 194 } 195 196 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm) 197 { 198 struct twl_pwmled_chip *twl = to_twl(chip); 199 int ret; 200 u8 val; 201 202 mutex_lock(&twl->mutex); 203 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2); 204 if (ret < 0) { 205 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n", 206 pwm->label); 207 goto out; 208 } 209 210 val &= ~TWL6040_LED_MODE_MASK; 211 val |= TWL6040_LED_MODE_ON; 212 213 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); 214 if (ret < 0) 215 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); 216 217 out: 218 mutex_unlock(&twl->mutex); 219 return ret; 220 } 221 222 static void twl6030_pwmled_disable(struct pwm_chip *chip, 223 struct pwm_device *pwm) 224 { 225 struct twl_pwmled_chip *twl = to_twl(chip); 226 int ret; 227 u8 val; 228 229 mutex_lock(&twl->mutex); 230 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2); 231 if (ret < 0) { 232 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n", 233 pwm->label); 234 goto out; 235 } 236 237 val &= ~TWL6040_LED_MODE_MASK; 238 val |= TWL6040_LED_MODE_OFF; 239 240 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); 241 if (ret < 0) 242 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); 243 244 out: 245 mutex_unlock(&twl->mutex); 246 } 247 248 static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, 249 const struct pwm_state *state) 250 { 251 int err; 252 253 if (state->polarity != pwm->state.polarity) 254 return -EINVAL; 255 256 if (!state->enabled) { 257 if (pwm->state.enabled) 258 twl6030_pwmled_disable(chip, pwm); 259 260 return 0; 261 } 262 263 err = twl6030_pwmled_config(pwm->chip, pwm, 264 state->duty_cycle, state->period); 265 if (err) 266 return err; 267 268 if (!pwm->state.enabled) 269 err = twl6030_pwmled_enable(chip, pwm); 270 271 return err; 272 } 273 274 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm) 275 { 276 struct twl_pwmled_chip *twl = to_twl(chip); 277 int ret; 278 u8 val; 279 280 mutex_lock(&twl->mutex); 281 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2); 282 if (ret < 0) { 283 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n", 284 pwm->label); 285 goto out; 286 } 287 288 val &= ~TWL6040_LED_MODE_MASK; 289 val |= TWL6040_LED_MODE_OFF; 290 291 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); 292 if (ret < 0) 293 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label); 294 295 out: 296 mutex_unlock(&twl->mutex); 297 return ret; 298 } 299 300 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm) 301 { 302 struct twl_pwmled_chip *twl = to_twl(chip); 303 int ret; 304 u8 val; 305 306 mutex_lock(&twl->mutex); 307 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2); 308 if (ret < 0) { 309 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n", 310 pwm->label); 311 goto out; 312 } 313 314 val &= ~TWL6040_LED_MODE_MASK; 315 val |= TWL6040_LED_MODE_HW; 316 317 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2); 318 if (ret < 0) 319 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label); 320 321 out: 322 mutex_unlock(&twl->mutex); 323 } 324 325 static const struct pwm_ops twl6030_pwmled_ops = { 326 .apply = twl6030_pwmled_apply, 327 .request = twl6030_pwmled_request, 328 .free = twl6030_pwmled_free, 329 .owner = THIS_MODULE, 330 }; 331 332 static int twl_pwmled_probe(struct platform_device *pdev) 333 { 334 struct twl_pwmled_chip *twl; 335 336 twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL); 337 if (!twl) 338 return -ENOMEM; 339 340 if (twl_class_is_4030()) { 341 twl->chip.ops = &twl4030_pwmled_ops; 342 twl->chip.npwm = 2; 343 } else { 344 twl->chip.ops = &twl6030_pwmled_ops; 345 twl->chip.npwm = 1; 346 } 347 348 twl->chip.dev = &pdev->dev; 349 350 mutex_init(&twl->mutex); 351 352 return devm_pwmchip_add(&pdev->dev, &twl->chip); 353 } 354 355 #ifdef CONFIG_OF 356 static const struct of_device_id twl_pwmled_of_match[] = { 357 { .compatible = "ti,twl4030-pwmled" }, 358 { .compatible = "ti,twl6030-pwmled" }, 359 { }, 360 }; 361 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match); 362 #endif 363 364 static struct platform_driver twl_pwmled_driver = { 365 .driver = { 366 .name = "twl-pwmled", 367 .of_match_table = of_match_ptr(twl_pwmled_of_match), 368 }, 369 .probe = twl_pwmled_probe, 370 }; 371 module_platform_driver(twl_pwmled_driver); 372 373 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>"); 374 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs"); 375 MODULE_ALIAS("platform:twl-pwmled"); 376 MODULE_LICENSE("GPL"); 377