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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver4 *5 * Copyright (C) 2012 Texas Instruments6 * 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 * Reference manual for the twl6030 is available at:12 * https://www.ti.com/lit/ds/symlink/twl6030.pdf13 *14 * Limitations:15 * - The twl6030 hardware only supports two period lengths (128 clock ticks and16 * 64 clock ticks), the driver only uses 128 ticks17 * - The hardware doesn't support ON = 0, so the active part of a period doesn't18 * start at its beginning.19 * - The hardware could support inverted polarity (with a similar limitation as20 * for normal: the last clock tick is always inactive).21 * - The hardware emits a constant low output when disabled.22 * - A request for .duty_cycle = 0 results in an output wave with one active23 * clock tick per period. This should better use the disabled state.24 * - The driver only implements setting the relative duty cycle.25 * - The driver doesn't implement .get_state().26 */27 28#include <linux/module.h>29#include <linux/of.h>30#include <linux/platform_device.h>31#include <linux/pwm.h>32#include <linux/mfd/twl.h>33#include <linux/slab.h>34 35/*36 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.37 * To generate the signal on TWL4030:38 * - LEDA uses PWMA39 * - LEDB uses PWMB40 * TWL6030 has one LED pin with dedicated LEDPWM41 */42 43#define TWL4030_LED_MAX 0x7f44#define TWL6030_LED_MAX 0xff45 46/* Registers, bits and macro for TWL4030 */47#define TWL4030_LEDEN_REG 0x0048#define TWL4030_PWMA_REG 0x0149 50#define TWL4030_LEDXON (1 << 0)51#define TWL4030_LEDXPWM (1 << 4)52#define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)53#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))54 55/* Register, bits and macro for TWL6030 */56#define TWL6030_LED_PWM_CTRL1 0xf457#define TWL6030_LED_PWM_CTRL2 0xf558 59#define TWL6040_LED_MODE_HW 0x0060#define TWL6040_LED_MODE_ON 0x0161#define TWL6040_LED_MODE_OFF 0x0262#define TWL6040_LED_MODE_MASK 0x0363 64struct twl_pwmled_chip {65 struct mutex mutex;66};67 68static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)69{70 return pwmchip_get_drvdata(chip);71}72 73static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,74 int duty_ns, int period_ns)75{76 int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;77 u8 pwm_config[2] = { 1, 0 };78 int base, ret;79 80 /*81 * To configure the duty period:82 * On-cycle is set to 1 (the minimum allowed value)83 * The off time of 0 is not configurable, so the mapping is:84 * 0 -> off cycle = 2,85 * 1 -> off cycle = 2,86 * 2 -> off cycle = 3,87 * 126 - > off cycle 127,88 * 127 - > off cycle 189 * When on cycle == off cycle the PWM will be always on90 */91 if (duty_cycle == 1)92 duty_cycle = 2;93 else if (duty_cycle > TWL4030_LED_MAX)94 duty_cycle = 1;95 96 base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;97 98 pwm_config[1] = duty_cycle;99 100 ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);101 if (ret < 0)102 dev_err(pwmchip_parent(chip), "%s: Failed to configure PWM\n", pwm->label);103 104 return ret;105}106 107static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)108{109 struct twl_pwmled_chip *twl = to_twl(chip);110 int ret;111 u8 val;112 113 mutex_lock(&twl->mutex);114 ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);115 if (ret < 0) {116 dev_err(pwmchip_parent(chip), "%s: Failed to read LEDEN\n", pwm->label);117 goto out;118 }119 120 val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);121 122 ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);123 if (ret < 0)124 dev_err(pwmchip_parent(chip), "%s: Failed to enable PWM\n", pwm->label);125 126out:127 mutex_unlock(&twl->mutex);128 return ret;129}130 131static void twl4030_pwmled_disable(struct pwm_chip *chip,132 struct pwm_device *pwm)133{134 struct twl_pwmled_chip *twl = to_twl(chip);135 int ret;136 u8 val;137 138 mutex_lock(&twl->mutex);139 ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);140 if (ret < 0) {141 dev_err(pwmchip_parent(chip), "%s: Failed to read LEDEN\n", pwm->label);142 goto out;143 }144 145 val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);146 147 ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);148 if (ret < 0)149 dev_err(pwmchip_parent(chip), "%s: Failed to disable PWM\n", pwm->label);150 151out:152 mutex_unlock(&twl->mutex);153}154 155static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,156 const struct pwm_state *state)157{158 int ret;159 160 if (state->polarity != PWM_POLARITY_NORMAL)161 return -EINVAL;162 163 if (!state->enabled) {164 if (pwm->state.enabled)165 twl4030_pwmled_disable(chip, pwm);166 167 return 0;168 }169 170 /*171 * We cannot skip calling ->config even if state->period ==172 * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle173 * because we might have exited early in the last call to174 * pwm_apply_might_sleep because of !state->enabled and so the two values in175 * pwm->state might not be configured in hardware.176 */177 ret = twl4030_pwmled_config(chip, pwm,178 state->duty_cycle, state->period);179 if (ret)180 return ret;181 182 if (!pwm->state.enabled)183 ret = twl4030_pwmled_enable(chip, pwm);184 185 return ret;186}187 188 189static const struct pwm_ops twl4030_pwmled_ops = {190 .apply = twl4030_pwmled_apply,191};192 193static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,194 int duty_ns, int period_ns)195{196 int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;197 u8 on_time;198 int ret;199 200 on_time = duty_cycle & 0xff;201 202 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,203 TWL6030_LED_PWM_CTRL1);204 if (ret < 0)205 dev_err(pwmchip_parent(chip), "%s: Failed to configure PWM\n", pwm->label);206 207 return ret;208}209 210static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)211{212 struct twl_pwmled_chip *twl = to_twl(chip);213 int ret;214 u8 val;215 216 mutex_lock(&twl->mutex);217 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);218 if (ret < 0) {219 dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",220 pwm->label);221 goto out;222 }223 224 val &= ~TWL6040_LED_MODE_MASK;225 val |= TWL6040_LED_MODE_ON;226 227 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);228 if (ret < 0)229 dev_err(pwmchip_parent(chip), "%s: Failed to enable PWM\n", pwm->label);230 231out:232 mutex_unlock(&twl->mutex);233 return ret;234}235 236static void twl6030_pwmled_disable(struct pwm_chip *chip,237 struct pwm_device *pwm)238{239 struct twl_pwmled_chip *twl = to_twl(chip);240 int ret;241 u8 val;242 243 mutex_lock(&twl->mutex);244 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);245 if (ret < 0) {246 dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",247 pwm->label);248 goto out;249 }250 251 val &= ~TWL6040_LED_MODE_MASK;252 val |= TWL6040_LED_MODE_OFF;253 254 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);255 if (ret < 0)256 dev_err(pwmchip_parent(chip), "%s: Failed to disable PWM\n", pwm->label);257 258out:259 mutex_unlock(&twl->mutex);260}261 262static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm,263 const struct pwm_state *state)264{265 int err;266 267 if (state->polarity != pwm->state.polarity)268 return -EINVAL;269 270 if (!state->enabled) {271 if (pwm->state.enabled)272 twl6030_pwmled_disable(chip, pwm);273 274 return 0;275 }276 277 err = twl6030_pwmled_config(chip, pwm,278 state->duty_cycle, state->period);279 if (err)280 return err;281 282 if (!pwm->state.enabled)283 err = twl6030_pwmled_enable(chip, pwm);284 285 return err;286}287 288static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)289{290 struct twl_pwmled_chip *twl = to_twl(chip);291 int ret;292 u8 val;293 294 mutex_lock(&twl->mutex);295 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);296 if (ret < 0) {297 dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",298 pwm->label);299 goto out;300 }301 302 val &= ~TWL6040_LED_MODE_MASK;303 val |= TWL6040_LED_MODE_OFF;304 305 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);306 if (ret < 0)307 dev_err(pwmchip_parent(chip), "%s: Failed to request PWM\n", pwm->label);308 309out:310 mutex_unlock(&twl->mutex);311 return ret;312}313 314static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)315{316 struct twl_pwmled_chip *twl = to_twl(chip);317 int ret;318 u8 val;319 320 mutex_lock(&twl->mutex);321 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);322 if (ret < 0) {323 dev_err(pwmchip_parent(chip), "%s: Failed to read PWM_CTRL2\n",324 pwm->label);325 goto out;326 }327 328 val &= ~TWL6040_LED_MODE_MASK;329 val |= TWL6040_LED_MODE_HW;330 331 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);332 if (ret < 0)333 dev_err(pwmchip_parent(chip), "%s: Failed to free PWM\n", pwm->label);334 335out:336 mutex_unlock(&twl->mutex);337}338 339static const struct pwm_ops twl6030_pwmled_ops = {340 .apply = twl6030_pwmled_apply,341 .request = twl6030_pwmled_request,342 .free = twl6030_pwmled_free,343};344 345static int twl_pwmled_probe(struct platform_device *pdev)346{347 struct pwm_chip *chip;348 struct twl_pwmled_chip *twl;349 unsigned int npwm;350 const struct pwm_ops *ops;351 352 if (twl_class_is_4030()) {353 ops = &twl4030_pwmled_ops;354 npwm = 2;355 } else {356 ops = &twl6030_pwmled_ops;357 npwm = 1;358 }359 360 chip = devm_pwmchip_alloc(&pdev->dev, npwm, sizeof(*twl));361 if (IS_ERR(chip))362 return PTR_ERR(chip);363 twl = to_twl(chip);364 365 chip->ops = ops;366 367 mutex_init(&twl->mutex);368 369 return devm_pwmchip_add(&pdev->dev, chip);370}371 372#ifdef CONFIG_OF373static const struct of_device_id twl_pwmled_of_match[] = {374 { .compatible = "ti,twl4030-pwmled" },375 { .compatible = "ti,twl6030-pwmled" },376 { },377};378MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);379#endif380 381static struct platform_driver twl_pwmled_driver = {382 .driver = {383 .name = "twl-pwmled",384 .of_match_table = of_match_ptr(twl_pwmled_of_match),385 },386 .probe = twl_pwmled_probe,387};388module_platform_driver(twl_pwmled_driver);389 390MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");391MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");392MODULE_ALIAS("platform:twl-pwmled");393MODULE_LICENSE("GPL");394