// SPDX-License-Identifier: GPL-2.0-only /* * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver * * Copyright (C) 2012 Texas Instruments * Author: Peter Ujfalusi <[email protected]> * * This driver is a complete rewrite of the former pwm-twl6030.c authorded by: * Hemanth V <[email protected]> * * Reference manual for the twl6030 is available at: * https://www.ti.com/lit/ds/symlink/twl6030.pdf * * Limitations: * - The twl6030 hardware only supports two period lengths (128 clock ticks and * 64 clock ticks), the driver only uses 128 ticks * - The hardware doesn't support ON = 0, so the active part of a period doesn't * start at its beginning. * - The hardware could support inverted polarity (with a similar limitation as * for normal: the last clock tick is always inactive). * - The hardware emits a constant low output when disabled. * - A request for .duty_cycle = 0 results in an output wave with one active * clock tick per period. This should better use the disabled state. * - The driver only implements setting the relative duty cycle. * - The driver doesn't implement .get_state(). */ #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/mfd/twl.h> #include <linux/slab.h> /* * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030. * To generate the signal on TWL4030: * - LEDA uses PWMA * - LEDB uses PWMB * TWL6030 has one LED pin with dedicated LEDPWM */ #define TWL4030_LED_MAX … #define TWL6030_LED_MAX … /* Registers, bits and macro for TWL4030 */ #define TWL4030_LEDEN_REG … #define TWL4030_PWMA_REG … #define TWL4030_LEDXON … #define TWL4030_LEDXPWM … #define TWL4030_LED_PINS … #define TWL4030_LED_TOGGLE(led, x) … /* Register, bits and macro for TWL6030 */ #define TWL6030_LED_PWM_CTRL1 … #define TWL6030_LED_PWM_CTRL2 … #define TWL6040_LED_MODE_HW … #define TWL6040_LED_MODE_ON … #define TWL6040_LED_MODE_OFF … #define TWL6040_LED_MODE_MASK … struct twl_pwmled_chip { … }; static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip) { … } static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { … } static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void twl4030_pwmled_disable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { … } static const struct pwm_ops twl4030_pwmled_ops = …; static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { … } static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void twl6030_pwmled_disable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static int twl6030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { … } static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm) { … } static const struct pwm_ops twl6030_pwmled_ops = …; static int twl_pwmled_probe(struct platform_device *pdev) { … } #ifdef CONFIG_OF static const struct of_device_id twl_pwmled_of_match[] = …; MODULE_DEVICE_TABLE(of, twl_pwmled_of_match); #endif static struct platform_driver twl_pwmled_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_ALIAS(…) …; MODULE_LICENSE(…) …;
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