// SPDX-License-Identifier: GPL-2.0-only // Copyright (C) 2014 Broadcom Corporation #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/slab.h> #include <linux/types.h> /* * The Kona PWM has some unusual characteristics. Here are the main points. * * 1) There is no disable bit and the hardware docs advise programming a zero * duty to achieve output equivalent to that of a normal disable operation. * * 2) Changes to prescale, duty, period, and polarity do not take effect until * a subsequent rising edge of the trigger bit. * * 3) If the smooth bit and trigger bit are both low, the output is a constant * high signal. Otherwise, the earlier waveform continues to be output. * * 4) If the smooth bit is set on the rising edge of the trigger bit, output * will transition to the new settings on a period boundary (which could be * seconds away). If the smooth bit is clear, new settings will be applied * as soon as possible (the hardware always has a 400ns delay). * * 5) When the external clock that feeds the PWM is disabled, output is pegged * high or low depending on its state at that exact instant. */ #define PWM_CONTROL_OFFSET … #define PWM_CONTROL_SMOOTH_SHIFT(chan) … #define PWM_CONTROL_TYPE_SHIFT(chan) … #define PWM_CONTROL_POLARITY_SHIFT(chan) … #define PWM_CONTROL_TRIGGER_SHIFT(chan) … #define PRESCALE_OFFSET … #define PRESCALE_SHIFT(chan) … #define PRESCALE_MASK(chan) … #define PRESCALE_MIN … #define PRESCALE_MAX … #define PERIOD_COUNT_OFFSET(chan) … #define PERIOD_COUNT_MIN … #define PERIOD_COUNT_MAX … #define DUTY_CYCLE_HIGH_OFFSET(chan) … #define DUTY_CYCLE_HIGH_MIN … #define DUTY_CYCLE_HIGH_MAX … struct kona_pwmc { … }; static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *chip) { … } /* * Clear trigger bit but set smooth bit to maintain old output. */ static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, unsigned int chan) { … } static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) { … } static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, u64 duty_ns, u64 period_ns) { … } static int kona_pwmc_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity) { … } static int kona_pwmc_enable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { … } static const struct pwm_ops kona_pwm_ops = …; static int kona_pwmc_probe(struct platform_device *pdev) { … } static const struct of_device_id bcm_kona_pwmc_dt[] = …; MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt); static struct platform_driver kona_pwmc_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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