// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2007 Ben Dooks * Copyright (c) 2008 Simtec Electronics * Ben Dooks <[email protected]>, <[email protected]> * Copyright (c) 2013 Tomasz Figa <[email protected]> * Copyright (c) 2017 Samsung Electronics Co., Ltd. * * PWM driver for Samsung SoCs */ #include <linux/bitops.h> #include <linux/clk.h> #include <linux/export.h> #include <linux/err.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/time.h> /* For struct samsung_timer_variant and samsung_pwm_lock. */ #include <clocksource/samsung_pwm.h> #define REG_TCFG0 … #define REG_TCFG1 … #define REG_TCON … #define REG_TCNTB(chan) … #define REG_TCMPB(chan) … #define TCFG0_PRESCALER_MASK … #define TCFG0_PRESCALER1_SHIFT … #define TCFG1_MUX_MASK … #define TCFG1_SHIFT(chan) … /* * Each channel occupies 4 bits in TCON register, but there is a gap of 4 * bits (one channel) after channel 0, so channels have different numbering * when accessing TCON register. See to_tcon_channel() function. * * In addition, the location of autoreload bit for channel 4 (TCON channel 5) * in its set of bits is 2 as opposed to 3 for other channels. */ #define TCON_START(chan) … #define TCON_MANUALUPDATE(chan) … #define TCON_INVERT(chan) … #define _TCON_AUTORELOAD(chan) … #define _TCON_AUTORELOAD4(chan) … #define TCON_AUTORELOAD(chan) … /** * struct samsung_pwm_channel - private data of PWM channel * @period_ns: current period in nanoseconds programmed to the hardware * @duty_ns: current duty time in nanoseconds programmed to the hardware * @tin_ns: time of one timer tick in nanoseconds with current timer rate */ struct samsung_pwm_channel { … }; /** * struct samsung_pwm_chip - private data of PWM chip * @variant: local copy of hardware variant data * @inverter_mask: inverter status for all channels - one bit per channel * @disabled_mask: disabled status for all channels - one bit per channel * @base: base address of mapped PWM registers * @base_clk: base clock used to drive the timers * @tclk0: external clock 0 (can be ERR_PTR if not present) * @tclk1: external clock 1 (can be ERR_PTR if not present) * @channel: per channel driver data */ struct samsung_pwm_chip { … }; #ifndef CONFIG_CLKSRC_SAMSUNG_PWM /* * PWM block is shared between pwm-samsung and samsung_pwm_timer drivers * and some registers need access synchronization. If both drivers are * compiled in, the spinlock is defined in the clocksource driver, * otherwise following definition is used. * * Currently we do not need any more complex synchronization method * because all the supported SoCs contain only one instance of the PWM * IP. Should this change, both drivers will need to be modified to * properly synchronize accesses to particular instances. */ static DEFINE_SPINLOCK(samsung_pwm_lock); #endif static inline struct samsung_pwm_chip *to_samsung_pwm_chip(struct pwm_chip *chip) { … } static inline unsigned int to_tcon_channel(unsigned int channel) { … } static void __pwm_samsung_manual_update(struct samsung_pwm_chip *our_chip, struct pwm_device *pwm) { … } static void pwm_samsung_set_divisor(struct samsung_pwm_chip *our_chip, unsigned int channel, u8 divisor) { … } static int pwm_samsung_is_tdiv(struct samsung_pwm_chip *our_chip, unsigned int chan) { … } static unsigned long pwm_samsung_get_tin_rate(struct samsung_pwm_chip *our_chip, unsigned int chan) { … } static unsigned long pwm_samsung_calc_tin(struct pwm_chip *chip, unsigned int chan, unsigned long freq) { … } static int pwm_samsung_request(struct pwm_chip *chip, struct pwm_device *pwm) { … } static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm) { … } static void pwm_samsung_manual_update(struct samsung_pwm_chip *our_chip, struct pwm_device *pwm) { … } static int __pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns, bool force_period) { … } static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { … } static void pwm_samsung_set_invert(struct samsung_pwm_chip *our_chip, unsigned int channel, bool invert) { … } static int pwm_samsung_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity) { … } static int pwm_samsung_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { … } static const struct pwm_ops pwm_samsung_ops = …; #ifdef CONFIG_OF static const struct samsung_pwm_variant s3c24xx_variant = …; static const struct samsung_pwm_variant s3c64xx_variant = …; static const struct samsung_pwm_variant s5p64x0_variant = …; static const struct samsung_pwm_variant s5pc100_variant = …; static const struct of_device_id samsung_pwm_matches[] = …; MODULE_DEVICE_TABLE(of, samsung_pwm_matches); static int pwm_samsung_parse_dt(struct pwm_chip *chip) { … } #else static int pwm_samsung_parse_dt(struct pwm_chip *chip) { return -ENODEV; } #endif static int pwm_samsung_probe(struct platform_device *pdev) { … } static int pwm_samsung_resume(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(pwm_samsung_pm_ops, NULL, pwm_samsung_resume); static struct platform_driver pwm_samsung_driver = …; module_platform_driver(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_ALIAS(…) …;
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