d1cd214277
The pwm_enable() function didn't clear the enabled bit if a call to the driver's ->enable() callback returned an error. The result was that the state of the PWM core was wrong. Clearing the bit when enable returns an error ensures the state is properly set. Tested-by: Jonathan Richardson <jonathar@broadcom.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: add missing kerneldoc for the lock] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
345 lines
8.4 KiB
C
345 lines
8.4 KiB
C
#ifndef __LINUX_PWM_H
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#define __LINUX_PWM_H
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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struct pwm_device;
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struct seq_file;
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#if IS_ENABLED(CONFIG_PWM)
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/*
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* pwm_request - request a PWM device
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*/
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struct pwm_device *pwm_request(int pwm_id, const char *label);
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/*
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* pwm_free - free a PWM device
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*/
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void pwm_free(struct pwm_device *pwm);
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/*
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* pwm_config - change a PWM device configuration
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*/
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int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
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/*
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* pwm_enable - start a PWM output toggling
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*/
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int pwm_enable(struct pwm_device *pwm);
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/*
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* pwm_disable - stop a PWM output toggling
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*/
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void pwm_disable(struct pwm_device *pwm);
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#else
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static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline void pwm_free(struct pwm_device *pwm)
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{
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}
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static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
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{
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return -EINVAL;
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}
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static inline int pwm_enable(struct pwm_device *pwm)
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{
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return -EINVAL;
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}
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static inline void pwm_disable(struct pwm_device *pwm)
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{
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}
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#endif
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struct pwm_chip;
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/**
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* enum pwm_polarity - polarity of a PWM signal
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* @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
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* cycle, followed by a low signal for the remainder of the pulse
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* period
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* @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
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* cycle, followed by a high signal for the remainder of the pulse
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* period
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*/
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enum pwm_polarity {
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PWM_POLARITY_NORMAL,
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PWM_POLARITY_INVERSED,
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};
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enum {
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PWMF_REQUESTED = 1 << 0,
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PWMF_ENABLED = 1 << 1,
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PWMF_EXPORTED = 1 << 2,
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};
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/**
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* struct pwm_device - PWM channel object
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* @label: name of the PWM device
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* @flags: flags associated with the PWM device
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* @hwpwm: per-chip relative index of the PWM device
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* @pwm: global index of the PWM device
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* @chip: PWM chip providing this PWM device
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* @chip_data: chip-private data associated with the PWM device
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* @lock: used to serialize accesses to the PWM device where necessary
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* @period: period of the PWM signal (in nanoseconds)
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* @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
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* @polarity: polarity of the PWM signal
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*/
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struct pwm_device {
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const char *label;
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unsigned long flags;
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unsigned int hwpwm;
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unsigned int pwm;
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struct pwm_chip *chip;
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void *chip_data;
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struct mutex lock;
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unsigned int period;
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unsigned int duty_cycle;
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enum pwm_polarity polarity;
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};
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static inline bool pwm_is_enabled(const struct pwm_device *pwm)
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{
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return test_bit(PWMF_ENABLED, &pwm->flags);
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}
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static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
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{
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if (pwm)
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pwm->period = period;
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}
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static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
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{
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return pwm ? pwm->period : 0;
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}
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static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
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{
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if (pwm)
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pwm->duty_cycle = duty;
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}
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static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
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{
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return pwm ? pwm->duty_cycle : 0;
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}
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/*
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* pwm_set_polarity - configure the polarity of a PWM signal
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*/
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int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
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static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
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{
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return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
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}
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/**
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* struct pwm_ops - PWM controller operations
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* @request: optional hook for requesting a PWM
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* @free: optional hook for freeing a PWM
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* @config: configure duty cycles and period length for this PWM
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* @set_polarity: configure the polarity of this PWM
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* @enable: enable PWM output toggling
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* @disable: disable PWM output toggling
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* @dbg_show: optional routine to show contents in debugfs
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* @owner: helps prevent removal of modules exporting active PWMs
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*/
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struct pwm_ops {
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int (*request)(struct pwm_chip *chip, struct pwm_device *pwm);
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void (*free)(struct pwm_chip *chip, struct pwm_device *pwm);
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int (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns);
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int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
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enum pwm_polarity polarity);
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int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
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void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
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#ifdef CONFIG_DEBUG_FS
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void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
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#endif
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struct module *owner;
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};
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/**
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* struct pwm_chip - abstract a PWM controller
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* @dev: device providing the PWMs
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* @list: list node for internal use
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* @ops: callbacks for this PWM controller
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* @base: number of first PWM controlled by this chip
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* @npwm: number of PWMs controlled by this chip
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* @pwms: array of PWM devices allocated by the framework
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* @of_xlate: request a PWM device given a device tree PWM specifier
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* @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
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* @can_sleep: must be true if the .config(), .enable() or .disable()
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* operations may sleep
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*/
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struct pwm_chip {
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struct device *dev;
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struct list_head list;
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const struct pwm_ops *ops;
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int base;
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unsigned int npwm;
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struct pwm_device *pwms;
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struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
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const struct of_phandle_args *args);
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unsigned int of_pwm_n_cells;
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bool can_sleep;
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};
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#if IS_ENABLED(CONFIG_PWM)
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int pwm_set_chip_data(struct pwm_device *pwm, void *data);
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void *pwm_get_chip_data(struct pwm_device *pwm);
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int pwmchip_add_with_polarity(struct pwm_chip *chip,
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enum pwm_polarity polarity);
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int pwmchip_add(struct pwm_chip *chip);
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int pwmchip_remove(struct pwm_chip *chip);
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struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
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unsigned int index,
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const char *label);
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struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
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const struct of_phandle_args *args);
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struct pwm_device *pwm_get(struct device *dev, const char *con_id);
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struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
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void pwm_put(struct pwm_device *pwm);
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struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
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struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
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const char *con_id);
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void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
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bool pwm_can_sleep(struct pwm_device *pwm);
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#else
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static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
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{
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return -EINVAL;
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}
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static inline void *pwm_get_chip_data(struct pwm_device *pwm)
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{
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return NULL;
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}
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static inline int pwmchip_add(struct pwm_chip *chip)
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{
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return -EINVAL;
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}
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static inline int pwmchip_add_inversed(struct pwm_chip *chip)
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{
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return -EINVAL;
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}
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static inline int pwmchip_remove(struct pwm_chip *chip)
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{
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return -EINVAL;
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}
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static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
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unsigned int index,
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const char *label)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline struct pwm_device *pwm_get(struct device *dev,
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const char *consumer)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline struct pwm_device *of_pwm_get(struct device_node *np,
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const char *con_id)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline void pwm_put(struct pwm_device *pwm)
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{
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}
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static inline struct pwm_device *devm_pwm_get(struct device *dev,
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const char *consumer)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
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struct device_node *np,
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const char *con_id)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
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{
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}
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static inline bool pwm_can_sleep(struct pwm_device *pwm)
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{
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return false;
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}
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#endif
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struct pwm_lookup {
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struct list_head list;
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const char *provider;
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unsigned int index;
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const char *dev_id;
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const char *con_id;
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unsigned int period;
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enum pwm_polarity polarity;
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};
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#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \
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{ \
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.provider = _provider, \
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.index = _index, \
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.dev_id = _dev_id, \
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.con_id = _con_id, \
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.period = _period, \
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.polarity = _polarity \
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}
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#if IS_ENABLED(CONFIG_PWM)
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void pwm_add_table(struct pwm_lookup *table, size_t num);
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void pwm_remove_table(struct pwm_lookup *table, size_t num);
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#else
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static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
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{
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}
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static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
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{
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}
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#endif
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#ifdef CONFIG_PWM_SYSFS
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void pwmchip_sysfs_export(struct pwm_chip *chip);
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void pwmchip_sysfs_unexport(struct pwm_chip *chip);
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#else
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static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
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{
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}
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static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
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{
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}
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#endif /* CONFIG_PWM_SYSFS */
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#endif /* __LINUX_PWM_H */
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