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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/cdev.h>#include <linux/device.h>#include <linux/err.h>#include <linux/gpio/driver.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/of.h>
MODULE_IMPORT_NS("PWM");
struct pwm_chip;
/** * enum pwm_polarity - polarity of a PWM signal * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty- * cycle, followed by a low signal for the remainder of the pulse * period * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty- * cycle, followed by a high signal for the remainder of the pulse * period */enum pwm_polarity { PWM_POLARITY_NORMAL, PWM_POLARITY_INVERSED,};
/** * struct pwm_args - board-dependent PWM arguments * @period: reference period * @polarity: reference polarity * * This structure describes board-dependent arguments attached to a PWM * device. These arguments are usually retrieved from the PWM lookup table or * device tree. * * Do not confuse this with the PWM state: PWM arguments represent the initial * configuration that users want to use on this PWM device rather than the * current PWM hardware state. */struct pwm_args { u64 period; enum pwm_polarity polarity;};
enum { PWMF_REQUESTED = 0, PWMF_EXPORTED = 1,};
/** * struct pwm_waveform - description of a PWM waveform * @period_length_ns: PWM period * @duty_length_ns: PWM duty cycle * @duty_offset_ns: offset of the rising edge from the period's start * * This is a representation of a PWM waveform alternative to struct pwm_state * below. It's more expressive than struct pwm_state as it contains a * duty_offset_ns and so can represent offsets other than zero (with .polarity = * PWM_POLARITY_NORMAL) and period - duty_cycle (.polarity = * PWM_POLARITY_INVERSED). * * Note there is no explicit bool for enabled. A "disabled" PWM is represented * by .period_length_ns = 0. Note further that the behaviour of a "disabled" PWM * is undefined. Depending on the hardware's capabilities it might drive the * active or inactive level, go high-z or even continue to toggle. * * The unit for all three members is nanoseconds. */struct pwm_waveform { u64 period_length_ns; u64 duty_length_ns; u64 duty_offset_ns;};
/* * struct pwm_state - state of a PWM channel * @period: PWM period (in nanoseconds) * @duty_cycle: PWM duty cycle (in nanoseconds) * @polarity: PWM polarity * @enabled: PWM enabled status * @usage_power: If set, the PWM driver is only required to maintain the power * output but has more freedom regarding signal form. * If supported, the signal can be optimized, for example to * improve EMI by phase shifting individual channels. */struct pwm_state { u64 period; u64 duty_cycle; enum pwm_polarity polarity; bool enabled; bool usage_power;};
/** * struct pwm_device - PWM channel object * @label: name of the PWM device * @flags: flags associated with the PWM device * @hwpwm: per-chip relative index of the PWM device * @chip: PWM chip providing this PWM device * @args: PWM arguments * @state: last applied state * @last: last implemented state (for PWM_DEBUG) */struct pwm_device { const char *label; unsigned long flags; unsigned int hwpwm; struct pwm_chip *chip;
struct pwm_args args; struct pwm_state state; struct pwm_state last;};
/** * pwm_get_state() - retrieve the current PWM state * @pwm: PWM device * @state: state to fill with the current PWM state * * The returned PWM state represents the state that was applied by a previous call to * pwm_apply_might_sleep(). Drivers may have to slightly tweak that state before programming it to * hardware. If pwm_apply_might_sleep() was never called, this returns either the current hardware * state (if supported) or the default settings. */static inline void pwm_get_state(const struct pwm_device *pwm, struct pwm_state *state){ *state = pwm->state;}
static inline bool pwm_is_enabled(const struct pwm_device *pwm){ struct pwm_state state;
pwm_get_state(pwm, &state);
return state.enabled;}
static inline u64 pwm_get_period(const struct pwm_device *pwm){ struct pwm_state state;
pwm_get_state(pwm, &state);
return state.period;}
static inline u64 pwm_get_duty_cycle(const struct pwm_device *pwm){ struct pwm_state state;
pwm_get_state(pwm, &state);
return state.duty_cycle;}
static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm){ struct pwm_state state;
pwm_get_state(pwm, &state);
return state.polarity;}
static inline void pwm_get_args(const struct pwm_device *pwm, struct pwm_args *args){ *args = pwm->args;}
/** * pwm_init_state() - prepare a new state to be applied with pwm_apply_might_sleep() * @pwm: PWM device * @state: state to fill with the prepared PWM state * * This functions prepares a state that can later be tweaked and applied * to the PWM device with pwm_apply_might_sleep(). This is a convenient function * that first retrieves the current PWM state and the replaces the period * and polarity fields with the reference values defined in pwm->args. * Once the function returns, you can adjust the ->enabled and ->duty_cycle * fields according to your needs before calling pwm_apply_might_sleep(). * * ->duty_cycle is initially set to zero to avoid cases where the current * ->duty_cycle value exceed the pwm_args->period one, which would trigger * an error if the user calls pwm_apply_might_sleep() without adjusting ->duty_cycle * first. */static inline void pwm_init_state(const struct pwm_device *pwm, struct pwm_state *state){ struct pwm_args args;
/* First get the current state. */ pwm_get_state(pwm, state);
/* Then fill it with the reference config */ pwm_get_args(pwm, &args);
state->period = args.period; state->polarity = args.polarity; state->duty_cycle = 0; state->usage_power = false;}
/** * pwm_get_relative_duty_cycle() - Get a relative duty cycle value * @state: PWM state to extract the duty cycle from * @scale: target scale of the relative duty cycle * * This functions converts the absolute duty cycle stored in @state (expressed * in nanosecond) into a value relative to the period. * * For example if you want to get the duty_cycle expressed in percent, call: * * pwm_get_state(pwm, &state); * duty = pwm_get_relative_duty_cycle(&state, 100); * * Returns: rounded relative duty cycle multiplied by @scale */static inline unsigned intpwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale){ if (!state->period) return 0;
return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale, state->period);}
/** * pwm_set_relative_duty_cycle() - Set a relative duty cycle value * @state: PWM state to fill * @duty_cycle: relative duty cycle value * @scale: scale in which @duty_cycle is expressed * * This functions converts a relative into an absolute duty cycle (expressed * in nanoseconds), and puts the result in state->duty_cycle. * * For example if you want to configure a 50% duty cycle, call: * * pwm_init_state(pwm, &state); * pwm_set_relative_duty_cycle(&state, 50, 100); * pwm_apply_might_sleep(pwm, &state); * * Returns: 0 on success or ``-EINVAL`` if @duty_cycle and/or @scale are * inconsistent (@scale == 0 or @duty_cycle > @scale) */static inline intpwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle, unsigned int scale){ if (!scale || duty_cycle > scale) return -EINVAL;
state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle * state->period, scale);
return 0;}
/** * struct pwm_capture - PWM capture data * @period: period of the PWM signal (in nanoseconds) * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) */struct pwm_capture { unsigned int period; unsigned int duty_cycle;};
#define PWM_WFHWSIZE 20
/** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM * @free: optional hook for freeing a PWM * @capture: capture and report PWM signal * @sizeof_wfhw: size (in bytes) of driver specific waveform presentation * @round_waveform_tohw: convert a struct pwm_waveform to driver specific presentation * @round_waveform_fromhw: convert a driver specific waveform presentation to struct pwm_waveform * @read_waveform: read driver specific waveform presentation from hardware * @write_waveform: write driver specific waveform presentation to hardware * @apply: atomically apply a new PWM config * @get_state: get the current PWM state. */struct pwm_ops { int (*request)(struct pwm_chip *chip, struct pwm_device *pwm); void (*free)(struct pwm_chip *chip, struct pwm_device *pwm); int (*capture)(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_capture *result, unsigned long timeout);
size_t sizeof_wfhw; int (*round_waveform_tohw)(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_waveform *wf, void *wfhw); int (*round_waveform_fromhw)(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw, struct pwm_waveform *wf); int (*read_waveform)(struct pwm_chip *chip, struct pwm_device *pwm, void *wfhw); int (*write_waveform)(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw);
int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state); int (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state);};
/** * struct pwm_chip - abstract a PWM controller * @dev: device providing the PWMs * @cdev: &struct cdev for this device * @ops: callbacks for this PWM controller * @owner: module providing this chip * @id: unique number of this PWM chip * @npwm: number of PWMs controlled by this chip * @of_xlate: request a PWM device given a device tree PWM specifier * @atomic: can the driver's ->apply() be called in atomic context * @gpio: &struct gpio_chip to operate this PWM chip's lines as GPO * @uses_pwmchip_alloc: signals if pwmchip_allow was used to allocate this chip * @operational: signals if the chip can be used (or is already deregistered) * @nonatomic_lock: mutex for nonatomic chips * @atomic_lock: mutex for atomic chips * @pwms: array of PWM devices allocated by the framework */struct pwm_chip { struct device dev; struct cdev cdev; const struct pwm_ops *ops; struct module *owner; unsigned int id; unsigned int npwm;
struct pwm_device * (*of_xlate)(struct pwm_chip *chip, const struct of_phandle_args *args); bool atomic;
/* only used internally by the PWM framework */ struct gpio_chip gpio; bool uses_pwmchip_alloc; bool operational; union { /* * depending on the chip being atomic or not either the mutex or * the spinlock is used. It protects .operational and * synchronizes the callbacks in .ops */ struct mutex nonatomic_lock; spinlock_t atomic_lock; }; struct pwm_device pwms[] __counted_by(npwm);};
/** * pwmchip_supports_waveform() - checks if the given chip supports waveform callbacks * @chip: The pwm_chip to test * * Returns: true iff the pwm chip support the waveform functions like * pwm_set_waveform_might_sleep() and pwm_round_waveform_might_sleep() */static inline bool pwmchip_supports_waveform(struct pwm_chip *chip){ /* * only check for .write_waveform(). If that is available, * .round_waveform_tohw() and .round_waveform_fromhw() asserted to be * available, too, in pwmchip_add(). */ return chip->ops->write_waveform != NULL;}
static inline struct device *pwmchip_parent(const struct pwm_chip *chip){ return chip->dev.parent;}
static inline void *pwmchip_get_drvdata(const struct pwm_chip *chip){ return dev_get_drvdata(&chip->dev);}
static inline void pwmchip_set_drvdata(struct pwm_chip *chip, void *data){ dev_set_drvdata(&chip->dev, data);}
#if IS_REACHABLE(CONFIG_PWM)
/* PWM consumer APIs */int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf);int pwm_get_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf);int pwm_set_waveform_might_sleep(struct pwm_device *pwm, const struct pwm_waveform *wf, bool exact);int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state);int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state);int pwm_get_state_hw(struct pwm_device *pwm, struct pwm_state *state);int pwm_adjust_config(struct pwm_device *pwm);
/** * pwm_config() - change a PWM device configuration * @pwm: PWM device * @duty_ns: "on" time (in nanoseconds) * @period_ns: duration (in nanoseconds) of one cycle * * Returns: 0 on success or a negative error code on failure. */static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns){ struct pwm_state state;
if (!pwm) return -EINVAL;
if (duty_ns < 0 || period_ns < 0) return -EINVAL;
pwm_get_state(pwm, &state); if (state.duty_cycle == duty_ns && state.period == period_ns) return 0;
state.duty_cycle = duty_ns; state.period = period_ns; return pwm_apply_might_sleep(pwm, &state);}
/** * pwm_enable() - start a PWM output toggling * @pwm: PWM device * * Returns: 0 on success or a negative error code on failure. */static inline int pwm_enable(struct pwm_device *pwm){ struct pwm_state state;
if (!pwm) return -EINVAL;
pwm_get_state(pwm, &state); if (state.enabled) return 0;
state.enabled = true; return pwm_apply_might_sleep(pwm, &state);}
/** * pwm_disable() - stop a PWM output toggling * @pwm: PWM device */static inline void pwm_disable(struct pwm_device *pwm){ struct pwm_state state;
if (!pwm) return;
pwm_get_state(pwm, &state); if (!state.enabled) return;
state.enabled = false; pwm_apply_might_sleep(pwm, &state);}
/** * pwm_might_sleep() - is pwm_apply_atomic() supported? * @pwm: PWM device * * Returns: false if pwm_apply_atomic() can be called from atomic context. */static inline bool pwm_might_sleep(struct pwm_device *pwm){ return !pwm->chip->atomic;}
/* PWM provider APIs */void pwmchip_put(struct pwm_chip *chip);struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv);struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv);
int __pwmchip_add(struct pwm_chip *chip, struct module *owner);#define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE)void pwmchip_remove(struct pwm_chip *chip);
/* * For FFI wrapper use only: * The Rust PWM abstraction needs this to properly free the pwm_chip. */void pwmchip_release(struct device *dev);
int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner);#define devm_pwmchip_add(dev, chip) __devm_pwmchip_add(dev, chip, THIS_MODULE)
struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args);struct pwm_device *of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args);
struct pwm_device *pwm_get(struct device *dev, const char *con_id);void pwm_put(struct pwm_device *pwm);
struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);struct pwm_device *devm_fwnode_pwm_get(struct device *dev, struct fwnode_handle *fwnode, const char *con_id);#elsestatic inline bool pwm_might_sleep(struct pwm_device *pwm){ return true;}
static inline int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state){ might_sleep(); return -EOPNOTSUPP;}
static inline int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state){ return -EOPNOTSUPP;}
static inline int pwm_get_state_hw(struct pwm_device *pwm, struct pwm_state *state){ return -EOPNOTSUPP;}
static inline int pwm_adjust_config(struct pwm_device *pwm){ return -EOPNOTSUPP;}
static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns){ might_sleep(); return -EINVAL;}
static inline int pwm_enable(struct pwm_device *pwm){ might_sleep(); return -EINVAL;}
static inline void pwm_disable(struct pwm_device *pwm){ might_sleep();}
static inline void pwmchip_put(struct pwm_chip *chip){}
static inline struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv){ return ERR_PTR(-EINVAL);}
static inline struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv){ return pwmchip_alloc(parent, npwm, sizeof_priv);}
static inline int pwmchip_add(struct pwm_chip *chip){ return -EINVAL;}
static inline int pwmchip_remove(struct pwm_chip *chip){ return -EINVAL;}
static inline int devm_pwmchip_add(struct device *dev, struct pwm_chip *chip){ return -EINVAL;}
static inline struct pwm_device *pwm_get(struct device *dev, const char *consumer){ might_sleep(); return ERR_PTR(-ENODEV);}
static inline void pwm_put(struct pwm_device *pwm){ might_sleep();}
static inline struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer){ might_sleep(); return ERR_PTR(-ENODEV);}
static inline struct pwm_device *devm_fwnode_pwm_get(struct device *dev, struct fwnode_handle *fwnode, const char *con_id){ might_sleep(); return ERR_PTR(-ENODEV);}#endif
struct pwm_lookup { struct list_head list; const char *provider; unsigned int index; const char *dev_id; const char *con_id; unsigned int period; enum pwm_polarity polarity; const char *module; /* optional, may be NULL */};
#define PWM_LOOKUP_WITH_MODULE(_provider, _index, _dev_id, _con_id, \ _period, _polarity, _module) \ { \ .provider = _provider, \ .index = _index, \ .dev_id = _dev_id, \ .con_id = _con_id, \ .period = _period, \ .polarity = _polarity, \ .module = _module, \ }
#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ PWM_LOOKUP_WITH_MODULE(_provider, _index, _dev_id, _con_id, _period, \ _polarity, NULL)
#if IS_REACHABLE(CONFIG_PWM)void pwm_add_table(struct pwm_lookup *table, size_t num);void pwm_remove_table(struct pwm_lookup *table, size_t num);#elsestatic inline void pwm_add_table(struct pwm_lookup *table, size_t num){}
static inline void pwm_remove_table(struct pwm_lookup *table, size_t num){}#endif
#endif /* __LINUX_PWM_H */