mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Uwe Kleine-König](/assets/img/avatar_default.png)
This is only defined with CONFIG_PWM unset and was introduced together with pwmchip_add_with_polarity() (which is only defined with CONFIG_PWM enabled). I guess the series that introduced pwmchip_add_with_polarity() had a different concept in earlier revisions and the !CONFIG_PWM part was just not updated accordingly. Given that there is no implementation for pwmchip_add_with_polarity() without CONFIG_PWM, just drop pwmchip_add_inversed() instead of renaming it to pwmchip_add_with_polarity(). Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
615 lines
16 KiB
C
615 lines
16 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_PWM_H
|
|
#define __LINUX_PWM_H
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/of.h>
|
|
|
|
struct pwm_capture;
|
|
struct seq_file;
|
|
|
|
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 = 1 << 0,
|
|
PWMF_EXPORTED = 1 << 1,
|
|
};
|
|
|
|
/*
|
|
* 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
|
|
*/
|
|
struct pwm_state {
|
|
u64 period;
|
|
u64 duty_cycle;
|
|
enum pwm_polarity polarity;
|
|
bool enabled;
|
|
};
|
|
|
|
/**
|
|
* 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
|
|
* @pwm: global index of the PWM device
|
|
* @chip: PWM chip providing this PWM device
|
|
* @chip_data: chip-private data associated with the 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;
|
|
unsigned int pwm;
|
|
struct pwm_chip *chip;
|
|
void *chip_data;
|
|
|
|
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
|
|
*/
|
|
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 void pwm_set_period(struct pwm_device *pwm, u64 period)
|
|
{
|
|
if (pwm)
|
|
pwm->state.period = period;
|
|
}
|
|
|
|
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 void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
|
|
{
|
|
if (pwm)
|
|
pwm->state.duty_cycle = duty;
|
|
}
|
|
|
|
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_state()
|
|
* @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_state(). 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_state().
|
|
*
|
|
* ->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_state() 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;
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
*/
|
|
static inline unsigned int
|
|
pwm_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_state(pwm, &state);
|
|
*
|
|
* This functions returns -EINVAL if @duty_cycle and/or @scale are
|
|
* inconsistent (@scale == 0 or @duty_cycle > @scale).
|
|
*/
|
|
static inline int
|
|
pwm_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_ops - PWM controller operations
|
|
* @request: optional hook for requesting a PWM
|
|
* @free: optional hook for freeing a PWM
|
|
* @capture: capture and report PWM signal
|
|
* @apply: atomically apply a new PWM config
|
|
* @get_state: get the current PWM state. This function is only
|
|
* called once per PWM device when the PWM chip is
|
|
* registered.
|
|
* @owner: helps prevent removal of modules exporting active PWMs
|
|
* @config: configure duty cycles and period length for this PWM
|
|
* @set_polarity: configure the polarity of this PWM
|
|
* @enable: enable PWM output toggling
|
|
* @disable: disable PWM output toggling
|
|
*/
|
|
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);
|
|
int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
const struct pwm_state *state);
|
|
void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
struct pwm_state *state);
|
|
struct module *owner;
|
|
|
|
/* Only used by legacy drivers */
|
|
int (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
int duty_ns, int period_ns);
|
|
int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
|
|
enum pwm_polarity polarity);
|
|
int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
|
|
void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
|
|
};
|
|
|
|
/**
|
|
* struct pwm_chip - abstract a PWM controller
|
|
* @dev: device providing the PWMs
|
|
* @ops: callbacks for this PWM controller
|
|
* @base: number of first PWM controlled by this chip
|
|
* @npwm: number of PWMs controlled by this chip
|
|
* @of_xlate: request a PWM device given a device tree PWM specifier
|
|
* @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
|
|
* @list: list node for internal use
|
|
* @pwms: array of PWM devices allocated by the framework
|
|
*/
|
|
struct pwm_chip {
|
|
struct device *dev;
|
|
const struct pwm_ops *ops;
|
|
int base;
|
|
unsigned int npwm;
|
|
|
|
struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
|
|
const struct of_phandle_args *args);
|
|
unsigned int of_pwm_n_cells;
|
|
|
|
/* only used internally by the PWM framework */
|
|
struct list_head list;
|
|
struct pwm_device *pwms;
|
|
};
|
|
|
|
/**
|
|
* 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;
|
|
};
|
|
|
|
#if IS_ENABLED(CONFIG_PWM)
|
|
/* PWM user APIs */
|
|
struct pwm_device *pwm_request(int pwm_id, const char *label);
|
|
void pwm_free(struct pwm_device *pwm);
|
|
int pwm_apply_state(struct pwm_device *pwm, const 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_state(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_state(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_state(pwm, &state);
|
|
}
|
|
|
|
/* PWM provider APIs */
|
|
int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
|
|
unsigned long timeout);
|
|
int pwm_set_chip_data(struct pwm_device *pwm, void *data);
|
|
void *pwm_get_chip_data(struct pwm_device *pwm);
|
|
|
|
int pwmchip_add_with_polarity(struct pwm_chip *chip,
|
|
enum pwm_polarity polarity);
|
|
int pwmchip_add(struct pwm_chip *chip);
|
|
int pwmchip_remove(struct pwm_chip *chip);
|
|
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
|
|
unsigned int index,
|
|
const char *label);
|
|
|
|
struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
|
|
const struct of_phandle_args *args);
|
|
|
|
struct pwm_device *pwm_get(struct device *dev, const char *con_id);
|
|
struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
|
|
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_of_pwm_get(struct device *dev, struct device_node *np,
|
|
const char *con_id);
|
|
struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
|
|
struct fwnode_handle *fwnode,
|
|
const char *con_id);
|
|
void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
|
|
#else
|
|
static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline void pwm_free(struct pwm_device *pwm)
|
|
{
|
|
}
|
|
|
|
static inline int pwm_apply_state(struct pwm_device *pwm,
|
|
const struct pwm_state *state)
|
|
{
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
static inline int pwm_adjust_config(struct pwm_device *pwm)
|
|
{
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
static inline int pwm_config(struct pwm_device *pwm, int duty_ns,
|
|
int period_ns)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline int pwm_capture(struct pwm_device *pwm,
|
|
struct pwm_capture *result,
|
|
unsigned long timeout)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline int pwm_enable(struct pwm_device *pwm)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline void pwm_disable(struct pwm_device *pwm)
|
|
{
|
|
}
|
|
|
|
static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline void *pwm_get_chip_data(struct pwm_device *pwm)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline int pwmchip_add(struct pwm_chip *chip)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline int pwmchip_remove(struct pwm_chip *chip)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
|
|
unsigned int index,
|
|
const char *label)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline struct pwm_device *pwm_get(struct device *dev,
|
|
const char *consumer)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline struct pwm_device *of_pwm_get(struct device *dev,
|
|
struct device_node *np,
|
|
const char *con_id)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline void pwm_put(struct pwm_device *pwm)
|
|
{
|
|
}
|
|
|
|
static inline struct pwm_device *devm_pwm_get(struct device *dev,
|
|
const char *consumer)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
|
|
struct device_node *np,
|
|
const char *con_id)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline struct pwm_device *
|
|
devm_fwnode_pwm_get(struct device *dev, struct fwnode_handle *fwnode,
|
|
const char *con_id)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static inline void pwm_apply_args(struct pwm_device *pwm)
|
|
{
|
|
struct pwm_state state = { };
|
|
|
|
/*
|
|
* PWM users calling pwm_apply_args() expect to have a fresh config
|
|
* where the polarity and period are set according to pwm_args info.
|
|
* The problem is, polarity can only be changed when the PWM is
|
|
* disabled.
|
|
*
|
|
* PWM drivers supporting hardware readout may declare the PWM device
|
|
* as enabled, and prevent polarity setting, which changes from the
|
|
* existing behavior, where all PWM devices are declared as disabled
|
|
* at startup (even if they are actually enabled), thus authorizing
|
|
* polarity setting.
|
|
*
|
|
* To fulfill this requirement, we apply a new state which disables
|
|
* the PWM device and set the reference period and polarity config.
|
|
*
|
|
* Note that PWM users requiring a smooth handover between the
|
|
* bootloader and the kernel (like critical regulators controlled by
|
|
* PWM devices) will have to switch to the atomic API and avoid calling
|
|
* pwm_apply_args().
|
|
*/
|
|
|
|
state.enabled = false;
|
|
state.polarity = pwm->args.polarity;
|
|
state.period = pwm->args.period;
|
|
|
|
pwm_apply_state(pwm, &state);
|
|
}
|
|
|
|
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_ENABLED(CONFIG_PWM)
|
|
void pwm_add_table(struct pwm_lookup *table, size_t num);
|
|
void pwm_remove_table(struct pwm_lookup *table, size_t num);
|
|
#else
|
|
static 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
|
|
|
|
#ifdef CONFIG_PWM_SYSFS
|
|
void pwmchip_sysfs_export(struct pwm_chip *chip);
|
|
void pwmchip_sysfs_unexport(struct pwm_chip *chip);
|
|
#else
|
|
static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
|
|
{
|
|
}
|
|
|
|
static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
|
|
{
|
|
}
|
|
#endif /* CONFIG_PWM_SYSFS */
|
|
|
|
#endif /* __LINUX_PWM_H */
|