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-rw-r--r--include/linux/mfd/cros_ec.h15
-rw-r--r--include/linux/mfd/cros_ec_commands.h31
-rw-r--r--include/linux/pwm.h113
3 files changed, 158 insertions, 1 deletions
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 64184d27e3cd..d641a18abacb 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -226,6 +226,21 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg);
/**
+ * cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC
+ *
+ * This function is identical to cros_ec_cmd_xfer, except it returns success
+ * status only if both the command was transmitted successfully and the EC
+ * replied with success status. It's not necessary to check msg->result when
+ * using this function.
+ *
+ * @ec_dev: EC device
+ * @msg: Message to write
+ * @return: Num. of bytes transferred on success, <0 on failure
+ */
+int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg);
+
+/**
* cros_ec_remove - Remove a ChromeOS EC
*
* Call this to deregister a ChromeOS EC, then clean up any private data.
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index 13b630c10d4c..7e7a8d4b4551 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -949,6 +949,37 @@ struct ec_params_pwm_set_fan_duty {
uint32_t percent;
} __packed;
+#define EC_CMD_PWM_SET_DUTY 0x25
+/* 16 bit duty cycle, 0xffff = 100% */
+#define EC_PWM_MAX_DUTY 0xffff
+
+enum ec_pwm_type {
+ /* All types, indexed by board-specific enum pwm_channel */
+ EC_PWM_TYPE_GENERIC = 0,
+ /* Keyboard backlight */
+ EC_PWM_TYPE_KB_LIGHT,
+ /* Display backlight */
+ EC_PWM_TYPE_DISPLAY_LIGHT,
+ EC_PWM_TYPE_COUNT,
+};
+
+struct ec_params_pwm_set_duty {
+ uint16_t duty; /* Duty cycle, EC_PWM_MAX_DUTY = 100% */
+ uint8_t pwm_type; /* ec_pwm_type */
+ uint8_t index; /* Type-specific index, or 0 if unique */
+} __packed;
+
+#define EC_CMD_PWM_GET_DUTY 0x26
+
+struct ec_params_pwm_get_duty {
+ uint8_t pwm_type; /* ec_pwm_type */
+ uint8_t index; /* Type-specific index, or 0 if unique */
+} __packed;
+
+struct ec_response_pwm_get_duty {
+ uint16_t duty; /* Duty cycle, EC_PWM_MAX_DUTY = 100% */
+} __packed;
+
/*****************************************************************************/
/*
* Lightbar commands. This looks worse than it is. Since we only use one HOST
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index c038ae36b10e..f1bbae014889 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -5,7 +5,9 @@
#include <linux/mutex.h>
#include <linux/of.h>
+struct pwm_capture;
struct seq_file;
+
struct pwm_chip;
/**
@@ -148,11 +150,100 @@ static inline void pwm_get_args(const struct pwm_device *pwm,
}
/**
+ * 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
* @config: configure duty cycles and period length for this PWM
* @set_polarity: configure the polarity of this PWM
+ * @capture: capture and report PWM signal
* @enable: enable PWM output toggling
* @disable: disable PWM output toggling
* @apply: atomically apply a new PWM config. The state argument
@@ -172,6 +263,8 @@ struct pwm_ops {
int duty_ns, int period_ns);
int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
enum pwm_polarity polarity);
+ int (*capture)(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_capture *result, unsigned long timeout);
int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -212,6 +305,16 @@ struct pwm_chip {
bool can_sleep;
};
+/**
+ * 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);
@@ -323,8 +426,9 @@ static inline void pwm_disable(struct pwm_device *pwm)
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);
@@ -376,6 +480,13 @@ static inline int pwm_config(struct pwm_device *pwm, int duty_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_set_polarity(struct pwm_device *pwm,
enum pwm_polarity polarity)
{