Merge tag 'pwm/for-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set of changes improve some aspects of the atomic API as well as
  make use of this new API in the regulator framework to allow properly
  dealing with critical regulators controlled by a PWM.

  Aside from that there's a bunch of updates and cleanups for existing
  drivers, as well as the addition of new drivers for the Broadcom
  iProc, STMPE and ChromeOS EC controllers"

* tag 'pwm/for-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (44 commits)
  regulator: pwm: Document pwm-dutycycle-unit and pwm-dutycycle-range
  regulator: pwm: Support extra continuous mode cases
  pwm: Add ChromeOS EC PWM driver
  dt-bindings: pwm: Add binding for ChromeOS EC PWM
  mfd: cros_ec: Add EC_PWM function definitions
  mfd: cros_ec: Add cros_ec_cmd_xfer_status() helper
  pwm: atmel: Use of_device_get_match_data()
  pwm: atmel: Fix checkpatch warnings
  pwm: atmel: Fix disabling of PWM channels
  dt-bindings: pwm: Add R-Car H3 device tree bindings
  pwm: rcar: Use ARCH_RENESAS
  pwm: tegra: Add support for Tegra186
  dt-bindings: pwm: tegra: Add compatible string for Tegra186
  pwm: tegra: Avoid overflow when calculating duty cycle
  pwm: tegra: Allow 100 % duty cycle
  pwm: tegra: Add support for reset control
  pwm: tegra: Rename mmio_base to regs
  pwm: tegra: Remove useless padding
  pwm: tegra: Drop NUM_PWM macro
  pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value
  ...

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)
 {