Tease the PWM driver out and fix some build issues after cleaning up behind the cpuload pieces.

apps/drivers/drv_pwm_output.h

@@ -41,14 +41,15 @@
  * channel.
  */
 
-#ifndef _DRV_PWM_OUTPUT_H
-#define _DRV_PWM_OUTPUT_H
+#pragma once
 
 #include <stdint.h>
 #include <sys/ioctl.h>
 
 #include "drv_orb_dev.h"
 
+__BEGIN_DECLS
+
 /**
  * Path for the default PWM output device.
  *
@@ -109,4 +110,63 @@ ORB_DECLARE(output_pwm);
 #define PWM_SERVO_GET(_servo)	_IOC(_PWM_SERVO_BASE, 0x40 + _servo)
 
 
-#endif /* _DRV_PWM_OUTPUT_H */
+/*
+ * Low-level PWM output interface.
+ *
+ * This is the low-level API to the platform-specific PWM driver.
+ */
+
+/**
+ * Intialise the PWM servo outputs using the specified configuration.
+ *
+ * @param channel_mask	Bitmask of channels (LSB = channel 0) to enable.
+ *			This allows some of the channels to remain configured
+ *			as GPIOs or as another function.
+ * @return		OK on success.
+ */
+__EXPORT extern int	up_pwm_servo_init(uint32_t channel_mask);
+
+/**
+ * De-initialise the PWM servo outputs.
+ */
+__EXPORT extern void	up_pwm_servo_deinit(void);
+
+/**
+ * Arm or disarm servo outputs.
+ *
+ * When disarmed, servos output no pulse.
+ *
+ * @bug This function should, but does not, guarantee that any pulse 
+ *      currently in progress is cleanly completed.
+ *
+ * @param armed		If true, outputs are armed; if false they
+ *			are disarmed.
+ */
+__EXPORT extern void	up_pwm_servo_arm(bool armed);
+
+/**
+ * Set the servo update rate
+ *
+ * @param rate		The update rate in Hz to set.
+ * @return		OK on success, -ERANGE if an unsupported update rate is set.
+ */
+__EXPORT extern int	up_pwm_servo_set_rate(unsigned rate);
+
+/**
+ * Set the current output value for a channel.
+ *
+ * @param channel	The channel to set.
+ * @param value		The output pulse width in microseconds.
+ */
+__EXPORT extern int	up_pwm_servo_set(unsigned channel, servo_position_t value);
+
+/**
+ * Get the current output value for a channel.
+ *
+ * @param channel	The channel to read.
+ * @return		The output pulse width in microseconds, or zero if
+ *			outputs are not armed or not configured.
+ */
+__EXPORT extern servo_position_t up_pwm_servo_get(unsigned channel);
+
+__END_DECLS