Make mixer ioctls load from a memory buffer rather than a file. This is prep for uploading the memory buffer to IO to be processed there.

1 files changed, 100 insertions, 40 deletions

diff --git a/apps/systemlib/mixer/mixer.h b/apps/systemlib/mixer/mixer.h
index 94c179eba..0023dc380 100644
--- a/apps/systemlib/mixer/mixer.h
+++ b/apps/systemlib/mixer/mixer.h
@@ -234,50 +234,45 @@ public:
 	void				add_mixer(Mixer *mixer);
 
 	/**
-	 * Reads a mixer definition from a file and configures a corresponding
-	 * group.
+	 * Adds mixers to the group based on a text description in a buffer.
 	 *
-	 * The mixer group must be empty when this function is called.
+	 * Mixer definitions begin with a single capital letter and a colon.
+	 * The actual format of the mixer definition varies with the individual
+	 * mixers; they are summarised here, but see ROMFS/mixers/README for 
+	 * more details.
 	 *
-	 * A mixer definition is a text representation of the configuration of a
-	 * mixer. Definition lines begin with a capital letter followed by a colon.
+	 * Null Mixer
+	 * ..........
+	 * 
+	 * The null mixer definition has the form:
+	 * 
+	 *   Z:
+	 * 
+	 * Simple Mixer
+	 * ............
+	 * 
+	 * A simple mixer definition begins with:
+	 * 
+	 *   M: <control count>
+	 *   O: <-ve scale> <+ve scale> <offset> <lower limit> <upper limit>
+	 * 
+	 * The definition continues with <control count> entries describing the control
+	 * inputs and their scaling, in the form:
+	 * 
+	 *   S: <group> <index> <-ve scale> <+ve scale> <offset> <lower limit> <upper limit>
+	 * 
+	 * Multirotor Mixer
+	 * ................
+	 * 
+	 * The multirotor mixer definition is a single line of the form:
+	 * 
+	 * R: <geometry> <roll scale> <pitch scale> <yaw scale> <deadband>
 	 *
-	 * Null Mixer:
-	 *
-	 * Z:
-	 *
-	 * This mixer generates a constant zero output, and is normally used to
-	 * skip over outputs that are not in use.
-	 *
-	 * Simple Mixer:
-	 *
-	 * M: <scaler count>
-	 * S: <control group> <control index> <negative_scale*> <positive_scale*> <offset*> <lower_limit*> <upper_limit*>
-	 * S: ...
-	 *
-	 * The definition consists of a single-line header indicating the
-	 * number of scalers and then one line defining each scaler.  The first
-	 * scaler in the file is always the output scaler, followed by the input
-	 * scalers.
-	 *
-	 * The <control ...> values for the output scaler are ignored by the mixer.
-	 *
-	 *
-	 *
-	 * Values marked * are integers representing floating point values; values are
-	 * scaled by 10000 on load/save.
-	 *
-	 * Multiple mixer definitions may be stored in a single file; it is assumed that
-	 * the reader will know how many to expect and read accordingly.
-	 *
-	 * A mixer entry with a scaler count of zero indicates a disabled mixer. This
-	 * will return NULL for the mixer when processed by this function, and will be
-	 * generated by passing NULL as the mixer to mixer_save.
-	 *
-	 * @param path			The mixer configuration file to read.
+	 * @param buf			The mixer configuration buffer.
+	 * @param buflen		The length of the buffer.
 	 * @return			Zero on successful load, nonzero otherwise.
 	 */
-	int				load_from_file(const char *path);
+	int				load_from_buf(const char *buf, unsigned buflen);
 
 private:
 	Mixer				*_first;	/**< linked list of mixers */
@@ -294,6 +289,21 @@ public:
 	NullMixer();
 	~NullMixer() {};
 
+	/**
+	 * Factory method.
+	 *
+	 * Given a pointer to a buffer containing a text description of the mixer,
+	 * returns a pointer to a new instance of the mixer.
+	 *
+	 * @param buf			Buffer containing a text description of
+	 *				the mixer.
+	 * @param buflen		Length of the buffer in bytes, adjusted
+	 *				to reflect the bytes consumed.
+	 * @return			A new NullMixer instance, or nullptr
+	 *				if the text format is bad.
+	 */
+	static NullMixer		*from_text(const char *buf, unsigned &buflen);
+
 	virtual unsigned		mix(float *outputs, unsigned space);
 	virtual void			groups_required(uint32_t &groups);
 };
@@ -318,6 +328,27 @@ public:
 		    mixer_simple_s *mixinfo);
 	~SimpleMixer();
 
+	/**
+	 * Factory method.
+	 *
+	 * Given a pointer to a buffer containing a text description of the mixer,
+	 * returns a pointer to a new instance of the mixer.
+	 *
+	 * @param control_cb		The callback to invoke when fetching a
+	 *				control value.
+	 * @param cb_handle		Handle passed to the control callback.
+	 * @param buf			Buffer containing a text description of
+	 *				the mixer.
+	 * @param buflen		Length of the buffer in bytes, adjusted
+	 *				to reflect the bytes consumed.
+	 * @return			A new SimpleMixer instance, or nullptr
+	 *				if the text format is bad.
+	 */
+	static SimpleMixer		*from_text(Mixer::ControlCallback control_cb,
+						uintptr_t cb_handle,
+						const char *buf,
+						unsigned &buflen);
+
 	virtual unsigned		mix(float *outputs, unsigned space);
 	virtual void			groups_required(uint32_t &groups);
 
@@ -330,10 +361,18 @@ public:
 	 * @return			Zero if the mixer makes sense, nonzero otherwise.
 	 */
 	int				check();
+
 protected:
 
 private:
-	mixer_simple_s		*_info;
+	mixer_simple_s			*_info;
+
+	static int			parse_output_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler);
+	static int			parse_control_scaler(const char *buf,
+						unsigned &buflen,
+						mixer_scaler_s &scaler,
+						uint8_t &control_group,
+						uint8_t &control_index);
 };
 
 /**
@@ -395,6 +434,27 @@ public:
 			float deadband);
 	~MultirotorMixer();
 
+	/**
+	 * Factory method.
+	 *
+	 * Given a pointer to a buffer containing a text description of the mixer,
+	 * returns a pointer to a new instance of the mixer.
+	 *
+	 * @param control_cb		The callback to invoke when fetching a
+	 *				control value.
+	 * @param cb_handle		Handle passed to the control callback.
+	 * @param buf			Buffer containing a text description of
+	 *				the mixer.
+	 * @param buflen		Length of the buffer in bytes, adjusted
+	 *				to reflect the bytes consumed.
+	 * @return			A new MultirotorMixer instance, or nullptr
+	 *				if the text format is bad.
+	 */
+	static MultirotorMixer		*from_text(Mixer::ControlCallback control_cb,
+						uintptr_t cb_handle,
+						const char *buf,
+						unsigned &buflen);
+
 	virtual unsigned		mix(float *outputs, unsigned space);
 	virtual void			groups_required(uint32_t &groups);