[PATCH 5/5] xen/sndif: Add explicit back and front parameter negotiation
From: Oleksandr Andrushchenko
Date: Thu Apr 12 2018 - 12:02:01 EST
In order to provide explicit stream parameter negotiation between
backend and frontend the following changes are introduced in the protocol:
add XENSND_OP_HW_PARAM_QUERY request to read/update
configuration space for the parameters given: request passes
desired parameter's intervals/masks and the response to this request
returns allowed min/max intervals/masks to be used.
Parameters supported by this request/response:
- format mask
- sample rate interval
- number of channels interval
- buffer size, interval, frames
- period size, interval, frames
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
---
include/xen/interface/io/sndif.h | 133 +++++++++++++++++++++++++++++--
1 file changed, 126 insertions(+), 7 deletions(-)
diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h
index 131c3b469d4a..78bb5d9f8d83 100644
--- a/include/xen/interface/io/sndif.h
+++ b/include/xen/interface/io/sndif.h
@@ -465,6 +465,7 @@
#define XENSND_OP_MUTE 6
#define XENSND_OP_UNMUTE 7
#define XENSND_OP_TRIGGER 8
+#define XENSND_OP_HW_PARAM_QUERY 9
#define XENSND_OP_TRIGGER_START 0
#define XENSND_OP_TRIGGER_PAUSE 1
@@ -832,28 +833,142 @@ struct xensnd_trigger_req {
};
/*
- *---------------------------------- Responses --------------------------------
+ * Request stream parameter ranges: request intervals and
+ * masks of supported ranges for stream configuration values.
*
- * All response packets have the same length (64 octets)
+ * Sound device configuration for a particular stream is a limited subset
+ * of the multidimensional configuration available on XenStore, e.g.
+ * once the frame rate has been selected there is a limited supported range
+ * for sample rates becomes available (which might be the same set configured
+ * on XenStore or less). For example, selecting 96kHz sample rate may limit
+ * number of channels available for such configuration from 4 to 2, etc.
+ * Thus, each call to XENSND_OP_HW_PARAM_QUERY may reduce configuration
+ * space making it possible to iteratively get the final stream configuration,
+ * used in XENSND_OP_OPEN request.
+ *
+ * See response format for this request.
*
- * Response for all requests:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
- * | id | operation | reserved | 4
+ * | id | _HW_PARAM_QUERY| reserved | 4
* +----------------+----------------+----------------+----------------+
- * | status | 8
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | formats mask low 32-bit | 12
+ * +----------------+----------------+----------------+----------------+
+ * | formats mask high 32-bit | 16
+ * +----------------+----------------+----------------+----------------+
+ * | min rate | 20
+ * +----------------+----------------+----------------+----------------+
+ * | max rate | 24
+ * +----------------+----------------+----------------+----------------+
+ * | min channels | 28
+ * +----------------+----------------+----------------+----------------+
+ * | max channels | 32
+ * +----------------+----------------+----------------+----------------+
+ * | min buffer frames | 36
+ * +----------------+----------------+----------------+----------------+
+ * | max buffer frames | 40
+ * +----------------+----------------+----------------+----------------+
+ * | min period frames | 44
+ * +----------------+----------------+----------------+----------------+
+ * | max period frames | 48
* +----------------+----------------+----------------+----------------+
- * | reserved | 12
+ * | reserved | 52
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
+ * formats - uint64_t, bit mask representing values of the parameter
+ * made as bitwise OR of (1 << XENSND_PCM_FORMAT_XXX) values
+ *
+ * For interval parameters:
+ * min - uint32_t, minimum value of the parameter
+ * max - uint32_t, maximum value of the parameter
+ *
+ * Frame is defined as a product of the number of channels by the
+ * number of octets per one sample.
+ */
+
+struct xensnd_query_hw_param {
+ uint64_t formats;
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } rates;
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } channels;
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } buffer;
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } period;
+};
+
+/*
+ *---------------------------------- Responses --------------------------------
+ *
+ * All response packets have the same length (64 octets)
+ *
+ * All response packets have common header:
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | operation | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | status | 8
+ * +----------------+----------------+----------------+----------------+
+ *
* id - uint16_t, copied from the request
* operation - uint8_t, XENSND_OP_* - copied from request
* status - int32_t, response status, zero on success and -XEN_EXX on failure
*
+ *
+ * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY:
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | operation | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | status | 8
+ * +----------------+----------------+----------------+----------------+
+ * | formats mask low 32-bit | 12
+ * +----------------+----------------+----------------+----------------+
+ * | formats mask high 32-bit | 16
+ * +----------------+----------------+----------------+----------------+
+ * | min rate | 20
+ * +----------------+----------------+----------------+----------------+
+ * | max rate | 24
+ * +----------------+----------------+----------------+----------------+
+ * | min channels | 28
+ * +----------------+----------------+----------------+----------------+
+ * | max channels | 32
+ * +----------------+----------------+----------------+----------------+
+ * | min buffer frames | 36
+ * +----------------+----------------+----------------+----------------+
+ * | max buffer frames | 40
+ * +----------------+----------------+----------------+----------------+
+ * | min period frames | 44
+ * +----------------+----------------+----------------+----------------+
+ * | max period frames | 48
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 52
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Meaning of the values in this response is the same as for
+ * XENSND_OP_HW_PARAM_QUERY request.
+ */
+
+/*
*----------------------------------- Events ----------------------------------
*
* Events are sent via shared page allocated by the front and propagated by
@@ -906,6 +1021,7 @@ struct xensnd_req {
struct xensnd_open_req open;
struct xensnd_rw_req rw;
struct xensnd_trigger_req trigger;
+ struct xensnd_query_hw_param hw_param;
uint8_t reserved[56];
} op;
};
@@ -915,7 +1031,10 @@ struct xensnd_resp {
uint8_t operation;
uint8_t reserved;
int32_t status;
- uint8_t reserved1[56];
+ union {
+ struct xensnd_query_hw_param hw_param;
+ uint8_t reserved1[56];
+ } resp;
};
struct xensnd_evt {
--
2.17.0