slimbus: stream: add stream support

This patch adds support to SLIMbus stream apis for slimbus device.
SLIMbus streaming involves adding support to Data Channel Management and
channel Reconfiguration Messages to slim core plus few stream apis.
>From slim device side the apis are very simple mostly inline with other
stream apis.

Currently it only supports Isochronous and Push/Pull transport protocols,
which are sufficient for audio use cases.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/linux/slimbus.h b/include/linux/slimbus.h
index 63801bcc5e60..12c9719b2a55 100644
--- a/include/linux/slimbus.h
+++ b/include/linux/slimbus.h
@@ -48,6 +48,8 @@ struct slim_controller;
  * @ctrl: slim controller instance.
  * @laddr: 1-byte Logical address of this device.
  * @is_laddr_valid: indicates if the laddr is valid or not
+ * @stream_list: List of streams on this device
+ * @stream_list_lock: lock to protect the stream list
  *
  * This is the client/device handle returned when a SLIMbus
  * device is registered with a controller.
@@ -60,6 +62,8 @@ struct slim_device {
 	enum slim_device_status	status;
 	u8			laddr;
 	bool			is_laddr_valid;
+	struct list_head	stream_list;
+	spinlock_t stream_list_lock;
 };
 
 #define to_slim_device(d) container_of(d, struct slim_device, dev)
@@ -108,6 +112,36 @@ struct slim_val_inf {
 	struct	completion	*comp;
 };
 
+#define SLIM_DEVICE_MAX_CHANNELS	256
+/* A SLIMBus Device may have frmo 0 to 31 Ports (inclusive) */
+#define SLIM_DEVICE_MAX_PORTS		32
+
+/**
+ * struct slim_stream_config - SLIMbus stream configuration
+ *	Configuring a stream is done at hw_params or prepare call
+ *	from audio drivers where they have all the required information
+ *	regarding rate, number of channels and so on.
+ *	There is a 1:1 mapping of channel and ports.
+ *
+ * @rate: data rate
+ * @bps: bits per data sample
+ * @ch_count: number of channels
+ * @chs: pointer to list of channel numbers
+ * @port_mask: port mask of ports to use for this stream
+ * @direction: direction of the stream, SNDRV_PCM_STREAM_PLAYBACK
+ *	or SNDRV_PCM_STREAM_CAPTURE.
+ */
+struct slim_stream_config {
+	unsigned int rate;
+	unsigned int bps;
+	/* MAX 256 channels */
+	unsigned int ch_count;
+	unsigned int *chs;
+	/* Max 32 ports per device */
+	unsigned long port_mask;
+	int direction;
+};
+
 /*
  * use a macro to avoid include chaining to get THIS_MODULE
  */
@@ -163,4 +197,16 @@ int slim_readb(struct slim_device *sdev, u32 addr);
 int slim_writeb(struct slim_device *sdev, u32 addr, u8 value);
 int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
 int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
+
+/* SLIMbus Stream apis */
+struct slim_stream_runtime;
+struct slim_stream_runtime *slim_stream_allocate(struct slim_device *dev,
+						 const char *sname);
+int slim_stream_prepare(struct slim_stream_runtime *stream,
+			struct slim_stream_config *c);
+int slim_stream_enable(struct slim_stream_runtime *stream);
+int slim_stream_disable(struct slim_stream_runtime *stream);
+int slim_stream_unprepare(struct slim_stream_runtime *stream);
+int slim_stream_free(struct slim_stream_runtime *stream);
+
 #endif /* _LINUX_SLIMBUS_H */