Thanks for the quick review Randy,
On Wed, Oct 18, 2017 at 08:33:08PM -0700, Randy Dunlap wrote:
On 10/18/17 20:03, Vinod Koul wrote:
+SoundWire is a new interface ratified in 2015 by the MIPI Alliance. +SoundWire is used for transporting data typically related to audio +functions. SoundWire interface is optimized to integrate audio devices in +mobile or mobile inspired systems.
+SoundWire is a 2-Pin multi-drop interface with data and clock line. It
2-pin
ok
+The SoundWire protocol supports up to eleven Slave interfaces. All the +interfaces share the common Bus containing data and clock line. Each of the +Slaves can support up to 14 Data Ports. 13 Data Ports are dedicated to audio +transport. Data Port0 is dedicated to transport of Bulk control information, +each of the audio Data Ports (1..14) can support up to 8 Channels in
(1..13) ??
nope. 1 to 14, both inclusive, thats why 14 Data Ports
+Bus: +Implements SoundWire Linux Bus which handles the SoundWire protocol. +It programs all the MIPI defined Slave registers. It represents a SoundWire
MIPI-defined+Master. There can be multiple instances of Bus maybe present in a system.
eh? Multiple instances of Bus may be present in a system.
sounds better
+int sdw_add_bus_master(struct sdw_bus *bus) +{
if (!bus->dev)return -ENODEV;mutex_init(&bus->lock);INIT_LIST_HEAD(&bus->slaves);- /* Check ACPI for Slave devices */
sdw_acpi_find_slaves(bus);- /* Check DT for Slave devices */
- sdw_of_find_slaves(bus);
Please use same indentation as sdw_acpi_find_slaves().
ah not sure why it came like this, thanks for pointing out
+The MIPI specification requires each Slave interface to expose a unique +48-bit identifier, stored in 6 read only dev_id registers. This dev_id
read-only
right
+identifier, Bus enumerates the Slave device based on the 48-bit identifier. +Slave device and driver match is done based on this 48-bit identifier. Probe +of the Slave driver is called by Bus on successful match between device and +driver id. A parent/child relationship is enforced between Slave and Master
maybe reverse this order............. Master and Slave
to be in the "parent/child" order? Unless I have them backwards?
right, will update this
+devices (the logical representation is aligned with the physical +connectivity).
+The information on Master/Slave dependencies is stored in platform data, +board-file, ACPI or DT. The MIPI Software specification defines an
ok