Skip to content

Commit

Permalink
soundwire: mipi-disco: add support for DP0/DPn 'lane-list' property
Browse files Browse the repository at this point in the history
The SoundWire specification did not clearly require that ports could
use all Lanes. Some SoundWire/SDCA peripheral adopters added
restrictions on which lanes can be used by what port, and the DisCo
for SoundWire 2.1 specification added a 'lane-list' property to model
this hardware limitation.

When not specified, the ports can use all Lanes. Otherwise, the
'lane-list' indicates which Lanes can be used, sorted by order of
preference (most-preferred-first).

This patch only reads the properties, the use of this property will
come at a later time with multi-lane support.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
  • Loading branch information
plbossart committed May 10, 2024
1 parent da5fe6b commit d94da24
Show file tree
Hide file tree
Showing 2 changed files with 40 additions and 0 deletions.
32 changes: 32 additions & 0 deletions drivers/soundwire/mipi_disco.c
Original file line number Diff line number Diff line change
Expand Up @@ -177,6 +177,22 @@ static int sdw_slave_read_dp0(struct sdw_slave *slave,
dp0->imp_def_interrupts = fwnode_property_read_bool(port,
"mipi-sdw-imp-def-dp0-interrupts-supported");

nval = fwnode_property_count_u32(port, "mipi-sdw-lane-list");
if (nval > 0) {
dp0->num_lanes = nval;
dp0->lane_list = devm_kcalloc(&slave->dev,
dp0->num_lanes, sizeof(*dp0->lane_list),
GFP_KERNEL);
if (!dp0->lane_list)
return -ENOMEM;

ret = fwnode_property_read_u32_array(port,
"mipi-sdw-lane-list",
dp0->lane_list, dp0->num_lanes);
if (ret < 0)
return ret;
}

return 0;
}

Expand Down Expand Up @@ -306,6 +322,22 @@ static int sdw_slave_read_dpn(struct sdw_slave *slave,
fwnode_property_read_u32(node, "mipi-sdw-port-encoding-type",
&dpn[i].port_encoding);

nval = fwnode_property_count_u32(node, "mipi-sdw-lane-list");
if (nval > 0) {
dpn[i].num_lanes = nval;
dpn[i].lane_list = devm_kcalloc(&slave->dev,
dpn[i].num_lanes, sizeof(*dpn[i].lane_list),
GFP_KERNEL);
if (!dpn[i].lane_list)
return -ENOMEM;

ret = fwnode_property_read_u32_array(node,
"mipi-sdw-lane-list",
dpn[i].lane_list, dpn[i].num_lanes);
if (ret < 0)
return ret;
}

fwnode_handle_put(node);

i++;
Expand Down
8 changes: 8 additions & 0 deletions include/linux/soundwire/sdw.h
Original file line number Diff line number Diff line change
Expand Up @@ -238,6 +238,8 @@ enum sdw_clk_stop_mode {
* @ch_prep_timeout: Port-specific timeout value, in milliseconds
* @imp_def_interrupts: If set, each bit corresponds to support for
* implementation-defined interrupts
* @num_lanes: array size of @lane_list
* @lane_list: indicates which Lanes can be used by DP0
*
* The wordlengths are specified by Spec as max, min AND number of
* discrete values, implementation can define based on the wordlengths they
Expand All @@ -252,6 +254,8 @@ struct sdw_dp0_prop {
bool simple_ch_prep_sm;
u32 ch_prep_timeout;
bool imp_def_interrupts;
int num_lanes;
u32 *lane_list;
};

/**
Expand Down Expand Up @@ -283,6 +287,8 @@ struct sdw_dp0_prop {
* @block_pack_mode: Type of block port mode supported
* @read_only_wordlength: Read Only wordlength field in DPN_BlockCtrl1 register
* @port_encoding: Payload Channel Sample encoding schemes supported
* @num_lanes: array size of @lane_list
* @lane_list: indicates which Lanes can be used by DPn
*/
struct sdw_dpn_prop {
u32 num;
Expand All @@ -306,6 +312,8 @@ struct sdw_dpn_prop {
bool block_pack_mode;
bool read_only_wordlength;
u32 port_encoding;
int num_lanes;
u32 *lane_list;
};

/**
Expand Down

0 comments on commit d94da24

Please sign in to comment.