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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2021-05-11 11:00:45 +0800
committerVinod Koul <vkoul@kernel.org>2021-05-11 17:50:32 +0530
commit345e9f5ca798600e44c0843646621f2804eb99f4 (patch)
treeb97dac32a46eb1db980c68ad7260ae0fbb2de5e3 /drivers/soundwire
parent0531e6b60569c71a34a9c5eb9bfbb1559b661cd8 (diff)
soundwire: bus: only use CLOCK_STOP_MODE0 and fix confusions
Existing devices and implementations only support the required CLOCK_STOP_MODE0. All the code related to CLOCK_STOP_MODE1 has not been tested and is highly questionable, with a clear confusion between CLOCK_STOP_MODE1 and the simple clock stop state machine. This patch removes all usages of CLOCK_STOP_MODE1 - which has no impact on any solution - and fixes the use of the simple clock stop state machine. The resulting code should be a lot more symmetrical and easier to maintain. Note that CLOCK_STOP_MODE1 is not supported in the SoundWire Device Class specification so it's rather unlikely that we need to re-add this mode later. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210511030048.25622-2-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
-rw-r--r--drivers/soundwire/bus.c100
1 files changed, 40 insertions, 60 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index a9e0aa72654d..dc4033b6f2e9 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -821,26 +821,6 @@ static void sdw_modify_slave_status(struct sdw_slave *slave,
mutex_unlock(&bus->bus_lock);
}
-static enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave)
-{
- enum sdw_clk_stop_mode mode;
-
- /*
- * Query for clock stop mode if Slave implements
- * ops->get_clk_stop_mode, else read from property.
- */
- if (slave->ops && slave->ops->get_clk_stop_mode) {
- mode = slave->ops->get_clk_stop_mode(slave);
- } else {
- if (slave->prop.clk_stop_mode1)
- mode = SDW_CLK_STOP_MODE1;
- else
- mode = SDW_CLK_STOP_MODE0;
- }
-
- return mode;
-}
-
static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
enum sdw_clk_stop_mode mode,
enum sdw_clk_stop_type type)
@@ -933,7 +913,6 @@ static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
*/
int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
{
- enum sdw_clk_stop_mode slave_mode;
bool simple_clk_stop = true;
struct sdw_slave *slave;
bool is_slave = false;
@@ -955,10 +934,8 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
/* Identify if Slave(s) are available on Bus */
is_slave = true;
- slave_mode = sdw_get_clk_stop_mode(slave);
- slave->curr_clk_stop_mode = slave_mode;
-
- ret = sdw_slave_clk_stop_callback(slave, slave_mode,
+ ret = sdw_slave_clk_stop_callback(slave,
+ SDW_CLK_STOP_MODE0,
SDW_CLK_PRE_PREPARE);
if (ret < 0) {
dev_err(&slave->dev,
@@ -966,22 +943,29 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
return ret;
}
- ret = sdw_slave_clk_stop_prepare(slave,
- slave_mode, true);
- if (ret < 0) {
- dev_err(&slave->dev,
- "pre-prepare failed:%d", ret);
- return ret;
- }
-
- if (slave_mode == SDW_CLK_STOP_MODE1)
+ /* Only prepare a Slave device if needed */
+ if (!slave->prop.simple_clk_stop_capable) {
simple_clk_stop = false;
+
+ ret = sdw_slave_clk_stop_prepare(slave,
+ SDW_CLK_STOP_MODE0,
+ true);
+ if (ret < 0) {
+ dev_err(&slave->dev,
+ "pre-prepare failed:%d", ret);
+ return ret;
+ }
+ }
}
/* Skip remaining clock stop preparation if no Slave is attached */
if (!is_slave)
return ret;
+ /*
+ * Don't wait for all Slaves to be ready if they follow the simple
+ * state machine
+ */
if (!simple_clk_stop) {
ret = sdw_bus_wait_for_clk_prep_deprep(bus,
SDW_BROADCAST_DEV_NUM);
@@ -998,17 +982,13 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
slave->status != SDW_SLAVE_ALERT)
continue;
- slave_mode = slave->curr_clk_stop_mode;
-
- if (slave_mode == SDW_CLK_STOP_MODE1) {
- ret = sdw_slave_clk_stop_callback(slave,
- slave_mode,
- SDW_CLK_POST_PREPARE);
+ ret = sdw_slave_clk_stop_callback(slave,
+ SDW_CLK_STOP_MODE0,
+ SDW_CLK_POST_PREPARE);
- if (ret < 0) {
- dev_err(&slave->dev,
- "post-prepare failed:%d", ret);
- }
+ if (ret < 0) {
+ dev_err(&slave->dev,
+ "post-prepare failed:%d", ret);
}
}
@@ -1059,7 +1039,6 @@ EXPORT_SYMBOL(sdw_bus_clk_stop);
*/
int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
{
- enum sdw_clk_stop_mode mode;
bool simple_clk_stop = true;
struct sdw_slave *slave;
bool is_slave = false;
@@ -1081,31 +1060,33 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
/* Identify if Slave(s) are available on Bus */
is_slave = true;
- mode = slave->curr_clk_stop_mode;
-
- if (mode == SDW_CLK_STOP_MODE1) {
- simple_clk_stop = false;
- continue;
- }
-
- ret = sdw_slave_clk_stop_callback(slave, mode,
+ ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
SDW_CLK_PRE_DEPREPARE);
if (ret < 0)
dev_warn(&slave->dev,
"clk stop deprep failed:%d", ret);
- ret = sdw_slave_clk_stop_prepare(slave, mode,
- false);
+ /* Only de-prepare a Slave device if needed */
+ if (!slave->prop.simple_clk_stop_capable) {
+ simple_clk_stop = false;
- if (ret < 0)
- dev_warn(&slave->dev,
- "clk stop deprep failed:%d", ret);
+ ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
+ false);
+
+ if (ret < 0)
+ dev_warn(&slave->dev,
+ "clk stop deprep failed:%d", ret);
+ }
}
/* Skip remaining clock stop de-preparation if no Slave is attached */
if (!is_slave)
return 0;
+ /*
+ * Don't wait for all Slaves to be ready if they follow the simple
+ * state machine
+ */
if (!simple_clk_stop)
sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
@@ -1117,8 +1098,7 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
slave->status != SDW_SLAVE_ALERT)
continue;
- mode = slave->curr_clk_stop_mode;
- sdw_slave_clk_stop_callback(slave, mode,
+ sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
SDW_CLK_POST_DEPREPARE);
}