From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

[ Upstream commit 345e9f5ca798600e44c0843646621f2804eb99f4 ]

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... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/soundwire/bus.c | 100 ++++++++++++++-------------------- include/linux/soundwire/sdw.h | 2 - 2 files changed, 40 insertions(+), 62 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); }

diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index ced07f8fde87..5d93d9949653 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -624,7 +624,6 @@ struct sdw_slave_ops { int (*port_prep)(struct sdw_slave *slave, struct sdw_prepare_ch *prepare_ch, enum sdw_port_prep_ops pre_ops); - int (*get_clk_stop_mode)(struct sdw_slave *slave); int (*clk_stop)(struct sdw_slave *slave, enum sdw_clk_stop_mode mode, enum sdw_clk_stop_type type); @@ -675,7 +674,6 @@ struct sdw_slave { struct list_head node; struct completion port_ready[SDW_MAX_PORTS]; unsigned int m_port_map[SDW_MAX_PORTS]; - enum sdw_clk_stop_mode curr_clk_stop_mode; u16 dev_num; u16 dev_num_sticky; bool probed;