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author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2021-05-11 11:00:45 +0800 |
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committer | Vinod Koul <vkoul@kernel.org> | 2021-05-11 17:50:32 +0530 |
commit | 345e9f5ca798600e44c0843646621f2804eb99f4 (patch) | |
tree | b97dac32a46eb1db980c68ad7260ae0fbb2de5e3 /drivers/soundwire/bus.c | |
parent | 0531e6b60569c71a34a9c5eb9bfbb1559b661cd8 (diff) | |
download | lwn-345e9f5ca798600e44c0843646621f2804eb99f4.tar.gz lwn-345e9f5ca798600e44c0843646621f2804eb99f4.zip |
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/bus.c')
-rw-r--r-- | drivers/soundwire/bus.c | 100 |
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); } |