From ffc363d970d1d04be0f12b2252aa21aaef3ecfd0 Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Thu, 18 May 2023 10:41:18 +0800 Subject: soundwire: intel/cadence: update hardware reset sequence Combining hardware reset with the multi-link mode leads to a shortened hardware reset pattern observed on the bus. The updated hardware programming sequence is to first enable the clock with the sync_arm/sync_go pattern, and only in a second step to issue the hardware reset sequence. Since there is no longer a dependency between sync_arm/sync_go and hw_reset, the behavior of sdw_cdns_exit_reset() is changed to wait for the self-clearing CONFIG_UPDATE to go back to zero, Link: https://github.com/thesofproject/linux/issues/4170 Signed-off-by: Pierre-Louis Bossart Reviewed-by: Rander Wang Signed-off-by: Bard Liao Link: https://lore.kernel.org/r/20230518024119.164160-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul --- drivers/soundwire/cadence_master.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'drivers/soundwire/cadence_master.c') diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 39502bc75712..58686ae50bbf 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -283,6 +283,29 @@ static int cdns_config_update(struct sdw_cdns *cdns) return ret; } +/** + * sdw_cdns_config_update() - Update configurations + * @cdns: Cadence instance + */ +void sdw_cdns_config_update(struct sdw_cdns *cdns) +{ + /* commit changes */ + cdns_writel(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT); +} +EXPORT_SYMBOL(sdw_cdns_config_update); + +/** + * sdw_cdns_config_update_set_wait() - wait until configuration update bit is self-cleared + * @cdns: Cadence instance + */ +int sdw_cdns_config_update_set_wait(struct sdw_cdns *cdns) +{ + /* the hardware recommendation is to wait at least 300us */ + return cdns_set_wait(cdns, CDNS_MCP_CONFIG_UPDATE, + CDNS_MCP_CONFIG_UPDATE_BIT, 0); +} +EXPORT_SYMBOL(sdw_cdns_config_update_set_wait); + /* * debugfs */ @@ -1116,13 +1139,7 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns) CDNS_MCP_CONTROL_HW_RST); /* commit changes */ - cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE, - CDNS_MCP_CONFIG_UPDATE_BIT, - CDNS_MCP_CONFIG_UPDATE_BIT); - - /* don't wait here */ - return 0; - + return cdns_config_update(cdns); } EXPORT_SYMBOL(sdw_cdns_exit_reset); -- cgit v1.2.3