soundwire: cadence: add interface to check clock status

If master is in clock stop state, driver can't modify registers
in master except the registers for clock stop setting.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200317163329.25501-4-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 941809e..1bfdc1d 100644 (file)
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -1208,6 +1208,17 @@ static const struct sdw_master_port_ops cdns_port_ops = {
 };
 
 /**
+ * sdw_cdns_is_clock_stop: Check clock status
+ *
+ * @cdns: Cadence instance
+ */
+bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns)
+{
+       return !!(cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP);
+}
+EXPORT_SYMBOL(sdw_cdns_is_clock_stop);
+
+/**
  * sdw_cdns_probe() - Cadence probe routine
  * @cdns: Cadence instance
  */

diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index 44e802b..691faa3 100644 (file)
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -144,6 +144,8 @@ int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
 int sdw_cdns_exit_reset(struct sdw_cdns *cdns);
 int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state);
 
+bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns);
+
 #ifdef CONFIG_DEBUG_FS
 void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root);
 #endif