soundwire: cadence_master: make clock stop exit configurable on init

The use of clock stop is not a requirement, the IP can e.g. be
completely power gated and not detect any wakes while in s2idle/deep
sleep.

For now clock-stop is not supported anyways so the control parameter
is always false. This will be revisited when we add clock stop.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191022235448.17586-6-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/cadence_master.c

@@ -979,7 +979,7 @@ static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols)
  * sdw_cdns_init() - Cadence initialization
  * @cdns: Cadence instance
  */
-int sdw_cdns_init(struct sdw_cdns *cdns)
+int sdw_cdns_init(struct sdw_cdns *cdns, bool clock_stop_exit)
 {
 	struct sdw_bus *bus = &cdns->bus;
 	struct sdw_master_prop *prop = &bus->prop;
@@ -987,12 +987,13 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
 	int divider;
 	int ret;
 
-	/* Exit clock stop */
-	ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL,
-			     CDNS_MCP_CONTROL_CLK_STOP_CLR);
-	if (ret < 0) {
-		dev_err(cdns->dev, "Couldn't exit from clock stop\n");
-		return ret;
+	if (clock_stop_exit) {
+		ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL,
+				     CDNS_MCP_CONTROL_CLK_STOP_CLR);
+		if (ret < 0) {
+			dev_err(cdns->dev, "Couldn't exit from clock stop\n");
+			return ret;
+		}
 	}
 
 	/* Set clock divider */

drivers/soundwire/cadence_master.h

@@ -138,7 +138,7 @@ extern struct sdw_master_ops sdw_cdns_master_ops;
 irqreturn_t sdw_cdns_irq(int irq, void *dev_id);
 irqreturn_t sdw_cdns_thread(int irq, void *dev_id);
 
-int sdw_cdns_init(struct sdw_cdns *cdns);
+int sdw_cdns_init(struct sdw_cdns *cdns, bool clock_stop_exit);
 int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
 		      struct sdw_cdns_stream_config config);
 int sdw_cdns_exit_reset(struct sdw_cdns *cdns);

drivers/soundwire/intel.c

@@ -903,7 +903,7 @@ static int intel_init(struct sdw_intel *sdw)
 	intel_link_power_up(sdw);
 	intel_shim_init(sdw);
 
-	return sdw_cdns_init(&sdw->cdns);
+	return sdw_cdns_init(&sdw->cdns, false);
 }
 
 /*