soundwire: cadence_master: fix divider setting in clock register

The existing code uses an OR operation which would mix the original
divider setting with the new one, resulting in an invalid
configuration that can make codecs hang.

Add the mask definition and use cdns_updatel to update divider

Signed-off-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190806005522.22642-14-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/cadence_master.c

@@ -58,6 +58,7 @@
 #define CDNS_MCP_SSP_CTRL1			0x28
 #define CDNS_MCP_CLK_CTRL0			0x30
 #define CDNS_MCP_CLK_CTRL1			0x38
+#define CDNS_MCP_CLK_MCLKD_MASK		GENMASK(7, 0)
 
 #define CDNS_MCP_STAT				0x40
 
@@ -842,10 +843,11 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
 
 	/* Set clock divider */
 	divider	= (prop->mclk_freq / prop->max_clk_freq) - 1;
-	val = cdns_readl(cdns, CDNS_MCP_CLK_CTRL0);
-	val |= divider;
-	cdns_writel(cdns, CDNS_MCP_CLK_CTRL0, val);
-	cdns_writel(cdns, CDNS_MCP_CLK_CTRL1, val);
+
+	cdns_updatel(cdns, CDNS_MCP_CLK_CTRL0,
+		     CDNS_MCP_CLK_MCLKD_MASK, divider);
+	cdns_updatel(cdns, CDNS_MCP_CLK_CTRL1,
+		     CDNS_MCP_CLK_MCLKD_MASK, divider);
 
 	/*
 	 * Frame shape changes after initialization have to be done
@@ -895,7 +897,7 @@ int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
 {
 	struct sdw_master_prop *prop = &bus->prop;
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
-	int mcp_clkctrl_off, mcp_clkctrl;
+	int mcp_clkctrl_off;
 	int divider;
 
 	if (!params->curr_dr_freq) {
@@ -912,9 +914,7 @@ int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
 	else
 		mcp_clkctrl_off = CDNS_MCP_CLK_CTRL0;
 
-	mcp_clkctrl = cdns_readl(cdns, mcp_clkctrl_off);
-	mcp_clkctrl |= divider;
-	cdns_writel(cdns, mcp_clkctrl_off, mcp_clkctrl);
+	cdns_updatel(cdns, mcp_clkctrl_off, CDNS_MCP_CLK_MCLKD_MASK, divider);
 
 	return 0;
 }