[alsa-devel] [RFC PATCH 26/40] soundwire: cadence_master: fix divider setting in clock register

[Pierre-Louis Bossart]

From: Rander Wang <rander.wang at linux.intel.com>

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 at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 10ebcef2e84e..18c6ac026e85 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -57,6 +57,7 @@
 #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
 
@@ -988,9 +989,11 @@ 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);
 
 	pr_err("plb: mclk %d max_freq %d divider %d register %x\n",
 	       prop->mclk_freq,
@@ -1064,8 +1067,7 @@ int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
 		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);
 
 	pr_err("plb: mclk * 2 %d curr_dr_freq %d divider %d register %x\n",
 	       prop->mclk_freq * SDW_DOUBLE_RATE_FACTOR,
-- 
2.20.1