[RFC PATCH 09/40] soundwire: cadence_master: fix usage of CONFIG_UPDATE

Pierre-Louis Bossart
2019-07-25T23:43:24Z

Per the hardware documentation, all changes to MCP_CONFIG,
MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL need to be validated with a
self-clearing write to MCP_CONFIG_UPDATE.

For some reason, the existing code only does this write to
CONFIG_UPDATE when enabling interrupts. Add a helper and do the update
when the CONFIG is changed.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
drivers/soundwire/cadence_master.c | 29 +++++++++++++++++++++--------
1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 9f611a1fff0a..eb46cf651d62 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -224,6 +224,22 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
return -EAGAIN;
}

+/*
+ * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL
+ * need to be confirmed with a write to MCP_CONFIG_UPDATE
+ */
+static int cdns_update_config(struct sdw_cdns *cdns)
+{
+ int ret;
+
+ ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE,
+ CDNS_MCP_CONFIG_UPDATE_BIT);
+ if (ret < 0)
+ dev_err(cdns->dev, "Config update timedout\n");
+
+ return ret;
+}
+
/*
* debugfs
*/
@@ -758,15 +774,9 @@ static int _cdns_enable_interrupt(struct sdw_cdns *cdns)
*/
int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns)
{
- int ret;
-
_cdns_enable_interrupt(cdns);
- ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE,
- CDNS_MCP_CONFIG_UPDATE_BIT);
- if (ret < 0)
- dev_err(cdns->dev, "Config update timedout\n");

- return ret;
+ return 0;
}
EXPORT_SYMBOL(sdw_cdns_enable_interrupt);

@@ -943,7 +953,10 @@ int sdw_cdns_init(struct sdw_cdns *cdns)

cdns_writel(cdns, CDNS_MCP_CONFIG, val);

- return 0;
+ /* commit changes */
+ ret = cdns_update_config(cdns);
+
+ return ret;
}
EXPORT_SYMBOL(sdw_cdns_init);

--
2.20.1