soundwire: cadence: make SSP interval programmable

In multi-master mode, the IP will only accept SSP intervals with
integer relationships between the frame rate and the gsync frequency.

E.g for a 48kHz frame rate and 4 kHz gsync signal, the SSP interval
can only be 1, 2, 3, 4, 6, 12.

To simplify we only allow one SSP per gsync interval.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200317163329.25501-11-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 fb697ff..7733415 100644 (file)
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -183,7 +183,6 @@ MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask");
 #define CDNS_PDI_CONFIG_PORT                   GENMASK(4, 0)
 
 /* Driver defaults */
-#define CDNS_DEFAULT_SSP_INTERVAL              0x18
 #define CDNS_TX_TIMEOUT                                2000
 
 #define CDNS_SCP_RX_FIFOLEVEL                  0x2
@@ -1048,6 +1047,7 @@ static void cdns_init_clock_ctrl(struct sdw_cdns *cdns)
        struct sdw_bus *bus = &cdns->bus;
        struct sdw_master_prop *prop = &bus->prop;
        u32 val;
+       u32 ssp_interval;
        int divider;
 
        /* Set clock divider */
@@ -1067,8 +1067,9 @@ static void cdns_init_clock_ctrl(struct sdw_cdns *cdns)
        cdns_writel(cdns, CDNS_MCP_FRAME_SHAPE_INIT, val);
 
        /* Set SSP interval to default value */
-       cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, CDNS_DEFAULT_SSP_INTERVAL);
-       cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, CDNS_DEFAULT_SSP_INTERVAL);
+       ssp_interval = prop->default_frame_rate / SDW_CADENCE_GSYNC_HZ;
+       cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, ssp_interval);
+       cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, ssp_interval);
 }
 
 /**

diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index e8fa5c7..b410656 100644 (file)
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -5,6 +5,9 @@
 #ifndef __SDW_CADENCE_H
 #define __SDW_CADENCE_H
 
+#define SDW_CADENCE_GSYNC_KHZ          4 /* 4 kHz */
+#define SDW_CADENCE_GSYNC_HZ           (SDW_CADENCE_GSYNC_KHZ * 1000)
+
 /**
  * struct sdw_cdns_pdi: PDI (Physical Data Interface) instance
  *