soundwire: cadence: add BTP support for DP0

The register definitions are missing a BULK_ENABLE bitfield which must
be set for DP0.

In addition, the existing mapping from PDI to Data Port is 1:1. That's
fine for PCM streams which are by construction in one direction
only. The BTP/BRA protocol is bidirectional and relies on DP0 only,
which breaks the 1:1 mapping. DP0 MUST be mapped to both PDI0 and
PDI1, with PDI0 taking care of the TX direction and PDI1 of the RX
direction.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: plbossart

drivers/soundwire/cadence_master.c

@@ -184,6 +184,7 @@ MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask");
 #define CDNS_PORTCTRL_TEST_FAILED		BIT(1)
 #define CDNS_PORTCTRL_DIRN			BIT(7)
 #define CDNS_PORTCTRL_BANK_INVERT		BIT(8)
+#define CDNS_PORTCTRL_BULK_ENABLE		BIT(16)
 
 #define CDNS_PORT_OFFSET			0x80
 
@@ -1917,13 +1918,20 @@ void sdw_cdns_config_stream(struct sdw_cdns *cdns,
 
 		if (cdns->bus.params.m_data_mode != SDW_PORT_DATA_MODE_NORMAL)
 			val |= CDNS_PORTCTRL_TEST_FAILED;
+	} else if (pdi->num == 0 || pdi->num == 1) {
+		val |= CDNS_PORTCTRL_BULK_ENABLE;
 	}
 	offset = CDNS_PORTCTRL + pdi->num * CDNS_PORT_OFFSET;
 	cdns_updatel(cdns, offset,
-		     CDNS_PORTCTRL_DIRN | CDNS_PORTCTRL_TEST_FAILED,
+		     CDNS_PORTCTRL_DIRN | CDNS_PORTCTRL_TEST_FAILED |
+		     CDNS_PORTCTRL_BULK_ENABLE,
 		     val);
 
-	val = pdi->num;
+	/* The DataPort0 needs to be mapped to both PDI0 and PDI1 ! */
+	if (pdi->num == 1)
+		val = 0;
+	else
+		val = pdi->num;
 	val |= CDNS_PDI_CONFIG_SOFT_RESET;
 	val |= FIELD_PREP(CDNS_PDI_CONFIG_CHANNEL, (1 << ch) - 1);
 	cdns_writel(cdns, CDNS_PDI_CONFIG(pdi->num), val);