[PATCH v2 2/2] ASoC: SOF: amd: Use dedicated MBOX for ACP and PSP communication

[Pierre-Louis Bossart]

From: Ajit Kumar Pandey <AjitKumar.Pandey at amd.com>

We are currently using generic PSP Mailbox register for sending SHA
complete command to PSP but observe random arbitration issue during
PSP validation as MP0_C2PMSG_26_REG used by other kernel modules.

Use separate mailbox registers and doorbell mechanism to send SHA_DMA
complete command to PSP. This fixes such validation issues and added
flexibility for sending more ACP commands to PSP in future as new mbox
registers i.e MP0_C2PMSG_114_REG and MP0_C2PMSG_73_REG are dedicated
by PSP for ACP communications.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao at linux.intel.com>
Signed-off-by: Ajit Kumar Pandey <AjitKumar.Pandey at amd.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/sof/amd/acp.c | 24 +++++++++++++++++++++---
 sound/soc/sof/amd/acp.h |  6 ++++--
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/sound/soc/sof/amd/acp.c b/sound/soc/sof/amd/acp.c
index 8e88ae597fb88..0c272573df979 100644
--- a/sound/soc/sof/amd/acp.c
+++ b/sound/soc/sof/amd/acp.c
@@ -152,7 +152,7 @@ static int psp_mbox_ready(struct acp_dev_data *adata, bool ack)
 
 	for (timeout = ACP_PSP_TIMEOUT_COUNTER; timeout > 0; timeout--) {
 		msleep(20);
-		smn_read(adata->smn_dev, MP0_C2PMSG_26_REG, &data);
+		smn_read(adata->smn_dev, MP0_C2PMSG_114_REG, &data);
 		if (data & MBOX_READY_MASK)
 			return 0;
 	}
@@ -173,17 +173,35 @@ static int psp_mbox_ready(struct acp_dev_data *adata, bool ack)
 
 static int psp_send_cmd(struct acp_dev_data *adata, int cmd)
 {
-	int ret;
+	struct snd_sof_dev *sdev = adata->dev;
+	int ret, timeout;
+	u32 data;
 
 	if (!cmd)
 		return -EINVAL;
 
+	/* Get a non-zero Doorbell value from PSP */
+	for (timeout = ACP_PSP_TIMEOUT_COUNTER; timeout > 0; timeout--) {
+		msleep(MBOX_DELAY);
+		smn_read(adata->smn_dev, MP0_C2PMSG_73_REG, &data);
+		if (data)
+			break;
+	}
+
+	if (!timeout) {
+		dev_err(sdev->dev, "Failed to get Doorbell from MBOX %x\n", MP0_C2PMSG_73_REG);
+		return -EINVAL;
+	}
+
 	/* Check if PSP is ready for new command */
 	ret = psp_mbox_ready(adata, 0);
 	if (ret)
 		return ret;
 
-	smn_write(adata->smn_dev, MP0_C2PMSG_26_REG, cmd);
+	smn_write(adata->smn_dev, MP0_C2PMSG_114_REG, cmd);
+
+	/* Ring the Doorbell for PSP */
+	smn_write(adata->smn_dev, MP0_C2PMSG_73_REG, data);
 
 	/* Check MBOX ready as PSP ack */
 	ret = psp_mbox_ready(adata, 1);
diff --git a/sound/soc/sof/amd/acp.h b/sound/soc/sof/amd/acp.h
index ca69b4969ca22..de526a1bce131 100644
--- a/sound/soc/sof/amd/acp.h
+++ b/sound/soc/sof/amd/acp.h
@@ -57,8 +57,10 @@
 #define ACP_SHA_STAT				0x8000
 #define ACP_PSP_TIMEOUT_COUNTER			5
 #define ACP_EXT_INTR_ERROR_STAT			0x20000000
-#define MP0_C2PMSG_26_REG			0x03810570
-#define MBOX_ACP_SHA_DMA_COMMAND		0x330000
+#define MP0_C2PMSG_114_REG			0x3810AC8
+#define MP0_C2PMSG_73_REG			0x3810A24
+#define MBOX_ACP_SHA_DMA_COMMAND		0x70000
+#define MBOX_DELAY				1000
 #define MBOX_READY_MASK				0x80000000
 #define MBOX_STATUS_MASK			0xFFFF
 
-- 
2.30.2