[PATCH v4 2/3] i3c: master: dw: Map CCC hardware errors to I3C M0/M2

[tze . yee . ng]

From: Adrian Ng Ho Yin <adrian.ho.yin.ng@xxxxxxxxxx>

Map DesignWare response-queue status to ccc->err:

- RESPONSE_ERROR_IBA_NACK -> I3C_ERROR_M2 (broadcast address not ACKed)
- RESPONSE_ERROR_CRC, RESPONSE_ERROR_PARITY, RESPONSE_ERROR_FRAME and
  RESPONSE_ERROR_TRANSF_ABORT -> I3C_ERROR_M0

Per the I3C spec, M2 is the case where the master does not receive ACK
for the broadcast address (7'h7E). Target-address NACK is not reported
as M2.

Return -EIO for RESPONSE_ERROR_ADDRESS_NACK so bus NACKs are not
reported as -EINVAL.

Reset ccc->err to I3C_ERROR_UNKNOWN before each transfer.

Signed-off-by: Adrian Ng Ho Yin <adrian.ho.yin.ng@xxxxxxxxxx>
Signed-off-by: Tze Yee Ng <tze.yee.ng@xxxxxxxxxx>
---
 drivers/i3c/master/dw-i3c-master.c | 32 +++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 856961da1827..c70f6876bd38 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -493,6 +493,7 @@ static void dw_i3c_master_end_xfer_locked(struct dw_i3c_master *master, u32 isr)
 			break;
 		case RESPONSE_ERROR_PARITY:
 		case RESPONSE_ERROR_IBA_NACK:
+		case RESPONSE_ERROR_ADDRESS_NACK:
 		case RESPONSE_ERROR_TRANSF_ABORT:
 		case RESPONSE_ERROR_CRC:
 		case RESPONSE_ERROR_FRAME:
@@ -502,7 +503,6 @@ static void dw_i3c_master_end_xfer_locked(struct dw_i3c_master *master, u32 isr)
 			ret = -ENOSPC;
 			break;
 		case RESPONSE_ERROR_I2C_W_NACK_ERR:
-		case RESPONSE_ERROR_ADDRESS_NACK:
 		default:
 			ret = -EINVAL;
 			break;
@@ -708,12 +708,29 @@ static void dw_i3c_master_bus_cleanup(struct i3c_master_controller *m)
 	dw_i3c_master_disable(master);
 }
 
+static enum i3c_error_code dw_i3c_ccc_map_err(u8 dw_err)
+{
+	switch (dw_err) {
+	case RESPONSE_ERROR_IBA_NACK:
+		return I3C_ERROR_M2;
+	case RESPONSE_ERROR_CRC:
+	case RESPONSE_ERROR_PARITY:
+	case RESPONSE_ERROR_FRAME:
+	case RESPONSE_ERROR_TRANSF_ABORT:
+		return I3C_ERROR_M0;
+	default:
+		return I3C_ERROR_UNKNOWN;
+	}
+}
+
 static int dw_i3c_ccc_set(struct dw_i3c_master *master,
 			  struct i3c_ccc_cmd *ccc)
 {
 	struct dw_i3c_cmd *cmd;
 	int ret, pos = 0;
 
+	ccc->err = I3C_ERROR_UNKNOWN;
+
 	if (ccc->id & I3C_CCC_DIRECT) {
 		pos = dw_i3c_master_get_addr_pos(master, ccc->dests[0].addr);
 		if (pos < 0)
@@ -743,10 +760,7 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
 
 	ret = xfer->ret;
 	cmd = &xfer->cmds[0];
-	if (!ret)
-		ccc->dests[0].payload.actual_len = cmd->rx_len;
-	if (cmd->error == RESPONSE_ERROR_IBA_NACK)
-		ccc->err = I3C_ERROR_M2;
+	ccc->err = dw_i3c_ccc_map_err(cmd->error);
 
 	return ret;
 }
@@ -756,6 +770,8 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
 	struct dw_i3c_cmd *cmd;
 	int ret, pos;
 
+	ccc->err = I3C_ERROR_UNKNOWN;
+
 	pos = dw_i3c_master_get_addr_pos(master, ccc->dests[0].addr);
 	if (pos < 0)
 		return pos;
@@ -783,8 +799,10 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
 		dw_i3c_master_dequeue_xfer(master, xfer);
 
 	ret = xfer->ret;
-	if (xfer->cmds[0].error == RESPONSE_ERROR_IBA_NACK)
-		ccc->err = I3C_ERROR_M2;
+	cmd = &xfer->cmds[0];
+	ccc->err = dw_i3c_ccc_map_err(cmd->error);
+	if (!ret)
+		ccc->dests[0].payload.actual_len = cmd->rx_len;
 
 	return ret;
 }
-- 
2.43.7