* [PATCH] i3c: master: dw-i3c-master: Add HDR-DDR support to Designware Controller.
@ 2026-10-13 7:31 Dineshkumar Parameswaran
2026-11-01 0:52 ` [PATCH v2] " Dineshkumar Parameswaran
0 siblings, 1 reply; 2+ messages in thread
From: Dineshkumar Parameswaran @ 2026-10-13 7:31 UTC (permalink / raw)
To: linux-i3c
Cc: alexandre.belloni, Frank.Li, linux-kernel, Dineshkumar Parameswaran
Implement HDR-DDR transfer support for the DesignWare Controller.
Only support for private transfers and does not support sending CCC
commands in HDR mode.
Key differences:
- Sends ENTHDR CCC for entering to HDR-DDR mode before sending data.
To do that we are setting the ENTHDR in controller cmd. Sets the speed
to HDR_DDR_SPEED(6) to do data transfer in HDR-DDR mode.
- HDR exit pattern must be sent instead of send a stop after transfer
completion.
Signed-off-by: Dineshkumar Parameswaran <parame@synopsys.com>
---
drivers/i3c/master/dw-i3c-master.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 05584ddaf104..58c54746bbe5 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -232,6 +232,8 @@
#define I3C_BUS_I2C_FMP_TLOW_MIN_NS 500
#define I3C_BUS_THIGH_MAX_NS 41
+#define DW_I3C_HDR_DDR_SPEED 6
+
#define XFER_TIMEOUT (msecs_to_jiffies(1000))
#define RPM_AUTOSUSPEND_TIMEOUT 1000 /* ms */
@@ -1017,6 +1019,11 @@ static int dw_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
COMMAND_PORT_DEV_INDEX(data->index) |
COMMAND_PORT_ROC;
+ if (mode == I3C_HDR_DDR)
+ cmd->cmd_lo |= COMMAND_PORT_CP |
+ COMMAND_PORT_CMD(I3C_CCC_ENTHDR(0)) |
+ COMMAND_PORT_SPEED(DW_I3C_HDR_DDR_SPEED);
+
if (i == (i3c_nxfers - 1))
cmd->cmd_lo |= COMMAND_PORT_TOC;
}
--
2.34.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH v2] i3c: master: dw-i3c-master: Add HDR-DDR support to Designware Controller.
2026-10-13 7:31 [PATCH] i3c: master: dw-i3c-master: Add HDR-DDR support to Designware Controller Dineshkumar Parameswaran
@ 2026-11-01 0:52 ` Dineshkumar Parameswaran
0 siblings, 0 replies; 2+ messages in thread
From: Dineshkumar Parameswaran @ 2026-11-01 0:52 UTC (permalink / raw)
To: Dineshkumar.Parameswaran
Cc: Frank.Li, alexandre.belloni, linux-i3c, linux-kernel,
Dineshkumar Parameswaran
Implement HDR-DDR transfer support for the DesignWare Controller.
Only support for private transfers and does not support sending CCC
commands in HDR mode.
Key differences:
- Sends ENTHDR CCC for entering to HDR-DDR mode before sending data.
To do that we are setting the ENTHDR in controller cmd. Sets the speed
to HDR_DDR_SPEED(6) to do data transfer in HDR-DDR mode.
- HDR exit pattern must be sent instead of send a stop after transfer
completion.
Signed-off-by: Dineshkumar Parameswaran <parame@synopsys.com>
---
changes in v2:
- Add HDR-DDR capability advertisement in dw_i3c_master_bus_init()
- ENTHDR0 CCC is generated by the hardware. No need to put that in the
command.
- Fix the speed field corruption in COMMAND_PORT_SPEED.
drivers/i3c/master/dw-i3c-master.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 05584ddaf104..149982a05477 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -232,6 +232,8 @@
#define I3C_BUS_I2C_FMP_TLOW_MIN_NS 500
#define I3C_BUS_THIGH_MAX_NS 41
+#define DW_I3C_HDR_DDR_SPEED 6
+
#define XFER_TIMEOUT (msecs_to_jiffies(1000))
#define RPM_AUTOSUSPEND_TIMEOUT 1000 /* ms */
@@ -726,6 +728,8 @@ static int dw_i3c_master_bus_init(struct i3c_master_controller *m)
memset(&info, 0, sizeof(info));
info.dyn_addr = ret;
+ info.hdr_cap = I3C_CCC_HDR_MODE(I3C_HDR_DDR);
+
ret = i3c_master_set_info(&master->base, &info);
if (ret)
goto rpm_out;
@@ -1003,20 +1007,25 @@ static int dw_i3c_master_i3c_xfers(struct i3c_dev_desc *dev,
if (i3c_xfers[i].rnw) {
cmd->rx_buf = i3c_xfers[i].data.in;
cmd->rx_len = i3c_xfers[i].len;
- cmd->cmd_lo = COMMAND_PORT_READ_TRANSFER |
- COMMAND_PORT_SPEED(dev->info.max_read_ds);
+ cmd->cmd_lo = COMMAND_PORT_READ_TRANSFER;
} else {
cmd->tx_buf = i3c_xfers[i].data.out;
cmd->tx_len = i3c_xfers[i].len;
- cmd->cmd_lo =
- COMMAND_PORT_SPEED(dev->info.max_write_ds);
}
cmd->cmd_lo |= COMMAND_PORT_TID(i) |
COMMAND_PORT_DEV_INDEX(data->index) |
COMMAND_PORT_ROC;
+ if (mode == I3C_HDR_DDR)
+ cmd->cmd_lo |= COMMAND_PORT_CP |
+ COMMAND_PORT_SPEED(DW_I3C_HDR_DDR_SPEED);
+ else
+ cmd->cmd_lo |= (i3c_xfers[i].rnw) ?
+ COMMAND_PORT_SPEED(dev->info.max_read_ds) :
+ COMMAND_PORT_SPEED(dev->info.max_write_ds);
+
if (i == (i3c_nxfers - 1))
cmd->cmd_lo |= COMMAND_PORT_TOC;
}
--
2.34.1
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-11-01 0:53 UTC | newest]
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2026-11-01 0:52 ` [PATCH v2] " Dineshkumar Parameswaran
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