Thanks Konrad for the review !
On 10/26/2024 12:18 AM, Konrad Dybcio wrote:
On 27.09.2024 8:31 AM, Mukesh Kumar Savaliya wrote:
GSI DMA provides specific TREs namely Lock and Unlock TRE, which
provides mutual exclusive access to SE from any of the subsystem
(E.g. Apps, TZ, ADSP etc). Lock prevents other subsystems from
concurrently performing DMA transfers and avoids disturbance to
data path. Basically for shared SE usecase, lock the SE for
particular subsystem, complete the transfer, unlock the SE.
Apply Lock TRE for the first transfer of shared SE and Apply Unlock
TRE for the last transfer.
Also change MAX_TRE macro to 5 from 3 because of the two additional TREs.
TRE = Transfer Ring Element, refers to the queued descriptor.
SE = Serial Engine
SS = Subsystems (Apps processor, TZ, ADSP, Modem)
Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@xxxxxxxxxxx>
---
drivers/dma/qcom/gpi.c | 37 +++++++++++++++++++++++++++++++-
include/linux/dma/qcom-gpi-dma.h | 6 ++++++
2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
index 52a7c8f2498f..120d91234442 100644
--- a/drivers/dma/qcom/gpi.c
+++ b/drivers/dma/qcom/gpi.c
@@ -2,6 +2,7 @@
/*
* Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
* Copyright (c) 2020, Linaro Limited
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <dt-bindings/dma/qcom-gpi.h>
@@ -65,6 +66,14 @@
/* DMA TRE */
#define TRE_DMA_LEN GENMASK(23, 0)
+/* Lock TRE */
+#define TRE_I2C_LOCK BIT(0)
+#define TRE_MINOR_TYPE GENMASK(19, 16)
+#define TRE_MAJOR_TYPE GENMASK(23, 20)
Is this solely I2C specific?
No, its generic. So i guess i should rename to TRE_LOCK only, we can use
for other protocols in future. Thanks!
Konrad
