[PATCH v2] remoteproc/mediatek: set to DEVAPC domain 3 for MT8192 SCP

[Tzung-Bi Shih]

DEVAPC (device access permission control) is a MPU (memory protection
unit) in MT8192.

To restrict SCP accesses to a specific memory range, sets SCP to DEVAPC
domain 3.  ATF (Arm trusted firmware) should setup memory range for the
domain.

Co-developed-by: Tinghan Shen <tinghan.shen at mediatek.com>
Signed-off-by: Tinghan Shen <tinghan.shen at mediatek.com>
Signed-off-by: Tzung-Bi Shih <tzungbi at google.com>
---
Changes from v1:
- Add "Co-developed-by" tag.

 drivers/remoteproc/mtk_common.h | 2 ++
 drivers/remoteproc/mtk_scp.c    | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index 61901f5efa05..2aa9fdf5e59b 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -51,6 +51,8 @@
 #define MT8192_CORE0_WDT_IRQ		0x10030
 #define MT8192_CORE0_WDT_CFG		0x10034
 
+#define MT8192_SCP_DEVAPC_DOMAIN	0x85080
+
 #define SCP_FW_VER_LEN			32
 #define SCP_SHARE_BUFFER_SIZE		288
 
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 9679cc26895e..50bdec5a97e3 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -374,6 +374,9 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
 	/* enable MPU for all memory regions */
 	writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF);
 
+	/* set to DEVAPC (device access permission control) domain 3 */
+	writel(3, scp->reg_base + MT8192_SCP_DEVAPC_DOMAIN);
+
 	return 0;
 }
 
-- 
2.31.0.rc2.261.g7f71774620-goog