[PATCH] imx8m: lock id_swap_bypass bit in tzc380 enable

[Andrey Zhizhikin]

According to TRM for i.MX8M Nano and Plus, GPR10 register contains lock
bit for TZASC_ID_SWAP_BYPASS bit. This bit is required to be set in
order to avoid AXI bus errors when GPU is enabled on the platform.
TZASC_ID_SWAP_BYPASS bit is alread set for all imx8m applicable
derivatives, but is missing a lock settings to be applied.

Set the TZASC_ID_SWAP_BYPASS_LOCK bit for those derivatives which have
it implemented.

Since we're here, provide also names to bits from TRM instead of using
BIT() macro in the code.

Fixes: deca6cfbf5d7 ("imx8mn: set BYPASS ID SWAP to avoid AXI bus errors")
Fixes: a07c7181296f ("imx8mp: set BYPASS ID SWAP to avoid AXI bus errors")
Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin at leica-geosystems.com>
Cc: Peng Fan <peng.fan at nxp.com>
---
 arch/arm/include/asm/arch-imx8m/imx-regs.h |  6 ++++--
 arch/arm/mach-imx/imx8m/soc.c              | 15 ++++++++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/arch-imx8m/imx-regs.h b/arch/arm/include/asm/arch-imx8m/imx-regs.h
index b800da13a1..45d95a7c19 100644
--- a/arch/arm/include/asm/arch-imx8m/imx-regs.h
+++ b/arch/arm/include/asm/arch-imx8m/imx-regs.h
@@ -80,8 +80,10 @@
 #include <linux/bitops.h>
 #include <stdbool.h>
 
-#define GPR_TZASC_EN		BIT(0)
-#define GPR_TZASC_EN_LOCK	BIT(16)
+#define GPR_TZASC_EN					BIT(0)
+#define GPR_TZASC_ID_SWAP_BYPASS		BIT(1)
+#define GPR_TZASC_EN_LOCK				BIT(16)
+#define GPR_TZASC_ID_SWAP_BYPASS_LOCK	BIT(17)
 
 #define SRC_SCR_M4_ENABLE_OFFSET	3
 #define SRC_SCR_M4_ENABLE_MASK		BIT(3)
diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index 863508776d..5f5175b4dd 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -66,8 +66,21 @@ void enable_tzc380(void)
 	/* Enable TZASC and lock setting */
 	setbits_le32(&gpr->gpr[10], GPR_TZASC_EN);
 	setbits_le32(&gpr->gpr[10], GPR_TZASC_EN_LOCK);
+
+	/*
+	 * According to TRM, TZASC_ID_SWAP_BYPASS should be set in
+	 * order to avoid AXI Bus errors when GPU is in use
+	 */
 	if (is_imx8mm() || is_imx8mn() || is_imx8mp())
-		setbits_le32(&gpr->gpr[10], BIT(1));
+		setbits_le32(&gpr->gpr[10], GPR_TZASC_ID_SWAP_BYPASS);
+
+	/*
+	 * imx8mn and imx8mp implements the lock bit for
+	 * TZASC_ID_SWAP_BYPASS, enable it to lock settings
+	 */
+	if (is_imx8mn() || is_imx8mp())
+		setbits_le32(&gpr->gpr[10], GPR_TZASC_ID_SWAP_BYPASS_LOCK);
+
 	/*
 	 * set Region 0 attribute to allow secure and non-secure
 	 * read/write permission. Found some masters like usb dwc3

base-commit: 21a1439d986a889cefbc2ed785c3f592fc9266de
-- 
2.25.1