[PATCH v2 2/3] arch: mach-k3: j721s2_init: Add workaround for errata i2437

[Udit Kumar <u-kumar1@ti.com>]

From: Neha Malcom Francis <n-francis@ti.com>

Add the workaround proposed for J721S2 errata i2437 (link) for SE
clock-gating turning off too early. Without this, a hardware bug present
in C7120 leads to C7120 CPU hanging.

Link: https://www.ti.com/lit/pdf/sprz530
Signed-off-by: Neha Malcom Francis <n-francis@ti.com>
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
---
 arch/arm/mach-k3/j721s2/j721s2_init.c | 39 +++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/arch/arm/mach-k3/j721s2/j721s2_init.c b/arch/arm/mach-k3/j721s2/j721s2_init.c
index b5453d8895d..780d853423f 100644
--- a/arch/arm/mach-k3/j721s2/j721s2_init.c
+++ b/arch/arm/mach-k3/j721s2/j721s2_init.c
@@ -40,6 +40,15 @@
 #define NB_THREADMAP_BIT1				BIT(1)
 #define NB_THREADMAP_BIT2				BIT(2)
 
+/*
+ * RAT mapping for errata ID: i2437
+ */
+#define RAT_ERRATA_2437_BASE_REGION0		0x40f90000
+#define RAT_ERRATA_2437_IN_ADDR			0xc0000000
+#define RAT_ERRATA_2437_OUT_ADDR_U		0x0000004d
+#define RAT_ERRATA_2437_OUT_ADDR_L		0x21000000
+#define RAT_ERRATA_2437_CTRL			0x80000010
+
 struct fwl_data cbass_hc_cfg0_fwls[] = {
 	{ "PCIE0_CFG", 2577, 7 },
 	{ "EMMC8SS0_CFG", 2579, 4 },
@@ -346,6 +355,36 @@ void board_init_f(ulong dummy)
 		if (ret)
 			printf("AVS init failed: %d\n", ret);
 	}
+
+	if (IS_ENABLED(CONFIG_CPU_V7R)) {
+		/*
+		 * Errata ID i2437: SE Clock-Gating Turning Off Too Early
+		 *
+		 * A hardware bug is present in the C7120 Streaming Engine top level
+		 * clock gating logic that can lead to the C7120 CPU hanging.
+
+		 * Workaround: The DSP_<COREID>_DEBUG_CLKEN_OVERRIDE fields of the
+		 * COMPUTE_CLUSTER_CFG_WRAP_0_CC_CNTRL register (where COREID is the
+		 * name of the specific C7120 core) must be enabled before power-up
+		 * of the C7120 core to override all clock-gating.
+		 */
+
+		/* Setup RAT mapping */
+		debug("Errata i2437: Use RAT for COMPUTE_CLUSTER_CFG_WRAP_0_CC_CNTRL register\n");
+		writel_verify(RAT_ERRATA_2437_IN_ADDR, RAT_ERRATA_2437_BASE_REGION0 + 0x24);
+		writel_verify(RAT_ERRATA_2437_OUT_ADDR_L, RAT_ERRATA_2437_BASE_REGION0 + 0x28);
+		writel_verify(RAT_ERRATA_2437_OUT_ADDR_U, RAT_ERRATA_2437_BASE_REGION0 + 0x2c);
+		writel_verify(RAT_ERRATA_2437_CTRL, RAT_ERRATA_2437_BASE_REGION0 + 0x20);
+
+		/* Enable DSP_X_DEBUG_CLKEN_OVERRIDE for C71x cores */
+		writel_verify(0x300, RAT_ERRATA_2437_IN_ADDR + 0x200);
+
+		/* Clear RAT mapping */
+		writel_verify(0, RAT_ERRATA_2437_BASE_REGION0 + 0x20);
+		writel_verify(0, RAT_ERRATA_2437_BASE_REGION0 + 0x24);
+		writel_verify(0, RAT_ERRATA_2437_BASE_REGION0 + 0x28);
+		writel_verify(0, RAT_ERRATA_2437_BASE_REGION0 + 0x2c);
+	}
 }
 #endif
 
-- 
2.34.1