[PATCH 7/9] ARM: tegra: Support EMC frequency tables on Tegra210

Thierry Reding thierry.reding at gmail.com
Fri Sep 3 15:16:23 CEST 2021


From: Thierry Reding <treding at nvidia.com>

The EMC frequency tables are created from a training sequence performed
during early boot and passed in via a reserved memory region by nvtboot.
Copy this table to the kernel DTB so that the kernel can use it to scale
the EMC frequency at runtime.

Note that early bootloaders store the EMC table at an address that
currently intersects with the load address of the initial ramdisk. In
order to avoid copying the table to a different address, simply change
the load address for the initial ramdisk in U-Boot.

Signed-off-by: Thierry Reding <treding at nvidia.com>
---
 board/nvidia/p2371-2180/p2371-2180.c | 1 +
 board/nvidia/p3450-0000/p3450-0000.c | 1 +
 include/configs/tegra210-common.h    | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/board/nvidia/p2371-2180/p2371-2180.c b/board/nvidia/p2371-2180/p2371-2180.c
index f5126c552b00..cd5dc2de629e 100644
--- a/board/nvidia/p2371-2180/p2371-2180.c
+++ b/board/nvidia/p2371-2180/p2371-2180.c
@@ -183,6 +183,7 @@ static void ft_carveout_setup(void *fdt)
 	static const char * const nodes[] = {
 		"/host1x at 50000000/dc at 54200000",
 		"/host1x at 50000000/dc at 54240000",
+		"/external-memory-controller at 7001b000",
 	};
 	unsigned int i;
 	int err;
diff --git a/board/nvidia/p3450-0000/p3450-0000.c b/board/nvidia/p3450-0000/p3450-0000.c
index 2c709d9b8117..dd408d2ebbf8 100644
--- a/board/nvidia/p3450-0000/p3450-0000.c
+++ b/board/nvidia/p3450-0000/p3450-0000.c
@@ -183,6 +183,7 @@ static void ft_carveout_setup(void *fdt)
 	static const char * const nodes[] = {
 		"/host1x at 50000000/dc at 54200000",
 		"/host1x at 50000000/dc at 54240000",
+		"/external-memory-controller at 7001b000",
 	};
 	unsigned int i;
 	int err;
diff --git a/include/configs/tegra210-common.h b/include/configs/tegra210-common.h
index 2226effe16ab..c38d0f831835 100644
--- a/include/configs/tegra210-common.h
+++ b/include/configs/tegra210-common.h
@@ -48,7 +48,7 @@
 	"kernel_addr_r=" __stringify(CONFIG_LOADADDR) "\0" \
 	"fdtfile=" FDTFILE "\0" \
 	"fdt_addr_r=0x83000000\0" \
-	"ramdisk_addr_r=0x83200000\0"
+	"ramdisk_addr_r=0x83420000\0"
 
 /* For USB EHCI controller */
 #define CONFIG_EHCI_IS_TDI
-- 
2.33.0



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