Re: [PATCH 1/2] memory: tegra: Add T238 MC support

From: Jon Hunter

Date: Tue Mar 31 2026 - 07:39:26 EST




On 31/03/2026 12:23, Ashish Mhetre wrote:
Add Memory Controller driver support for Tegra238 SOC, including:
- MC client definitions with Tegra238-specific stream IDs
- Reuse of Tegra234 ICC operations for bandwidth management via BPMP-FW
- Device tree compatible string "nvidia,tegra238-mc"

Export tegra234_mc_icc_ops so it can be shared with the Tegra238 MC
driver, as both SoCs use the same ICC aggregation and bandwidth
management logic.

Signed-off-by: Ashish Mhetre <amhetre@xxxxxxxxxx>
---
drivers/memory/tegra/Makefile | 1 +
drivers/memory/tegra/mc.c | 3 +
drivers/memory/tegra/mc.h | 6 +
drivers/memory/tegra/tegra234.c | 2 +-
drivers/memory/tegra/tegra238.c | 395 ++++++++++++++++++++++++++++++++
5 files changed, 406 insertions(+), 1 deletion(-)
create mode 100644 drivers/memory/tegra/tegra238.c

diff --git a/drivers/memory/tegra/Makefile b/drivers/memory/tegra/Makefile
index 6334601e6120..0d50e37d43af 100644
--- a/drivers/memory/tegra/Makefile
+++ b/drivers/memory/tegra/Makefile
@@ -10,6 +10,7 @@ tegra-mc-$(CONFIG_ARCH_TEGRA_210_SOC) += tegra210.o
tegra-mc-$(CONFIG_ARCH_TEGRA_186_SOC) += tegra186.o
tegra-mc-$(CONFIG_ARCH_TEGRA_194_SOC) += tegra186.o tegra194.o
tegra-mc-$(CONFIG_ARCH_TEGRA_234_SOC) += tegra186.o tegra234.o
+tegra-mc-$(CONFIG_ARCH_TEGRA_238_SOC) += tegra186.o tegra238.o
tegra-mc-$(CONFIG_ARCH_TEGRA_264_SOC) += tegra186.o tegra264.o
obj-$(CONFIG_TEGRA_MC) += tegra-mc.o
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index d620660da331..10ef3c323e22 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -49,6 +49,9 @@ static const struct of_device_id tegra_mc_of_match[] = {
#ifdef CONFIG_ARCH_TEGRA_234_SOC
{ .compatible = "nvidia,tegra234-mc", .data = &tegra234_mc_soc },
#endif
+#ifdef CONFIG_ARCH_TEGRA_238_SOC
+ { .compatible = "nvidia,tegra238-mc", .data = &tegra238_mc_soc },
+#endif

It is always better/preferred for the dt-binding patch to be 1st in the series. The above does not exist until after patch 2 is applied.

#ifdef CONFIG_ARCH_TEGRA_264_SOC
{ .compatible = "nvidia,tegra264-mc", .data = &tegra264_mc_soc },
#endif
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index 649b54369263..d0da4a5f192d 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -238,6 +238,11 @@ extern const struct tegra_mc_soc tegra194_mc_soc;
#ifdef CONFIG_ARCH_TEGRA_234_SOC
extern const struct tegra_mc_soc tegra234_mc_soc;
+extern const struct tegra_mc_icc_ops tegra234_mc_icc_ops;
+#endif
+
+#ifdef CONFIG_ARCH_TEGRA_238_SOC
+extern const struct tegra_mc_soc tegra238_mc_soc;
#endif

Does this work? Tegra238 is dependent upon stuff in Tegra234, but there is no guarantee that both of these CONFIG options are always enabled?

#ifdef CONFIG_ARCH_TEGRA_264_SOC
@@ -256,6 +261,7 @@ extern const struct tegra_mc_ops tegra30_mc_ops;
#if defined(CONFIG_ARCH_TEGRA_186_SOC) || \
defined(CONFIG_ARCH_TEGRA_194_SOC) || \
defined(CONFIG_ARCH_TEGRA_234_SOC) || \
+ defined(CONFIG_ARCH_TEGRA_238_SOC) || \
defined(CONFIG_ARCH_TEGRA_264_SOC)
extern const struct tegra_mc_ops tegra186_mc_ops;
#endif
diff --git a/drivers/memory/tegra/tegra234.c b/drivers/memory/tegra/tegra234.c
index 87b22038a5fb..9fbd34d4abe0 100644
--- a/drivers/memory/tegra/tegra234.c
+++ b/drivers/memory/tegra/tegra234.c
@@ -1125,7 +1125,7 @@ static int tegra234_mc_icc_get_init_bw(struct icc_node *node, u32 *avg, u32 *pea
return 0;
}
-static const struct tegra_mc_icc_ops tegra234_mc_icc_ops = {
+const struct tegra_mc_icc_ops tegra234_mc_icc_ops = {
.xlate = tegra_mc_icc_xlate,
.aggregate = tegra234_mc_icc_aggregate,
.get_bw = tegra234_mc_icc_get_init_bw,
diff --git a/drivers/memory/tegra/tegra238.c b/drivers/memory/tegra/tegra238.c
new file mode 100644
index 000000000000..5abdca16a275
--- /dev/null
+++ b/drivers/memory/tegra/tegra238.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026, NVIDIA CORPORATION. All rights reserved.
+ */

...

+const struct tegra_mc_soc tegra238_mc_soc = {
+ .num_clients = ARRAY_SIZE(tegra238_mc_clients),
+ .clients = tegra238_mc_clients,
+ .num_address_bits = 40,
+ .num_channels = 8,
+ .client_id_mask = 0x1ff,
+ .intmasks = tegra238_mc_intmasks,
+ .num_intmasks = ARRAY_SIZE(tegra238_mc_intmasks),
+ .has_addr_hi_reg = true,
+ .ops = &tegra186_mc_ops,
+ .icc_ops = &tegra234_mc_icc_ops,
+ .ch_intmask = 0x0000ff00,
+ .global_intstatus_channel_shift = 8,
+ /*
+ * Additionally, there are lite carveouts but those are not currently
+ * supported.
+ */

I don't know what this means?

+ .num_carveouts = 32,
+ .regs = &tegra20_mc_regs,
+ .handle_irq = tegra30_mc_irq_handlers,
+ .num_interrupts = ARRAY_SIZE(tegra30_mc_irq_handlers),
+ .mc_addr_hi_mask = 0x3,
+ .mc_err_status_type_mask = (0x7 << 28),
+};

Jon

--
nvpublic