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

[Jon Hunter <jonathanh@nvidia.com>]

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@nvidia.com>
> ---
>   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

-- 
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