Re: [PATCH v4 07/10] memory: tegra: Introduce Tegra30 EMC driver

Thierry Reding
2019-06-17T09:50:48Z

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On Mon, Jun 17, 2019 at 02:35:48AM +0300, Dmitry Osipenko wrote:
> Introduce driver for the External Memory Controller (EMC) found on Tegra30
> chips, it controls the external DRAM on the board. The purpose of this
> driver is to program memory timing for external memory on the EMC clock
> rate change.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/memory/tegra/Kconfig | 10 +
> drivers/memory/tegra/Makefile | 1 +
> drivers/memory/tegra/mc.c | 9 +-
> drivers/memory/tegra/mc.h | 30 +-
> drivers/memory/tegra/tegra30-emc.c | 1197 ++++++++++++++++++++++++++++
> drivers/memory/tegra/tegra30.c | 44 +
> include/soc/tegra/mc.h | 2 +-
> 7 files changed, 1278 insertions(+), 15 deletions(-)
> create mode 100644 drivers/memory/tegra/tegra30-emc.c
>
> diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
> index 4680124ddcab..fbfbaada61a2 100644
> --- a/drivers/memory/tegra/Kconfig
> +++ b/drivers/memory/tegra/Kconfig
> @@ -17,6 +17,16 @@ config TEGRA20_EMC
> This driver is required to change memory timings / clock rate for
> external memory.
>
> +config TEGRA30_EMC
> + bool "NVIDIA Tegra30 External Memory Controller driver"
> + default y
> + depends on TEGRA_MC && ARCH_TEGRA_3x_SOC
> + help
> + This driver is for the External Memory Controller (EMC) found on
> + Tegra30 chips. The EMC controls the external DRAM on the board.
> + This driver is required to change memory timings / clock rate for
> + external memory.
> +
> config TEGRA124_EMC
> bool "NVIDIA Tegra124 External Memory Controller driver"
> default y
> diff --git a/drivers/memory/tegra/Makefile b/drivers/memory/tegra/Makefile
> index 3971a6b7c487..3d23c4261104 100644
> --- a/drivers/memory/tegra/Makefile
> +++ b/drivers/memory/tegra/Makefile
> @@ -11,5 +11,6 @@ tegra-mc-$(CONFIG_ARCH_TEGRA_210_SOC) += tegra210.o
> obj-$(CONFIG_TEGRA_MC) += tegra-mc.o
>
> obj-$(CONFIG_TEGRA20_EMC) += tegra20-emc.o
> +obj-$(CONFIG_TEGRA30_EMC) += tegra30-emc.o
> obj-$(CONFIG_TEGRA124_EMC) += tegra124-emc.o
> obj-$(CONFIG_ARCH_TEGRA_186_SOC) += tegra186.o
> diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
> index 163b6c69e651..eaebe371625c 100644
> --- a/drivers/memory/tegra/mc.c
> +++ b/drivers/memory/tegra/mc.c
> @@ -51,9 +51,6 @@
> #define MC_EMEM_ADR_CFG 0x54
> #define MC_EMEM_ADR_CFG_EMEM_NUMDEV BIT(0)
>
> -#define MC_TIMING_CONTROL 0xfc
> -#define MC_TIMING_UPDATE BIT(0)
> -
> static const struct of_device_id tegra_mc_of_match[] = {
> #ifdef CONFIG_ARCH_TEGRA_2x_SOC
> { .compatible = "nvidia,tegra20-mc-gart", .data = &tegra20_mc_soc },
> @@ -310,7 +307,7 @@ static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
> return 0;
> }
>
> -void tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
> +int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
> {
> unsigned int i;
> struct tegra_mc_timing *timing = NULL;
> @@ -325,11 +322,13 @@ void tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
> if (!timing) {
> dev_err(mc->dev, "no memory timing registered for rate %lu\n",
> rate);
> - return;
> + return -EINVAL;
> }
>
> for (i = 0; i < mc->soc->num_emem_regs; ++i)
> mc_writel(mc, timing->emem_data[i], mc->soc->emem_regs[i]);
> +
> + return 0;
> }
>
> unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
> diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
> index 392993955c93..0720a1d2023e 100644
> --- a/drivers/memory/tegra/mc.h
> +++ b/drivers/memory/tegra/mc.h
> @@ -9,20 +9,32 @@
> #ifndef MEMORY_TEGRA_MC_H
> #define MEMORY_TEGRA_MC_H
>
> +#include <linux/bits.h>
> #include <linux/io.h>
> #include <linux/types.h>
>
> #include <soc/tegra/mc.h>
>
> -#define MC_INT_DECERR_MTS (1 << 16)
> -#define MC_INT_SECERR_SEC (1 << 13)
> -#define MC_INT_DECERR_VPR (1 << 12)
> -#define MC_INT_INVALID_APB_ASID_UPDATE (1 << 11)
> -#define MC_INT_INVALID_SMMU_PAGE (1 << 10)
> -#define MC_INT_ARBITRATION_EMEM (1 << 9)
> -#define MC_INT_SECURITY_VIOLATION (1 << 8)
> -#define MC_INT_INVALID_GART_PAGE (1 << 7)
> -#define MC_INT_DECERR_EMEM (1 << 6)
> +#define MC_INT_DECERR_MTS BIT(16)
> +#define MC_INT_SECERR_SEC BIT(13)
> +#define MC_INT_DECERR_VPR BIT(12)
> +#define MC_INT_INVALID_APB_ASID_UPDATE BIT(11)
> +#define MC_INT_INVALID_SMMU_PAGE BIT(10)
> +#define MC_INT_ARBITRATION_EMEM BIT(9)
> +#define MC_INT_SECURITY_VIOLATION BIT(8)
> +#define MC_INT_INVALID_GART_PAGE BIT(7)
> +#define MC_INT_DECERR_EMEM BIT(6)

This /could/ be a separate patch, with it being unrelated to the EMC
support, but probably not worth it.

> +#define MC_EMEM_ARB_OUTSTANDING_REQ 0x94
> +#define MC_EMEM_ARB_OUTSTANDING_REQ_MAX_MASK 0x1ff
> +#define MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE BIT(30)
> +#define MC_EMEM_ARB_OUTSTANDING_REQ_LIMIT_ENABLE BIT(31)
> +
> +#define MC_EMEM_ARB_OVERRIDE 0xe8
> +#define MC_EMEM_ARB_OVERRIDE_EACK_MASK 0x3
> +
> +#define MC_TIMING_CONTROL 0xfc
> +#define MC_TIMING_UPDATE BIT(0)
>
> static inline u32 mc_readl(struct tegra_mc *mc, unsigned long offset)
> {
> diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
> new file mode 100644
> index 000000000000..4700f7c8022e
> --- /dev/null
> +++ b/drivers/memory/tegra/tegra30-emc.c
> @@ -0,0 +1,1197 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Tegra30 External Memory Controller driver
> + *
> + * Author: Dmitry Osipenko <digetx@gmail.com>
> + */

Copyright?

Otherwise looks good to me.

Thierry

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