On 18/12/2021 00:47, Dmitry Osipenko wrote:
> Print out memory type and LPDDR2 configuration on Tegra30, making it
> similar to the memory info printed by the Tegra20 memory driver. This
> info is useful for debugging purposes.
>
> Tested-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx> # T30 ASUS TF201 LPDDR2
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/memory/tegra/Kconfig | 1 +
> drivers/memory/tegra/tegra30-emc.c | 131 ++++++++++++++++++++++++++---
> 2 files changed, 122 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
> index 7951764b4efe..3fe83d7c2bf8 100644
> --- a/drivers/memory/tegra/Kconfig
> +++ b/drivers/memory/tegra/Kconfig
> @@ -28,6 +28,7 @@ config TEGRA30_EMC
> default y
> depends on ARCH_TEGRA_3x_SOC || COMPILE_TEST
> select PM_OPP
> + select DDR
> help
> This driver is for the External Memory Controller (EMC) found on
> Tegra30 chips. The EMC controls the external DRAM on the board.
> diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
> index 80f98d717e13..4c0432704f46 100644
> --- a/drivers/memory/tegra/tegra30-emc.c
> +++ b/drivers/memory/tegra/tegra30-emc.c
> @@ -9,6 +9,7 @@
> * Copyright (C) 2019 GRATE-DRIVER project
> */
>
> +#include <linux/bitfield.h>
> #include <linux/clk.h>
> #include <linux/clk/tegra.h>
> #include <linux/debugfs.h>
> @@ -31,11 +32,15 @@
> #include <soc/tegra/common.h>
> #include <soc/tegra/fuse.h>
>
> +#include "../jedec_ddr.h"
> +#include "../of_memory.h"
> +
> #include "mc.h"
>
> #define EMC_INTSTATUS 0x000
> #define EMC_INTMASK 0x004
> #define EMC_DBG 0x008
> +#define EMC_ADR_CFG 0x010
> #define EMC_CFG 0x00c
> #define EMC_REFCTRL 0x020
> #define EMC_TIMING_CONTROL 0x028
> @@ -81,6 +86,7 @@
> #define EMC_EMRS 0x0d0
> #define EMC_SELF_REF 0x0e0
> #define EMC_MRW 0x0e8
> +#define EMC_MRR 0x0ec
> #define EMC_XM2DQSPADCTRL3 0x0f8
> #define EMC_FBIO_SPARE 0x100
> #define EMC_FBIO_CFG5 0x104
> @@ -208,6 +214,13 @@
>
> #define EMC_REFRESH_OVERFLOW_INT BIT(3)
> #define EMC_CLKCHANGE_COMPLETE_INT BIT(4)
> +#define EMC_MRR_DIVLD_INT BIT(5)
> +
> +#define EMC_MRR_DEV_SELECTN GENMASK(31, 30)
> +#define EMC_MRR_MRR_MA GENMASK(23, 16)
> +#define EMC_MRR_MRR_DATA GENMASK(15, 0)
> +
> +#define EMC_ADR_CFG_EMEM_NUMDEV BIT(0)
>
> enum emc_dram_type {
> DRAM_TYPE_DDR3,
> @@ -378,6 +391,8 @@ struct tegra_emc {
>
> /* protect shared rate-change code path */
> struct mutex rate_lock;
> +
> + bool mrr_error;
> };
>
> static int emc_seq_update_timing(struct tegra_emc *emc)
> @@ -1008,12 +1023,18 @@ static int emc_load_timings_from_dt(struct tegra_emc *emc,
> return 0;
> }
>
> -static struct device_node *emc_find_node_by_ram_code(struct device *dev)
> +static struct device_node *emc_find_node_by_ram_code(struct tegra_emc *emc)
> {
> + struct device *dev = emc->dev;
> struct device_node *np;
> u32 value, ram_code;
> int err;
>
> + if (emc->mrr_error) {
> + dev_warn(dev, "memory timings skipped due to MRR error\n");
> + return NULL;
> + }
> +
> if (of_get_child_count(dev->of_node) == 0) {
> dev_info_once(dev, "device-tree doesn't have memory timings\n");
> return NULL;
> @@ -1035,11 +1056,73 @@ static struct device_node *emc_find_node_by_ram_code(struct device *dev)
> return NULL;
> }
>
> +static int emc_read_lpddr_mode_register(struct tegra_emc *emc,
> + unsigned int emem_dev,
> + unsigned int register_addr,
> + unsigned int *register_data)
> +{
> + u32 memory_dev = emem_dev + 1;
> + u32 val, mr_mask = 0xff;
> + int err;
> +
> + /* clear data-valid interrupt status */
> + writel_relaxed(EMC_MRR_DIVLD_INT, emc->regs + EMC_INTSTATUS);
> +
> + /* issue mode register read request */
> + val = FIELD_PREP(EMC_MRR_DEV_SELECTN, memory_dev);
> + val |= FIELD_PREP(EMC_MRR_MRR_MA, register_addr);
> +
> + writel_relaxed(val, emc->regs + EMC_MRR);
> +
> + /* wait for the LPDDR2 data-valid interrupt */
> + err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, val,
> + val & EMC_MRR_DIVLD_INT,
> + 1, 100);
> + if (err) {
> + dev_err(emc->dev, "mode register %u read failed: %d\n",
> + register_addr, err);
> + emc->mrr_error = true;
> + return err;
> + }
> +
> + /* read out mode register data */
> + val = readl_relaxed(emc->regs + EMC_MRR);
> + *register_data = FIELD_GET(EMC_MRR_MRR_DATA, val) & mr_mask;
> +
> + return 0;
> +}
> +
> +static void emc_read_lpddr_sdram_info(struct tegra_emc *emc,
> + unsigned int emem_dev)
> +{
> + union lpddr2_basic_config4 basic_conf4;
> + unsigned int manufacturer_id;
> + unsigned int revision_id1;
> + unsigned int revision_id2;
> +
> + /* these registers are standard for all LPDDR JEDEC memory chips */
> + emc_read_lpddr_mode_register(emc, emem_dev, 5, &manufacturer_id);
> + emc_read_lpddr_mode_register(emc, emem_dev, 6, &revision_id1);
> + emc_read_lpddr_mode_register(emc, emem_dev, 7, &revision_id2);
> + emc_read_lpddr_mode_register(emc, emem_dev, 8, &basic_conf4.value);
> +
> + dev_info(emc->dev, "SDRAM[dev%u]: manufacturer: 0x%x (%s) rev1: 0x%x rev2: 0x%x prefetch: S%u density: %uMbit iowidth: %ubit\n",
> + emem_dev, manufacturer_id,
> + lpddr2_jedec_manufacturer(manufacturer_id),
> + revision_id1, revision_id2,
> + 4 >> basic_conf4.arch_type,
> + 64 << basic_conf4.density,
> + 32 >> basic_conf4.io_width);
> +}
> +
Quickly looking, these two functions are exactly the same as ones in
tegra20-emc.c
. Later you might come up with another set for other SoCs, so it looks
it is worth to share these.
Best regards,
Krzysztof
