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memory: tegra30-emc: Print more memory info
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Print out additional info about Tegra30 memory hardware during driver
probe, making it similar to the info printed by Tegra20 driver. This info
is useful for debugging purposes.

Signed-off-by: Dmitry Osipenko <[email protected]>
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@digetx
digetx committed Dec 12, 2021
1 parent 93cae38 commit ae1eb3b
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Showing 2 changed files with 122 additions and 10 deletions.
1 change: 1 addition & 0 deletions drivers/memory/tegra/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down
131 changes: 121 additions & 10 deletions drivers/memory/tegra/tegra30-emc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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;
Expand All @@ -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);
}

static int emc_setup_hw(struct tegra_emc *emc)
{
u32 fbio_cfg5, emc_cfg, emc_dbg, emc_adr_cfg;
u32 intmask = EMC_REFRESH_OVERFLOW_INT;
u32 fbio_cfg5, emc_cfg, emc_dbg;
static bool print_sdram_info_once;
enum emc_dram_type dram_type;
const char *dram_type_str;
unsigned int emem_numdev;

fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
Expand Down Expand Up @@ -1076,6 +1159,34 @@ static int emc_setup_hw(struct tegra_emc *emc)
emc_dbg &= ~EMC_DBG_FORCE_UPDATE;
writel_relaxed(emc_dbg, emc->regs + EMC_DBG);

switch (dram_type) {
case DRAM_TYPE_DDR1:
dram_type_str = "DDR1";
break;
case DRAM_TYPE_LPDDR2:
dram_type_str = "LPDDR2";
break;
case DRAM_TYPE_DDR2:
dram_type_str = "DDR2";
break;
case DRAM_TYPE_DDR3:
dram_type_str = "DDR3";
break;
}

emc_adr_cfg = readl_relaxed(emc->regs + EMC_ADR_CFG);
emem_numdev = FIELD_GET(EMC_ADR_CFG_EMEM_NUMDEV, emc_adr_cfg) + 1;

dev_info_once(emc->dev, "%u %s %s attached\n", emem_numdev,
dram_type_str, emem_numdev == 2 ? "devices" : "device");

if (dram_type == DRAM_TYPE_LPDDR2 && !print_sdram_info_once) {
while (emem_numdev--)
emc_read_lpddr_sdram_info(emc, emem_numdev);

print_sdram_info_once = true;
}

return 0;
}

Expand Down Expand Up @@ -1538,14 +1649,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
emc->clk_nb.notifier_call = emc_clk_change_notify;
emc->dev = &pdev->dev;

np = emc_find_node_by_ram_code(&pdev->dev);
if (np) {
err = emc_load_timings_from_dt(emc, np);
of_node_put(np);
if (err)
return err;
}

emc->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(emc->regs))
return PTR_ERR(emc->regs);
Expand All @@ -1554,6 +1657,14 @@ static int tegra_emc_probe(struct platform_device *pdev)
if (err)
return err;

np = emc_find_node_by_ram_code(emc);
if (np) {
err = emc_load_timings_from_dt(emc, np);
of_node_put(np);
if (err)
return err;
}

err = platform_get_irq(pdev, 0);
if (err < 0)
return err;
Expand Down

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