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>
---
Changelog:
v2: - Corrected swapped chip-select mask in emc_read_lpddr_mode_register().
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..9ba2a9e5316b 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 : 2;
+ 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;
@@ -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;
}
@@ -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);
@@ -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;
--
2.33.1
