memory: tegra30-emc: Print additional memory info

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@gmail.com> # T30 ASUS TF201 LPDDR2
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20211222043215.28237-1-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 7951764b4efeca25075f0395d5bc91ec2a1543e8..3fe83d7c2bf8bea14b7e2ec54d91f860899567be 100644 (file)
--- 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 80f98d717e139c710e22def0db4001b8fcad5ede..9ba2a9e5316bd0efe165bc97f85d0ea6d1a9cd49 100644 (file)
--- 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;