Merge tag 'memory-controller-drv-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-mem-ctrl into arm/drivers

Memory controller drivers for v5.16, part two

1. Convert LPDDR2 bindings to dtschema and extend them with new
   properties.
2. Tegra 20 EMC: support matching timings by LPDDR2 configuration from
   devicetree.

* tag 'memory-controller-drv-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-mem-ctrl:
  memory: tegra20-emc: Add runtime dependency on devfreq governor module
  memory: tegra20-emc: Support matching timings by LPDDR2 configuration
  memory: Add LPDDR2-info helpers
  dt-bindings: memory: tegra20: emc: Document new LPDDR2 sub-node
  dt-bindings: Add vendor prefix for Elpida Memory
  dt-bindings: memory: lpddr2: Document Elpida B8132B2PB-6D-F
  dt-bindings: memory: lpddr2: Add revision-id properties
  dt-bindings: memory: lpddr2: Convert to schema
  dt-bindings: Relocate DDR bindings

Link: https://lore.kernel.org/r/20211021093002.118192-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 187 insertions, 14 deletions

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index f9bae36c03a3..7951764b4efe 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -16,6 +16,7 @@ config TEGRA20_EMC
 	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	select PM_DEVFREQ
+	select DDR
 	help
 	  This driver is for the External Memory Controller (EMC) found on
 	  Tegra20 chips. The EMC controls the external DRAM on the board.
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index c3462dbc8c22..497b6edbf3ca 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -5,6 +5,7 @@
  * Author: Dmitry Osipenko <digetx@gmail.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/clk/tegra.h>
 #include <linux/debugfs.h>
@@ -27,11 +28,15 @@
 #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_0				0x010
 #define EMC_TIMING_CONTROL			0x028
 #define EMC_RC					0x02c
 #define EMC_RFC					0x030
@@ -68,6 +73,7 @@
 #define EMC_QUSE_EXTRA				0x0ac
 #define EMC_ODT_WRITE				0x0b0
 #define EMC_ODT_READ				0x0b4
+#define EMC_MRR					0x0ec
 #define EMC_FBIO_CFG5				0x104
 #define EMC_FBIO_CFG6				0x114
 #define EMC_STAT_CONTROL			0x160
@@ -94,6 +100,7 @@
 
 #define EMC_REFRESH_OVERFLOW_INT		BIT(3)
 #define EMC_CLKCHANGE_COMPLETE_INT		BIT(4)
+#define EMC_MRR_DIVLD_INT			BIT(5)
 
 #define EMC_DBG_READ_MUX_ASSEMBLY		BIT(0)
 #define EMC_DBG_WRITE_MUX_ACTIVE		BIT(1)
@@ -102,11 +109,25 @@
 #define EMC_DBG_CFG_PRIORITY			BIT(24)
 
 #define EMC_FBIO_CFG5_DRAM_WIDTH_X16		BIT(4)
+#define EMC_FBIO_CFG5_DRAM_TYPE			GENMASK(1, 0)
+
+#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_0_EMEM_NUMDEV		GENMASK(25, 24)
 
 #define EMC_PWR_GATHER_CLEAR			(1 << 8)
 #define EMC_PWR_GATHER_DISABLE			(2 << 8)
 #define EMC_PWR_GATHER_ENABLE			(3 << 8)
 
+enum emc_dram_type {
+	DRAM_TYPE_RESERVED,
+	DRAM_TYPE_DDR1,
+	DRAM_TYPE_LPDDR2,
+	DRAM_TYPE_DDR2,
+};
+
 static const u16 emc_timing_registers[] = {
 	EMC_RC,
 	EMC_RFC,
@@ -201,6 +222,14 @@ struct tegra_emc {
 	struct mutex rate_lock;
 
 	struct devfreq_simple_ondemand_data ondemand_data;
+
+	/* memory chip identity information */
+	union lpddr2_basic_config4 basic_conf4;
+	unsigned int manufacturer_id;
+	unsigned int revision_id1;
+	unsigned int revision_id2;
+
+	bool mrr_error;
 };
 
 static irqreturn_t tegra_emc_isr(int irq, void *data)
@@ -397,15 +426,19 @@ static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
 	if (!emc->timings)
 		return -ENOMEM;
 
-	emc->num_timings = child_count;
 	timing = emc->timings;
 
 	for_each_child_of_node(node, child) {
+		if (of_node_name_eq(child, "lpddr2"))
+			continue;
+
 		err = load_one_timing_from_dt(emc, timing++, child);
 		if (err) {
 			of_node_put(child);
 			return err;
 		}
+
+		emc->num_timings++;
 	}
 
 	sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
@@ -422,12 +455,18 @@ static int tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
 }
 
 static struct device_node *
-tegra_emc_find_node_by_ram_code(struct device *dev)
+tegra_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;
@@ -442,8 +481,49 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
 	     np = of_find_node_by_name(np, "emc-tables")) {
 		err = of_property_read_u32(np, "nvidia,ram-code", &value);
 		if (err || value != ram_code) {
-			of_node_put(np);
-			continue;
+			struct device_node *lpddr2_np;
+			bool cfg_mismatches = false;
+
+			lpddr2_np = of_find_node_by_name(np, "lpddr2");
+			if (lpddr2_np) {
+				const struct lpddr2_info *info;
+
+				info = of_lpddr2_get_info(lpddr2_np, dev);
+				if (info) {
+					if (info->manufacturer_id >= 0 &&
+					    info->manufacturer_id != emc->manufacturer_id)
+						cfg_mismatches = true;
+
+					if (info->revision_id1 >= 0 &&
+					    info->revision_id1 != emc->revision_id1)
+						cfg_mismatches = true;
+
+					if (info->revision_id2 >= 0 &&
+					    info->revision_id2 != emc->revision_id2)
+						cfg_mismatches = true;
+
+					if (info->density != emc->basic_conf4.density)
+						cfg_mismatches = true;
+
+					if (info->io_width != emc->basic_conf4.io_width)
+						cfg_mismatches = true;
+
+					if (info->arch_type != emc->basic_conf4.arch_type)
+						cfg_mismatches = true;
+				} else {
+					dev_err(dev, "failed to parse %pOF\n", lpddr2_np);
+					cfg_mismatches = true;
+				}
+
+				of_node_put(lpddr2_np);
+			} else {
+				cfg_mismatches = true;
+			}
+
+			if (cfg_mismatches) {
+				of_node_put(np);
+				continue;
+			}
 		}
 
 		return np;
@@ -455,10 +535,72 @@ tegra_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,
+				      bool print_out)
+{
+	/* these registers are standard for all LPDDR JEDEC memory chips */
+	emc_read_lpddr_mode_register(emc, emem_dev, 5, &emc->manufacturer_id);
+	emc_read_lpddr_mode_register(emc, emem_dev, 6, &emc->revision_id1);
+	emc_read_lpddr_mode_register(emc, emem_dev, 7, &emc->revision_id2);
+	emc_read_lpddr_mode_register(emc, emem_dev, 8, &emc->basic_conf4.value);
+
+	if (!print_out)
+		return;
+
+	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, emc->manufacturer_id,
+		 lpddr2_jedec_manufacturer(emc->manufacturer_id),
+		 emc->revision_id1, emc->revision_id2,
+		 4 >> emc->basic_conf4.arch_type,
+		 64 << emc->basic_conf4.density,
+		 32 >> emc->basic_conf4.io_width);
+}
+
 static int emc_setup_hw(struct tegra_emc *emc)
 {
+	u32 emc_cfg, emc_dbg, emc_fbio, emc_adr_cfg;
 	u32 intmask = EMC_REFRESH_OVERFLOW_INT;
-	u32 emc_cfg, emc_dbg, emc_fbio;
+	static bool print_sdram_info_once;
+	enum emc_dram_type dram_type;
+	const char *dram_type_str;
+	unsigned int emem_numdev;
 
 	emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
 
@@ -496,7 +638,36 @@ static int emc_setup_hw(struct tegra_emc *emc)
 	else
 		emc->dram_bus_width = 32;
 
-	dev_info_once(emc->dev, "%ubit DRAM bus\n", emc->dram_bus_width);
+	dram_type = FIELD_GET(EMC_FBIO_CFG5_DRAM_TYPE, emc_fbio);
+
+	switch (dram_type) {
+	case DRAM_TYPE_RESERVED:
+		dram_type_str = "INVALID";
+		break;
+	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;
+	}
+
+	emc_adr_cfg = readl_relaxed(emc->regs + EMC_ADR_CFG_0);
+	emem_numdev = FIELD_GET(EMC_ADR_CFG_0_EMEM_NUMDEV, emc_adr_cfg) + 1;
+
+	dev_info_once(emc->dev, "%ubit DRAM bus, %u %s %s attached\n",
+		      emc->dram_bus_width, emem_numdev, dram_type_str,
+		      emem_numdev == 2 ? "devices" : "device");
+
+	if (dram_type == DRAM_TYPE_LPDDR2) {
+		while (emem_numdev--)
+			emc_read_lpddr_sdram_info(emc, emem_numdev,
+						  !print_sdram_info_once);
+		print_sdram_info_once = true;
+	}
 
 	return 0;
 }
@@ -1049,14 +1220,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	emc->clk_nb.notifier_call = tegra_emc_clk_change_notify;
 	emc->dev = &pdev->dev;
 
-	np = tegra_emc_find_node_by_ram_code(&pdev->dev);
-	if (np) {
-		err = tegra_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);
@@ -1065,6 +1228,14 @@ static int tegra_emc_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	np = tegra_emc_find_node_by_ram_code(emc);
+	if (np) {
+		err = tegra_emc_load_timings_from_dt(emc, np);
+		of_node_put(np);
+		if (err)
+			return err;
+	}
+
 	err = devm_request_irq(&pdev->dev, irq, tegra_emc_isr, 0,
 			       dev_name(&pdev->dev), emc);
 	if (err) {
@@ -1117,4 +1288,5 @@ module_platform_driver(tegra_emc_driver);
 
 MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
 MODULE_DESCRIPTION("NVIDIA Tegra20 EMC driver");
+MODULE_SOFTDEP("pre: governor_simpleondemand");
 MODULE_LICENSE("GPL v2");