Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1751 insertions, 0 deletions

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
new file mode 100644
index 0000000000..9eae25c57e
--- /dev/null
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -0,0 +1,1751 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Tegra30 External Memory Controller driver
+ *
+ * Based on downstream driver from NVIDIA and tegra124-emc.c
+ * Copyright (C) 2011-2014 NVIDIA Corporation
+ *
+ * Author: Dmitry Osipenko <digetx@gmail.com>
+ * Copyright (C) 2019 GRATE-DRIVER project
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk/tegra.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interconnect-provider.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <linux/types.h>
+
+#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
+#define EMC_RC					0x02c
+#define EMC_RFC					0x030
+#define EMC_RAS					0x034
+#define EMC_RP					0x038
+#define EMC_R2W					0x03c
+#define EMC_W2R					0x040
+#define EMC_R2P					0x044
+#define EMC_W2P					0x048
+#define EMC_RD_RCD				0x04c
+#define EMC_WR_RCD				0x050
+#define EMC_RRD					0x054
+#define EMC_REXT				0x058
+#define EMC_WDV					0x05c
+#define EMC_QUSE				0x060
+#define EMC_QRST				0x064
+#define EMC_QSAFE				0x068
+#define EMC_RDV					0x06c
+#define EMC_REFRESH				0x070
+#define EMC_BURST_REFRESH_NUM			0x074
+#define EMC_PDEX2WR				0x078
+#define EMC_PDEX2RD				0x07c
+#define EMC_PCHG2PDEN				0x080
+#define EMC_ACT2PDEN				0x084
+#define EMC_AR2PDEN				0x088
+#define EMC_RW2PDEN				0x08c
+#define EMC_TXSR				0x090
+#define EMC_TCKE				0x094
+#define EMC_TFAW				0x098
+#define EMC_TRPAB				0x09c
+#define EMC_TCLKSTABLE				0x0a0
+#define EMC_TCLKSTOP				0x0a4
+#define EMC_TREFBW				0x0a8
+#define EMC_QUSE_EXTRA				0x0ac
+#define EMC_ODT_WRITE				0x0b0
+#define EMC_ODT_READ				0x0b4
+#define EMC_WEXT				0x0b8
+#define EMC_CTT					0x0bc
+#define EMC_MRS_WAIT_CNT			0x0c8
+#define EMC_MRS					0x0cc
+#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
+#define EMC_FBIO_CFG6				0x114
+#define EMC_CFG_RSV				0x120
+#define EMC_AUTO_CAL_CONFIG			0x2a4
+#define EMC_AUTO_CAL_INTERVAL			0x2a8
+#define EMC_AUTO_CAL_STATUS			0x2ac
+#define EMC_STATUS				0x2b4
+#define EMC_CFG_2				0x2b8
+#define EMC_CFG_DIG_DLL				0x2bc
+#define EMC_CFG_DIG_DLL_PERIOD			0x2c0
+#define EMC_CTT_DURATION			0x2d8
+#define EMC_CTT_TERM_CTRL			0x2dc
+#define EMC_ZCAL_INTERVAL			0x2e0
+#define EMC_ZCAL_WAIT_CNT			0x2e4
+#define EMC_ZQ_CAL				0x2ec
+#define EMC_XM2CMDPADCTRL			0x2f0
+#define EMC_XM2DQSPADCTRL2			0x2fc
+#define EMC_XM2DQPADCTRL2			0x304
+#define EMC_XM2CLKPADCTRL			0x308
+#define EMC_XM2COMPPADCTRL			0x30c
+#define EMC_XM2VTTGENPADCTRL			0x310
+#define EMC_XM2VTTGENPADCTRL2			0x314
+#define EMC_XM2QUSEPADCTRL			0x318
+#define EMC_DLL_XFORM_DQS0			0x328
+#define EMC_DLL_XFORM_DQS1			0x32c
+#define EMC_DLL_XFORM_DQS2			0x330
+#define EMC_DLL_XFORM_DQS3			0x334
+#define EMC_DLL_XFORM_DQS4			0x338
+#define EMC_DLL_XFORM_DQS5			0x33c
+#define EMC_DLL_XFORM_DQS6			0x340
+#define EMC_DLL_XFORM_DQS7			0x344
+#define EMC_DLL_XFORM_QUSE0			0x348
+#define EMC_DLL_XFORM_QUSE1			0x34c
+#define EMC_DLL_XFORM_QUSE2			0x350
+#define EMC_DLL_XFORM_QUSE3			0x354
+#define EMC_DLL_XFORM_QUSE4			0x358
+#define EMC_DLL_XFORM_QUSE5			0x35c
+#define EMC_DLL_XFORM_QUSE6			0x360
+#define EMC_DLL_XFORM_QUSE7			0x364
+#define EMC_DLL_XFORM_DQ0			0x368
+#define EMC_DLL_XFORM_DQ1			0x36c
+#define EMC_DLL_XFORM_DQ2			0x370
+#define EMC_DLL_XFORM_DQ3			0x374
+#define EMC_DLI_TRIM_TXDQS0			0x3a8
+#define EMC_DLI_TRIM_TXDQS1			0x3ac
+#define EMC_DLI_TRIM_TXDQS2			0x3b0
+#define EMC_DLI_TRIM_TXDQS3			0x3b4
+#define EMC_DLI_TRIM_TXDQS4			0x3b8
+#define EMC_DLI_TRIM_TXDQS5			0x3bc
+#define EMC_DLI_TRIM_TXDQS6			0x3c0
+#define EMC_DLI_TRIM_TXDQS7			0x3c4
+#define EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE	0x3c8
+#define EMC_STALL_THEN_EXE_AFTER_CLKCHANGE	0x3cc
+#define EMC_UNSTALL_RW_AFTER_CLKCHANGE		0x3d0
+#define EMC_SEL_DPD_CTRL			0x3d8
+#define EMC_PRE_REFRESH_REQ_CNT			0x3dc
+#define EMC_DYN_SELF_REF_CONTROL		0x3e0
+#define EMC_TXSRDLL				0x3e4
+
+#define EMC_STATUS_TIMING_UPDATE_STALLED	BIT(23)
+
+#define EMC_MODE_SET_DLL_RESET			BIT(8)
+#define EMC_MODE_SET_LONG_CNT			BIT(26)
+
+#define EMC_SELF_REF_CMD_ENABLED		BIT(0)
+
+#define DRAM_DEV_SEL_ALL			(0 << 30)
+#define DRAM_DEV_SEL_0				BIT(31)
+#define DRAM_DEV_SEL_1				BIT(30)
+#define DRAM_BROADCAST(num) \
+	((num) > 1 ? DRAM_DEV_SEL_ALL : DRAM_DEV_SEL_0)
+
+#define EMC_ZQ_CAL_CMD				BIT(0)
+#define EMC_ZQ_CAL_LONG				BIT(4)
+#define EMC_ZQ_CAL_LONG_CMD_DEV0 \
+	(DRAM_DEV_SEL_0 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
+#define EMC_ZQ_CAL_LONG_CMD_DEV1 \
+	(DRAM_DEV_SEL_1 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
+
+#define EMC_DBG_READ_MUX_ASSEMBLY		BIT(0)
+#define EMC_DBG_WRITE_MUX_ACTIVE		BIT(1)
+#define EMC_DBG_FORCE_UPDATE			BIT(2)
+#define EMC_DBG_CFG_PRIORITY			BIT(24)
+
+#define EMC_CFG5_QUSE_MODE_SHIFT		13
+#define EMC_CFG5_QUSE_MODE_MASK			(7 << EMC_CFG5_QUSE_MODE_SHIFT)
+
+#define EMC_CFG5_QUSE_MODE_INTERNAL_LPBK	2
+#define EMC_CFG5_QUSE_MODE_PULSE_INTERN		3
+
+#define EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE	BIT(9)
+
+#define EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE	BIT(10)
+
+#define EMC_XM2QUSEPADCTRL_IVREF_ENABLE		BIT(4)
+
+#define EMC_XM2DQSPADCTRL2_VREF_ENABLE		BIT(5)
+#define EMC_XM2DQSPADCTRL3_VREF_ENABLE		BIT(5)
+
+#define EMC_AUTO_CAL_STATUS_ACTIVE		BIT(31)
+
+#define	EMC_FBIO_CFG5_DRAM_TYPE_MASK		0x3
+
+#define EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK	0x3ff
+#define EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT	16
+#define EMC_MRS_WAIT_CNT_LONG_WAIT_MASK \
+	(0x3ff << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
+
+#define EMC_REFCTRL_DEV_SEL_MASK		0x3
+#define EMC_REFCTRL_ENABLE			BIT(31)
+#define EMC_REFCTRL_ENABLE_ALL(num) \
+	(((num) > 1 ? 0 : 2) | EMC_REFCTRL_ENABLE)
+#define EMC_REFCTRL_DISABLE_ALL(num)		((num) > 1 ? 0 : 2)
+
+#define EMC_CFG_PERIODIC_QRST			BIT(21)
+#define EMC_CFG_DYN_SREF_ENABLE			BIT(28)
+
+#define EMC_CLKCHANGE_REQ_ENABLE		BIT(0)
+#define EMC_CLKCHANGE_PD_ENABLE			BIT(1)
+#define EMC_CLKCHANGE_SR_ENABLE			BIT(2)
+
+#define EMC_TIMING_UPDATE			BIT(0)
+
+#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,
+	DRAM_TYPE_DDR1,
+	DRAM_TYPE_LPDDR2,
+	DRAM_TYPE_DDR2,
+};
+
+enum emc_dll_change {
+	DLL_CHANGE_NONE,
+	DLL_CHANGE_ON,
+	DLL_CHANGE_OFF
+};
+
+static const u16 emc_timing_registers[] = {
+	[0] = EMC_RC,
+	[1] = EMC_RFC,
+	[2] = EMC_RAS,
+	[3] = EMC_RP,
+	[4] = EMC_R2W,
+	[5] = EMC_W2R,
+	[6] = EMC_R2P,
+	[7] = EMC_W2P,
+	[8] = EMC_RD_RCD,
+	[9] = EMC_WR_RCD,
+	[10] = EMC_RRD,
+	[11] = EMC_REXT,
+	[12] = EMC_WEXT,
+	[13] = EMC_WDV,
+	[14] = EMC_QUSE,
+	[15] = EMC_QRST,
+	[16] = EMC_QSAFE,
+	[17] = EMC_RDV,
+	[18] = EMC_REFRESH,
+	[19] = EMC_BURST_REFRESH_NUM,
+	[20] = EMC_PRE_REFRESH_REQ_CNT,
+	[21] = EMC_PDEX2WR,
+	[22] = EMC_PDEX2RD,
+	[23] = EMC_PCHG2PDEN,
+	[24] = EMC_ACT2PDEN,
+	[25] = EMC_AR2PDEN,
+	[26] = EMC_RW2PDEN,
+	[27] = EMC_TXSR,
+	[28] = EMC_TXSRDLL,
+	[29] = EMC_TCKE,
+	[30] = EMC_TFAW,
+	[31] = EMC_TRPAB,
+	[32] = EMC_TCLKSTABLE,
+	[33] = EMC_TCLKSTOP,
+	[34] = EMC_TREFBW,
+	[35] = EMC_QUSE_EXTRA,
+	[36] = EMC_FBIO_CFG6,
+	[37] = EMC_ODT_WRITE,
+	[38] = EMC_ODT_READ,
+	[39] = EMC_FBIO_CFG5,
+	[40] = EMC_CFG_DIG_DLL,
+	[41] = EMC_CFG_DIG_DLL_PERIOD,
+	[42] = EMC_DLL_XFORM_DQS0,
+	[43] = EMC_DLL_XFORM_DQS1,
+	[44] = EMC_DLL_XFORM_DQS2,
+	[45] = EMC_DLL_XFORM_DQS3,
+	[46] = EMC_DLL_XFORM_DQS4,
+	[47] = EMC_DLL_XFORM_DQS5,
+	[48] = EMC_DLL_XFORM_DQS6,
+	[49] = EMC_DLL_XFORM_DQS7,
+	[50] = EMC_DLL_XFORM_QUSE0,
+	[51] = EMC_DLL_XFORM_QUSE1,
+	[52] = EMC_DLL_XFORM_QUSE2,
+	[53] = EMC_DLL_XFORM_QUSE3,
+	[54] = EMC_DLL_XFORM_QUSE4,
+	[55] = EMC_DLL_XFORM_QUSE5,
+	[56] = EMC_DLL_XFORM_QUSE6,
+	[57] = EMC_DLL_XFORM_QUSE7,
+	[58] = EMC_DLI_TRIM_TXDQS0,
+	[59] = EMC_DLI_TRIM_TXDQS1,
+	[60] = EMC_DLI_TRIM_TXDQS2,
+	[61] = EMC_DLI_TRIM_TXDQS3,
+	[62] = EMC_DLI_TRIM_TXDQS4,
+	[63] = EMC_DLI_TRIM_TXDQS5,
+	[64] = EMC_DLI_TRIM_TXDQS6,
+	[65] = EMC_DLI_TRIM_TXDQS7,
+	[66] = EMC_DLL_XFORM_DQ0,
+	[67] = EMC_DLL_XFORM_DQ1,
+	[68] = EMC_DLL_XFORM_DQ2,
+	[69] = EMC_DLL_XFORM_DQ3,
+	[70] = EMC_XM2CMDPADCTRL,
+	[71] = EMC_XM2DQSPADCTRL2,
+	[72] = EMC_XM2DQPADCTRL2,
+	[73] = EMC_XM2CLKPADCTRL,
+	[74] = EMC_XM2COMPPADCTRL,
+	[75] = EMC_XM2VTTGENPADCTRL,
+	[76] = EMC_XM2VTTGENPADCTRL2,
+	[77] = EMC_XM2QUSEPADCTRL,
+	[78] = EMC_XM2DQSPADCTRL3,
+	[79] = EMC_CTT_TERM_CTRL,
+	[80] = EMC_ZCAL_INTERVAL,
+	[81] = EMC_ZCAL_WAIT_CNT,
+	[82] = EMC_MRS_WAIT_CNT,
+	[83] = EMC_AUTO_CAL_CONFIG,
+	[84] = EMC_CTT,
+	[85] = EMC_CTT_DURATION,
+	[86] = EMC_DYN_SELF_REF_CONTROL,
+	[87] = EMC_FBIO_SPARE,
+	[88] = EMC_CFG_RSV,
+};
+
+struct emc_timing {
+	unsigned long rate;
+
+	u32 data[ARRAY_SIZE(emc_timing_registers)];
+
+	u32 emc_auto_cal_interval;
+	u32 emc_mode_1;
+	u32 emc_mode_2;
+	u32 emc_mode_reset;
+	u32 emc_zcal_cnt_long;
+	bool emc_cfg_periodic_qrst;
+	bool emc_cfg_dyn_self_ref;
+};
+
+enum emc_rate_request_type {
+	EMC_RATE_DEBUG,
+	EMC_RATE_ICC,
+	EMC_RATE_TYPE_MAX,
+};
+
+struct emc_rate_request {
+	unsigned long min_rate;
+	unsigned long max_rate;
+};
+
+struct tegra_emc {
+	struct device *dev;
+	struct tegra_mc *mc;
+	struct icc_provider provider;
+	struct notifier_block clk_nb;
+	struct clk *clk;
+	void __iomem *regs;
+	unsigned int irq;
+	bool bad_state;
+
+	struct emc_timing *new_timing;
+	struct emc_timing *timings;
+	unsigned int num_timings;
+
+	u32 mc_override;
+	u32 emc_cfg;
+
+	u32 emc_mode_1;
+	u32 emc_mode_2;
+	u32 emc_mode_reset;
+
+	bool vref_cal_toggle : 1;
+	bool zcal_long : 1;
+	bool dll_on : 1;
+
+	struct {
+		struct dentry *root;
+		unsigned long min_rate;
+		unsigned long max_rate;
+	} debugfs;
+
+	/*
+	 * There are multiple sources in the EMC driver which could request
+	 * a min/max clock rate, these rates are contained in this array.
+	 */
+	struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX];
+
+	/* protect shared rate-change code path */
+	struct mutex rate_lock;
+
+	bool mrr_error;
+};
+
+static int emc_seq_update_timing(struct tegra_emc *emc)
+{
+	u32 val;
+	int err;
+
+	writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL);
+
+	err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_STATUS, val,
+				!(val & EMC_STATUS_TIMING_UPDATE_STALLED),
+				1, 200);
+	if (err) {
+		dev_err(emc->dev, "failed to update timing: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static irqreturn_t tegra_emc_isr(int irq, void *data)
+{
+	struct tegra_emc *emc = data;
+	u32 intmask = EMC_REFRESH_OVERFLOW_INT;
+	u32 status;
+
+	status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask;
+	if (!status)
+		return IRQ_NONE;
+
+	/* notify about HW problem */
+	if (status & EMC_REFRESH_OVERFLOW_INT)
+		dev_err_ratelimited(emc->dev,
+				    "refresh request overflow timeout\n");
+
+	/* clear interrupts */
+	writel_relaxed(status, emc->regs + EMC_INTSTATUS);
+
+	return IRQ_HANDLED;
+}
+
+static struct emc_timing *emc_find_timing(struct tegra_emc *emc,
+					  unsigned long rate)
+{
+	struct emc_timing *timing = NULL;
+	unsigned int i;
+
+	for (i = 0; i < emc->num_timings; i++) {
+		if (emc->timings[i].rate >= rate) {
+			timing = &emc->timings[i];
+			break;
+		}
+	}
+
+	if (!timing) {
+		dev_err(emc->dev, "no timing for rate %lu\n", rate);
+		return NULL;
+	}
+
+	return timing;
+}
+
+static bool emc_dqs_preset(struct tegra_emc *emc, struct emc_timing *timing,
+			   bool *schmitt_to_vref)
+{
+	bool preset = false;
+	u32 val;
+
+	if (timing->data[71] & EMC_XM2DQSPADCTRL2_VREF_ENABLE) {
+		val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL2);
+
+		if (!(val & EMC_XM2DQSPADCTRL2_VREF_ENABLE)) {
+			val |= EMC_XM2DQSPADCTRL2_VREF_ENABLE;
+			writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL2);
+
+			preset = true;
+		}
+	}
+
+	if (timing->data[78] & EMC_XM2DQSPADCTRL3_VREF_ENABLE) {
+		val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL3);
+
+		if (!(val & EMC_XM2DQSPADCTRL3_VREF_ENABLE)) {
+			val |= EMC_XM2DQSPADCTRL3_VREF_ENABLE;
+			writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL3);
+
+			preset = true;
+		}
+	}
+
+	if (timing->data[77] & EMC_XM2QUSEPADCTRL_IVREF_ENABLE) {
+		val = readl_relaxed(emc->regs + EMC_XM2QUSEPADCTRL);
+
+		if (!(val & EMC_XM2QUSEPADCTRL_IVREF_ENABLE)) {
+			val |= EMC_XM2QUSEPADCTRL_IVREF_ENABLE;
+			writel_relaxed(val, emc->regs + EMC_XM2QUSEPADCTRL);
+
+			*schmitt_to_vref = true;
+			preset = true;
+		}
+	}
+
+	return preset;
+}
+
+static int emc_prepare_mc_clk_cfg(struct tegra_emc *emc, unsigned long rate)
+{
+	struct tegra_mc *mc = emc->mc;
+	unsigned int misc0_index = 16;
+	unsigned int i;
+	bool same;
+
+	for (i = 0; i < mc->num_timings; i++) {
+		if (mc->timings[i].rate != rate)
+			continue;
+
+		if (mc->timings[i].emem_data[misc0_index] & BIT(27))
+			same = true;
+		else
+			same = false;
+
+		return tegra20_clk_prepare_emc_mc_same_freq(emc->clk, same);
+	}
+
+	return -EINVAL;
+}
+
+static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
+{
+	struct emc_timing *timing = emc_find_timing(emc, rate);
+	enum emc_dll_change dll_change;
+	enum emc_dram_type dram_type;
+	bool schmitt_to_vref = false;
+	unsigned int pre_wait = 0;
+	bool qrst_used = false;
+	unsigned int dram_num;
+	unsigned int i;
+	u32 fbio_cfg5;
+	u32 emc_dbg;
+	u32 val;
+	int err;
+
+	if (!timing || emc->bad_state)
+		return -EINVAL;
+
+	dev_dbg(emc->dev, "%s: using timing rate %lu for requested rate %lu\n",
+		__func__, timing->rate, rate);
+
+	emc->bad_state = true;
+
+	err = emc_prepare_mc_clk_cfg(emc, rate);
+	if (err) {
+		dev_err(emc->dev, "mc clock preparation failed: %d\n", err);
+		return err;
+	}
+
+	emc->vref_cal_toggle = false;
+	emc->mc_override = mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
+	emc->emc_cfg = readl_relaxed(emc->regs + EMC_CFG);
+	emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
+
+	if (emc->dll_on == !!(timing->emc_mode_1 & 0x1))
+		dll_change = DLL_CHANGE_NONE;
+	else if (timing->emc_mode_1 & 0x1)
+		dll_change = DLL_CHANGE_ON;
+	else
+		dll_change = DLL_CHANGE_OFF;
+
+	emc->dll_on = !!(timing->emc_mode_1 & 0x1);
+
+	if (timing->data[80] && !readl_relaxed(emc->regs + EMC_ZCAL_INTERVAL))
+		emc->zcal_long = true;
+	else
+		emc->zcal_long = false;
+
+	fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
+	dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
+
+	dram_num = tegra_mc_get_emem_device_count(emc->mc);
+
+	/* disable dynamic self-refresh */
+	if (emc->emc_cfg & EMC_CFG_DYN_SREF_ENABLE) {
+		emc->emc_cfg &= ~EMC_CFG_DYN_SREF_ENABLE;
+		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
+
+		pre_wait = 5;
+	}
+
+	/* update MC arbiter settings */
+	val = mc_readl(emc->mc, MC_EMEM_ARB_OUTSTANDING_REQ);
+	if (!(val & MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE) ||
+	    ((val & MC_EMEM_ARB_OUTSTANDING_REQ_MAX_MASK) > 0x50)) {
+
+		val = MC_EMEM_ARB_OUTSTANDING_REQ_LIMIT_ENABLE |
+		      MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE | 0x50;
+		mc_writel(emc->mc, val, MC_EMEM_ARB_OUTSTANDING_REQ);
+		mc_writel(emc->mc, MC_TIMING_UPDATE, MC_TIMING_CONTROL);
+	}
+
+	if (emc->mc_override & MC_EMEM_ARB_OVERRIDE_EACK_MASK)
+		mc_writel(emc->mc,
+			  emc->mc_override & ~MC_EMEM_ARB_OVERRIDE_EACK_MASK,
+			  MC_EMEM_ARB_OVERRIDE);
+
+	/* check DQ/DQS VREF delay */
+	if (emc_dqs_preset(emc, timing, &schmitt_to_vref)) {
+		if (pre_wait < 3)
+			pre_wait = 3;
+	}
+
+	if (pre_wait) {
+		err = emc_seq_update_timing(emc);
+		if (err)
+			return err;
+
+		udelay(pre_wait);
+	}
+
+	/* disable auto-calibration if VREF mode is switching */
+	if (timing->emc_auto_cal_interval) {
+		val = readl_relaxed(emc->regs + EMC_XM2COMPPADCTRL);
+		val ^= timing->data[74];
+
+		if (val & EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE) {
+			writel_relaxed(0, emc->regs + EMC_AUTO_CAL_INTERVAL);
+
+			err = readl_relaxed_poll_timeout_atomic(
+				emc->regs + EMC_AUTO_CAL_STATUS, val,
+				!(val & EMC_AUTO_CAL_STATUS_ACTIVE), 1, 300);
+			if (err) {
+				dev_err(emc->dev,
+					"auto-cal finish timeout: %d\n", err);
+				return err;
+			}
+
+			emc->vref_cal_toggle = true;
+		}
+	}
+
+	/* program shadow registers */
+	for (i = 0; i < ARRAY_SIZE(timing->data); i++) {
+		/* EMC_XM2CLKPADCTRL should be programmed separately */
+		if (i != 73)
+			writel_relaxed(timing->data[i],
+				       emc->regs + emc_timing_registers[i]);
+	}
+
+	err = tegra_mc_write_emem_configuration(emc->mc, timing->rate);
+	if (err)
+		return err;
+
+	/* DDR3: predict MRS long wait count */
+	if (dram_type == DRAM_TYPE_DDR3 && dll_change == DLL_CHANGE_ON) {
+		u32 cnt = 512;
+
+		if (emc->zcal_long)
+			cnt -= dram_num * 256;
+
+		val = timing->data[82] & EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK;
+		if (cnt < val)
+			cnt = val;
+
+		val = timing->data[82] & ~EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
+		val |= (cnt << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT) &
+			EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
+
+		writel_relaxed(val, emc->regs + EMC_MRS_WAIT_CNT);
+	}
+
+	/* this read also completes the writes */
+	val = readl_relaxed(emc->regs + EMC_SEL_DPD_CTRL);
+
+	if (!(val & EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE) && schmitt_to_vref) {
+		u32 cur_mode, new_mode;
+
+		cur_mode = fbio_cfg5 & EMC_CFG5_QUSE_MODE_MASK;
+		cur_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
+
+		new_mode = timing->data[39] & EMC_CFG5_QUSE_MODE_MASK;
+		new_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
+
+		if ((cur_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
+		     cur_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK) ||
+		    (new_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
+		     new_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK))
+			qrst_used = true;
+	}
+
+	/* flow control marker 1 */
+	writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE);
+
+	/* enable periodic reset */
+	if (qrst_used) {
+		writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE,
+			       emc->regs + EMC_DBG);
+		writel_relaxed(emc->emc_cfg | EMC_CFG_PERIODIC_QRST,
+			       emc->regs + EMC_CFG);
+		writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
+	}
+
+	/* disable auto-refresh to save time after clock change */
+	writel_relaxed(EMC_REFCTRL_DISABLE_ALL(dram_num),
+		       emc->regs + EMC_REFCTRL);
+
+	/* turn off DLL and enter self-refresh on DDR3 */
+	if (dram_type == DRAM_TYPE_DDR3) {
+		if (dll_change == DLL_CHANGE_OFF)
+			writel_relaxed(timing->emc_mode_1,
+				       emc->regs + EMC_EMRS);
+
+		writel_relaxed(DRAM_BROADCAST(dram_num) |
+			       EMC_SELF_REF_CMD_ENABLED,
+			       emc->regs + EMC_SELF_REF);
+	}
+
+	/* flow control marker 2 */
+	writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_AFTER_CLKCHANGE);
+
+	/* enable write-active MUX, update unshadowed pad control */
+	writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE, emc->regs + EMC_DBG);
+	writel_relaxed(timing->data[73], emc->regs + EMC_XM2CLKPADCTRL);
+
+	/* restore periodic QRST and disable write-active MUX */
+	val = !!(emc->emc_cfg & EMC_CFG_PERIODIC_QRST);
+	if (qrst_used || timing->emc_cfg_periodic_qrst != val) {
+		if (timing->emc_cfg_periodic_qrst)
+			emc->emc_cfg |= EMC_CFG_PERIODIC_QRST;
+		else
+			emc->emc_cfg &= ~EMC_CFG_PERIODIC_QRST;
+
+		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
+	}
+	writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
+
+	/* exit self-refresh on DDR3 */
+	if (dram_type == DRAM_TYPE_DDR3)
+		writel_relaxed(DRAM_BROADCAST(dram_num),
+			       emc->regs + EMC_SELF_REF);
+
+	/* set DRAM-mode registers */
+	if (dram_type == DRAM_TYPE_DDR3) {
+		if (timing->emc_mode_1 != emc->emc_mode_1)
+			writel_relaxed(timing->emc_mode_1,
+				       emc->regs + EMC_EMRS);
+
+		if (timing->emc_mode_2 != emc->emc_mode_2)
+			writel_relaxed(timing->emc_mode_2,
+				       emc->regs + EMC_EMRS);
+
+		if (timing->emc_mode_reset != emc->emc_mode_reset ||
+		    dll_change == DLL_CHANGE_ON) {
+			val = timing->emc_mode_reset;
+			if (dll_change == DLL_CHANGE_ON) {
+				val |= EMC_MODE_SET_DLL_RESET;
+				val |= EMC_MODE_SET_LONG_CNT;
+			} else {
+				val &= ~EMC_MODE_SET_DLL_RESET;
+			}
+			writel_relaxed(val, emc->regs + EMC_MRS);
+		}
+	} else {
+		if (timing->emc_mode_2 != emc->emc_mode_2)
+			writel_relaxed(timing->emc_mode_2,
+				       emc->regs + EMC_MRW);
+
+		if (timing->emc_mode_1 != emc->emc_mode_1)
+			writel_relaxed(timing->emc_mode_1,
+				       emc->regs + EMC_MRW);
+	}
+
+	emc->emc_mode_1 = timing->emc_mode_1;
+	emc->emc_mode_2 = timing->emc_mode_2;
+	emc->emc_mode_reset = timing->emc_mode_reset;
+
+	/* issue ZCAL command if turning ZCAL on */
+	if (emc->zcal_long) {
+		writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV0,
+			       emc->regs + EMC_ZQ_CAL);
+
+		if (dram_num > 1)
+			writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV1,
+				       emc->regs + EMC_ZQ_CAL);
+	}
+
+	/* flow control marker 3 */
+	writel_relaxed(0x1, emc->regs + EMC_UNSTALL_RW_AFTER_CLKCHANGE);
+
+	/*
+	 * Read and discard an arbitrary MC register (Note: EMC registers
+	 * can't be used) to ensure the register writes are completed.
+	 */
+	mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
+
+	return 0;
+}
+
+static int emc_complete_timing_change(struct tegra_emc *emc,
+				      unsigned long rate)
+{
+	struct emc_timing *timing = emc_find_timing(emc, rate);
+	unsigned int dram_num;
+	int err;
+	u32 v;
+
+	err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, v,
+						v & EMC_CLKCHANGE_COMPLETE_INT,
+						1, 100);
+	if (err) {
+		dev_err(emc->dev, "emc-car handshake timeout: %d\n", err);
+		return err;
+	}
+
+	/* re-enable auto-refresh */
+	dram_num = tegra_mc_get_emem_device_count(emc->mc);
+	writel_relaxed(EMC_REFCTRL_ENABLE_ALL(dram_num),
+		       emc->regs + EMC_REFCTRL);
+
+	/* restore auto-calibration */
+	if (emc->vref_cal_toggle)
+		writel_relaxed(timing->emc_auto_cal_interval,
+			       emc->regs + EMC_AUTO_CAL_INTERVAL);
+
+	/* restore dynamic self-refresh */
+	if (timing->emc_cfg_dyn_self_ref) {
+		emc->emc_cfg |= EMC_CFG_DYN_SREF_ENABLE;
+		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
+	}
+
+	/* set number of clocks to wait after each ZQ command */
+	if (emc->zcal_long)
+		writel_relaxed(timing->emc_zcal_cnt_long,
+			       emc->regs + EMC_ZCAL_WAIT_CNT);
+
+	/* wait for writes to settle */
+	udelay(2);
+
+	/* update restored timing */
+	err = emc_seq_update_timing(emc);
+	if (!err)
+		emc->bad_state = false;
+
+	/* restore early ACK */
+	mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);
+
+	return err;
+}
+
+static int emc_unprepare_timing_change(struct tegra_emc *emc,
+				       unsigned long rate)
+{
+	if (!emc->bad_state) {
+		/* shouldn't ever happen in practice */
+		dev_err(emc->dev, "timing configuration can't be reverted\n");
+		emc->bad_state = true;
+	}
+
+	return 0;
+}
+
+static int emc_clk_change_notify(struct notifier_block *nb,
+				 unsigned long msg, void *data)
+{
+	struct tegra_emc *emc = container_of(nb, struct tegra_emc, clk_nb);
+	struct clk_notifier_data *cnd = data;
+	int err;
+
+	switch (msg) {
+	case PRE_RATE_CHANGE:
+		/*
+		 * Disable interrupt since read accesses are prohibited after
+		 * stalling.
+		 */
+		disable_irq(emc->irq);
+		err = emc_prepare_timing_change(emc, cnd->new_rate);
+		enable_irq(emc->irq);
+		break;
+
+	case ABORT_RATE_CHANGE:
+		err = emc_unprepare_timing_change(emc, cnd->old_rate);
+		break;
+
+	case POST_RATE_CHANGE:
+		err = emc_complete_timing_change(emc, cnd->new_rate);
+		break;
+
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return notifier_from_errno(err);
+}
+
+static int load_one_timing_from_dt(struct tegra_emc *emc,
+				   struct emc_timing *timing,
+				   struct device_node *node)
+{
+	u32 value;
+	int err;
+
+	err = of_property_read_u32(node, "clock-frequency", &value);
+	if (err) {
+		dev_err(emc->dev, "timing %pOF: failed to read rate: %d\n",
+			node, err);
+		return err;
+	}
+
+	timing->rate = value;
+
+	err = of_property_read_u32_array(node, "nvidia,emc-configuration",
+					 timing->data,
+					 ARRAY_SIZE(emc_timing_registers));
+	if (err) {
+		dev_err(emc->dev,
+			"timing %pOF: failed to read emc timing data: %d\n",
+			node, err);
+		return err;
+	}
+
+#define EMC_READ_BOOL(prop, dtprop) \
+	timing->prop = of_property_read_bool(node, dtprop);
+
+#define EMC_READ_U32(prop, dtprop) \
+	err = of_property_read_u32(node, dtprop, &timing->prop); \
+	if (err) { \
+		dev_err(emc->dev, \
+			"timing %pOFn: failed to read " #prop ": %d\n", \
+			node, err); \
+		return err; \
+	}
+
+	EMC_READ_U32(emc_auto_cal_interval, "nvidia,emc-auto-cal-interval")
+	EMC_READ_U32(emc_mode_1, "nvidia,emc-mode-1")
+	EMC_READ_U32(emc_mode_2, "nvidia,emc-mode-2")
+	EMC_READ_U32(emc_mode_reset, "nvidia,emc-mode-reset")
+	EMC_READ_U32(emc_zcal_cnt_long, "nvidia,emc-zcal-cnt-long")
+	EMC_READ_BOOL(emc_cfg_dyn_self_ref, "nvidia,emc-cfg-dyn-self-ref")
+	EMC_READ_BOOL(emc_cfg_periodic_qrst, "nvidia,emc-cfg-periodic-qrst")
+
+#undef EMC_READ_U32
+#undef EMC_READ_BOOL
+
+	dev_dbg(emc->dev, "%s: %pOF: rate %lu\n", __func__, node, timing->rate);
+
+	return 0;
+}
+
+static int cmp_timings(const void *_a, const void *_b)
+{
+	const struct emc_timing *a = _a;
+	const struct emc_timing *b = _b;
+
+	if (a->rate < b->rate)
+		return -1;
+
+	if (a->rate > b->rate)
+		return 1;
+
+	return 0;
+}
+
+static int emc_check_mc_timings(struct tegra_emc *emc)
+{
+	struct tegra_mc *mc = emc->mc;
+	unsigned int i;
+
+	if (emc->num_timings != mc->num_timings) {
+		dev_err(emc->dev, "emc/mc timings number mismatch: %u %u\n",
+			emc->num_timings, mc->num_timings);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < mc->num_timings; i++) {
+		if (emc->timings[i].rate != mc->timings[i].rate) {
+			dev_err(emc->dev,
+				"emc/mc timing rate mismatch: %lu %lu\n",
+				emc->timings[i].rate, mc->timings[i].rate);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int emc_load_timings_from_dt(struct tegra_emc *emc,
+				    struct device_node *node)
+{
+	struct device_node *child;
+	struct emc_timing *timing;
+	int child_count;
+	int err;
+
+	child_count = of_get_child_count(node);
+	if (!child_count) {
+		dev_err(emc->dev, "no memory timings in: %pOF\n", node);
+		return -EINVAL;
+	}
+
+	emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing),
+				    GFP_KERNEL);
+	if (!emc->timings)
+		return -ENOMEM;
+
+	emc->num_timings = child_count;
+	timing = emc->timings;
+
+	for_each_child_of_node(node, child) {
+		err = load_one_timing_from_dt(emc, timing++, child);
+		if (err) {
+			of_node_put(child);
+			return err;
+		}
+	}
+
+	sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
+	     NULL);
+
+	err = emc_check_mc_timings(emc);
+	if (err)
+		return err;
+
+	dev_info_once(emc->dev,
+		      "got %u timings for RAM code %u (min %luMHz max %luMHz)\n",
+		      emc->num_timings,
+		      tegra_read_ram_code(),
+		      emc->timings[0].rate / 1000000,
+		      emc->timings[emc->num_timings - 1].rate / 1000000);
+
+	return 0;
+}
+
+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;
+	}
+
+	ram_code = tegra_read_ram_code();
+
+	for_each_child_of_node(dev->of_node, np) {
+		err = of_property_read_u32(np, "nvidia,ram-code", &value);
+		if (err || value != ram_code)
+			continue;
+
+		return np;
+	}
+
+	dev_err(dev, "no memory timings for RAM code %u found in device-tree\n",
+		ram_code);
+
+	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;
+	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;
+
+	emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
+
+	/* enable EMC and CAR to handshake on PLL divider/source changes */
+	emc_cfg |= EMC_CLKCHANGE_REQ_ENABLE;
+
+	/* configure clock change mode accordingly to DRAM type */
+	switch (dram_type) {
+	case DRAM_TYPE_LPDDR2:
+		emc_cfg |= EMC_CLKCHANGE_PD_ENABLE;
+		emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
+		break;
+
+	default:
+		emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
+		emc_cfg &= ~EMC_CLKCHANGE_PD_ENABLE;
+		break;
+	}
+
+	writel_relaxed(emc_cfg, emc->regs + EMC_CFG_2);
+
+	/* initialize interrupt */
+	writel_relaxed(intmask, emc->regs + EMC_INTMASK);
+	writel_relaxed(0xffffffff, emc->regs + EMC_INTSTATUS);
+
+	/* ensure that unwanted debug features are disabled */
+	emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
+	emc_dbg |= EMC_DBG_CFG_PRIORITY;
+	emc_dbg &= ~EMC_DBG_READ_MUX_ASSEMBLY;
+	emc_dbg &= ~EMC_DBG_WRITE_MUX_ACTIVE;
+	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;
+}
+
+static long emc_round_rate(unsigned long rate,
+			   unsigned long min_rate,
+			   unsigned long max_rate,
+			   void *arg)
+{
+	struct emc_timing *timing = NULL;
+	struct tegra_emc *emc = arg;
+	unsigned int i;
+
+	if (!emc->num_timings)
+		return clk_get_rate(emc->clk);
+
+	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
+
+	for (i = 0; i < emc->num_timings; i++) {
+		if (emc->timings[i].rate < rate && i != emc->num_timings - 1)
+			continue;
+
+		if (emc->timings[i].rate > max_rate) {
+			i = max(i, 1u) - 1;
+
+			if (emc->timings[i].rate < min_rate)
+				break;
+		}
+
+		if (emc->timings[i].rate < min_rate)
+			continue;
+
+		timing = &emc->timings[i];
+		break;
+	}
+
+	if (!timing) {
+		dev_err(emc->dev, "no timing for rate %lu min %lu max %lu\n",
+			rate, min_rate, max_rate);
+		return -EINVAL;
+	}
+
+	return timing->rate;
+}
+
+static void tegra_emc_rate_requests_init(struct tegra_emc *emc)
+{
+	unsigned int i;
+
+	for (i = 0; i < EMC_RATE_TYPE_MAX; i++) {
+		emc->requested_rate[i].min_rate = 0;
+		emc->requested_rate[i].max_rate = ULONG_MAX;
+	}
+}
+
+static int emc_request_rate(struct tegra_emc *emc,
+			    unsigned long new_min_rate,
+			    unsigned long new_max_rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = emc->requested_rate;
+	unsigned long min_rate = 0, max_rate = ULONG_MAX;
+	unsigned int i;
+	int err;
+
+	/* select minimum and maximum rates among the requested rates */
+	for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) {
+		if (i == type) {
+			min_rate = max(new_min_rate, min_rate);
+			max_rate = min(new_max_rate, max_rate);
+		} else {
+			min_rate = max(req->min_rate, min_rate);
+			max_rate = min(req->max_rate, max_rate);
+		}
+	}
+
+	if (min_rate > max_rate) {
+		dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n",
+				    __func__, type, min_rate, max_rate);
+		return -ERANGE;
+	}
+
+	/*
+	 * EMC rate-changes should go via OPP API because it manages voltage
+	 * changes.
+	 */
+	err = dev_pm_opp_set_rate(emc->dev, min_rate);
+	if (err)
+		return err;
+
+	emc->requested_rate[type].min_rate = new_min_rate;
+	emc->requested_rate[type].max_rate = new_max_rate;
+
+	return 0;
+}
+
+static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = &emc->requested_rate[type];
+	int ret;
+
+	mutex_lock(&emc->rate_lock);
+	ret = emc_request_rate(emc, rate, req->max_rate, type);
+	mutex_unlock(&emc->rate_lock);
+
+	return ret;
+}
+
+static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = &emc->requested_rate[type];
+	int ret;
+
+	mutex_lock(&emc->rate_lock);
+	ret = emc_request_rate(emc, req->min_rate, rate, type);
+	mutex_unlock(&emc->rate_lock);
+
+	return ret;
+}
+
+/*
+ * debugfs interface
+ *
+ * The memory controller driver exposes some files in debugfs that can be used
+ * to control the EMC frequency. The top-level directory can be found here:
+ *
+ *   /sys/kernel/debug/emc
+ *
+ * It contains the following files:
+ *
+ *   - available_rates: This file contains a list of valid, space-separated
+ *     EMC frequencies.
+ *
+ *   - min_rate: Writing a value to this file sets the given frequency as the
+ *       floor of the permitted range. If this is higher than the currently
+ *       configured EMC frequency, this will cause the frequency to be
+ *       increased so that it stays within the valid range.
+ *
+ *   - max_rate: Similarily to the min_rate file, writing a value to this file
+ *       sets the given frequency as the ceiling of the permitted range. If
+ *       the value is lower than the currently configured EMC frequency, this
+ *       will cause the frequency to be decreased so that it stays within the
+ *       valid range.
+ */
+
+static bool tegra_emc_validate_rate(struct tegra_emc *emc, unsigned long rate)
+{
+	unsigned int i;
+
+	for (i = 0; i < emc->num_timings; i++)
+		if (rate == emc->timings[i].rate)
+			return true;
+
+	return false;
+}
+
+static int tegra_emc_debug_available_rates_show(struct seq_file *s, void *data)
+{
+	struct tegra_emc *emc = s->private;
+	const char *prefix = "";
+	unsigned int i;
+
+	for (i = 0; i < emc->num_timings; i++) {
+		seq_printf(s, "%s%lu", prefix, emc->timings[i].rate);
+		prefix = " ";
+	}
+
+	seq_puts(s, "\n");
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(tegra_emc_debug_available_rates);
+
+static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
+{
+	struct tegra_emc *emc = data;
+
+	*rate = emc->debugfs.min_rate;
+
+	return 0;
+}
+
+static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
+{
+	struct tegra_emc *emc = data;
+	int err;
+
+	if (!tegra_emc_validate_rate(emc, rate))
+		return -EINVAL;
+
+	err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
+	if (err < 0)
+		return err;
+
+	emc->debugfs.min_rate = rate;
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
+			tegra_emc_debug_min_rate_get,
+			tegra_emc_debug_min_rate_set, "%llu\n");
+
+static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
+{
+	struct tegra_emc *emc = data;
+
+	*rate = emc->debugfs.max_rate;
+
+	return 0;
+}
+
+static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
+{
+	struct tegra_emc *emc = data;
+	int err;
+
+	if (!tegra_emc_validate_rate(emc, rate))
+		return -EINVAL;
+
+	err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
+	if (err < 0)
+		return err;
+
+	emc->debugfs.max_rate = rate;
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
+			tegra_emc_debug_max_rate_get,
+			tegra_emc_debug_max_rate_set, "%llu\n");
+
+static void tegra_emc_debugfs_init(struct tegra_emc *emc)
+{
+	struct device *dev = emc->dev;
+	unsigned int i;
+	int err;
+
+	emc->debugfs.min_rate = ULONG_MAX;
+	emc->debugfs.max_rate = 0;
+
+	for (i = 0; i < emc->num_timings; i++) {
+		if (emc->timings[i].rate < emc->debugfs.min_rate)
+			emc->debugfs.min_rate = emc->timings[i].rate;
+
+		if (emc->timings[i].rate > emc->debugfs.max_rate)
+			emc->debugfs.max_rate = emc->timings[i].rate;
+	}
+
+	if (!emc->num_timings) {
+		emc->debugfs.min_rate = clk_get_rate(emc->clk);
+		emc->debugfs.max_rate = emc->debugfs.min_rate;
+	}
+
+	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
+				 emc->debugfs.max_rate);
+	if (err < 0) {
+		dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
+			emc->debugfs.min_rate, emc->debugfs.max_rate,
+			emc->clk);
+	}
+
+	emc->debugfs.root = debugfs_create_dir("emc", NULL);
+
+	debugfs_create_file("available_rates", 0444, emc->debugfs.root,
+			    emc, &tegra_emc_debug_available_rates_fops);
+	debugfs_create_file("min_rate", 0644, emc->debugfs.root,
+			    emc, &tegra_emc_debug_min_rate_fops);
+	debugfs_create_file("max_rate", 0644, emc->debugfs.root,
+			    emc, &tegra_emc_debug_max_rate_fops);
+}
+
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
+{
+	return container_of(provider, struct tegra_emc, provider);
+}
+
+static struct icc_node_data *
+emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
+{
+	struct icc_provider *provider = data;
+	struct icc_node_data *ndata;
+	struct icc_node *node;
+
+	/* External Memory is the only possible ICC route */
+	list_for_each_entry(node, &provider->nodes, node_list) {
+		if (node->id != TEGRA_ICC_EMEM)
+			continue;
+
+		ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
+		if (!ndata)
+			return ERR_PTR(-ENOMEM);
+
+		/*
+		 * SRC and DST nodes should have matching TAG in order to have
+		 * it set by default for a requested path.
+		 */
+		ndata->tag = TEGRA_MC_ICC_TAG_ISO;
+		ndata->node = node;
+
+		return ndata;
+	}
+
+	return ERR_PTR(-EPROBE_DEFER);
+}
+
+static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
+	unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
+	unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
+	unsigned long long rate = max(avg_bw, peak_bw);
+	const unsigned int dram_data_bus_width_bytes = 4;
+	const unsigned int ddr = 2;
+	int err;
+
+	/*
+	 * Tegra30 EMC runs on a clock rate of SDRAM bus.  This means that
+	 * EMC clock rate is twice smaller than the peak data rate because
+	 * data is sampled on both EMC clock edges.
+	 */
+	do_div(rate, ddr * dram_data_bus_width_bytes);
+	rate = min_t(u64, rate, U32_MAX);
+
+	err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int tegra_emc_interconnect_init(struct tegra_emc *emc)
+{
+	const struct tegra_mc_soc *soc = emc->mc->soc;
+	struct icc_node *node;
+	int err;
+
+	emc->provider.dev = emc->dev;
+	emc->provider.set = emc_icc_set;
+	emc->provider.data = &emc->provider;
+	emc->provider.aggregate = soc->icc_ops->aggregate;
+	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
+
+	icc_provider_init(&emc->provider);
+
+	/* create External Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_EMC);
+	if (IS_ERR(node)) {
+		err = PTR_ERR(node);
+		goto err_msg;
+	}
+
+	node->name = "External Memory Controller";
+	icc_node_add(node, &emc->provider);
+
+	/* link External Memory Controller to External Memory (DRAM) */
+	err = icc_link_create(node, TEGRA_ICC_EMEM);
+	if (err)
+		goto remove_nodes;
+
+	/* create External Memory node */
+	node = icc_node_create(TEGRA_ICC_EMEM);
+	if (IS_ERR(node)) {
+		err = PTR_ERR(node);
+		goto remove_nodes;
+	}
+
+	node->name = "External Memory (DRAM)";
+	icc_node_add(node, &emc->provider);
+
+	err = icc_provider_register(&emc->provider);
+	if (err)
+		goto remove_nodes;
+
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&emc->provider);
+err_msg:
+	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
+static void devm_tegra_emc_unset_callback(void *data)
+{
+	tegra20_clk_set_emc_round_callback(NULL, NULL);
+}
+
+static void devm_tegra_emc_unreg_clk_notifier(void *data)
+{
+	struct tegra_emc *emc = data;
+
+	clk_notifier_unregister(emc->clk, &emc->clk_nb);
+}
+
+static int tegra_emc_init_clk(struct tegra_emc *emc)
+{
+	int err;
+
+	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
+
+	err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback,
+				       NULL);
+	if (err)
+		return err;
+
+	emc->clk = devm_clk_get(emc->dev, NULL);
+	if (IS_ERR(emc->clk)) {
+		dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk);
+		return PTR_ERR(emc->clk);
+	}
+
+	err = clk_notifier_register(emc->clk, &emc->clk_nb);
+	if (err) {
+		dev_err(emc->dev, "failed to register clk notifier: %d\n", err);
+		return err;
+	}
+
+	err = devm_add_action_or_reset(emc->dev,
+				       devm_tegra_emc_unreg_clk_notifier, emc);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int tegra_emc_probe(struct platform_device *pdev)
+{
+	struct tegra_core_opp_params opp_params = {};
+	struct device_node *np;
+	struct tegra_emc *emc;
+	int err;
+
+	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
+	if (!emc)
+		return -ENOMEM;
+
+	emc->mc = devm_tegra_memory_controller_get(&pdev->dev);
+	if (IS_ERR(emc->mc))
+		return PTR_ERR(emc->mc);
+
+	mutex_init(&emc->rate_lock);
+	emc->clk_nb.notifier_call = emc_clk_change_notify;
+	emc->dev = &pdev->dev;
+
+	emc->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(emc->regs))
+		return PTR_ERR(emc->regs);
+
+	err = emc_setup_hw(emc);
+	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;
+
+	emc->irq = err;
+
+	err = devm_request_irq(&pdev->dev, emc->irq, tegra_emc_isr, 0,
+			       dev_name(&pdev->dev), emc);
+	if (err) {
+		dev_err(&pdev->dev, "failed to request irq: %d\n", err);
+		return err;
+	}
+
+	err = tegra_emc_init_clk(emc);
+	if (err)
+		return err;
+
+	opp_params.init_state = true;
+
+	err = devm_tegra_core_dev_init_opp_table(&pdev->dev, &opp_params);
+	if (err)
+		return err;
+
+	platform_set_drvdata(pdev, emc);
+	tegra_emc_rate_requests_init(emc);
+	tegra_emc_debugfs_init(emc);
+	tegra_emc_interconnect_init(emc);
+
+	/*
+	 * Don't allow the kernel module to be unloaded. Unloading adds some
+	 * extra complexity which doesn't really worth the effort in a case of
+	 * this driver.
+	 */
+	try_module_get(THIS_MODULE);
+
+	return 0;
+}
+
+static int tegra_emc_suspend(struct device *dev)
+{
+	struct tegra_emc *emc = dev_get_drvdata(dev);
+	int err;
+
+	/* take exclusive control over the clock's rate */
+	err = clk_rate_exclusive_get(emc->clk);
+	if (err) {
+		dev_err(emc->dev, "failed to acquire clk: %d\n", err);
+		return err;
+	}
+
+	/* suspending in a bad state will hang machine */
+	if (WARN(emc->bad_state, "hardware in a bad state\n"))
+		return -EINVAL;
+
+	emc->bad_state = true;
+
+	return 0;
+}
+
+static int tegra_emc_resume(struct device *dev)
+{
+	struct tegra_emc *emc = dev_get_drvdata(dev);
+
+	emc_setup_hw(emc);
+	emc->bad_state = false;
+
+	clk_rate_exclusive_put(emc->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tegra_emc_pm_ops = {
+	.suspend = tegra_emc_suspend,
+	.resume = tegra_emc_resume,
+};
+
+static const struct of_device_id tegra_emc_of_match[] = {
+	{ .compatible = "nvidia,tegra30-emc", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
+
+static struct platform_driver tegra_emc_driver = {
+	.probe = tegra_emc_probe,
+	.driver = {
+		.name = "tegra30-emc",
+		.of_match_table = tegra_emc_of_match,
+		.pm = &tegra_emc_pm_ops,
+		.suppress_bind_attrs = true,
+		.sync_state = icc_sync_state,
+	},
+};
+module_platform_driver(tegra_emc_driver);
+
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra30 EMC driver");
+MODULE_LICENSE("GPL v2");