1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Tegra30 External Memory Controller driver
4 *
5 * Based on downstream driver from NVIDIA and tegra124-emc.c
6 * Copyright (C) 2011-2014 NVIDIA Corporation
7 *
8 * Author: Dmitry Osipenko <digetx@gmail.com>
9 * Copyright (C) 2019 GRATE-DRIVER project
10 */
11
12#include <linux/clk.h>
13#include <linux/clk/tegra.h>
14#include <linux/debugfs.h>
15#include <linux/delay.h>
16#include <linux/err.h>
17#include <linux/interrupt.h>
18#include <linux/io.h>
19#include <linux/iopoll.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/of_platform.h>
23#include <linux/platform_device.h>
24#include <linux/sort.h>
25#include <linux/types.h>
26
27#include <soc/tegra/fuse.h>
28
29#include "mc.h"
30
31#define EMC_INTSTATUS				0x000
32#define EMC_INTMASK				0x004
33#define EMC_DBG					0x008
34#define EMC_CFG					0x00c
35#define EMC_REFCTRL				0x020
36#define EMC_TIMING_CONTROL			0x028
37#define EMC_RC					0x02c
38#define EMC_RFC					0x030
39#define EMC_RAS					0x034
40#define EMC_RP					0x038
41#define EMC_R2W					0x03c
42#define EMC_W2R					0x040
43#define EMC_R2P					0x044
44#define EMC_W2P					0x048
45#define EMC_RD_RCD				0x04c
46#define EMC_WR_RCD				0x050
47#define EMC_RRD					0x054
48#define EMC_REXT				0x058
49#define EMC_WDV					0x05c
50#define EMC_QUSE				0x060
51#define EMC_QRST				0x064
52#define EMC_QSAFE				0x068
53#define EMC_RDV					0x06c
54#define EMC_REFRESH				0x070
55#define EMC_BURST_REFRESH_NUM			0x074
56#define EMC_PDEX2WR				0x078
57#define EMC_PDEX2RD				0x07c
58#define EMC_PCHG2PDEN				0x080
59#define EMC_ACT2PDEN				0x084
60#define EMC_AR2PDEN				0x088
61#define EMC_RW2PDEN				0x08c
62#define EMC_TXSR				0x090
63#define EMC_TCKE				0x094
64#define EMC_TFAW				0x098
65#define EMC_TRPAB				0x09c
66#define EMC_TCLKSTABLE				0x0a0
67#define EMC_TCLKSTOP				0x0a4
68#define EMC_TREFBW				0x0a8
69#define EMC_QUSE_EXTRA				0x0ac
70#define EMC_ODT_WRITE				0x0b0
71#define EMC_ODT_READ				0x0b4
72#define EMC_WEXT				0x0b8
73#define EMC_CTT					0x0bc
74#define EMC_MRS_WAIT_CNT			0x0c8
75#define EMC_MRS					0x0cc
76#define EMC_EMRS				0x0d0
77#define EMC_SELF_REF				0x0e0
78#define EMC_MRW					0x0e8
79#define EMC_XM2DQSPADCTRL3			0x0f8
80#define EMC_FBIO_SPARE				0x100
81#define EMC_FBIO_CFG5				0x104
82#define EMC_FBIO_CFG6				0x114
83#define EMC_CFG_RSV				0x120
84#define EMC_AUTO_CAL_CONFIG			0x2a4
85#define EMC_AUTO_CAL_INTERVAL			0x2a8
86#define EMC_AUTO_CAL_STATUS			0x2ac
87#define EMC_STATUS				0x2b4
88#define EMC_CFG_2				0x2b8
89#define EMC_CFG_DIG_DLL				0x2bc
90#define EMC_CFG_DIG_DLL_PERIOD			0x2c0
91#define EMC_CTT_DURATION			0x2d8
92#define EMC_CTT_TERM_CTRL			0x2dc
93#define EMC_ZCAL_INTERVAL			0x2e0
94#define EMC_ZCAL_WAIT_CNT			0x2e4
95#define EMC_ZQ_CAL				0x2ec
96#define EMC_XM2CMDPADCTRL			0x2f0
97#define EMC_XM2DQSPADCTRL2			0x2fc
98#define EMC_XM2DQPADCTRL2			0x304
99#define EMC_XM2CLKPADCTRL			0x308
100#define EMC_XM2COMPPADCTRL			0x30c
101#define EMC_XM2VTTGENPADCTRL			0x310
102#define EMC_XM2VTTGENPADCTRL2			0x314
103#define EMC_XM2QUSEPADCTRL			0x318
104#define EMC_DLL_XFORM_DQS0			0x328
105#define EMC_DLL_XFORM_DQS1			0x32c
106#define EMC_DLL_XFORM_DQS2			0x330
107#define EMC_DLL_XFORM_DQS3			0x334
108#define EMC_DLL_XFORM_DQS4			0x338
109#define EMC_DLL_XFORM_DQS5			0x33c
110#define EMC_DLL_XFORM_DQS6			0x340
111#define EMC_DLL_XFORM_DQS7			0x344
112#define EMC_DLL_XFORM_QUSE0			0x348
113#define EMC_DLL_XFORM_QUSE1			0x34c
114#define EMC_DLL_XFORM_QUSE2			0x350
115#define EMC_DLL_XFORM_QUSE3			0x354
116#define EMC_DLL_XFORM_QUSE4			0x358
117#define EMC_DLL_XFORM_QUSE5			0x35c
118#define EMC_DLL_XFORM_QUSE6			0x360
119#define EMC_DLL_XFORM_QUSE7			0x364
120#define EMC_DLL_XFORM_DQ0			0x368
121#define EMC_DLL_XFORM_DQ1			0x36c
122#define EMC_DLL_XFORM_DQ2			0x370
123#define EMC_DLL_XFORM_DQ3			0x374
124#define EMC_DLI_TRIM_TXDQS0			0x3a8
125#define EMC_DLI_TRIM_TXDQS1			0x3ac
126#define EMC_DLI_TRIM_TXDQS2			0x3b0
127#define EMC_DLI_TRIM_TXDQS3			0x3b4
128#define EMC_DLI_TRIM_TXDQS4			0x3b8
129#define EMC_DLI_TRIM_TXDQS5			0x3bc
130#define EMC_DLI_TRIM_TXDQS6			0x3c0
131#define EMC_DLI_TRIM_TXDQS7			0x3c4
132#define EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE	0x3c8
133#define EMC_STALL_THEN_EXE_AFTER_CLKCHANGE	0x3cc
134#define EMC_UNSTALL_RW_AFTER_CLKCHANGE		0x3d0
135#define EMC_SEL_DPD_CTRL			0x3d8
136#define EMC_PRE_REFRESH_REQ_CNT			0x3dc
137#define EMC_DYN_SELF_REF_CONTROL		0x3e0
138#define EMC_TXSRDLL				0x3e4
139
140#define EMC_STATUS_TIMING_UPDATE_STALLED	BIT(23)
141
142#define EMC_MODE_SET_DLL_RESET			BIT(8)
143#define EMC_MODE_SET_LONG_CNT			BIT(26)
144
145#define EMC_SELF_REF_CMD_ENABLED		BIT(0)
146
147#define DRAM_DEV_SEL_ALL			(0 << 30)
148#define DRAM_DEV_SEL_0				BIT(31)
149#define DRAM_DEV_SEL_1				BIT(30)
150#define DRAM_BROADCAST(num) \
151	((num) > 1 ? DRAM_DEV_SEL_ALL : DRAM_DEV_SEL_0)
152
153#define EMC_ZQ_CAL_CMD				BIT(0)
154#define EMC_ZQ_CAL_LONG				BIT(4)
155#define EMC_ZQ_CAL_LONG_CMD_DEV0 \
156	(DRAM_DEV_SEL_0 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
157#define EMC_ZQ_CAL_LONG_CMD_DEV1 \
158	(DRAM_DEV_SEL_1 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
159
160#define EMC_DBG_READ_MUX_ASSEMBLY		BIT(0)
161#define EMC_DBG_WRITE_MUX_ACTIVE		BIT(1)
162#define EMC_DBG_FORCE_UPDATE			BIT(2)
163#define EMC_DBG_CFG_PRIORITY			BIT(24)
164
165#define EMC_CFG5_QUSE_MODE_SHIFT		13
166#define EMC_CFG5_QUSE_MODE_MASK			(7 << EMC_CFG5_QUSE_MODE_SHIFT)
167
168#define EMC_CFG5_QUSE_MODE_INTERNAL_LPBK	2
169#define EMC_CFG5_QUSE_MODE_PULSE_INTERN		3
170
171#define EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE	BIT(9)
172
173#define EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE	BIT(10)
174
175#define EMC_XM2QUSEPADCTRL_IVREF_ENABLE		BIT(4)
176
177#define EMC_XM2DQSPADCTRL2_VREF_ENABLE		BIT(5)
178#define EMC_XM2DQSPADCTRL3_VREF_ENABLE		BIT(5)
179
180#define EMC_AUTO_CAL_STATUS_ACTIVE		BIT(31)
181
182#define	EMC_FBIO_CFG5_DRAM_TYPE_MASK		0x3
183
184#define EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK	0x3ff
185#define EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT	16
186#define EMC_MRS_WAIT_CNT_LONG_WAIT_MASK \
187	(0x3ff << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
188
189#define EMC_REFCTRL_DEV_SEL_MASK		0x3
190#define EMC_REFCTRL_ENABLE			BIT(31)
191#define EMC_REFCTRL_ENABLE_ALL(num) \
192	(((num) > 1 ? 0 : 2) | EMC_REFCTRL_ENABLE)
193#define EMC_REFCTRL_DISABLE_ALL(num)		((num) > 1 ? 0 : 2)
194
195#define EMC_CFG_PERIODIC_QRST			BIT(21)
196#define EMC_CFG_DYN_SREF_ENABLE			BIT(28)
197
198#define EMC_CLKCHANGE_REQ_ENABLE		BIT(0)
199#define EMC_CLKCHANGE_PD_ENABLE			BIT(1)
200#define EMC_CLKCHANGE_SR_ENABLE			BIT(2)
201
202#define EMC_TIMING_UPDATE			BIT(0)
203
204#define EMC_REFRESH_OVERFLOW_INT		BIT(3)
205#define EMC_CLKCHANGE_COMPLETE_INT		BIT(4)
206
207enum emc_dram_type {
208	DRAM_TYPE_DDR3,
209	DRAM_TYPE_DDR1,
210	DRAM_TYPE_LPDDR2,
211	DRAM_TYPE_DDR2,
212};
213
214enum emc_dll_change {
215	DLL_CHANGE_NONE,
216	DLL_CHANGE_ON,
217	DLL_CHANGE_OFF
218};
219
220static const u16 emc_timing_registers[] = {
221	[0] = EMC_RC,
222	[1] = EMC_RFC,
223	[2] = EMC_RAS,
224	[3] = EMC_RP,
225	[4] = EMC_R2W,
226	[5] = EMC_W2R,
227	[6] = EMC_R2P,
228	[7] = EMC_W2P,
229	[8] = EMC_RD_RCD,
230	[9] = EMC_WR_RCD,
231	[10] = EMC_RRD,
232	[11] = EMC_REXT,
233	[12] = EMC_WEXT,
234	[13] = EMC_WDV,
235	[14] = EMC_QUSE,
236	[15] = EMC_QRST,
237	[16] = EMC_QSAFE,
238	[17] = EMC_RDV,
239	[18] = EMC_REFRESH,
240	[19] = EMC_BURST_REFRESH_NUM,
241	[20] = EMC_PRE_REFRESH_REQ_CNT,
242	[21] = EMC_PDEX2WR,
243	[22] = EMC_PDEX2RD,
244	[23] = EMC_PCHG2PDEN,
245	[24] = EMC_ACT2PDEN,
246	[25] = EMC_AR2PDEN,
247	[26] = EMC_RW2PDEN,
248	[27] = EMC_TXSR,
249	[28] = EMC_TXSRDLL,
250	[29] = EMC_TCKE,
251	[30] = EMC_TFAW,
252	[31] = EMC_TRPAB,
253	[32] = EMC_TCLKSTABLE,
254	[33] = EMC_TCLKSTOP,
255	[34] = EMC_TREFBW,
256	[35] = EMC_QUSE_EXTRA,
257	[36] = EMC_FBIO_CFG6,
258	[37] = EMC_ODT_WRITE,
259	[38] = EMC_ODT_READ,
260	[39] = EMC_FBIO_CFG5,
261	[40] = EMC_CFG_DIG_DLL,
262	[41] = EMC_CFG_DIG_DLL_PERIOD,
263	[42] = EMC_DLL_XFORM_DQS0,
264	[43] = EMC_DLL_XFORM_DQS1,
265	[44] = EMC_DLL_XFORM_DQS2,
266	[45] = EMC_DLL_XFORM_DQS3,
267	[46] = EMC_DLL_XFORM_DQS4,
268	[47] = EMC_DLL_XFORM_DQS5,
269	[48] = EMC_DLL_XFORM_DQS6,
270	[49] = EMC_DLL_XFORM_DQS7,
271	[50] = EMC_DLL_XFORM_QUSE0,
272	[51] = EMC_DLL_XFORM_QUSE1,
273	[52] = EMC_DLL_XFORM_QUSE2,
274	[53] = EMC_DLL_XFORM_QUSE3,
275	[54] = EMC_DLL_XFORM_QUSE4,
276	[55] = EMC_DLL_XFORM_QUSE5,
277	[56] = EMC_DLL_XFORM_QUSE6,
278	[57] = EMC_DLL_XFORM_QUSE7,
279	[58] = EMC_DLI_TRIM_TXDQS0,
280	[59] = EMC_DLI_TRIM_TXDQS1,
281	[60] = EMC_DLI_TRIM_TXDQS2,
282	[61] = EMC_DLI_TRIM_TXDQS3,
283	[62] = EMC_DLI_TRIM_TXDQS4,
284	[63] = EMC_DLI_TRIM_TXDQS5,
285	[64] = EMC_DLI_TRIM_TXDQS6,
286	[65] = EMC_DLI_TRIM_TXDQS7,
287	[66] = EMC_DLL_XFORM_DQ0,
288	[67] = EMC_DLL_XFORM_DQ1,
289	[68] = EMC_DLL_XFORM_DQ2,
290	[69] = EMC_DLL_XFORM_DQ3,
291	[70] = EMC_XM2CMDPADCTRL,
292	[71] = EMC_XM2DQSPADCTRL2,
293	[72] = EMC_XM2DQPADCTRL2,
294	[73] = EMC_XM2CLKPADCTRL,
295	[74] = EMC_XM2COMPPADCTRL,
296	[75] = EMC_XM2VTTGENPADCTRL,
297	[76] = EMC_XM2VTTGENPADCTRL2,
298	[77] = EMC_XM2QUSEPADCTRL,
299	[78] = EMC_XM2DQSPADCTRL3,
300	[79] = EMC_CTT_TERM_CTRL,
301	[80] = EMC_ZCAL_INTERVAL,
302	[81] = EMC_ZCAL_WAIT_CNT,
303	[82] = EMC_MRS_WAIT_CNT,
304	[83] = EMC_AUTO_CAL_CONFIG,
305	[84] = EMC_CTT,
306	[85] = EMC_CTT_DURATION,
307	[86] = EMC_DYN_SELF_REF_CONTROL,
308	[87] = EMC_FBIO_SPARE,
309	[88] = EMC_CFG_RSV,
310};
311
312struct emc_timing {
313	unsigned long rate;
314
315	u32 data[ARRAY_SIZE(emc_timing_registers)];
316
317	u32 emc_auto_cal_interval;
318	u32 emc_mode_1;
319	u32 emc_mode_2;
320	u32 emc_mode_reset;
321	u32 emc_zcal_cnt_long;
322	bool emc_cfg_periodic_qrst;
323	bool emc_cfg_dyn_self_ref;
324};
325
326struct tegra_emc {
327	struct device *dev;
328	struct tegra_mc *mc;
329	struct notifier_block clk_nb;
330	struct clk *clk;
331	void __iomem *regs;
332	unsigned int irq;
333	bool bad_state;
334
335	struct emc_timing *new_timing;
336	struct emc_timing *timings;
337	unsigned int num_timings;
338
339	u32 mc_override;
340	u32 emc_cfg;
341
342	u32 emc_mode_1;
343	u32 emc_mode_2;
344	u32 emc_mode_reset;
345
346	bool vref_cal_toggle : 1;
347	bool zcal_long : 1;
348	bool dll_on : 1;
349
350	struct {
351		struct dentry *root;
352		unsigned long min_rate;
353		unsigned long max_rate;
354	} debugfs;
355};
356
357static int emc_seq_update_timing(struct tegra_emc *emc)
358{
359	u32 val;
360	int err;
361
362	writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL);
363
364	err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_STATUS, val,
365				!(val & EMC_STATUS_TIMING_UPDATE_STALLED),
366				1, 200);
367	if (err) {
368		dev_err(emc->dev, "failed to update timing: %d\n", err);
369		return err;
370	}
371
372	return 0;
373}
374
375static irqreturn_t tegra_emc_isr(int irq, void *data)
376{
377	struct tegra_emc *emc = data;
378	u32 intmask = EMC_REFRESH_OVERFLOW_INT;
379	u32 status;
380
381	status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask;
382	if (!status)
383		return IRQ_NONE;
384
385	/* notify about HW problem */
386	if (status & EMC_REFRESH_OVERFLOW_INT)
387		dev_err_ratelimited(emc->dev,
388				    "refresh request overflow timeout\n");
389
390	/* clear interrupts */
391	writel_relaxed(status, emc->regs + EMC_INTSTATUS);
392
393	return IRQ_HANDLED;
394}
395
396static struct emc_timing *emc_find_timing(struct tegra_emc *emc,
397					  unsigned long rate)
398{
399	struct emc_timing *timing = NULL;
400	unsigned int i;
401
402	for (i = 0; i < emc->num_timings; i++) {
403		if (emc->timings[i].rate >= rate) {
404			timing = &emc->timings[i];
405			break;
406		}
407	}
408
409	if (!timing) {
410		dev_err(emc->dev, "no timing for rate %lu\n", rate);
411		return NULL;
412	}
413
414	return timing;
415}
416
417static bool emc_dqs_preset(struct tegra_emc *emc, struct emc_timing *timing,
418			   bool *schmitt_to_vref)
419{
420	bool preset = false;
421	u32 val;
422
423	if (timing->data[71] & EMC_XM2DQSPADCTRL2_VREF_ENABLE) {
424		val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL2);
425
426		if (!(val & EMC_XM2DQSPADCTRL2_VREF_ENABLE)) {
427			val |= EMC_XM2DQSPADCTRL2_VREF_ENABLE;
428			writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL2);
429
430			preset = true;
431		}
432	}
433
434	if (timing->data[78] & EMC_XM2DQSPADCTRL3_VREF_ENABLE) {
435		val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL3);
436
437		if (!(val & EMC_XM2DQSPADCTRL3_VREF_ENABLE)) {
438			val |= EMC_XM2DQSPADCTRL3_VREF_ENABLE;
439			writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL3);
440
441			preset = true;
442		}
443	}
444
445	if (timing->data[77] & EMC_XM2QUSEPADCTRL_IVREF_ENABLE) {
446		val = readl_relaxed(emc->regs + EMC_XM2QUSEPADCTRL);
447
448		if (!(val & EMC_XM2QUSEPADCTRL_IVREF_ENABLE)) {
449			val |= EMC_XM2QUSEPADCTRL_IVREF_ENABLE;
450			writel_relaxed(val, emc->regs + EMC_XM2QUSEPADCTRL);
451
452			*schmitt_to_vref = true;
453			preset = true;
454		}
455	}
456
457	return preset;
458}
459
460static int emc_prepare_mc_clk_cfg(struct tegra_emc *emc, unsigned long rate)
461{
462	struct tegra_mc *mc = emc->mc;
463	unsigned int misc0_index = 16;
464	unsigned int i;
465	bool same;
466
467	for (i = 0; i < mc->num_timings; i++) {
468		if (mc->timings[i].rate != rate)
469			continue;
470
471		if (mc->timings[i].emem_data[misc0_index] & BIT(27))
472			same = true;
473		else
474			same = false;
475
476		return tegra20_clk_prepare_emc_mc_same_freq(emc->clk, same);
477	}
478
479	return -EINVAL;
480}
481
482static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
483{
484	struct emc_timing *timing = emc_find_timing(emc, rate);
485	enum emc_dll_change dll_change;
486	enum emc_dram_type dram_type;
487	bool schmitt_to_vref = false;
488	unsigned int pre_wait = 0;
489	bool qrst_used = false;
490	unsigned int dram_num;
491	unsigned int i;
492	u32 fbio_cfg5;
493	u32 emc_dbg;
494	u32 val;
495	int err;
496
497	if (!timing || emc->bad_state)
498		return -EINVAL;
499
500	dev_dbg(emc->dev, "%s: using timing rate %lu for requested rate %lu\n",
501		__func__, timing->rate, rate);
502
503	emc->bad_state = true;
504
505	err = emc_prepare_mc_clk_cfg(emc, rate);
506	if (err) {
507		dev_err(emc->dev, "mc clock preparation failed: %d\n", err);
508		return err;
509	}
510
511	emc->vref_cal_toggle = false;
512	emc->mc_override = mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
513	emc->emc_cfg = readl_relaxed(emc->regs + EMC_CFG);
514	emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
515
516	if (emc->dll_on == !!(timing->emc_mode_1 & 0x1))
517		dll_change = DLL_CHANGE_NONE;
518	else if (timing->emc_mode_1 & 0x1)
519		dll_change = DLL_CHANGE_ON;
520	else
521		dll_change = DLL_CHANGE_OFF;
522
523	emc->dll_on = !!(timing->emc_mode_1 & 0x1);
524
525	if (timing->data[80] && !readl_relaxed(emc->regs + EMC_ZCAL_INTERVAL))
526		emc->zcal_long = true;
527	else
528		emc->zcal_long = false;
529
530	fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
531	dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
532
533	dram_num = tegra_mc_get_emem_device_count(emc->mc);
534
535	/* disable dynamic self-refresh */
536	if (emc->emc_cfg & EMC_CFG_DYN_SREF_ENABLE) {
537		emc->emc_cfg &= ~EMC_CFG_DYN_SREF_ENABLE;
538		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
539
540		pre_wait = 5;
541	}
542
543	/* update MC arbiter settings */
544	val = mc_readl(emc->mc, MC_EMEM_ARB_OUTSTANDING_REQ);
545	if (!(val & MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE) ||
546	    ((val & MC_EMEM_ARB_OUTSTANDING_REQ_MAX_MASK) > 0x50)) {
547
548		val = MC_EMEM_ARB_OUTSTANDING_REQ_LIMIT_ENABLE |
549		      MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE | 0x50;
550		mc_writel(emc->mc, val, MC_EMEM_ARB_OUTSTANDING_REQ);
551		mc_writel(emc->mc, MC_TIMING_UPDATE, MC_TIMING_CONTROL);
552	}
553
554	if (emc->mc_override & MC_EMEM_ARB_OVERRIDE_EACK_MASK)
555		mc_writel(emc->mc,
556			  emc->mc_override & ~MC_EMEM_ARB_OVERRIDE_EACK_MASK,
557			  MC_EMEM_ARB_OVERRIDE);
558
559	/* check DQ/DQS VREF delay */
560	if (emc_dqs_preset(emc, timing, &schmitt_to_vref)) {
561		if (pre_wait < 3)
562			pre_wait = 3;
563	}
564
565	if (pre_wait) {
566		err = emc_seq_update_timing(emc);
567		if (err)
568			return err;
569
570		udelay(pre_wait);
571	}
572
573	/* disable auto-calibration if VREF mode is switching */
574	if (timing->emc_auto_cal_interval) {
575		val = readl_relaxed(emc->regs + EMC_XM2COMPPADCTRL);
576		val ^= timing->data[74];
577
578		if (val & EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE) {
579			writel_relaxed(0, emc->regs + EMC_AUTO_CAL_INTERVAL);
580
581			err = readl_relaxed_poll_timeout_atomic(
582				emc->regs + EMC_AUTO_CAL_STATUS, val,
583				!(val & EMC_AUTO_CAL_STATUS_ACTIVE), 1, 300);
584			if (err) {
585				dev_err(emc->dev,
586					"auto-cal finish timeout: %d\n", err);
587				return err;
588			}
589
590			emc->vref_cal_toggle = true;
591		}
592	}
593
594	/* program shadow registers */
595	for (i = 0; i < ARRAY_SIZE(timing->data); i++) {
596		/* EMC_XM2CLKPADCTRL should be programmed separately */
597		if (i != 73)
598			writel_relaxed(timing->data[i],
599				       emc->regs + emc_timing_registers[i]);
600	}
601
602	err = tegra_mc_write_emem_configuration(emc->mc, timing->rate);
603	if (err)
604		return err;
605
606	/* DDR3: predict MRS long wait count */
607	if (dram_type == DRAM_TYPE_DDR3 && dll_change == DLL_CHANGE_ON) {
608		u32 cnt = 512;
609
610		if (emc->zcal_long)
611			cnt -= dram_num * 256;
612
613		val = timing->data[82] & EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK;
614		if (cnt < val)
615			cnt = val;
616
617		val = timing->data[82] & ~EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
618		val |= (cnt << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT) &
619			EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
620
621		writel_relaxed(val, emc->regs + EMC_MRS_WAIT_CNT);
622	}
623
624	/* this read also completes the writes */
625	val = readl_relaxed(emc->regs + EMC_SEL_DPD_CTRL);
626
627	if (!(val & EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE) && schmitt_to_vref) {
628		u32 cur_mode, new_mode;
629
630		cur_mode = fbio_cfg5 & EMC_CFG5_QUSE_MODE_MASK;
631		cur_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
632
633		new_mode = timing->data[39] & EMC_CFG5_QUSE_MODE_MASK;
634		new_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
635
636		if ((cur_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
637		     cur_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK) ||
638		    (new_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
639		     new_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK))
640			qrst_used = true;
641	}
642
643	/* flow control marker 1 */
644	writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE);
645
646	/* enable periodic reset */
647	if (qrst_used) {
648		writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE,
649			       emc->regs + EMC_DBG);
650		writel_relaxed(emc->emc_cfg | EMC_CFG_PERIODIC_QRST,
651			       emc->regs + EMC_CFG);
652		writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
653	}
654
655	/* disable auto-refresh to save time after clock change */
656	writel_relaxed(EMC_REFCTRL_DISABLE_ALL(dram_num),
657		       emc->regs + EMC_REFCTRL);
658
659	/* turn off DLL and enter self-refresh on DDR3 */
660	if (dram_type == DRAM_TYPE_DDR3) {
661		if (dll_change == DLL_CHANGE_OFF)
662			writel_relaxed(timing->emc_mode_1,
663				       emc->regs + EMC_EMRS);
664
665		writel_relaxed(DRAM_BROADCAST(dram_num) |
666			       EMC_SELF_REF_CMD_ENABLED,
667			       emc->regs + EMC_SELF_REF);
668	}
669
670	/* flow control marker 2 */
671	writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_AFTER_CLKCHANGE);
672
673	/* enable write-active MUX, update unshadowed pad control */
674	writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE, emc->regs + EMC_DBG);
675	writel_relaxed(timing->data[73], emc->regs + EMC_XM2CLKPADCTRL);
676
677	/* restore periodic QRST and disable write-active MUX */
678	val = !!(emc->emc_cfg & EMC_CFG_PERIODIC_QRST);
679	if (qrst_used || timing->emc_cfg_periodic_qrst != val) {
680		if (timing->emc_cfg_periodic_qrst)
681			emc->emc_cfg |= EMC_CFG_PERIODIC_QRST;
682		else
683			emc->emc_cfg &= ~EMC_CFG_PERIODIC_QRST;
684
685		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
686	}
687	writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
688
689	/* exit self-refresh on DDR3 */
690	if (dram_type == DRAM_TYPE_DDR3)
691		writel_relaxed(DRAM_BROADCAST(dram_num),
692			       emc->regs + EMC_SELF_REF);
693
694	/* set DRAM-mode registers */
695	if (dram_type == DRAM_TYPE_DDR3) {
696		if (timing->emc_mode_1 != emc->emc_mode_1)
697			writel_relaxed(timing->emc_mode_1,
698				       emc->regs + EMC_EMRS);
699
700		if (timing->emc_mode_2 != emc->emc_mode_2)
701			writel_relaxed(timing->emc_mode_2,
702				       emc->regs + EMC_EMRS);
703
704		if (timing->emc_mode_reset != emc->emc_mode_reset ||
705		    dll_change == DLL_CHANGE_ON) {
706			val = timing->emc_mode_reset;
707			if (dll_change == DLL_CHANGE_ON) {
708				val |= EMC_MODE_SET_DLL_RESET;
709				val |= EMC_MODE_SET_LONG_CNT;
710			} else {
711				val &= ~EMC_MODE_SET_DLL_RESET;
712			}
713			writel_relaxed(val, emc->regs + EMC_MRS);
714		}
715	} else {
716		if (timing->emc_mode_2 != emc->emc_mode_2)
717			writel_relaxed(timing->emc_mode_2,
718				       emc->regs + EMC_MRW);
719
720		if (timing->emc_mode_1 != emc->emc_mode_1)
721			writel_relaxed(timing->emc_mode_1,
722				       emc->regs + EMC_MRW);
723	}
724
725	emc->emc_mode_1 = timing->emc_mode_1;
726	emc->emc_mode_2 = timing->emc_mode_2;
727	emc->emc_mode_reset = timing->emc_mode_reset;
728
729	/* issue ZCAL command if turning ZCAL on */
730	if (emc->zcal_long) {
731		writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV0,
732			       emc->regs + EMC_ZQ_CAL);
733
734		if (dram_num > 1)
735			writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV1,
736				       emc->regs + EMC_ZQ_CAL);
737	}
738
739	/* flow control marker 3 */
740	writel_relaxed(0x1, emc->regs + EMC_UNSTALL_RW_AFTER_CLKCHANGE);
741
742	/*
743	 * Read and discard an arbitrary MC register (Note: EMC registers
744	 * can't be used) to ensure the register writes are completed.
745	 */
746	mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
747
748	return 0;
749}
750
751static int emc_complete_timing_change(struct tegra_emc *emc,
752				      unsigned long rate)
753{
754	struct emc_timing *timing = emc_find_timing(emc, rate);
755	unsigned int dram_num;
756	int err;
757	u32 v;
758
759	err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, v,
760						v & EMC_CLKCHANGE_COMPLETE_INT,
761						1, 100);
762	if (err) {
763		dev_err(emc->dev, "emc-car handshake timeout: %d\n", err);
764		return err;
765	}
766
767	/* re-enable auto-refresh */
768	dram_num = tegra_mc_get_emem_device_count(emc->mc);
769	writel_relaxed(EMC_REFCTRL_ENABLE_ALL(dram_num),
770		       emc->regs + EMC_REFCTRL);
771
772	/* restore auto-calibration */
773	if (emc->vref_cal_toggle)
774		writel_relaxed(timing->emc_auto_cal_interval,
775			       emc->regs + EMC_AUTO_CAL_INTERVAL);
776
777	/* restore dynamic self-refresh */
778	if (timing->emc_cfg_dyn_self_ref) {
779		emc->emc_cfg |= EMC_CFG_DYN_SREF_ENABLE;
780		writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
781	}
782
783	/* set number of clocks to wait after each ZQ command */
784	if (emc->zcal_long)
785		writel_relaxed(timing->emc_zcal_cnt_long,
786			       emc->regs + EMC_ZCAL_WAIT_CNT);
787
788	/* wait for writes to settle */
789	udelay(2);
790
791	/* update restored timing */
792	err = emc_seq_update_timing(emc);
793	if (!err)
794		emc->bad_state = false;
795
796	/* restore early ACK */
797	mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);
798
799	return err;
800}
801
802static int emc_unprepare_timing_change(struct tegra_emc *emc,
803				       unsigned long rate)
804{
805	if (!emc->bad_state) {
806		/* shouldn't ever happen in practice */
807		dev_err(emc->dev, "timing configuration can't be reverted\n");
808		emc->bad_state = true;
809	}
810
811	return 0;
812}
813
814static int emc_clk_change_notify(struct notifier_block *nb,
815				 unsigned long msg, void *data)
816{
817	struct tegra_emc *emc = container_of(nb, struct tegra_emc, clk_nb);
818	struct clk_notifier_data *cnd = data;
819	int err;
820
821	switch (msg) {
822	case PRE_RATE_CHANGE:
823		/*
824		 * Disable interrupt since read accesses are prohibited after
825		 * stalling.
826		 */
827		disable_irq(emc->irq);
828		err = emc_prepare_timing_change(emc, cnd->new_rate);
829		enable_irq(emc->irq);
830		break;
831
832	case ABORT_RATE_CHANGE:
833		err = emc_unprepare_timing_change(emc, cnd->old_rate);
834		break;
835
836	case POST_RATE_CHANGE:
837		err = emc_complete_timing_change(emc, cnd->new_rate);
838		break;
839
840	default:
841		return NOTIFY_DONE;
842	}
843
844	return notifier_from_errno(err);
845}
846
847static int load_one_timing_from_dt(struct tegra_emc *emc,
848				   struct emc_timing *timing,
849				   struct device_node *node)
850{
851	u32 value;
852	int err;
853
854	err = of_property_read_u32(node, "clock-frequency", &value);
855	if (err) {
856		dev_err(emc->dev, "timing %pOF: failed to read rate: %d\n",
857			node, err);
858		return err;
859	}
860
861	timing->rate = value;
862
863	err = of_property_read_u32_array(node, "nvidia,emc-configuration",
864					 timing->data,
865					 ARRAY_SIZE(emc_timing_registers));
866	if (err) {
867		dev_err(emc->dev,
868			"timing %pOF: failed to read emc timing data: %d\n",
869			node, err);
870		return err;
871	}
872
873#define EMC_READ_BOOL(prop, dtprop) \
874	timing->prop = of_property_read_bool(node, dtprop);
875
876#define EMC_READ_U32(prop, dtprop) \
877	err = of_property_read_u32(node, dtprop, &timing->prop); \
878	if (err) { \
879		dev_err(emc->dev, \
880			"timing %pOFn: failed to read " #prop ": %d\n", \
881			node, err); \
882		return err; \
883	}
884
885	EMC_READ_U32(emc_auto_cal_interval, "nvidia,emc-auto-cal-interval")
886	EMC_READ_U32(emc_mode_1, "nvidia,emc-mode-1")
887	EMC_READ_U32(emc_mode_2, "nvidia,emc-mode-2")
888	EMC_READ_U32(emc_mode_reset, "nvidia,emc-mode-reset")
889	EMC_READ_U32(emc_zcal_cnt_long, "nvidia,emc-zcal-cnt-long")
890	EMC_READ_BOOL(emc_cfg_dyn_self_ref, "nvidia,emc-cfg-dyn-self-ref")
891	EMC_READ_BOOL(emc_cfg_periodic_qrst, "nvidia,emc-cfg-periodic-qrst")
892
893#undef EMC_READ_U32
894#undef EMC_READ_BOOL
895
896	dev_dbg(emc->dev, "%s: %pOF: rate %lu\n", __func__, node, timing->rate);
897
898	return 0;
899}
900
901static int cmp_timings(const void *_a, const void *_b)
902{
903	const struct emc_timing *a = _a;
904	const struct emc_timing *b = _b;
905
906	if (a->rate < b->rate)
907		return -1;
908
909	if (a->rate > b->rate)
910		return 1;
911
912	return 0;
913}
914
915static int emc_check_mc_timings(struct tegra_emc *emc)
916{
917	struct tegra_mc *mc = emc->mc;
918	unsigned int i;
919
920	if (emc->num_timings != mc->num_timings) {
921		dev_err(emc->dev, "emc/mc timings number mismatch: %u %u\n",
922			emc->num_timings, mc->num_timings);
923		return -EINVAL;
924	}
925
926	for (i = 0; i < mc->num_timings; i++) {
927		if (emc->timings[i].rate != mc->timings[i].rate) {
928			dev_err(emc->dev,
929				"emc/mc timing rate mismatch: %lu %lu\n",
930				emc->timings[i].rate, mc->timings[i].rate);
931			return -EINVAL;
932		}
933	}
934
935	return 0;
936}
937
938static int emc_load_timings_from_dt(struct tegra_emc *emc,
939				    struct device_node *node)
940{
941	struct device_node *child;
942	struct emc_timing *timing;
943	int child_count;
944	int err;
945
946	child_count = of_get_child_count(node);
947	if (!child_count) {
948		dev_err(emc->dev, "no memory timings in: %pOF\n", node);
949		return -EINVAL;
950	}
951
952	emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing),
953				    GFP_KERNEL);
954	if (!emc->timings)
955		return -ENOMEM;
956
957	emc->num_timings = child_count;
958	timing = emc->timings;
959
960	for_each_child_of_node(node, child) {
961		err = load_one_timing_from_dt(emc, timing++, child);
962		if (err) {
963			of_node_put(child);
964			return err;
965		}
966	}
967
968	sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
969	     NULL);
970
971	err = emc_check_mc_timings(emc);
972	if (err)
973		return err;
974
975	dev_info(emc->dev,
976		 "got %u timings for RAM code %u (min %luMHz max %luMHz)\n",
977		 emc->num_timings,
978		 tegra_read_ram_code(),
979		 emc->timings[0].rate / 1000000,
980		 emc->timings[emc->num_timings - 1].rate / 1000000);
981
982	return 0;
983}
984
985static struct device_node *emc_find_node_by_ram_code(struct device *dev)
986{
987	struct device_node *np;
988	u32 value, ram_code;
989	int err;
990
991	ram_code = tegra_read_ram_code();
992
993	for_each_child_of_node(dev->of_node, np) {
994		err = of_property_read_u32(np, "nvidia,ram-code", &value);
995		if (err || value != ram_code)
996			continue;
997
998		return np;
999	}
1000
1001	dev_err(dev, "no memory timings for RAM code %u found in device-tree\n",
1002		ram_code);
1003
1004	return NULL;
1005}
1006
1007static int emc_setup_hw(struct tegra_emc *emc)
1008{
1009	u32 intmask = EMC_REFRESH_OVERFLOW_INT;
1010	u32 fbio_cfg5, emc_cfg, emc_dbg;
1011	enum emc_dram_type dram_type;
1012
1013	fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
1014	dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
1015
1016	emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
1017
1018	/* enable EMC and CAR to handshake on PLL divider/source changes */
1019	emc_cfg |= EMC_CLKCHANGE_REQ_ENABLE;
1020
1021	/* configure clock change mode accordingly to DRAM type */
1022	switch (dram_type) {
1023	case DRAM_TYPE_LPDDR2:
1024		emc_cfg |= EMC_CLKCHANGE_PD_ENABLE;
1025		emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
1026		break;
1027
1028	default:
1029		emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
1030		emc_cfg &= ~EMC_CLKCHANGE_PD_ENABLE;
1031		break;
1032	}
1033
1034	writel_relaxed(emc_cfg, emc->regs + EMC_CFG_2);
1035
1036	/* initialize interrupt */
1037	writel_relaxed(intmask, emc->regs + EMC_INTMASK);
1038	writel_relaxed(0xffffffff, emc->regs + EMC_INTSTATUS);
1039
1040	/* ensure that unwanted debug features are disabled */
1041	emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
1042	emc_dbg |= EMC_DBG_CFG_PRIORITY;
1043	emc_dbg &= ~EMC_DBG_READ_MUX_ASSEMBLY;
1044	emc_dbg &= ~EMC_DBG_WRITE_MUX_ACTIVE;
1045	emc_dbg &= ~EMC_DBG_FORCE_UPDATE;
1046	writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
1047
1048	return 0;
1049}
1050
1051static long emc_round_rate(unsigned long rate,
1052			   unsigned long min_rate,
1053			   unsigned long max_rate,
1054			   void *arg)
1055{
1056	struct emc_timing *timing = NULL;
1057	struct tegra_emc *emc = arg;
1058	unsigned int i;
1059
1060	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
1061
1062	for (i = 0; i < emc->num_timings; i++) {
1063		if (emc->timings[i].rate < rate && i != emc->num_timings - 1)
1064			continue;
1065
1066		if (emc->timings[i].rate > max_rate) {
1067			i = max(i, 1u) - 1;
1068
1069			if (emc->timings[i].rate < min_rate)
1070				break;
1071		}
1072
1073		if (emc->timings[i].rate < min_rate)
1074			continue;
1075
1076		timing = &emc->timings[i];
1077		break;
1078	}
1079
1080	if (!timing) {
1081		dev_err(emc->dev, "no timing for rate %lu min %lu max %lu\n",
1082			rate, min_rate, max_rate);
1083		return -EINVAL;
1084	}
1085
1086	return timing->rate;
1087}
1088
1089/*
1090 * debugfs interface
1091 *
1092 * The memory controller driver exposes some files in debugfs that can be used
1093 * to control the EMC frequency. The top-level directory can be found here:
1094 *
1095 *   /sys/kernel/debug/emc
1096 *
1097 * It contains the following files:
1098 *
1099 *   - available_rates: This file contains a list of valid, space-separated
1100 *     EMC frequencies.
1101 *
1102 *   - min_rate: Writing a value to this file sets the given frequency as the
1103 *       floor of the permitted range. If this is higher than the currently
1104 *       configured EMC frequency, this will cause the frequency to be
1105 *       increased so that it stays within the valid range.
1106 *
1107 *   - max_rate: Similarily to the min_rate file, writing a value to this file
1108 *       sets the given frequency as the ceiling of the permitted range. If
1109 *       the value is lower than the currently configured EMC frequency, this
1110 *       will cause the frequency to be decreased so that it stays within the
1111 *       valid range.
1112 */
1113
1114static bool tegra_emc_validate_rate(struct tegra_emc *emc, unsigned long rate)
1115{
1116	unsigned int i;
1117
1118	for (i = 0; i < emc->num_timings; i++)
1119		if (rate == emc->timings[i].rate)
1120			return true;
1121
1122	return false;
1123}
1124
1125static int tegra_emc_debug_available_rates_show(struct seq_file *s, void *data)
1126{
1127	struct tegra_emc *emc = s->private;
1128	const char *prefix = "";
1129	unsigned int i;
1130
1131	for (i = 0; i < emc->num_timings; i++) {
1132		seq_printf(s, "%s%lu", prefix, emc->timings[i].rate);
1133		prefix = " ";
1134	}
1135
1136	seq_puts(s, "\n");
1137
1138	return 0;
1139}
1140
1141static int tegra_emc_debug_available_rates_open(struct inode *inode,
1142						struct file *file)
1143{
1144	return single_open(file, tegra_emc_debug_available_rates_show,
1145			   inode->i_private);
1146}
1147
1148static const struct file_operations tegra_emc_debug_available_rates_fops = {
1149	.open = tegra_emc_debug_available_rates_open,
1150	.read = seq_read,
1151	.llseek = seq_lseek,
1152	.release = single_release,
1153};
1154
1155static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
1156{
1157	struct tegra_emc *emc = data;
1158
1159	*rate = emc->debugfs.min_rate;
1160
1161	return 0;
1162}
1163
1164static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
1165{
1166	struct tegra_emc *emc = data;
1167	int err;
1168
1169	if (!tegra_emc_validate_rate(emc, rate))
1170		return -EINVAL;
1171
1172	err = clk_set_min_rate(emc->clk, rate);
1173	if (err < 0)
1174		return err;
1175
1176	emc->debugfs.min_rate = rate;
1177
1178	return 0;
1179}
1180
1181DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
1182			tegra_emc_debug_min_rate_get,
1183			tegra_emc_debug_min_rate_set, "%llu\n");
1184
1185static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
1186{
1187	struct tegra_emc *emc = data;
1188
1189	*rate = emc->debugfs.max_rate;
1190
1191	return 0;
1192}
1193
1194static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
1195{
1196	struct tegra_emc *emc = data;
1197	int err;
1198
1199	if (!tegra_emc_validate_rate(emc, rate))
1200		return -EINVAL;
1201
1202	err = clk_set_max_rate(emc->clk, rate);
1203	if (err < 0)
1204		return err;
1205
1206	emc->debugfs.max_rate = rate;
1207
1208	return 0;
1209}
1210
1211DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
1212			tegra_emc_debug_max_rate_get,
1213			tegra_emc_debug_max_rate_set, "%llu\n");
1214
1215static void tegra_emc_debugfs_init(struct tegra_emc *emc)
1216{
1217	struct device *dev = emc->dev;
1218	unsigned int i;
1219	int err;
1220
1221	emc->debugfs.min_rate = ULONG_MAX;
1222	emc->debugfs.max_rate = 0;
1223
1224	for (i = 0; i < emc->num_timings; i++) {
1225		if (emc->timings[i].rate < emc->debugfs.min_rate)
1226			emc->debugfs.min_rate = emc->timings[i].rate;
1227
1228		if (emc->timings[i].rate > emc->debugfs.max_rate)
1229			emc->debugfs.max_rate = emc->timings[i].rate;
1230	}
1231
1232	if (!emc->num_timings) {
1233		emc->debugfs.min_rate = clk_get_rate(emc->clk);
1234		emc->debugfs.max_rate = emc->debugfs.min_rate;
1235	}
1236
1237	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
1238				 emc->debugfs.max_rate);
1239	if (err < 0) {
1240		dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
1241			emc->debugfs.min_rate, emc->debugfs.max_rate,
1242			emc->clk);
1243	}
1244
1245	emc->debugfs.root = debugfs_create_dir("emc", NULL);
1246	if (!emc->debugfs.root) {
1247		dev_err(emc->dev, "failed to create debugfs directory\n");
1248		return;
1249	}
1250
1251	debugfs_create_file("available_rates", 0444, emc->debugfs.root,
1252			    emc, &tegra_emc_debug_available_rates_fops);
1253	debugfs_create_file("min_rate", 0644, emc->debugfs.root,
1254			    emc, &tegra_emc_debug_min_rate_fops);
1255	debugfs_create_file("max_rate", 0644, emc->debugfs.root,
1256			    emc, &tegra_emc_debug_max_rate_fops);
1257}
1258
1259static int tegra_emc_probe(struct platform_device *pdev)
1260{
1261	struct platform_device *mc;
1262	struct device_node *np;
1263	struct tegra_emc *emc;
1264	int err;
1265
1266	if (of_get_child_count(pdev->dev.of_node) == 0) {
1267		dev_info(&pdev->dev,
1268			 "device-tree node doesn't have memory timings\n");
1269		return -ENODEV;
1270	}
1271
1272	np = of_parse_phandle(pdev->dev.of_node, "nvidia,memory-controller", 0);
1273	if (!np) {
1274		dev_err(&pdev->dev, "could not get memory controller node\n");
1275		return -ENOENT;
1276	}
1277
1278	mc = of_find_device_by_node(np);
1279	of_node_put(np);
1280	if (!mc)
1281		return -ENOENT;
1282
1283	np = emc_find_node_by_ram_code(&pdev->dev);
1284	if (!np)
1285		return -EINVAL;
1286
1287	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
1288	if (!emc) {
1289		of_node_put(np);
1290		return -ENOMEM;
1291	}
1292
1293	emc->mc = platform_get_drvdata(mc);
1294	if (!emc->mc)
1295		return -EPROBE_DEFER;
1296
1297	emc->clk_nb.notifier_call = emc_clk_change_notify;
1298	emc->dev = &pdev->dev;
1299
1300	err = emc_load_timings_from_dt(emc, np);
1301	of_node_put(np);
1302	if (err)
1303		return err;
1304
1305	emc->regs = devm_platform_ioremap_resource(pdev, 0);
1306	if (IS_ERR(emc->regs))
1307		return PTR_ERR(emc->regs);
1308
1309	err = emc_setup_hw(emc);
1310	if (err)
1311		return err;
1312
1313	err = platform_get_irq(pdev, 0);
1314	if (err < 0) {
1315		dev_err(&pdev->dev, "interrupt not specified: %d\n", err);
1316		return err;
1317	}
1318	emc->irq = err;
1319
1320	err = devm_request_irq(&pdev->dev, emc->irq, tegra_emc_isr, 0,
1321			       dev_name(&pdev->dev), emc);
1322	if (err) {
1323		dev_err(&pdev->dev, "failed to request irq: %d\n", err);
1324		return err;
1325	}
1326
1327	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
1328
1329	emc->clk = devm_clk_get(&pdev->dev, "emc");
1330	if (IS_ERR(emc->clk)) {
1331		err = PTR_ERR(emc->clk);
1332		dev_err(&pdev->dev, "failed to get emc clock: %d\n", err);
1333		goto unset_cb;
1334	}
1335
1336	err = clk_notifier_register(emc->clk, &emc->clk_nb);
1337	if (err) {
1338		dev_err(&pdev->dev, "failed to register clk notifier: %d\n",
1339			err);
1340		goto unset_cb;
1341	}
1342
1343	platform_set_drvdata(pdev, emc);
1344	tegra_emc_debugfs_init(emc);
1345
1346	return 0;
1347
1348unset_cb:
1349	tegra20_clk_set_emc_round_callback(NULL, NULL);
1350
1351	return err;
1352}
1353
1354static int tegra_emc_suspend(struct device *dev)
1355{
1356	struct tegra_emc *emc = dev_get_drvdata(dev);
1357	int err;
1358
1359	/* take exclusive control over the clock's rate */
1360	err = clk_rate_exclusive_get(emc->clk);
1361	if (err) {
1362		dev_err(emc->dev, "failed to acquire clk: %d\n", err);
1363		return err;
1364	}
1365
1366	/* suspending in a bad state will hang machine */
1367	if (WARN(emc->bad_state, "hardware in a bad state\n"))
1368		return -EINVAL;
1369
1370	emc->bad_state = true;
1371
1372	return 0;
1373}
1374
1375static int tegra_emc_resume(struct device *dev)
1376{
1377	struct tegra_emc *emc = dev_get_drvdata(dev);
1378
1379	emc_setup_hw(emc);
1380	emc->bad_state = false;
1381
1382	clk_rate_exclusive_put(emc->clk);
1383
1384	return 0;
1385}
1386
1387static const struct dev_pm_ops tegra_emc_pm_ops = {
1388	.suspend = tegra_emc_suspend,
1389	.resume = tegra_emc_resume,
1390};
1391
1392static const struct of_device_id tegra_emc_of_match[] = {
1393	{ .compatible = "nvidia,tegra30-emc", },
1394	{},
1395};
1396
1397static struct platform_driver tegra_emc_driver = {
1398	.probe = tegra_emc_probe,
1399	.driver = {
1400		.name = "tegra30-emc",
1401		.of_match_table = tegra_emc_of_match,
1402		.pm = &tegra_emc_pm_ops,
1403		.suppress_bind_attrs = true,
1404	},
1405};
1406
1407static int __init tegra_emc_init(void)
1408{
1409	return platform_driver_register(&tegra_emc_driver);
1410}
1411subsys_initcall(tegra_emc_init);
1412