xref: /kernel/linux/linux-5.10/drivers/memory/emif.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * EMIF driver
4 *
5 * Copyright (C) 2012 Texas Instruments, Inc.
6 *
7 * Aneesh V <aneesh@ti.com>
8 * Santosh Shilimkar <santosh.shilimkar@ti.com>
9 */
10#include <linux/err.h>
11#include <linux/kernel.h>
12#include <linux/reboot.h>
13#include <linux/platform_data/emif_plat.h>
14#include <linux/io.h>
15#include <linux/device.h>
16#include <linux/platform_device.h>
17#include <linux/interrupt.h>
18#include <linux/slab.h>
19#include <linux/of.h>
20#include <linux/debugfs.h>
21#include <linux/seq_file.h>
22#include <linux/module.h>
23#include <linux/list.h>
24#include <linux/spinlock.h>
25#include <linux/pm.h>
26
27#include "emif.h"
28#include "jedec_ddr.h"
29#include "of_memory.h"
30
31/**
32 * struct emif_data - Per device static data for driver's use
33 * @duplicate:			Whether the DDR devices attached to this EMIF
34 *				instance are exactly same as that on EMIF1. In
35 *				this case we can save some memory and processing
36 * @temperature_level:		Maximum temperature of LPDDR2 devices attached
37 *				to this EMIF - read from MR4 register. If there
38 *				are two devices attached to this EMIF, this
39 *				value is the maximum of the two temperature
40 *				levels.
41 * @node:			node in the device list
42 * @base:			base address of memory-mapped IO registers.
43 * @dev:			device pointer.
44 * @addressing			table with addressing information from the spec
45 * @regs_cache:			An array of 'struct emif_regs' that stores
46 *				calculated register values for different
47 *				frequencies, to avoid re-calculating them on
48 *				each DVFS transition.
49 * @curr_regs:			The set of register values used in the last
50 *				frequency change (i.e. corresponding to the
51 *				frequency in effect at the moment)
52 * @plat_data:			Pointer to saved platform data.
53 * @debugfs_root:		dentry to the root folder for EMIF in debugfs
54 * @np_ddr:			Pointer to ddr device tree node
55 */
56struct emif_data {
57	u8				duplicate;
58	u8				temperature_level;
59	u8				lpmode;
60	struct list_head		node;
61	unsigned long			irq_state;
62	void __iomem			*base;
63	struct device			*dev;
64	const struct lpddr2_addressing	*addressing;
65	struct emif_regs		*regs_cache[EMIF_MAX_NUM_FREQUENCIES];
66	struct emif_regs		*curr_regs;
67	struct emif_platform_data	*plat_data;
68	struct dentry			*debugfs_root;
69	struct device_node		*np_ddr;
70};
71
72static struct emif_data *emif1;
73static spinlock_t	emif_lock;
74static unsigned long	irq_state;
75static u32		t_ck; /* DDR clock period in ps */
76static LIST_HEAD(device_list);
77
78#ifdef CONFIG_DEBUG_FS
79static void do_emif_regdump_show(struct seq_file *s, struct emif_data *emif,
80	struct emif_regs *regs)
81{
82	u32 type = emif->plat_data->device_info->type;
83	u32 ip_rev = emif->plat_data->ip_rev;
84
85	seq_printf(s, "EMIF register cache dump for %dMHz\n",
86		regs->freq/1000000);
87
88	seq_printf(s, "ref_ctrl_shdw\t: 0x%08x\n", regs->ref_ctrl_shdw);
89	seq_printf(s, "sdram_tim1_shdw\t: 0x%08x\n", regs->sdram_tim1_shdw);
90	seq_printf(s, "sdram_tim2_shdw\t: 0x%08x\n", regs->sdram_tim2_shdw);
91	seq_printf(s, "sdram_tim3_shdw\t: 0x%08x\n", regs->sdram_tim3_shdw);
92
93	if (ip_rev == EMIF_4D) {
94		seq_printf(s, "read_idle_ctrl_shdw_normal\t: 0x%08x\n",
95			regs->read_idle_ctrl_shdw_normal);
96		seq_printf(s, "read_idle_ctrl_shdw_volt_ramp\t: 0x%08x\n",
97			regs->read_idle_ctrl_shdw_volt_ramp);
98	} else if (ip_rev == EMIF_4D5) {
99		seq_printf(s, "dll_calib_ctrl_shdw_normal\t: 0x%08x\n",
100			regs->dll_calib_ctrl_shdw_normal);
101		seq_printf(s, "dll_calib_ctrl_shdw_volt_ramp\t: 0x%08x\n",
102			regs->dll_calib_ctrl_shdw_volt_ramp);
103	}
104
105	if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4) {
106		seq_printf(s, "ref_ctrl_shdw_derated\t: 0x%08x\n",
107			regs->ref_ctrl_shdw_derated);
108		seq_printf(s, "sdram_tim1_shdw_derated\t: 0x%08x\n",
109			regs->sdram_tim1_shdw_derated);
110		seq_printf(s, "sdram_tim3_shdw_derated\t: 0x%08x\n",
111			regs->sdram_tim3_shdw_derated);
112	}
113}
114
115static int emif_regdump_show(struct seq_file *s, void *unused)
116{
117	struct emif_data	*emif	= s->private;
118	struct emif_regs	**regs_cache;
119	int			i;
120
121	if (emif->duplicate)
122		regs_cache = emif1->regs_cache;
123	else
124		regs_cache = emif->regs_cache;
125
126	for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++) {
127		do_emif_regdump_show(s, emif, regs_cache[i]);
128		seq_putc(s, '\n');
129	}
130
131	return 0;
132}
133
134DEFINE_SHOW_ATTRIBUTE(emif_regdump);
135
136static int emif_mr4_show(struct seq_file *s, void *unused)
137{
138	struct emif_data *emif = s->private;
139
140	seq_printf(s, "MR4=%d\n", emif->temperature_level);
141	return 0;
142}
143
144DEFINE_SHOW_ATTRIBUTE(emif_mr4);
145
146static int __init_or_module emif_debugfs_init(struct emif_data *emif)
147{
148	emif->debugfs_root = debugfs_create_dir(dev_name(emif->dev), NULL);
149	debugfs_create_file("regcache_dump", S_IRUGO, emif->debugfs_root, emif,
150			    &emif_regdump_fops);
151	debugfs_create_file("mr4", S_IRUGO, emif->debugfs_root, emif,
152			    &emif_mr4_fops);
153	return 0;
154}
155
156static void __exit emif_debugfs_exit(struct emif_data *emif)
157{
158	debugfs_remove_recursive(emif->debugfs_root);
159	emif->debugfs_root = NULL;
160}
161#else
162static inline int __init_or_module emif_debugfs_init(struct emif_data *emif)
163{
164	return 0;
165}
166
167static inline void __exit emif_debugfs_exit(struct emif_data *emif)
168{
169}
170#endif
171
172/*
173 * Calculate the period of DDR clock from frequency value
174 */
175static void set_ddr_clk_period(u32 freq)
176{
177	/* Divide 10^12 by frequency to get period in ps */
178	t_ck = (u32)DIV_ROUND_UP_ULL(1000000000000ull, freq);
179}
180
181/*
182 * Get bus width used by EMIF. Note that this may be different from the
183 * bus width of the DDR devices used. For instance two 16-bit DDR devices
184 * may be connected to a given CS of EMIF. In this case bus width as far
185 * as EMIF is concerned is 32, where as the DDR bus width is 16 bits.
186 */
187static u32 get_emif_bus_width(struct emif_data *emif)
188{
189	u32		width;
190	void __iomem	*base = emif->base;
191
192	width = (readl(base + EMIF_SDRAM_CONFIG) & NARROW_MODE_MASK)
193			>> NARROW_MODE_SHIFT;
194	width = width == 0 ? 32 : 16;
195
196	return width;
197}
198
199/*
200 * Get the CL from SDRAM_CONFIG register
201 */
202static u32 get_cl(struct emif_data *emif)
203{
204	u32		cl;
205	void __iomem	*base = emif->base;
206
207	cl = (readl(base + EMIF_SDRAM_CONFIG) & CL_MASK) >> CL_SHIFT;
208
209	return cl;
210}
211
212static void set_lpmode(struct emif_data *emif, u8 lpmode)
213{
214	u32 temp;
215	void __iomem *base = emif->base;
216
217	/*
218	 * Workaround for errata i743 - LPDDR2 Power-Down State is Not
219	 * Efficient
220	 *
221	 * i743 DESCRIPTION:
222	 * The EMIF supports power-down state for low power. The EMIF
223	 * automatically puts the SDRAM into power-down after the memory is
224	 * not accessed for a defined number of cycles and the
225	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field is set to 0x4.
226	 * As the EMIF supports automatic output impedance calibration, a ZQ
227	 * calibration long command is issued every time it exits active
228	 * power-down and precharge power-down modes. The EMIF waits and
229	 * blocks any other command during this calibration.
230	 * The EMIF does not allow selective disabling of ZQ calibration upon
231	 * exit of power-down mode. Due to very short periods of power-down
232	 * cycles, ZQ calibration overhead creates bandwidth issues and
233	 * increases overall system power consumption. On the other hand,
234	 * issuing ZQ calibration long commands when exiting self-refresh is
235	 * still required.
236	 *
237	 * WORKAROUND
238	 * Because there is no power consumption benefit of the power-down due
239	 * to the calibration and there is a performance risk, the guideline
240	 * is to not allow power-down state and, therefore, to not have set
241	 * the EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field to 0x4.
242	 */
243	if ((emif->plat_data->ip_rev == EMIF_4D) &&
244	    (lpmode == EMIF_LP_MODE_PWR_DN)) {
245		WARN_ONCE(1,
246			  "REG_LP_MODE = LP_MODE_PWR_DN(4) is prohibited by erratum i743 switch to LP_MODE_SELF_REFRESH(2)\n");
247		/* rollback LP_MODE to Self-refresh mode */
248		lpmode = EMIF_LP_MODE_SELF_REFRESH;
249	}
250
251	temp = readl(base + EMIF_POWER_MANAGEMENT_CONTROL);
252	temp &= ~LP_MODE_MASK;
253	temp |= (lpmode << LP_MODE_SHIFT);
254	writel(temp, base + EMIF_POWER_MANAGEMENT_CONTROL);
255}
256
257static void do_freq_update(void)
258{
259	struct emif_data *emif;
260
261	/*
262	 * Workaround for errata i728: Disable LPMODE during FREQ_UPDATE
263	 *
264	 * i728 DESCRIPTION:
265	 * The EMIF automatically puts the SDRAM into self-refresh mode
266	 * after the EMIF has not performed accesses during
267	 * EMIF_PWR_MGMT_CTRL[7:4] REG_SR_TIM number of DDR clock cycles
268	 * and the EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field is set
269	 * to 0x2. If during a small window the following three events
270	 * occur:
271	 * - The SR_TIMING counter expires
272	 * - And frequency change is requested
273	 * - And OCP access is requested
274	 * Then it causes instable clock on the DDR interface.
275	 *
276	 * WORKAROUND
277	 * To avoid the occurrence of the three events, the workaround
278	 * is to disable the self-refresh when requesting a frequency
279	 * change. Before requesting a frequency change the software must
280	 * program EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x0. When the
281	 * frequency change has been done, the software can reprogram
282	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x2
283	 */
284	list_for_each_entry(emif, &device_list, node) {
285		if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
286			set_lpmode(emif, EMIF_LP_MODE_DISABLE);
287	}
288
289	/*
290	 * TODO: Do FREQ_UPDATE here when an API
291	 * is available for this as part of the new
292	 * clock framework
293	 */
294
295	list_for_each_entry(emif, &device_list, node) {
296		if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
297			set_lpmode(emif, EMIF_LP_MODE_SELF_REFRESH);
298	}
299}
300
301/* Find addressing table entry based on the device's type and density */
302static const struct lpddr2_addressing *get_addressing_table(
303	const struct ddr_device_info *device_info)
304{
305	u32		index, type, density;
306
307	type = device_info->type;
308	density = device_info->density;
309
310	switch (type) {
311	case DDR_TYPE_LPDDR2_S4:
312		index = density - 1;
313		break;
314	case DDR_TYPE_LPDDR2_S2:
315		switch (density) {
316		case DDR_DENSITY_1Gb:
317		case DDR_DENSITY_2Gb:
318			index = density + 3;
319			break;
320		default:
321			index = density - 1;
322		}
323		break;
324	default:
325		return NULL;
326	}
327
328	return &lpddr2_jedec_addressing_table[index];
329}
330
331/*
332 * Find the the right timing table from the array of timing
333 * tables of the device using DDR clock frequency
334 */
335static const struct lpddr2_timings *get_timings_table(struct emif_data *emif,
336		u32 freq)
337{
338	u32				i, min, max, freq_nearest;
339	const struct lpddr2_timings	*timings = NULL;
340	const struct lpddr2_timings	*timings_arr = emif->plat_data->timings;
341	struct				device *dev = emif->dev;
342
343	/* Start with a very high frequency - 1GHz */
344	freq_nearest = 1000000000;
345
346	/*
347	 * Find the timings table such that:
348	 *  1. the frequency range covers the required frequency(safe) AND
349	 *  2. the max_freq is closest to the required frequency(optimal)
350	 */
351	for (i = 0; i < emif->plat_data->timings_arr_size; i++) {
352		max = timings_arr[i].max_freq;
353		min = timings_arr[i].min_freq;
354		if ((freq >= min) && (freq <= max) && (max < freq_nearest)) {
355			freq_nearest = max;
356			timings = &timings_arr[i];
357		}
358	}
359
360	if (!timings)
361		dev_err(dev, "%s: couldn't find timings for - %dHz\n",
362			__func__, freq);
363
364	dev_dbg(dev, "%s: timings table: freq %d, speed bin freq %d\n",
365		__func__, freq, freq_nearest);
366
367	return timings;
368}
369
370static u32 get_sdram_ref_ctrl_shdw(u32 freq,
371		const struct lpddr2_addressing *addressing)
372{
373	u32 ref_ctrl_shdw = 0, val = 0, freq_khz, t_refi;
374
375	/* Scale down frequency and t_refi to avoid overflow */
376	freq_khz = freq / 1000;
377	t_refi = addressing->tREFI_ns / 100;
378
379	/*
380	 * refresh rate to be set is 'tREFI(in us) * freq in MHz
381	 * division by 10000 to account for change in units
382	 */
383	val = t_refi * freq_khz / 10000;
384	ref_ctrl_shdw |= val << REFRESH_RATE_SHIFT;
385
386	return ref_ctrl_shdw;
387}
388
389static u32 get_sdram_tim_1_shdw(const struct lpddr2_timings *timings,
390		const struct lpddr2_min_tck *min_tck,
391		const struct lpddr2_addressing *addressing)
392{
393	u32 tim1 = 0, val = 0;
394
395	val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
396	tim1 |= val << T_WTR_SHIFT;
397
398	if (addressing->num_banks == B8)
399		val = DIV_ROUND_UP(timings->tFAW, t_ck*4);
400	else
401		val = max(min_tck->tRRD, DIV_ROUND_UP(timings->tRRD, t_ck));
402	tim1 |= (val - 1) << T_RRD_SHIFT;
403
404	val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab, t_ck) - 1;
405	tim1 |= val << T_RC_SHIFT;
406
407	val = max(min_tck->tRASmin, DIV_ROUND_UP(timings->tRAS_min, t_ck));
408	tim1 |= (val - 1) << T_RAS_SHIFT;
409
410	val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
411	tim1 |= val << T_WR_SHIFT;
412
413	val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD, t_ck)) - 1;
414	tim1 |= val << T_RCD_SHIFT;
415
416	val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab, t_ck)) - 1;
417	tim1 |= val << T_RP_SHIFT;
418
419	return tim1;
420}
421
422static u32 get_sdram_tim_1_shdw_derated(const struct lpddr2_timings *timings,
423		const struct lpddr2_min_tck *min_tck,
424		const struct lpddr2_addressing *addressing)
425{
426	u32 tim1 = 0, val = 0;
427
428	val = max(min_tck->tWTR, DIV_ROUND_UP(timings->tWTR, t_ck)) - 1;
429	tim1 = val << T_WTR_SHIFT;
430
431	/*
432	 * tFAW is approximately 4 times tRRD. So add 1875*4 = 7500ps
433	 * to tFAW for de-rating
434	 */
435	if (addressing->num_banks == B8) {
436		val = DIV_ROUND_UP(timings->tFAW + 7500, 4 * t_ck) - 1;
437	} else {
438		val = DIV_ROUND_UP(timings->tRRD + 1875, t_ck);
439		val = max(min_tck->tRRD, val) - 1;
440	}
441	tim1 |= val << T_RRD_SHIFT;
442
443	val = DIV_ROUND_UP(timings->tRAS_min + timings->tRPab + 1875, t_ck);
444	tim1 |= (val - 1) << T_RC_SHIFT;
445
446	val = DIV_ROUND_UP(timings->tRAS_min + 1875, t_ck);
447	val = max(min_tck->tRASmin, val) - 1;
448	tim1 |= val << T_RAS_SHIFT;
449
450	val = max(min_tck->tWR, DIV_ROUND_UP(timings->tWR, t_ck)) - 1;
451	tim1 |= val << T_WR_SHIFT;
452
453	val = max(min_tck->tRCD, DIV_ROUND_UP(timings->tRCD + 1875, t_ck));
454	tim1 |= (val - 1) << T_RCD_SHIFT;
455
456	val = max(min_tck->tRPab, DIV_ROUND_UP(timings->tRPab + 1875, t_ck));
457	tim1 |= (val - 1) << T_RP_SHIFT;
458
459	return tim1;
460}
461
462static u32 get_sdram_tim_2_shdw(const struct lpddr2_timings *timings,
463		const struct lpddr2_min_tck *min_tck,
464		const struct lpddr2_addressing *addressing,
465		u32 type)
466{
467	u32 tim2 = 0, val = 0;
468
469	val = min_tck->tCKE - 1;
470	tim2 |= val << T_CKE_SHIFT;
471
472	val = max(min_tck->tRTP, DIV_ROUND_UP(timings->tRTP, t_ck)) - 1;
473	tim2 |= val << T_RTP_SHIFT;
474
475	/* tXSNR = tRFCab_ps + 10 ns(tRFCab_ps for LPDDR2). */
476	val = DIV_ROUND_UP(addressing->tRFCab_ps + 10000, t_ck) - 1;
477	tim2 |= val << T_XSNR_SHIFT;
478
479	/* XSRD same as XSNR for LPDDR2 */
480	tim2 |= val << T_XSRD_SHIFT;
481
482	val = max(min_tck->tXP, DIV_ROUND_UP(timings->tXP, t_ck)) - 1;
483	tim2 |= val << T_XP_SHIFT;
484
485	return tim2;
486}
487
488static u32 get_sdram_tim_3_shdw(const struct lpddr2_timings *timings,
489		const struct lpddr2_min_tck *min_tck,
490		const struct lpddr2_addressing *addressing,
491		u32 type, u32 ip_rev, u32 derated)
492{
493	u32 tim3 = 0, val = 0, t_dqsck;
494
495	val = timings->tRAS_max_ns / addressing->tREFI_ns - 1;
496	val = val > 0xF ? 0xF : val;
497	tim3 |= val << T_RAS_MAX_SHIFT;
498
499	val = DIV_ROUND_UP(addressing->tRFCab_ps, t_ck) - 1;
500	tim3 |= val << T_RFC_SHIFT;
501
502	t_dqsck = (derated == EMIF_DERATED_TIMINGS) ?
503		timings->tDQSCK_max_derated : timings->tDQSCK_max;
504	if (ip_rev == EMIF_4D5)
505		val = DIV_ROUND_UP(t_dqsck + 1000, t_ck) - 1;
506	else
507		val = DIV_ROUND_UP(t_dqsck, t_ck) - 1;
508
509	tim3 |= val << T_TDQSCKMAX_SHIFT;
510
511	val = DIV_ROUND_UP(timings->tZQCS, t_ck) - 1;
512	tim3 |= val << ZQ_ZQCS_SHIFT;
513
514	val = DIV_ROUND_UP(timings->tCKESR, t_ck);
515	val = max(min_tck->tCKESR, val) - 1;
516	tim3 |= val << T_CKESR_SHIFT;
517
518	if (ip_rev == EMIF_4D5) {
519		tim3 |= (EMIF_T_CSTA - 1) << T_CSTA_SHIFT;
520
521		val = DIV_ROUND_UP(EMIF_T_PDLL_UL, 128) - 1;
522		tim3 |= val << T_PDLL_UL_SHIFT;
523	}
524
525	return tim3;
526}
527
528static u32 get_zq_config_reg(const struct lpddr2_addressing *addressing,
529		bool cs1_used, bool cal_resistors_per_cs)
530{
531	u32 zq = 0, val = 0;
532
533	val = EMIF_ZQCS_INTERVAL_US * 1000 / addressing->tREFI_ns;
534	zq |= val << ZQ_REFINTERVAL_SHIFT;
535
536	val = DIV_ROUND_UP(T_ZQCL_DEFAULT_NS, T_ZQCS_DEFAULT_NS) - 1;
537	zq |= val << ZQ_ZQCL_MULT_SHIFT;
538
539	val = DIV_ROUND_UP(T_ZQINIT_DEFAULT_NS, T_ZQCL_DEFAULT_NS) - 1;
540	zq |= val << ZQ_ZQINIT_MULT_SHIFT;
541
542	zq |= ZQ_SFEXITEN_ENABLE << ZQ_SFEXITEN_SHIFT;
543
544	if (cal_resistors_per_cs)
545		zq |= ZQ_DUALCALEN_ENABLE << ZQ_DUALCALEN_SHIFT;
546	else
547		zq |= ZQ_DUALCALEN_DISABLE << ZQ_DUALCALEN_SHIFT;
548
549	zq |= ZQ_CS0EN_MASK; /* CS0 is used for sure */
550
551	val = cs1_used ? 1 : 0;
552	zq |= val << ZQ_CS1EN_SHIFT;
553
554	return zq;
555}
556
557static u32 get_temp_alert_config(const struct lpddr2_addressing *addressing,
558		const struct emif_custom_configs *custom_configs, bool cs1_used,
559		u32 sdram_io_width, u32 emif_bus_width)
560{
561	u32 alert = 0, interval, devcnt;
562
563	if (custom_configs && (custom_configs->mask &
564				EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL))
565		interval = custom_configs->temp_alert_poll_interval_ms;
566	else
567		interval = TEMP_ALERT_POLL_INTERVAL_DEFAULT_MS;
568
569	interval *= 1000000;			/* Convert to ns */
570	interval /= addressing->tREFI_ns;	/* Convert to refresh cycles */
571	alert |= (interval << TA_REFINTERVAL_SHIFT);
572
573	/*
574	 * sdram_io_width is in 'log2(x) - 1' form. Convert emif_bus_width
575	 * also to this form and subtract to get TA_DEVCNT, which is
576	 * in log2(x) form.
577	 */
578	emif_bus_width = __fls(emif_bus_width) - 1;
579	devcnt = emif_bus_width - sdram_io_width;
580	alert |= devcnt << TA_DEVCNT_SHIFT;
581
582	/* DEVWDT is in 'log2(x) - 3' form */
583	alert |= (sdram_io_width - 2) << TA_DEVWDT_SHIFT;
584
585	alert |= 1 << TA_SFEXITEN_SHIFT;
586	alert |= 1 << TA_CS0EN_SHIFT;
587	alert |= (cs1_used ? 1 : 0) << TA_CS1EN_SHIFT;
588
589	return alert;
590}
591
592static u32 get_read_idle_ctrl_shdw(u8 volt_ramp)
593{
594	u32 idle = 0, val = 0;
595
596	/*
597	 * Maximum value in normal conditions and increased frequency
598	 * when voltage is ramping
599	 */
600	if (volt_ramp)
601		val = READ_IDLE_INTERVAL_DVFS / t_ck / 64 - 1;
602	else
603		val = 0x1FF;
604
605	/*
606	 * READ_IDLE_CTRL register in EMIF4D has same offset and fields
607	 * as DLL_CALIB_CTRL in EMIF4D5, so use the same shifts
608	 */
609	idle |= val << DLL_CALIB_INTERVAL_SHIFT;
610	idle |= EMIF_READ_IDLE_LEN_VAL << ACK_WAIT_SHIFT;
611
612	return idle;
613}
614
615static u32 get_dll_calib_ctrl_shdw(u8 volt_ramp)
616{
617	u32 calib = 0, val = 0;
618
619	if (volt_ramp == DDR_VOLTAGE_RAMPING)
620		val = DLL_CALIB_INTERVAL_DVFS / t_ck / 16 - 1;
621	else
622		val = 0; /* Disabled when voltage is stable */
623
624	calib |= val << DLL_CALIB_INTERVAL_SHIFT;
625	calib |= DLL_CALIB_ACK_WAIT_VAL << ACK_WAIT_SHIFT;
626
627	return calib;
628}
629
630static u32 get_ddr_phy_ctrl_1_attilaphy_4d(const struct lpddr2_timings *timings,
631	u32 freq, u8 RL)
632{
633	u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY, val = 0;
634
635	val = RL + DIV_ROUND_UP(timings->tDQSCK_max, t_ck) - 1;
636	phy |= val << READ_LATENCY_SHIFT_4D;
637
638	if (freq <= 100000000)
639		val = EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY;
640	else if (freq <= 200000000)
641		val = EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY;
642	else
643		val = EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY;
644
645	phy |= val << DLL_SLAVE_DLY_CTRL_SHIFT_4D;
646
647	return phy;
648}
649
650static u32 get_phy_ctrl_1_intelliphy_4d5(u32 freq, u8 cl)
651{
652	u32 phy = EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY, half_delay;
653
654	/*
655	 * DLL operates at 266 MHz. If DDR frequency is near 266 MHz,
656	 * half-delay is not needed else set half-delay
657	 */
658	if (freq >= 265000000 && freq < 267000000)
659		half_delay = 0;
660	else
661		half_delay = 1;
662
663	phy |= half_delay << DLL_HALF_DELAY_SHIFT_4D5;
664	phy |= ((cl + DIV_ROUND_UP(EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS,
665			t_ck) - 1) << READ_LATENCY_SHIFT_4D5);
666
667	return phy;
668}
669
670static u32 get_ext_phy_ctrl_2_intelliphy_4d5(void)
671{
672	u32 fifo_we_slave_ratio;
673
674	fifo_we_slave_ratio =  DIV_ROUND_CLOSEST(
675		EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256, t_ck);
676
677	return fifo_we_slave_ratio | fifo_we_slave_ratio << 11 |
678		fifo_we_slave_ratio << 22;
679}
680
681static u32 get_ext_phy_ctrl_3_intelliphy_4d5(void)
682{
683	u32 fifo_we_slave_ratio;
684
685	fifo_we_slave_ratio =  DIV_ROUND_CLOSEST(
686		EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256, t_ck);
687
688	return fifo_we_slave_ratio >> 10 | fifo_we_slave_ratio << 1 |
689		fifo_we_slave_ratio << 12 | fifo_we_slave_ratio << 23;
690}
691
692static u32 get_ext_phy_ctrl_4_intelliphy_4d5(void)
693{
694	u32 fifo_we_slave_ratio;
695
696	fifo_we_slave_ratio =  DIV_ROUND_CLOSEST(
697		EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS * 256, t_ck);
698
699	return fifo_we_slave_ratio >> 9 | fifo_we_slave_ratio << 2 |
700		fifo_we_slave_ratio << 13;
701}
702
703static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
704{
705	u32 pwr_mgmt_ctrl	= 0, timeout;
706	u32 lpmode		= EMIF_LP_MODE_SELF_REFRESH;
707	u32 timeout_perf	= EMIF_LP_MODE_TIMEOUT_PERFORMANCE;
708	u32 timeout_pwr		= EMIF_LP_MODE_TIMEOUT_POWER;
709	u32 freq_threshold	= EMIF_LP_MODE_FREQ_THRESHOLD;
710	u32 mask;
711	u8 shift;
712
713	struct emif_custom_configs *cust_cfgs = emif->plat_data->custom_configs;
714
715	if (cust_cfgs && (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE)) {
716		lpmode		= cust_cfgs->lpmode;
717		timeout_perf	= cust_cfgs->lpmode_timeout_performance;
718		timeout_pwr	= cust_cfgs->lpmode_timeout_power;
719		freq_threshold  = cust_cfgs->lpmode_freq_threshold;
720	}
721
722	/* Timeout based on DDR frequency */
723	timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr;
724
725	/*
726	 * The value to be set in register is "log2(timeout) - 3"
727	 * if timeout < 16 load 0 in register
728	 * if timeout is not a power of 2, round to next highest power of 2
729	 */
730	if (timeout < 16) {
731		timeout = 0;
732	} else {
733		if (timeout & (timeout - 1))
734			timeout <<= 1;
735		timeout = __fls(timeout) - 3;
736	}
737
738	switch (lpmode) {
739	case EMIF_LP_MODE_CLOCK_STOP:
740		shift = CS_TIM_SHIFT;
741		mask = CS_TIM_MASK;
742		break;
743	case EMIF_LP_MODE_SELF_REFRESH:
744		/* Workaround for errata i735 */
745		if (timeout < 6)
746			timeout = 6;
747
748		shift = SR_TIM_SHIFT;
749		mask = SR_TIM_MASK;
750		break;
751	case EMIF_LP_MODE_PWR_DN:
752		shift = PD_TIM_SHIFT;
753		mask = PD_TIM_MASK;
754		break;
755	case EMIF_LP_MODE_DISABLE:
756	default:
757		mask = 0;
758		shift = 0;
759		break;
760	}
761	/* Round to maximum in case of overflow, BUT warn! */
762	if (lpmode != EMIF_LP_MODE_DISABLE && timeout > mask >> shift) {
763		pr_err("TIMEOUT Overflow - lpmode=%d perf=%d pwr=%d freq=%d\n",
764		       lpmode,
765		       timeout_perf,
766		       timeout_pwr,
767		       freq_threshold);
768		WARN(1, "timeout=0x%02x greater than 0x%02x. Using max\n",
769		     timeout, mask >> shift);
770		timeout = mask >> shift;
771	}
772
773	/* Setup required timing */
774	pwr_mgmt_ctrl = (timeout << shift) & mask;
775	/* setup a default mask for rest of the modes */
776	pwr_mgmt_ctrl |= (SR_TIM_MASK | CS_TIM_MASK | PD_TIM_MASK) &
777			  ~mask;
778
779	/* No CS_TIM in EMIF_4D5 */
780	if (ip_rev == EMIF_4D5)
781		pwr_mgmt_ctrl &= ~CS_TIM_MASK;
782
783	pwr_mgmt_ctrl |= lpmode << LP_MODE_SHIFT;
784
785	return pwr_mgmt_ctrl;
786}
787
788/*
789 * Get the temperature level of the EMIF instance:
790 * Reads the MR4 register of attached SDRAM parts to find out the temperature
791 * level. If there are two parts attached(one on each CS), then the temperature
792 * level for the EMIF instance is the higher of the two temperatures.
793 */
794static void get_temperature_level(struct emif_data *emif)
795{
796	u32		temp, temperature_level;
797	void __iomem	*base;
798
799	base = emif->base;
800
801	/* Read mode register 4 */
802	writel(DDR_MR4, base + EMIF_LPDDR2_MODE_REG_CONFIG);
803	temperature_level = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
804	temperature_level = (temperature_level & MR4_SDRAM_REF_RATE_MASK) >>
805				MR4_SDRAM_REF_RATE_SHIFT;
806
807	if (emif->plat_data->device_info->cs1_used) {
808		writel(DDR_MR4 | CS_MASK, base + EMIF_LPDDR2_MODE_REG_CONFIG);
809		temp = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
810		temp = (temp & MR4_SDRAM_REF_RATE_MASK)
811				>> MR4_SDRAM_REF_RATE_SHIFT;
812		temperature_level = max(temp, temperature_level);
813	}
814
815	/* treat everything less than nominal(3) in MR4 as nominal */
816	if (unlikely(temperature_level < SDRAM_TEMP_NOMINAL))
817		temperature_level = SDRAM_TEMP_NOMINAL;
818
819	/* if we get reserved value in MR4 persist with the existing value */
820	if (likely(temperature_level != SDRAM_TEMP_RESERVED_4))
821		emif->temperature_level = temperature_level;
822}
823
824/*
825 * Program EMIF shadow registers that are not dependent on temperature
826 * or voltage
827 */
828static void setup_registers(struct emif_data *emif, struct emif_regs *regs)
829{
830	void __iomem	*base = emif->base;
831
832	writel(regs->sdram_tim2_shdw, base + EMIF_SDRAM_TIMING_2_SHDW);
833	writel(regs->phy_ctrl_1_shdw, base + EMIF_DDR_PHY_CTRL_1_SHDW);
834	writel(regs->pwr_mgmt_ctrl_shdw,
835	       base + EMIF_POWER_MANAGEMENT_CTRL_SHDW);
836
837	/* Settings specific for EMIF4D5 */
838	if (emif->plat_data->ip_rev != EMIF_4D5)
839		return;
840	writel(regs->ext_phy_ctrl_2_shdw, base + EMIF_EXT_PHY_CTRL_2_SHDW);
841	writel(regs->ext_phy_ctrl_3_shdw, base + EMIF_EXT_PHY_CTRL_3_SHDW);
842	writel(regs->ext_phy_ctrl_4_shdw, base + EMIF_EXT_PHY_CTRL_4_SHDW);
843}
844
845/*
846 * When voltage ramps dll calibration and forced read idle should
847 * happen more often
848 */
849static void setup_volt_sensitive_regs(struct emif_data *emif,
850		struct emif_regs *regs, u32 volt_state)
851{
852	u32		calib_ctrl;
853	void __iomem	*base = emif->base;
854
855	/*
856	 * EMIF_READ_IDLE_CTRL in EMIF4D refers to the same register as
857	 * EMIF_DLL_CALIB_CTRL in EMIF4D5 and dll_calib_ctrl_shadow_*
858	 * is an alias of the respective read_idle_ctrl_shdw_* (members of
859	 * a union). So, the below code takes care of both cases
860	 */
861	if (volt_state == DDR_VOLTAGE_RAMPING)
862		calib_ctrl = regs->dll_calib_ctrl_shdw_volt_ramp;
863	else
864		calib_ctrl = regs->dll_calib_ctrl_shdw_normal;
865
866	writel(calib_ctrl, base + EMIF_DLL_CALIB_CTRL_SHDW);
867}
868
869/*
870 * setup_temperature_sensitive_regs() - set the timings for temperature
871 * sensitive registers. This happens once at initialisation time based
872 * on the temperature at boot time and subsequently based on the temperature
873 * alert interrupt. Temperature alert can happen when the temperature
874 * increases or drops. So this function can have the effect of either
875 * derating the timings or going back to nominal values.
876 */
877static void setup_temperature_sensitive_regs(struct emif_data *emif,
878		struct emif_regs *regs)
879{
880	u32		tim1, tim3, ref_ctrl, type;
881	void __iomem	*base = emif->base;
882	u32		temperature;
883
884	type = emif->plat_data->device_info->type;
885
886	tim1 = regs->sdram_tim1_shdw;
887	tim3 = regs->sdram_tim3_shdw;
888	ref_ctrl = regs->ref_ctrl_shdw;
889
890	/* No de-rating for non-lpddr2 devices */
891	if (type != DDR_TYPE_LPDDR2_S2 && type != DDR_TYPE_LPDDR2_S4)
892		goto out;
893
894	temperature = emif->temperature_level;
895	if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH) {
896		ref_ctrl = regs->ref_ctrl_shdw_derated;
897	} else if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH_AND_TIMINGS) {
898		tim1 = regs->sdram_tim1_shdw_derated;
899		tim3 = regs->sdram_tim3_shdw_derated;
900		ref_ctrl = regs->ref_ctrl_shdw_derated;
901	}
902
903out:
904	writel(tim1, base + EMIF_SDRAM_TIMING_1_SHDW);
905	writel(tim3, base + EMIF_SDRAM_TIMING_3_SHDW);
906	writel(ref_ctrl, base + EMIF_SDRAM_REFRESH_CTRL_SHDW);
907}
908
909static irqreturn_t handle_temp_alert(void __iomem *base, struct emif_data *emif)
910{
911	u32		old_temp_level;
912	irqreturn_t	ret = IRQ_HANDLED;
913	struct emif_custom_configs *custom_configs;
914
915	spin_lock_irqsave(&emif_lock, irq_state);
916	old_temp_level = emif->temperature_level;
917	get_temperature_level(emif);
918
919	if (unlikely(emif->temperature_level == old_temp_level)) {
920		goto out;
921	} else if (!emif->curr_regs) {
922		dev_err(emif->dev, "temperature alert before registers are calculated, not de-rating timings\n");
923		goto out;
924	}
925
926	custom_configs = emif->plat_data->custom_configs;
927
928	/*
929	 * IF we detect higher than "nominal rating" from DDR sensor
930	 * on an unsupported DDR part, shutdown system
931	 */
932	if (custom_configs && !(custom_configs->mask &
933				EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART)) {
934		if (emif->temperature_level >= SDRAM_TEMP_HIGH_DERATE_REFRESH) {
935			dev_err(emif->dev,
936				"%s:NOT Extended temperature capable memory. Converting MR4=0x%02x as shutdown event\n",
937				__func__, emif->temperature_level);
938			/*
939			 * Temperature far too high - do kernel_power_off()
940			 * from thread context
941			 */
942			emif->temperature_level = SDRAM_TEMP_VERY_HIGH_SHUTDOWN;
943			ret = IRQ_WAKE_THREAD;
944			goto out;
945		}
946	}
947
948	if (emif->temperature_level < old_temp_level ||
949		emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) {
950		/*
951		 * Temperature coming down - defer handling to thread OR
952		 * Temperature far too high - do kernel_power_off() from
953		 * thread context
954		 */
955		ret = IRQ_WAKE_THREAD;
956	} else {
957		/* Temperature is going up - handle immediately */
958		setup_temperature_sensitive_regs(emif, emif->curr_regs);
959		do_freq_update();
960	}
961
962out:
963	spin_unlock_irqrestore(&emif_lock, irq_state);
964	return ret;
965}
966
967static irqreturn_t emif_interrupt_handler(int irq, void *dev_id)
968{
969	u32			interrupts;
970	struct emif_data	*emif = dev_id;
971	void __iomem		*base = emif->base;
972	struct device		*dev = emif->dev;
973	irqreturn_t		ret = IRQ_HANDLED;
974
975	/* Save the status and clear it */
976	interrupts = readl(base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
977	writel(interrupts, base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
978
979	/*
980	 * Handle temperature alert
981	 * Temperature alert should be same for all ports
982	 * So, it's enough to process it only for one of the ports
983	 */
984	if (interrupts & TA_SYS_MASK)
985		ret = handle_temp_alert(base, emif);
986
987	if (interrupts & ERR_SYS_MASK)
988		dev_err(dev, "Access error from SYS port - %x\n", interrupts);
989
990	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE) {
991		/* Save the status and clear it */
992		interrupts = readl(base + EMIF_LL_OCP_INTERRUPT_STATUS);
993		writel(interrupts, base + EMIF_LL_OCP_INTERRUPT_STATUS);
994
995		if (interrupts & ERR_LL_MASK)
996			dev_err(dev, "Access error from LL port - %x\n",
997				interrupts);
998	}
999
1000	return ret;
1001}
1002
1003static irqreturn_t emif_threaded_isr(int irq, void *dev_id)
1004{
1005	struct emif_data	*emif = dev_id;
1006
1007	if (emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) {
1008		dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
1009
1010		/* If we have Power OFF ability, use it, else try restarting */
1011		if (pm_power_off) {
1012			kernel_power_off();
1013		} else {
1014			WARN(1, "FIXME: NO pm_power_off!!! trying restart\n");
1015			kernel_restart("SDRAM Over-temp Emergency restart");
1016		}
1017		return IRQ_HANDLED;
1018	}
1019
1020	spin_lock_irqsave(&emif_lock, irq_state);
1021
1022	if (emif->curr_regs) {
1023		setup_temperature_sensitive_regs(emif, emif->curr_regs);
1024		do_freq_update();
1025	} else {
1026		dev_err(emif->dev, "temperature alert before registers are calculated, not de-rating timings\n");
1027	}
1028
1029	spin_unlock_irqrestore(&emif_lock, irq_state);
1030
1031	return IRQ_HANDLED;
1032}
1033
1034static void clear_all_interrupts(struct emif_data *emif)
1035{
1036	void __iomem	*base = emif->base;
1037
1038	writel(readl(base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS),
1039		base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
1040	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
1041		writel(readl(base + EMIF_LL_OCP_INTERRUPT_STATUS),
1042			base + EMIF_LL_OCP_INTERRUPT_STATUS);
1043}
1044
1045static void disable_and_clear_all_interrupts(struct emif_data *emif)
1046{
1047	void __iomem		*base = emif->base;
1048
1049	/* Disable all interrupts */
1050	writel(readl(base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_SET),
1051		base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_CLEAR);
1052	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
1053		writel(readl(base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET),
1054			base + EMIF_LL_OCP_INTERRUPT_ENABLE_CLEAR);
1055
1056	/* Clear all interrupts */
1057	clear_all_interrupts(emif);
1058}
1059
1060static int __init_or_module setup_interrupts(struct emif_data *emif, u32 irq)
1061{
1062	u32		interrupts, type;
1063	void __iomem	*base = emif->base;
1064
1065	type = emif->plat_data->device_info->type;
1066
1067	clear_all_interrupts(emif);
1068
1069	/* Enable interrupts for SYS interface */
1070	interrupts = EN_ERR_SYS_MASK;
1071	if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4)
1072		interrupts |= EN_TA_SYS_MASK;
1073	writel(interrupts, base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_SET);
1074
1075	/* Enable interrupts for LL interface */
1076	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE) {
1077		/* TA need not be enabled for LL */
1078		interrupts = EN_ERR_LL_MASK;
1079		writel(interrupts, base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET);
1080	}
1081
1082	/* setup IRQ handlers */
1083	return devm_request_threaded_irq(emif->dev, irq,
1084				    emif_interrupt_handler,
1085				    emif_threaded_isr,
1086				    0, dev_name(emif->dev),
1087				    emif);
1088
1089}
1090
1091static void __init_or_module emif_onetime_settings(struct emif_data *emif)
1092{
1093	u32				pwr_mgmt_ctrl, zq, temp_alert_cfg;
1094	void __iomem			*base = emif->base;
1095	const struct lpddr2_addressing	*addressing;
1096	const struct ddr_device_info	*device_info;
1097
1098	device_info = emif->plat_data->device_info;
1099	addressing = get_addressing_table(device_info);
1100
1101	/*
1102	 * Init power management settings
1103	 * We don't know the frequency yet. Use a high frequency
1104	 * value for a conservative timeout setting
1105	 */
1106	pwr_mgmt_ctrl = get_pwr_mgmt_ctrl(1000000000, emif,
1107			emif->plat_data->ip_rev);
1108	emif->lpmode = (pwr_mgmt_ctrl & LP_MODE_MASK) >> LP_MODE_SHIFT;
1109	writel(pwr_mgmt_ctrl, base + EMIF_POWER_MANAGEMENT_CONTROL);
1110
1111	/* Init ZQ calibration settings */
1112	zq = get_zq_config_reg(addressing, device_info->cs1_used,
1113		device_info->cal_resistors_per_cs);
1114	writel(zq, base + EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG);
1115
1116	/* Check temperature level temperature level*/
1117	get_temperature_level(emif);
1118	if (emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN)
1119		dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
1120
1121	/* Init temperature polling */
1122	temp_alert_cfg = get_temp_alert_config(addressing,
1123		emif->plat_data->custom_configs, device_info->cs1_used,
1124		device_info->io_width, get_emif_bus_width(emif));
1125	writel(temp_alert_cfg, base + EMIF_TEMPERATURE_ALERT_CONFIG);
1126
1127	/*
1128	 * Program external PHY control registers that are not frequency
1129	 * dependent
1130	 */
1131	if (emif->plat_data->phy_type != EMIF_PHY_TYPE_INTELLIPHY)
1132		return;
1133	writel(EMIF_EXT_PHY_CTRL_1_VAL, base + EMIF_EXT_PHY_CTRL_1_SHDW);
1134	writel(EMIF_EXT_PHY_CTRL_5_VAL, base + EMIF_EXT_PHY_CTRL_5_SHDW);
1135	writel(EMIF_EXT_PHY_CTRL_6_VAL, base + EMIF_EXT_PHY_CTRL_6_SHDW);
1136	writel(EMIF_EXT_PHY_CTRL_7_VAL, base + EMIF_EXT_PHY_CTRL_7_SHDW);
1137	writel(EMIF_EXT_PHY_CTRL_8_VAL, base + EMIF_EXT_PHY_CTRL_8_SHDW);
1138	writel(EMIF_EXT_PHY_CTRL_9_VAL, base + EMIF_EXT_PHY_CTRL_9_SHDW);
1139	writel(EMIF_EXT_PHY_CTRL_10_VAL, base + EMIF_EXT_PHY_CTRL_10_SHDW);
1140	writel(EMIF_EXT_PHY_CTRL_11_VAL, base + EMIF_EXT_PHY_CTRL_11_SHDW);
1141	writel(EMIF_EXT_PHY_CTRL_12_VAL, base + EMIF_EXT_PHY_CTRL_12_SHDW);
1142	writel(EMIF_EXT_PHY_CTRL_13_VAL, base + EMIF_EXT_PHY_CTRL_13_SHDW);
1143	writel(EMIF_EXT_PHY_CTRL_14_VAL, base + EMIF_EXT_PHY_CTRL_14_SHDW);
1144	writel(EMIF_EXT_PHY_CTRL_15_VAL, base + EMIF_EXT_PHY_CTRL_15_SHDW);
1145	writel(EMIF_EXT_PHY_CTRL_16_VAL, base + EMIF_EXT_PHY_CTRL_16_SHDW);
1146	writel(EMIF_EXT_PHY_CTRL_17_VAL, base + EMIF_EXT_PHY_CTRL_17_SHDW);
1147	writel(EMIF_EXT_PHY_CTRL_18_VAL, base + EMIF_EXT_PHY_CTRL_18_SHDW);
1148	writel(EMIF_EXT_PHY_CTRL_19_VAL, base + EMIF_EXT_PHY_CTRL_19_SHDW);
1149	writel(EMIF_EXT_PHY_CTRL_20_VAL, base + EMIF_EXT_PHY_CTRL_20_SHDW);
1150	writel(EMIF_EXT_PHY_CTRL_21_VAL, base + EMIF_EXT_PHY_CTRL_21_SHDW);
1151	writel(EMIF_EXT_PHY_CTRL_22_VAL, base + EMIF_EXT_PHY_CTRL_22_SHDW);
1152	writel(EMIF_EXT_PHY_CTRL_23_VAL, base + EMIF_EXT_PHY_CTRL_23_SHDW);
1153	writel(EMIF_EXT_PHY_CTRL_24_VAL, base + EMIF_EXT_PHY_CTRL_24_SHDW);
1154}
1155
1156static void get_default_timings(struct emif_data *emif)
1157{
1158	struct emif_platform_data *pd = emif->plat_data;
1159
1160	pd->timings		= lpddr2_jedec_timings;
1161	pd->timings_arr_size	= ARRAY_SIZE(lpddr2_jedec_timings);
1162
1163	dev_warn(emif->dev, "%s: using default timings\n", __func__);
1164}
1165
1166static int is_dev_data_valid(u32 type, u32 density, u32 io_width, u32 phy_type,
1167		u32 ip_rev, struct device *dev)
1168{
1169	int valid;
1170
1171	valid = (type == DDR_TYPE_LPDDR2_S4 ||
1172			type == DDR_TYPE_LPDDR2_S2)
1173		&& (density >= DDR_DENSITY_64Mb
1174			&& density <= DDR_DENSITY_8Gb)
1175		&& (io_width >= DDR_IO_WIDTH_8
1176			&& io_width <= DDR_IO_WIDTH_32);
1177
1178	/* Combinations of EMIF and PHY revisions that we support today */
1179	switch (ip_rev) {
1180	case EMIF_4D:
1181		valid = valid && (phy_type == EMIF_PHY_TYPE_ATTILAPHY);
1182		break;
1183	case EMIF_4D5:
1184		valid = valid && (phy_type == EMIF_PHY_TYPE_INTELLIPHY);
1185		break;
1186	default:
1187		valid = 0;
1188	}
1189
1190	if (!valid)
1191		dev_err(dev, "%s: invalid DDR details\n", __func__);
1192	return valid;
1193}
1194
1195static int is_custom_config_valid(struct emif_custom_configs *cust_cfgs,
1196		struct device *dev)
1197{
1198	int valid = 1;
1199
1200	if ((cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE) &&
1201		(cust_cfgs->lpmode != EMIF_LP_MODE_DISABLE))
1202		valid = cust_cfgs->lpmode_freq_threshold &&
1203			cust_cfgs->lpmode_timeout_performance &&
1204			cust_cfgs->lpmode_timeout_power;
1205
1206	if (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL)
1207		valid = valid && cust_cfgs->temp_alert_poll_interval_ms;
1208
1209	if (!valid)
1210		dev_warn(dev, "%s: invalid custom configs\n", __func__);
1211
1212	return valid;
1213}
1214
1215#if defined(CONFIG_OF)
1216static void __init_or_module of_get_custom_configs(struct device_node *np_emif,
1217		struct emif_data *emif)
1218{
1219	struct emif_custom_configs	*cust_cfgs = NULL;
1220	int				len;
1221	const __be32			*lpmode, *poll_intvl;
1222
1223	lpmode = of_get_property(np_emif, "low-power-mode", &len);
1224	poll_intvl = of_get_property(np_emif, "temp-alert-poll-interval", &len);
1225
1226	if (lpmode || poll_intvl)
1227		cust_cfgs = devm_kzalloc(emif->dev, sizeof(*cust_cfgs),
1228			GFP_KERNEL);
1229
1230	if (!cust_cfgs)
1231		return;
1232
1233	if (lpmode) {
1234		cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_LPMODE;
1235		cust_cfgs->lpmode = be32_to_cpup(lpmode);
1236		of_property_read_u32(np_emif,
1237				"low-power-mode-timeout-performance",
1238				&cust_cfgs->lpmode_timeout_performance);
1239		of_property_read_u32(np_emif,
1240				"low-power-mode-timeout-power",
1241				&cust_cfgs->lpmode_timeout_power);
1242		of_property_read_u32(np_emif,
1243				"low-power-mode-freq-threshold",
1244				&cust_cfgs->lpmode_freq_threshold);
1245	}
1246
1247	if (poll_intvl) {
1248		cust_cfgs->mask |=
1249				EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL;
1250		cust_cfgs->temp_alert_poll_interval_ms =
1251						be32_to_cpup(poll_intvl);
1252	}
1253
1254	if (of_find_property(np_emif, "extended-temp-part", &len))
1255		cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART;
1256
1257	if (!is_custom_config_valid(cust_cfgs, emif->dev)) {
1258		devm_kfree(emif->dev, cust_cfgs);
1259		return;
1260	}
1261
1262	emif->plat_data->custom_configs = cust_cfgs;
1263}
1264
1265static void __init_or_module of_get_ddr_info(struct device_node *np_emif,
1266		struct device_node *np_ddr,
1267		struct ddr_device_info *dev_info)
1268{
1269	u32 density = 0, io_width = 0;
1270	int len;
1271
1272	if (of_find_property(np_emif, "cs1-used", &len))
1273		dev_info->cs1_used = true;
1274
1275	if (of_find_property(np_emif, "cal-resistor-per-cs", &len))
1276		dev_info->cal_resistors_per_cs = true;
1277
1278	if (of_device_is_compatible(np_ddr, "jedec,lpddr2-s4"))
1279		dev_info->type = DDR_TYPE_LPDDR2_S4;
1280	else if (of_device_is_compatible(np_ddr, "jedec,lpddr2-s2"))
1281		dev_info->type = DDR_TYPE_LPDDR2_S2;
1282
1283	of_property_read_u32(np_ddr, "density", &density);
1284	of_property_read_u32(np_ddr, "io-width", &io_width);
1285
1286	/* Convert from density in Mb to the density encoding in jedc_ddr.h */
1287	if (density & (density - 1))
1288		dev_info->density = 0;
1289	else
1290		dev_info->density = __fls(density) - 5;
1291
1292	/* Convert from io_width in bits to io_width encoding in jedc_ddr.h */
1293	if (io_width & (io_width - 1))
1294		dev_info->io_width = 0;
1295	else
1296		dev_info->io_width = __fls(io_width) - 1;
1297}
1298
1299static struct emif_data * __init_or_module of_get_memory_device_details(
1300		struct device_node *np_emif, struct device *dev)
1301{
1302	struct emif_data		*emif = NULL;
1303	struct ddr_device_info		*dev_info = NULL;
1304	struct emif_platform_data	*pd = NULL;
1305	struct device_node		*np_ddr;
1306	int				len;
1307
1308	np_ddr = of_parse_phandle(np_emif, "device-handle", 0);
1309	if (!np_ddr)
1310		goto error;
1311	emif	= devm_kzalloc(dev, sizeof(struct emif_data), GFP_KERNEL);
1312	pd	= devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
1313	dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
1314
1315	if (!emif || !pd || !dev_info) {
1316		dev_err(dev, "%s: Out of memory!!\n",
1317			__func__);
1318		goto error;
1319	}
1320
1321	emif->plat_data		= pd;
1322	pd->device_info		= dev_info;
1323	emif->dev		= dev;
1324	emif->np_ddr		= np_ddr;
1325	emif->temperature_level	= SDRAM_TEMP_NOMINAL;
1326
1327	if (of_device_is_compatible(np_emif, "ti,emif-4d"))
1328		emif->plat_data->ip_rev = EMIF_4D;
1329	else if (of_device_is_compatible(np_emif, "ti,emif-4d5"))
1330		emif->plat_data->ip_rev = EMIF_4D5;
1331
1332	of_property_read_u32(np_emif, "phy-type", &pd->phy_type);
1333
1334	if (of_find_property(np_emif, "hw-caps-ll-interface", &len))
1335		pd->hw_caps |= EMIF_HW_CAPS_LL_INTERFACE;
1336
1337	of_get_ddr_info(np_emif, np_ddr, dev_info);
1338	if (!is_dev_data_valid(pd->device_info->type, pd->device_info->density,
1339			pd->device_info->io_width, pd->phy_type, pd->ip_rev,
1340			emif->dev)) {
1341		dev_err(dev, "%s: invalid device data!!\n", __func__);
1342		goto error;
1343	}
1344	/*
1345	 * For EMIF instances other than EMIF1 see if the devices connected
1346	 * are exactly same as on EMIF1(which is typically the case). If so,
1347	 * mark it as a duplicate of EMIF1. This will save some memory and
1348	 * computation.
1349	 */
1350	if (emif1 && emif1->np_ddr == np_ddr) {
1351		emif->duplicate = true;
1352		goto out;
1353	} else if (emif1) {
1354		dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
1355			__func__);
1356	}
1357
1358	of_get_custom_configs(np_emif, emif);
1359	emif->plat_data->timings = of_get_ddr_timings(np_ddr, emif->dev,
1360					emif->plat_data->device_info->type,
1361					&emif->plat_data->timings_arr_size);
1362
1363	emif->plat_data->min_tck = of_get_min_tck(np_ddr, emif->dev);
1364	goto out;
1365
1366error:
1367	return NULL;
1368out:
1369	return emif;
1370}
1371
1372#else
1373
1374static struct emif_data * __init_or_module of_get_memory_device_details(
1375		struct device_node *np_emif, struct device *dev)
1376{
1377	return NULL;
1378}
1379#endif
1380
1381static struct emif_data *__init_or_module get_device_details(
1382		struct platform_device *pdev)
1383{
1384	u32				size;
1385	struct emif_data		*emif = NULL;
1386	struct ddr_device_info		*dev_info;
1387	struct emif_custom_configs	*cust_cfgs;
1388	struct emif_platform_data	*pd;
1389	struct device			*dev;
1390	void				*temp;
1391
1392	pd = pdev->dev.platform_data;
1393	dev = &pdev->dev;
1394
1395	if (!(pd && pd->device_info && is_dev_data_valid(pd->device_info->type,
1396			pd->device_info->density, pd->device_info->io_width,
1397			pd->phy_type, pd->ip_rev, dev))) {
1398		dev_err(dev, "%s: invalid device data\n", __func__);
1399		goto error;
1400	}
1401
1402	emif	= devm_kzalloc(dev, sizeof(*emif), GFP_KERNEL);
1403	temp	= devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
1404	dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
1405
1406	if (!emif || !temp || !dev_info) {
1407		dev_err(dev, "%s:%d: allocation error\n", __func__, __LINE__);
1408		goto error;
1409	}
1410
1411	memcpy(temp, pd, sizeof(*pd));
1412	pd = temp;
1413	memcpy(dev_info, pd->device_info, sizeof(*dev_info));
1414
1415	pd->device_info		= dev_info;
1416	emif->plat_data		= pd;
1417	emif->dev		= dev;
1418	emif->temperature_level	= SDRAM_TEMP_NOMINAL;
1419
1420	/*
1421	 * For EMIF instances other than EMIF1 see if the devices connected
1422	 * are exactly same as on EMIF1(which is typically the case). If so,
1423	 * mark it as a duplicate of EMIF1 and skip copying timings data.
1424	 * This will save some memory and some computation later.
1425	 */
1426	emif->duplicate = emif1 && (memcmp(dev_info,
1427		emif1->plat_data->device_info,
1428		sizeof(struct ddr_device_info)) == 0);
1429
1430	if (emif->duplicate) {
1431		pd->timings = NULL;
1432		pd->min_tck = NULL;
1433		goto out;
1434	} else if (emif1) {
1435		dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
1436			__func__);
1437	}
1438
1439	/*
1440	 * Copy custom configs - ignore allocation error, if any, as
1441	 * custom_configs is not very critical
1442	 */
1443	cust_cfgs = pd->custom_configs;
1444	if (cust_cfgs && is_custom_config_valid(cust_cfgs, dev)) {
1445		temp = devm_kzalloc(dev, sizeof(*cust_cfgs), GFP_KERNEL);
1446		if (temp)
1447			memcpy(temp, cust_cfgs, sizeof(*cust_cfgs));
1448		else
1449			dev_warn(dev, "%s:%d: allocation error\n", __func__,
1450				__LINE__);
1451		pd->custom_configs = temp;
1452	}
1453
1454	/*
1455	 * Copy timings and min-tck values from platform data. If it is not
1456	 * available or if memory allocation fails, use JEDEC defaults
1457	 */
1458	size = sizeof(struct lpddr2_timings) * pd->timings_arr_size;
1459	if (pd->timings) {
1460		temp = devm_kzalloc(dev, size, GFP_KERNEL);
1461		if (temp) {
1462			memcpy(temp, pd->timings, size);
1463			pd->timings = temp;
1464		} else {
1465			dev_warn(dev, "%s:%d: allocation error\n", __func__,
1466				__LINE__);
1467			get_default_timings(emif);
1468		}
1469	} else {
1470		get_default_timings(emif);
1471	}
1472
1473	if (pd->min_tck) {
1474		temp = devm_kzalloc(dev, sizeof(*pd->min_tck), GFP_KERNEL);
1475		if (temp) {
1476			memcpy(temp, pd->min_tck, sizeof(*pd->min_tck));
1477			pd->min_tck = temp;
1478		} else {
1479			dev_warn(dev, "%s:%d: allocation error\n", __func__,
1480				__LINE__);
1481			pd->min_tck = &lpddr2_jedec_min_tck;
1482		}
1483	} else {
1484		pd->min_tck = &lpddr2_jedec_min_tck;
1485	}
1486
1487out:
1488	return emif;
1489
1490error:
1491	return NULL;
1492}
1493
1494static int __init_or_module emif_probe(struct platform_device *pdev)
1495{
1496	struct emif_data	*emif;
1497	struct resource		*res;
1498	int			irq, ret;
1499
1500	if (pdev->dev.of_node)
1501		emif = of_get_memory_device_details(pdev->dev.of_node, &pdev->dev);
1502	else
1503		emif = get_device_details(pdev);
1504
1505	if (!emif) {
1506		pr_err("%s: error getting device data\n", __func__);
1507		goto error;
1508	}
1509
1510	list_add(&emif->node, &device_list);
1511	emif->addressing = get_addressing_table(emif->plat_data->device_info);
1512
1513	/* Save pointers to each other in emif and device structures */
1514	emif->dev = &pdev->dev;
1515	platform_set_drvdata(pdev, emif);
1516
1517	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1518	emif->base = devm_ioremap_resource(emif->dev, res);
1519	if (IS_ERR(emif->base))
1520		goto error;
1521
1522	irq = platform_get_irq(pdev, 0);
1523	if (irq < 0)
1524		goto error;
1525
1526	emif_onetime_settings(emif);
1527	emif_debugfs_init(emif);
1528	disable_and_clear_all_interrupts(emif);
1529	ret = setup_interrupts(emif, irq);
1530	if (ret)
1531		goto error;
1532
1533	/* One-time actions taken on probing the first device */
1534	if (!emif1) {
1535		emif1 = emif;
1536		spin_lock_init(&emif_lock);
1537
1538		/*
1539		 * TODO: register notifiers for frequency and voltage
1540		 * change here once the respective frameworks are
1541		 * available
1542		 */
1543	}
1544
1545	dev_info(&pdev->dev, "%s: device configured with addr = %p and IRQ%d\n",
1546		__func__, emif->base, irq);
1547
1548	return 0;
1549error:
1550	return -ENODEV;
1551}
1552
1553static int __exit emif_remove(struct platform_device *pdev)
1554{
1555	struct emif_data *emif = platform_get_drvdata(pdev);
1556
1557	emif_debugfs_exit(emif);
1558
1559	return 0;
1560}
1561
1562static void emif_shutdown(struct platform_device *pdev)
1563{
1564	struct emif_data	*emif = platform_get_drvdata(pdev);
1565
1566	disable_and_clear_all_interrupts(emif);
1567}
1568
1569static int get_emif_reg_values(struct emif_data *emif, u32 freq,
1570		struct emif_regs *regs)
1571{
1572	u32				ip_rev, phy_type;
1573	u32				cl, type;
1574	const struct lpddr2_timings	*timings;
1575	const struct lpddr2_min_tck	*min_tck;
1576	const struct ddr_device_info	*device_info;
1577	const struct lpddr2_addressing	*addressing;
1578	struct emif_data		*emif_for_calc;
1579	struct device			*dev;
1580
1581	dev = emif->dev;
1582	/*
1583	 * If the devices on this EMIF instance is duplicate of EMIF1,
1584	 * use EMIF1 details for the calculation
1585	 */
1586	emif_for_calc	= emif->duplicate ? emif1 : emif;
1587	timings		= get_timings_table(emif_for_calc, freq);
1588	addressing	= emif_for_calc->addressing;
1589	if (!timings || !addressing) {
1590		dev_err(dev, "%s: not enough data available for %dHz",
1591			__func__, freq);
1592		return -1;
1593	}
1594
1595	device_info	= emif_for_calc->plat_data->device_info;
1596	type		= device_info->type;
1597	ip_rev		= emif_for_calc->plat_data->ip_rev;
1598	phy_type	= emif_for_calc->plat_data->phy_type;
1599
1600	min_tck		= emif_for_calc->plat_data->min_tck;
1601
1602	set_ddr_clk_period(freq);
1603
1604	regs->ref_ctrl_shdw = get_sdram_ref_ctrl_shdw(freq, addressing);
1605	regs->sdram_tim1_shdw = get_sdram_tim_1_shdw(timings, min_tck,
1606			addressing);
1607	regs->sdram_tim2_shdw = get_sdram_tim_2_shdw(timings, min_tck,
1608			addressing, type);
1609	regs->sdram_tim3_shdw = get_sdram_tim_3_shdw(timings, min_tck,
1610		addressing, type, ip_rev, EMIF_NORMAL_TIMINGS);
1611
1612	cl = get_cl(emif);
1613
1614	if (phy_type == EMIF_PHY_TYPE_ATTILAPHY && ip_rev == EMIF_4D) {
1615		regs->phy_ctrl_1_shdw = get_ddr_phy_ctrl_1_attilaphy_4d(
1616			timings, freq, cl);
1617	} else if (phy_type == EMIF_PHY_TYPE_INTELLIPHY && ip_rev == EMIF_4D5) {
1618		regs->phy_ctrl_1_shdw = get_phy_ctrl_1_intelliphy_4d5(freq, cl);
1619		regs->ext_phy_ctrl_2_shdw = get_ext_phy_ctrl_2_intelliphy_4d5();
1620		regs->ext_phy_ctrl_3_shdw = get_ext_phy_ctrl_3_intelliphy_4d5();
1621		regs->ext_phy_ctrl_4_shdw = get_ext_phy_ctrl_4_intelliphy_4d5();
1622	} else {
1623		return -1;
1624	}
1625
1626	/* Only timeout values in pwr_mgmt_ctrl_shdw register */
1627	regs->pwr_mgmt_ctrl_shdw =
1628		get_pwr_mgmt_ctrl(freq, emif_for_calc, ip_rev) &
1629		(CS_TIM_MASK | SR_TIM_MASK | PD_TIM_MASK);
1630
1631	if (ip_rev & EMIF_4D) {
1632		regs->read_idle_ctrl_shdw_normal =
1633			get_read_idle_ctrl_shdw(DDR_VOLTAGE_STABLE);
1634
1635		regs->read_idle_ctrl_shdw_volt_ramp =
1636			get_read_idle_ctrl_shdw(DDR_VOLTAGE_RAMPING);
1637	} else if (ip_rev & EMIF_4D5) {
1638		regs->dll_calib_ctrl_shdw_normal =
1639			get_dll_calib_ctrl_shdw(DDR_VOLTAGE_STABLE);
1640
1641		regs->dll_calib_ctrl_shdw_volt_ramp =
1642			get_dll_calib_ctrl_shdw(DDR_VOLTAGE_RAMPING);
1643	}
1644
1645	if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4) {
1646		regs->ref_ctrl_shdw_derated = get_sdram_ref_ctrl_shdw(freq / 4,
1647			addressing);
1648
1649		regs->sdram_tim1_shdw_derated =
1650			get_sdram_tim_1_shdw_derated(timings, min_tck,
1651				addressing);
1652
1653		regs->sdram_tim3_shdw_derated = get_sdram_tim_3_shdw(timings,
1654			min_tck, addressing, type, ip_rev,
1655			EMIF_DERATED_TIMINGS);
1656	}
1657
1658	regs->freq = freq;
1659
1660	return 0;
1661}
1662
1663/*
1664 * get_regs() - gets the cached emif_regs structure for a given EMIF instance
1665 * given frequency(freq):
1666 *
1667 * As an optimisation, every EMIF instance other than EMIF1 shares the
1668 * register cache with EMIF1 if the devices connected on this instance
1669 * are same as that on EMIF1(indicated by the duplicate flag)
1670 *
1671 * If we do not have an entry corresponding to the frequency given, we
1672 * allocate a new entry and calculate the values
1673 *
1674 * Upon finding the right reg dump, save it in curr_regs. It can be
1675 * directly used for thermal de-rating and voltage ramping changes.
1676 */
1677static struct emif_regs *get_regs(struct emif_data *emif, u32 freq)
1678{
1679	int			i;
1680	struct emif_regs	**regs_cache;
1681	struct emif_regs	*regs = NULL;
1682	struct device		*dev;
1683
1684	dev = emif->dev;
1685	if (emif->curr_regs && emif->curr_regs->freq == freq) {
1686		dev_dbg(dev, "%s: using curr_regs - %u Hz", __func__, freq);
1687		return emif->curr_regs;
1688	}
1689
1690	if (emif->duplicate)
1691		regs_cache = emif1->regs_cache;
1692	else
1693		regs_cache = emif->regs_cache;
1694
1695	for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++) {
1696		if (regs_cache[i]->freq == freq) {
1697			regs = regs_cache[i];
1698			dev_dbg(dev,
1699				"%s: reg dump found in reg cache for %u Hz\n",
1700				__func__, freq);
1701			break;
1702		}
1703	}
1704
1705	/*
1706	 * If we don't have an entry for this frequency in the cache create one
1707	 * and calculate the values
1708	 */
1709	if (!regs) {
1710		regs = devm_kzalloc(emif->dev, sizeof(*regs), GFP_ATOMIC);
1711		if (!regs)
1712			return NULL;
1713
1714		if (get_emif_reg_values(emif, freq, regs)) {
1715			devm_kfree(emif->dev, regs);
1716			return NULL;
1717		}
1718
1719		/*
1720		 * Now look for an un-used entry in the cache and save the
1721		 * newly created struct. If there are no free entries
1722		 * over-write the last entry
1723		 */
1724		for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++)
1725			;
1726
1727		if (i >= EMIF_MAX_NUM_FREQUENCIES) {
1728			dev_warn(dev, "%s: regs_cache full - reusing a slot!!\n",
1729				__func__);
1730			i = EMIF_MAX_NUM_FREQUENCIES - 1;
1731			devm_kfree(emif->dev, regs_cache[i]);
1732		}
1733		regs_cache[i] = regs;
1734	}
1735
1736	return regs;
1737}
1738
1739static void do_volt_notify_handling(struct emif_data *emif, u32 volt_state)
1740{
1741	dev_dbg(emif->dev, "%s: voltage notification : %d", __func__,
1742		volt_state);
1743
1744	if (!emif->curr_regs) {
1745		dev_err(emif->dev,
1746			"%s: volt-notify before registers are ready: %d\n",
1747			__func__, volt_state);
1748		return;
1749	}
1750
1751	setup_volt_sensitive_regs(emif, emif->curr_regs, volt_state);
1752}
1753
1754/*
1755 * TODO: voltage notify handling should be hooked up to
1756 * regulator framework as soon as the necessary support
1757 * is available in mainline kernel. This function is un-used
1758 * right now.
1759 */
1760static void __attribute__((unused)) volt_notify_handling(u32 volt_state)
1761{
1762	struct emif_data *emif;
1763
1764	spin_lock_irqsave(&emif_lock, irq_state);
1765
1766	list_for_each_entry(emif, &device_list, node)
1767		do_volt_notify_handling(emif, volt_state);
1768	do_freq_update();
1769
1770	spin_unlock_irqrestore(&emif_lock, irq_state);
1771}
1772
1773static void do_freq_pre_notify_handling(struct emif_data *emif, u32 new_freq)
1774{
1775	struct emif_regs *regs;
1776
1777	regs = get_regs(emif, new_freq);
1778	if (!regs)
1779		return;
1780
1781	emif->curr_regs = regs;
1782
1783	/*
1784	 * Update the shadow registers:
1785	 * Temperature and voltage-ramp sensitive settings are also configured
1786	 * in terms of DDR cycles. So, we need to update them too when there
1787	 * is a freq change
1788	 */
1789	dev_dbg(emif->dev, "%s: setting up shadow registers for %uHz",
1790		__func__, new_freq);
1791	setup_registers(emif, regs);
1792	setup_temperature_sensitive_regs(emif, regs);
1793	setup_volt_sensitive_regs(emif, regs, DDR_VOLTAGE_STABLE);
1794
1795	/*
1796	 * Part of workaround for errata i728. See do_freq_update()
1797	 * for more details
1798	 */
1799	if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
1800		set_lpmode(emif, EMIF_LP_MODE_DISABLE);
1801}
1802
1803/*
1804 * TODO: frequency notify handling should be hooked up to
1805 * clock framework as soon as the necessary support is
1806 * available in mainline kernel. This function is un-used
1807 * right now.
1808 */
1809static void __attribute__((unused)) freq_pre_notify_handling(u32 new_freq)
1810{
1811	struct emif_data *emif;
1812
1813	/*
1814	 * NOTE: we are taking the spin-lock here and releases it
1815	 * only in post-notifier. This doesn't look good and
1816	 * Sparse complains about it, but this seems to be
1817	 * un-avoidable. We need to lock a sequence of events
1818	 * that is split between EMIF and clock framework.
1819	 *
1820	 * 1. EMIF driver updates EMIF timings in shadow registers in the
1821	 *    frequency pre-notify callback from clock framework
1822	 * 2. clock framework sets up the registers for the new frequency
1823	 * 3. clock framework initiates a hw-sequence that updates
1824	 *    the frequency EMIF timings synchronously.
1825	 *
1826	 * All these 3 steps should be performed as an atomic operation
1827	 * vis-a-vis similar sequence in the EMIF interrupt handler
1828	 * for temperature events. Otherwise, there could be race
1829	 * conditions that could result in incorrect EMIF timings for
1830	 * a given frequency
1831	 */
1832	spin_lock_irqsave(&emif_lock, irq_state);
1833
1834	list_for_each_entry(emif, &device_list, node)
1835		do_freq_pre_notify_handling(emif, new_freq);
1836}
1837
1838static void do_freq_post_notify_handling(struct emif_data *emif)
1839{
1840	/*
1841	 * Part of workaround for errata i728. See do_freq_update()
1842	 * for more details
1843	 */
1844	if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
1845		set_lpmode(emif, EMIF_LP_MODE_SELF_REFRESH);
1846}
1847
1848/*
1849 * TODO: frequency notify handling should be hooked up to
1850 * clock framework as soon as the necessary support is
1851 * available in mainline kernel. This function is un-used
1852 * right now.
1853 */
1854static void __attribute__((unused)) freq_post_notify_handling(void)
1855{
1856	struct emif_data *emif;
1857
1858	list_for_each_entry(emif, &device_list, node)
1859		do_freq_post_notify_handling(emif);
1860
1861	/*
1862	 * Lock is done in pre-notify handler. See freq_pre_notify_handling()
1863	 * for more details
1864	 */
1865	spin_unlock_irqrestore(&emif_lock, irq_state);
1866}
1867
1868#if defined(CONFIG_OF)
1869static const struct of_device_id emif_of_match[] = {
1870		{ .compatible = "ti,emif-4d" },
1871		{ .compatible = "ti,emif-4d5" },
1872		{},
1873};
1874MODULE_DEVICE_TABLE(of, emif_of_match);
1875#endif
1876
1877static struct platform_driver emif_driver = {
1878	.remove		= __exit_p(emif_remove),
1879	.shutdown	= emif_shutdown,
1880	.driver = {
1881		.name = "emif",
1882		.of_match_table = of_match_ptr(emif_of_match),
1883	},
1884};
1885
1886module_platform_driver_probe(emif_driver, emif_probe);
1887
1888MODULE_DESCRIPTION("TI EMIF SDRAM Controller Driver");
1889MODULE_LICENSE("GPL");
1890MODULE_ALIAS("platform:emif");
1891MODULE_AUTHOR("Texas Instruments Inc");
1892