xref: /openbmc/linux/drivers/memory/emif.c (revision 9a29f5fc)
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  * @regs_cache:			An array of 'struct emif_regs' that stores
45  *				calculated register values for different
46  *				frequencies, to avoid re-calculating them on
47  *				each DVFS transition.
48  * @curr_regs:			The set of register values used in the last
49  *				frequency change (i.e. corresponding to the
50  *				frequency in effect at the moment)
51  * @plat_data:			Pointer to saved platform data.
52  * @debugfs_root:		dentry to the root folder for EMIF in debugfs
53  * @np_ddr:			Pointer to ddr device tree node
54  */
55 struct emif_data {
56 	u8				duplicate;
57 	u8				temperature_level;
58 	u8				lpmode;
59 	struct list_head		node;
60 	unsigned long			irq_state;
61 	void __iomem			*base;
62 	struct device			*dev;
63 	struct emif_regs		*regs_cache[EMIF_MAX_NUM_FREQUENCIES];
64 	struct emif_regs		*curr_regs;
65 	struct emif_platform_data	*plat_data;
66 	struct dentry			*debugfs_root;
67 	struct device_node		*np_ddr;
68 };
69 
70 static struct emif_data *emif1;
71 static DEFINE_SPINLOCK(emif_lock);
72 static unsigned long	irq_state;
73 static LIST_HEAD(device_list);
74 
75 #ifdef CONFIG_DEBUG_FS
76 static void do_emif_regdump_show(struct seq_file *s, struct emif_data *emif,
77 	struct emif_regs *regs)
78 {
79 	u32 type = emif->plat_data->device_info->type;
80 	u32 ip_rev = emif->plat_data->ip_rev;
81 
82 	seq_printf(s, "EMIF register cache dump for %dMHz\n",
83 		regs->freq/1000000);
84 
85 	seq_printf(s, "ref_ctrl_shdw\t: 0x%08x\n", regs->ref_ctrl_shdw);
86 	seq_printf(s, "sdram_tim1_shdw\t: 0x%08x\n", regs->sdram_tim1_shdw);
87 	seq_printf(s, "sdram_tim2_shdw\t: 0x%08x\n", regs->sdram_tim2_shdw);
88 	seq_printf(s, "sdram_tim3_shdw\t: 0x%08x\n", regs->sdram_tim3_shdw);
89 
90 	if (ip_rev == EMIF_4D) {
91 		seq_printf(s, "read_idle_ctrl_shdw_normal\t: 0x%08x\n",
92 			regs->read_idle_ctrl_shdw_normal);
93 		seq_printf(s, "read_idle_ctrl_shdw_volt_ramp\t: 0x%08x\n",
94 			regs->read_idle_ctrl_shdw_volt_ramp);
95 	} else if (ip_rev == EMIF_4D5) {
96 		seq_printf(s, "dll_calib_ctrl_shdw_normal\t: 0x%08x\n",
97 			regs->dll_calib_ctrl_shdw_normal);
98 		seq_printf(s, "dll_calib_ctrl_shdw_volt_ramp\t: 0x%08x\n",
99 			regs->dll_calib_ctrl_shdw_volt_ramp);
100 	}
101 
102 	if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4) {
103 		seq_printf(s, "ref_ctrl_shdw_derated\t: 0x%08x\n",
104 			regs->ref_ctrl_shdw_derated);
105 		seq_printf(s, "sdram_tim1_shdw_derated\t: 0x%08x\n",
106 			regs->sdram_tim1_shdw_derated);
107 		seq_printf(s, "sdram_tim3_shdw_derated\t: 0x%08x\n",
108 			regs->sdram_tim3_shdw_derated);
109 	}
110 }
111 
112 static int emif_regdump_show(struct seq_file *s, void *unused)
113 {
114 	struct emif_data	*emif	= s->private;
115 	struct emif_regs	**regs_cache;
116 	int			i;
117 
118 	if (emif->duplicate)
119 		regs_cache = emif1->regs_cache;
120 	else
121 		regs_cache = emif->regs_cache;
122 
123 	for (i = 0; i < EMIF_MAX_NUM_FREQUENCIES && regs_cache[i]; i++) {
124 		do_emif_regdump_show(s, emif, regs_cache[i]);
125 		seq_putc(s, '\n');
126 	}
127 
128 	return 0;
129 }
130 
131 DEFINE_SHOW_ATTRIBUTE(emif_regdump);
132 
133 static int emif_mr4_show(struct seq_file *s, void *unused)
134 {
135 	struct emif_data *emif = s->private;
136 
137 	seq_printf(s, "MR4=%d\n", emif->temperature_level);
138 	return 0;
139 }
140 
141 DEFINE_SHOW_ATTRIBUTE(emif_mr4);
142 
143 static int __init_or_module emif_debugfs_init(struct emif_data *emif)
144 {
145 	emif->debugfs_root = debugfs_create_dir(dev_name(emif->dev), NULL);
146 	debugfs_create_file("regcache_dump", S_IRUGO, emif->debugfs_root, emif,
147 			    &emif_regdump_fops);
148 	debugfs_create_file("mr4", S_IRUGO, emif->debugfs_root, emif,
149 			    &emif_mr4_fops);
150 	return 0;
151 }
152 
153 static void __exit emif_debugfs_exit(struct emif_data *emif)
154 {
155 	debugfs_remove_recursive(emif->debugfs_root);
156 	emif->debugfs_root = NULL;
157 }
158 #else
159 static inline int __init_or_module emif_debugfs_init(struct emif_data *emif)
160 {
161 	return 0;
162 }
163 
164 static inline void __exit emif_debugfs_exit(struct emif_data *emif)
165 {
166 }
167 #endif
168 
169 /*
170  * Get bus width used by EMIF. Note that this may be different from the
171  * bus width of the DDR devices used. For instance two 16-bit DDR devices
172  * may be connected to a given CS of EMIF. In this case bus width as far
173  * as EMIF is concerned is 32, where as the DDR bus width is 16 bits.
174  */
175 static u32 get_emif_bus_width(struct emif_data *emif)
176 {
177 	u32		width;
178 	void __iomem	*base = emif->base;
179 
180 	width = (readl(base + EMIF_SDRAM_CONFIG) & NARROW_MODE_MASK)
181 			>> NARROW_MODE_SHIFT;
182 	width = width == 0 ? 32 : 16;
183 
184 	return width;
185 }
186 
187 static void set_lpmode(struct emif_data *emif, u8 lpmode)
188 {
189 	u32 temp;
190 	void __iomem *base = emif->base;
191 
192 	/*
193 	 * Workaround for errata i743 - LPDDR2 Power-Down State is Not
194 	 * Efficient
195 	 *
196 	 * i743 DESCRIPTION:
197 	 * The EMIF supports power-down state for low power. The EMIF
198 	 * automatically puts the SDRAM into power-down after the memory is
199 	 * not accessed for a defined number of cycles and the
200 	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field is set to 0x4.
201 	 * As the EMIF supports automatic output impedance calibration, a ZQ
202 	 * calibration long command is issued every time it exits active
203 	 * power-down and precharge power-down modes. The EMIF waits and
204 	 * blocks any other command during this calibration.
205 	 * The EMIF does not allow selective disabling of ZQ calibration upon
206 	 * exit of power-down mode. Due to very short periods of power-down
207 	 * cycles, ZQ calibration overhead creates bandwidth issues and
208 	 * increases overall system power consumption. On the other hand,
209 	 * issuing ZQ calibration long commands when exiting self-refresh is
210 	 * still required.
211 	 *
212 	 * WORKAROUND
213 	 * Because there is no power consumption benefit of the power-down due
214 	 * to the calibration and there is a performance risk, the guideline
215 	 * is to not allow power-down state and, therefore, to not have set
216 	 * the EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field to 0x4.
217 	 */
218 	if ((emif->plat_data->ip_rev == EMIF_4D) &&
219 	    (lpmode == EMIF_LP_MODE_PWR_DN)) {
220 		WARN_ONCE(1,
221 			  "REG_LP_MODE = LP_MODE_PWR_DN(4) is prohibited by erratum i743 switch to LP_MODE_SELF_REFRESH(2)\n");
222 		/* rollback LP_MODE to Self-refresh mode */
223 		lpmode = EMIF_LP_MODE_SELF_REFRESH;
224 	}
225 
226 	temp = readl(base + EMIF_POWER_MANAGEMENT_CONTROL);
227 	temp &= ~LP_MODE_MASK;
228 	temp |= (lpmode << LP_MODE_SHIFT);
229 	writel(temp, base + EMIF_POWER_MANAGEMENT_CONTROL);
230 }
231 
232 static void do_freq_update(void)
233 {
234 	struct emif_data *emif;
235 
236 	/*
237 	 * Workaround for errata i728: Disable LPMODE during FREQ_UPDATE
238 	 *
239 	 * i728 DESCRIPTION:
240 	 * The EMIF automatically puts the SDRAM into self-refresh mode
241 	 * after the EMIF has not performed accesses during
242 	 * EMIF_PWR_MGMT_CTRL[7:4] REG_SR_TIM number of DDR clock cycles
243 	 * and the EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE bit field is set
244 	 * to 0x2. If during a small window the following three events
245 	 * occur:
246 	 * - The SR_TIMING counter expires
247 	 * - And frequency change is requested
248 	 * - And OCP access is requested
249 	 * Then it causes instable clock on the DDR interface.
250 	 *
251 	 * WORKAROUND
252 	 * To avoid the occurrence of the three events, the workaround
253 	 * is to disable the self-refresh when requesting a frequency
254 	 * change. Before requesting a frequency change the software must
255 	 * program EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x0. When the
256 	 * frequency change has been done, the software can reprogram
257 	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x2
258 	 */
259 	list_for_each_entry(emif, &device_list, node) {
260 		if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
261 			set_lpmode(emif, EMIF_LP_MODE_DISABLE);
262 	}
263 
264 	/*
265 	 * TODO: Do FREQ_UPDATE here when an API
266 	 * is available for this as part of the new
267 	 * clock framework
268 	 */
269 
270 	list_for_each_entry(emif, &device_list, node) {
271 		if (emif->lpmode == EMIF_LP_MODE_SELF_REFRESH)
272 			set_lpmode(emif, EMIF_LP_MODE_SELF_REFRESH);
273 	}
274 }
275 
276 /* Find addressing table entry based on the device's type and density */
277 static const struct lpddr2_addressing *get_addressing_table(
278 	const struct ddr_device_info *device_info)
279 {
280 	u32		index, type, density;
281 
282 	type = device_info->type;
283 	density = device_info->density;
284 
285 	switch (type) {
286 	case DDR_TYPE_LPDDR2_S4:
287 		index = density - 1;
288 		break;
289 	case DDR_TYPE_LPDDR2_S2:
290 		switch (density) {
291 		case DDR_DENSITY_1Gb:
292 		case DDR_DENSITY_2Gb:
293 			index = density + 3;
294 			break;
295 		default:
296 			index = density - 1;
297 		}
298 		break;
299 	default:
300 		return NULL;
301 	}
302 
303 	return &lpddr2_jedec_addressing_table[index];
304 }
305 
306 static u32 get_zq_config_reg(const struct lpddr2_addressing *addressing,
307 		bool cs1_used, bool cal_resistors_per_cs)
308 {
309 	u32 zq = 0, val = 0;
310 
311 	val = EMIF_ZQCS_INTERVAL_US * 1000 / addressing->tREFI_ns;
312 	zq |= val << ZQ_REFINTERVAL_SHIFT;
313 
314 	val = DIV_ROUND_UP(T_ZQCL_DEFAULT_NS, T_ZQCS_DEFAULT_NS) - 1;
315 	zq |= val << ZQ_ZQCL_MULT_SHIFT;
316 
317 	val = DIV_ROUND_UP(T_ZQINIT_DEFAULT_NS, T_ZQCL_DEFAULT_NS) - 1;
318 	zq |= val << ZQ_ZQINIT_MULT_SHIFT;
319 
320 	zq |= ZQ_SFEXITEN_ENABLE << ZQ_SFEXITEN_SHIFT;
321 
322 	if (cal_resistors_per_cs)
323 		zq |= ZQ_DUALCALEN_ENABLE << ZQ_DUALCALEN_SHIFT;
324 	else
325 		zq |= ZQ_DUALCALEN_DISABLE << ZQ_DUALCALEN_SHIFT;
326 
327 	zq |= ZQ_CS0EN_MASK; /* CS0 is used for sure */
328 
329 	val = cs1_used ? 1 : 0;
330 	zq |= val << ZQ_CS1EN_SHIFT;
331 
332 	return zq;
333 }
334 
335 static u32 get_temp_alert_config(const struct lpddr2_addressing *addressing,
336 		const struct emif_custom_configs *custom_configs, bool cs1_used,
337 		u32 sdram_io_width, u32 emif_bus_width)
338 {
339 	u32 alert = 0, interval, devcnt;
340 
341 	if (custom_configs && (custom_configs->mask &
342 				EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL))
343 		interval = custom_configs->temp_alert_poll_interval_ms;
344 	else
345 		interval = TEMP_ALERT_POLL_INTERVAL_DEFAULT_MS;
346 
347 	interval *= 1000000;			/* Convert to ns */
348 	interval /= addressing->tREFI_ns;	/* Convert to refresh cycles */
349 	alert |= (interval << TA_REFINTERVAL_SHIFT);
350 
351 	/*
352 	 * sdram_io_width is in 'log2(x) - 1' form. Convert emif_bus_width
353 	 * also to this form and subtract to get TA_DEVCNT, which is
354 	 * in log2(x) form.
355 	 */
356 	emif_bus_width = __fls(emif_bus_width) - 1;
357 	devcnt = emif_bus_width - sdram_io_width;
358 	alert |= devcnt << TA_DEVCNT_SHIFT;
359 
360 	/* DEVWDT is in 'log2(x) - 3' form */
361 	alert |= (sdram_io_width - 2) << TA_DEVWDT_SHIFT;
362 
363 	alert |= 1 << TA_SFEXITEN_SHIFT;
364 	alert |= 1 << TA_CS0EN_SHIFT;
365 	alert |= (cs1_used ? 1 : 0) << TA_CS1EN_SHIFT;
366 
367 	return alert;
368 }
369 
370 static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
371 {
372 	u32 pwr_mgmt_ctrl	= 0, timeout;
373 	u32 lpmode		= EMIF_LP_MODE_SELF_REFRESH;
374 	u32 timeout_perf	= EMIF_LP_MODE_TIMEOUT_PERFORMANCE;
375 	u32 timeout_pwr		= EMIF_LP_MODE_TIMEOUT_POWER;
376 	u32 freq_threshold	= EMIF_LP_MODE_FREQ_THRESHOLD;
377 	u32 mask;
378 	u8 shift;
379 
380 	struct emif_custom_configs *cust_cfgs = emif->plat_data->custom_configs;
381 
382 	if (cust_cfgs && (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE)) {
383 		lpmode		= cust_cfgs->lpmode;
384 		timeout_perf	= cust_cfgs->lpmode_timeout_performance;
385 		timeout_pwr	= cust_cfgs->lpmode_timeout_power;
386 		freq_threshold  = cust_cfgs->lpmode_freq_threshold;
387 	}
388 
389 	/* Timeout based on DDR frequency */
390 	timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr;
391 
392 	/*
393 	 * The value to be set in register is "log2(timeout) - 3"
394 	 * if timeout < 16 load 0 in register
395 	 * if timeout is not a power of 2, round to next highest power of 2
396 	 */
397 	if (timeout < 16) {
398 		timeout = 0;
399 	} else {
400 		if (timeout & (timeout - 1))
401 			timeout <<= 1;
402 		timeout = __fls(timeout) - 3;
403 	}
404 
405 	switch (lpmode) {
406 	case EMIF_LP_MODE_CLOCK_STOP:
407 		shift = CS_TIM_SHIFT;
408 		mask = CS_TIM_MASK;
409 		break;
410 	case EMIF_LP_MODE_SELF_REFRESH:
411 		/* Workaround for errata i735 */
412 		if (timeout < 6)
413 			timeout = 6;
414 
415 		shift = SR_TIM_SHIFT;
416 		mask = SR_TIM_MASK;
417 		break;
418 	case EMIF_LP_MODE_PWR_DN:
419 		shift = PD_TIM_SHIFT;
420 		mask = PD_TIM_MASK;
421 		break;
422 	case EMIF_LP_MODE_DISABLE:
423 	default:
424 		mask = 0;
425 		shift = 0;
426 		break;
427 	}
428 	/* Round to maximum in case of overflow, BUT warn! */
429 	if (lpmode != EMIF_LP_MODE_DISABLE && timeout > mask >> shift) {
430 		pr_err("TIMEOUT Overflow - lpmode=%d perf=%d pwr=%d freq=%d\n",
431 		       lpmode,
432 		       timeout_perf,
433 		       timeout_pwr,
434 		       freq_threshold);
435 		WARN(1, "timeout=0x%02x greater than 0x%02x. Using max\n",
436 		     timeout, mask >> shift);
437 		timeout = mask >> shift;
438 	}
439 
440 	/* Setup required timing */
441 	pwr_mgmt_ctrl = (timeout << shift) & mask;
442 	/* setup a default mask for rest of the modes */
443 	pwr_mgmt_ctrl |= (SR_TIM_MASK | CS_TIM_MASK | PD_TIM_MASK) &
444 			  ~mask;
445 
446 	/* No CS_TIM in EMIF_4D5 */
447 	if (ip_rev == EMIF_4D5)
448 		pwr_mgmt_ctrl &= ~CS_TIM_MASK;
449 
450 	pwr_mgmt_ctrl |= lpmode << LP_MODE_SHIFT;
451 
452 	return pwr_mgmt_ctrl;
453 }
454 
455 /*
456  * Get the temperature level of the EMIF instance:
457  * Reads the MR4 register of attached SDRAM parts to find out the temperature
458  * level. If there are two parts attached(one on each CS), then the temperature
459  * level for the EMIF instance is the higher of the two temperatures.
460  */
461 static void get_temperature_level(struct emif_data *emif)
462 {
463 	u32		temp, temperature_level;
464 	void __iomem	*base;
465 
466 	base = emif->base;
467 
468 	/* Read mode register 4 */
469 	writel(DDR_MR4, base + EMIF_LPDDR2_MODE_REG_CONFIG);
470 	temperature_level = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
471 	temperature_level = (temperature_level & MR4_SDRAM_REF_RATE_MASK) >>
472 				MR4_SDRAM_REF_RATE_SHIFT;
473 
474 	if (emif->plat_data->device_info->cs1_used) {
475 		writel(DDR_MR4 | CS_MASK, base + EMIF_LPDDR2_MODE_REG_CONFIG);
476 		temp = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
477 		temp = (temp & MR4_SDRAM_REF_RATE_MASK)
478 				>> MR4_SDRAM_REF_RATE_SHIFT;
479 		temperature_level = max(temp, temperature_level);
480 	}
481 
482 	/* treat everything less than nominal(3) in MR4 as nominal */
483 	if (unlikely(temperature_level < SDRAM_TEMP_NOMINAL))
484 		temperature_level = SDRAM_TEMP_NOMINAL;
485 
486 	/* if we get reserved value in MR4 persist with the existing value */
487 	if (likely(temperature_level != SDRAM_TEMP_RESERVED_4))
488 		emif->temperature_level = temperature_level;
489 }
490 
491 /*
492  * setup_temperature_sensitive_regs() - set the timings for temperature
493  * sensitive registers. This happens once at initialisation time based
494  * on the temperature at boot time and subsequently based on the temperature
495  * alert interrupt. Temperature alert can happen when the temperature
496  * increases or drops. So this function can have the effect of either
497  * derating the timings or going back to nominal values.
498  */
499 static void setup_temperature_sensitive_regs(struct emif_data *emif,
500 		struct emif_regs *regs)
501 {
502 	u32		tim1, tim3, ref_ctrl, type;
503 	void __iomem	*base = emif->base;
504 	u32		temperature;
505 
506 	type = emif->plat_data->device_info->type;
507 
508 	tim1 = regs->sdram_tim1_shdw;
509 	tim3 = regs->sdram_tim3_shdw;
510 	ref_ctrl = regs->ref_ctrl_shdw;
511 
512 	/* No de-rating for non-lpddr2 devices */
513 	if (type != DDR_TYPE_LPDDR2_S2 && type != DDR_TYPE_LPDDR2_S4)
514 		goto out;
515 
516 	temperature = emif->temperature_level;
517 	if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH) {
518 		ref_ctrl = regs->ref_ctrl_shdw_derated;
519 	} else if (temperature == SDRAM_TEMP_HIGH_DERATE_REFRESH_AND_TIMINGS) {
520 		tim1 = regs->sdram_tim1_shdw_derated;
521 		tim3 = regs->sdram_tim3_shdw_derated;
522 		ref_ctrl = regs->ref_ctrl_shdw_derated;
523 	}
524 
525 out:
526 	writel(tim1, base + EMIF_SDRAM_TIMING_1_SHDW);
527 	writel(tim3, base + EMIF_SDRAM_TIMING_3_SHDW);
528 	writel(ref_ctrl, base + EMIF_SDRAM_REFRESH_CTRL_SHDW);
529 }
530 
531 static irqreturn_t handle_temp_alert(void __iomem *base, struct emif_data *emif)
532 {
533 	u32		old_temp_level;
534 	irqreturn_t	ret = IRQ_HANDLED;
535 	struct emif_custom_configs *custom_configs;
536 
537 	spin_lock_irqsave(&emif_lock, irq_state);
538 	old_temp_level = emif->temperature_level;
539 	get_temperature_level(emif);
540 
541 	if (unlikely(emif->temperature_level == old_temp_level)) {
542 		goto out;
543 	} else if (!emif->curr_regs) {
544 		dev_err(emif->dev, "temperature alert before registers are calculated, not de-rating timings\n");
545 		goto out;
546 	}
547 
548 	custom_configs = emif->plat_data->custom_configs;
549 
550 	/*
551 	 * IF we detect higher than "nominal rating" from DDR sensor
552 	 * on an unsupported DDR part, shutdown system
553 	 */
554 	if (custom_configs && !(custom_configs->mask &
555 				EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART)) {
556 		if (emif->temperature_level >= SDRAM_TEMP_HIGH_DERATE_REFRESH) {
557 			dev_err(emif->dev,
558 				"%s:NOT Extended temperature capable memory. Converting MR4=0x%02x as shutdown event\n",
559 				__func__, emif->temperature_level);
560 			/*
561 			 * Temperature far too high - do kernel_power_off()
562 			 * from thread context
563 			 */
564 			emif->temperature_level = SDRAM_TEMP_VERY_HIGH_SHUTDOWN;
565 			ret = IRQ_WAKE_THREAD;
566 			goto out;
567 		}
568 	}
569 
570 	if (emif->temperature_level < old_temp_level ||
571 		emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) {
572 		/*
573 		 * Temperature coming down - defer handling to thread OR
574 		 * Temperature far too high - do kernel_power_off() from
575 		 * thread context
576 		 */
577 		ret = IRQ_WAKE_THREAD;
578 	} else {
579 		/* Temperature is going up - handle immediately */
580 		setup_temperature_sensitive_regs(emif, emif->curr_regs);
581 		do_freq_update();
582 	}
583 
584 out:
585 	spin_unlock_irqrestore(&emif_lock, irq_state);
586 	return ret;
587 }
588 
589 static irqreturn_t emif_interrupt_handler(int irq, void *dev_id)
590 {
591 	u32			interrupts;
592 	struct emif_data	*emif = dev_id;
593 	void __iomem		*base = emif->base;
594 	struct device		*dev = emif->dev;
595 	irqreturn_t		ret = IRQ_HANDLED;
596 
597 	/* Save the status and clear it */
598 	interrupts = readl(base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
599 	writel(interrupts, base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
600 
601 	/*
602 	 * Handle temperature alert
603 	 * Temperature alert should be same for all ports
604 	 * So, it's enough to process it only for one of the ports
605 	 */
606 	if (interrupts & TA_SYS_MASK)
607 		ret = handle_temp_alert(base, emif);
608 
609 	if (interrupts & ERR_SYS_MASK)
610 		dev_err(dev, "Access error from SYS port - %x\n", interrupts);
611 
612 	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE) {
613 		/* Save the status and clear it */
614 		interrupts = readl(base + EMIF_LL_OCP_INTERRUPT_STATUS);
615 		writel(interrupts, base + EMIF_LL_OCP_INTERRUPT_STATUS);
616 
617 		if (interrupts & ERR_LL_MASK)
618 			dev_err(dev, "Access error from LL port - %x\n",
619 				interrupts);
620 	}
621 
622 	return ret;
623 }
624 
625 static irqreturn_t emif_threaded_isr(int irq, void *dev_id)
626 {
627 	struct emif_data	*emif = dev_id;
628 
629 	if (emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) {
630 		dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
631 
632 		/* If we have Power OFF ability, use it, else try restarting */
633 		if (kernel_can_power_off()) {
634 			kernel_power_off();
635 		} else {
636 			WARN(1, "FIXME: NO pm_power_off!!! trying restart\n");
637 			kernel_restart("SDRAM Over-temp Emergency restart");
638 		}
639 		return IRQ_HANDLED;
640 	}
641 
642 	spin_lock_irqsave(&emif_lock, irq_state);
643 
644 	if (emif->curr_regs) {
645 		setup_temperature_sensitive_regs(emif, emif->curr_regs);
646 		do_freq_update();
647 	} else {
648 		dev_err(emif->dev, "temperature alert before registers are calculated, not de-rating timings\n");
649 	}
650 
651 	spin_unlock_irqrestore(&emif_lock, irq_state);
652 
653 	return IRQ_HANDLED;
654 }
655 
656 static void clear_all_interrupts(struct emif_data *emif)
657 {
658 	void __iomem	*base = emif->base;
659 
660 	writel(readl(base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS),
661 		base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
662 	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
663 		writel(readl(base + EMIF_LL_OCP_INTERRUPT_STATUS),
664 			base + EMIF_LL_OCP_INTERRUPT_STATUS);
665 }
666 
667 static void disable_and_clear_all_interrupts(struct emif_data *emif)
668 {
669 	void __iomem		*base = emif->base;
670 
671 	/* Disable all interrupts */
672 	writel(readl(base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_SET),
673 		base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_CLEAR);
674 	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
675 		writel(readl(base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET),
676 			base + EMIF_LL_OCP_INTERRUPT_ENABLE_CLEAR);
677 
678 	/* Clear all interrupts */
679 	clear_all_interrupts(emif);
680 }
681 
682 static int __init_or_module setup_interrupts(struct emif_data *emif, u32 irq)
683 {
684 	u32		interrupts, type;
685 	void __iomem	*base = emif->base;
686 
687 	type = emif->plat_data->device_info->type;
688 
689 	clear_all_interrupts(emif);
690 
691 	/* Enable interrupts for SYS interface */
692 	interrupts = EN_ERR_SYS_MASK;
693 	if (type == DDR_TYPE_LPDDR2_S2 || type == DDR_TYPE_LPDDR2_S4)
694 		interrupts |= EN_TA_SYS_MASK;
695 	writel(interrupts, base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_SET);
696 
697 	/* Enable interrupts for LL interface */
698 	if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE) {
699 		/* TA need not be enabled for LL */
700 		interrupts = EN_ERR_LL_MASK;
701 		writel(interrupts, base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET);
702 	}
703 
704 	/* setup IRQ handlers */
705 	return devm_request_threaded_irq(emif->dev, irq,
706 				    emif_interrupt_handler,
707 				    emif_threaded_isr,
708 				    0, dev_name(emif->dev),
709 				    emif);
710 
711 }
712 
713 static void __init_or_module emif_onetime_settings(struct emif_data *emif)
714 {
715 	u32				pwr_mgmt_ctrl, zq, temp_alert_cfg;
716 	void __iomem			*base = emif->base;
717 	const struct lpddr2_addressing	*addressing;
718 	const struct ddr_device_info	*device_info;
719 
720 	device_info = emif->plat_data->device_info;
721 	addressing = get_addressing_table(device_info);
722 
723 	/*
724 	 * Init power management settings
725 	 * We don't know the frequency yet. Use a high frequency
726 	 * value for a conservative timeout setting
727 	 */
728 	pwr_mgmt_ctrl = get_pwr_mgmt_ctrl(1000000000, emif,
729 			emif->plat_data->ip_rev);
730 	emif->lpmode = (pwr_mgmt_ctrl & LP_MODE_MASK) >> LP_MODE_SHIFT;
731 	writel(pwr_mgmt_ctrl, base + EMIF_POWER_MANAGEMENT_CONTROL);
732 
733 	/* Init ZQ calibration settings */
734 	zq = get_zq_config_reg(addressing, device_info->cs1_used,
735 		device_info->cal_resistors_per_cs);
736 	writel(zq, base + EMIF_SDRAM_OUTPUT_IMPEDANCE_CALIBRATION_CONFIG);
737 
738 	/* Check temperature level temperature level*/
739 	get_temperature_level(emif);
740 	if (emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN)
741 		dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
742 
743 	/* Init temperature polling */
744 	temp_alert_cfg = get_temp_alert_config(addressing,
745 		emif->plat_data->custom_configs, device_info->cs1_used,
746 		device_info->io_width, get_emif_bus_width(emif));
747 	writel(temp_alert_cfg, base + EMIF_TEMPERATURE_ALERT_CONFIG);
748 
749 	/*
750 	 * Program external PHY control registers that are not frequency
751 	 * dependent
752 	 */
753 	if (emif->plat_data->phy_type != EMIF_PHY_TYPE_INTELLIPHY)
754 		return;
755 	writel(EMIF_EXT_PHY_CTRL_1_VAL, base + EMIF_EXT_PHY_CTRL_1_SHDW);
756 	writel(EMIF_EXT_PHY_CTRL_5_VAL, base + EMIF_EXT_PHY_CTRL_5_SHDW);
757 	writel(EMIF_EXT_PHY_CTRL_6_VAL, base + EMIF_EXT_PHY_CTRL_6_SHDW);
758 	writel(EMIF_EXT_PHY_CTRL_7_VAL, base + EMIF_EXT_PHY_CTRL_7_SHDW);
759 	writel(EMIF_EXT_PHY_CTRL_8_VAL, base + EMIF_EXT_PHY_CTRL_8_SHDW);
760 	writel(EMIF_EXT_PHY_CTRL_9_VAL, base + EMIF_EXT_PHY_CTRL_9_SHDW);
761 	writel(EMIF_EXT_PHY_CTRL_10_VAL, base + EMIF_EXT_PHY_CTRL_10_SHDW);
762 	writel(EMIF_EXT_PHY_CTRL_11_VAL, base + EMIF_EXT_PHY_CTRL_11_SHDW);
763 	writel(EMIF_EXT_PHY_CTRL_12_VAL, base + EMIF_EXT_PHY_CTRL_12_SHDW);
764 	writel(EMIF_EXT_PHY_CTRL_13_VAL, base + EMIF_EXT_PHY_CTRL_13_SHDW);
765 	writel(EMIF_EXT_PHY_CTRL_14_VAL, base + EMIF_EXT_PHY_CTRL_14_SHDW);
766 	writel(EMIF_EXT_PHY_CTRL_15_VAL, base + EMIF_EXT_PHY_CTRL_15_SHDW);
767 	writel(EMIF_EXT_PHY_CTRL_16_VAL, base + EMIF_EXT_PHY_CTRL_16_SHDW);
768 	writel(EMIF_EXT_PHY_CTRL_17_VAL, base + EMIF_EXT_PHY_CTRL_17_SHDW);
769 	writel(EMIF_EXT_PHY_CTRL_18_VAL, base + EMIF_EXT_PHY_CTRL_18_SHDW);
770 	writel(EMIF_EXT_PHY_CTRL_19_VAL, base + EMIF_EXT_PHY_CTRL_19_SHDW);
771 	writel(EMIF_EXT_PHY_CTRL_20_VAL, base + EMIF_EXT_PHY_CTRL_20_SHDW);
772 	writel(EMIF_EXT_PHY_CTRL_21_VAL, base + EMIF_EXT_PHY_CTRL_21_SHDW);
773 	writel(EMIF_EXT_PHY_CTRL_22_VAL, base + EMIF_EXT_PHY_CTRL_22_SHDW);
774 	writel(EMIF_EXT_PHY_CTRL_23_VAL, base + EMIF_EXT_PHY_CTRL_23_SHDW);
775 	writel(EMIF_EXT_PHY_CTRL_24_VAL, base + EMIF_EXT_PHY_CTRL_24_SHDW);
776 }
777 
778 static void get_default_timings(struct emif_data *emif)
779 {
780 	struct emif_platform_data *pd = emif->plat_data;
781 
782 	pd->timings		= lpddr2_jedec_timings;
783 	pd->timings_arr_size	= ARRAY_SIZE(lpddr2_jedec_timings);
784 
785 	dev_warn(emif->dev, "%s: using default timings\n", __func__);
786 }
787 
788 static int is_dev_data_valid(u32 type, u32 density, u32 io_width, u32 phy_type,
789 		u32 ip_rev, struct device *dev)
790 {
791 	int valid;
792 
793 	valid = (type == DDR_TYPE_LPDDR2_S4 ||
794 			type == DDR_TYPE_LPDDR2_S2)
795 		&& (density >= DDR_DENSITY_64Mb
796 			&& density <= DDR_DENSITY_8Gb)
797 		&& (io_width >= DDR_IO_WIDTH_8
798 			&& io_width <= DDR_IO_WIDTH_32);
799 
800 	/* Combinations of EMIF and PHY revisions that we support today */
801 	switch (ip_rev) {
802 	case EMIF_4D:
803 		valid = valid && (phy_type == EMIF_PHY_TYPE_ATTILAPHY);
804 		break;
805 	case EMIF_4D5:
806 		valid = valid && (phy_type == EMIF_PHY_TYPE_INTELLIPHY);
807 		break;
808 	default:
809 		valid = 0;
810 	}
811 
812 	if (!valid)
813 		dev_err(dev, "%s: invalid DDR details\n", __func__);
814 	return valid;
815 }
816 
817 static int is_custom_config_valid(struct emif_custom_configs *cust_cfgs,
818 		struct device *dev)
819 {
820 	int valid = 1;
821 
822 	if ((cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE) &&
823 		(cust_cfgs->lpmode != EMIF_LP_MODE_DISABLE))
824 		valid = cust_cfgs->lpmode_freq_threshold &&
825 			cust_cfgs->lpmode_timeout_performance &&
826 			cust_cfgs->lpmode_timeout_power;
827 
828 	if (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL)
829 		valid = valid && cust_cfgs->temp_alert_poll_interval_ms;
830 
831 	if (!valid)
832 		dev_warn(dev, "%s: invalid custom configs\n", __func__);
833 
834 	return valid;
835 }
836 
837 #if defined(CONFIG_OF)
838 static void __init_or_module of_get_custom_configs(struct device_node *np_emif,
839 		struct emif_data *emif)
840 {
841 	struct emif_custom_configs	*cust_cfgs = NULL;
842 	int				len;
843 	const __be32			*lpmode, *poll_intvl;
844 
845 	lpmode = of_get_property(np_emif, "low-power-mode", &len);
846 	poll_intvl = of_get_property(np_emif, "temp-alert-poll-interval", &len);
847 
848 	if (lpmode || poll_intvl)
849 		cust_cfgs = devm_kzalloc(emif->dev, sizeof(*cust_cfgs),
850 			GFP_KERNEL);
851 
852 	if (!cust_cfgs)
853 		return;
854 
855 	if (lpmode) {
856 		cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_LPMODE;
857 		cust_cfgs->lpmode = be32_to_cpup(lpmode);
858 		of_property_read_u32(np_emif,
859 				"low-power-mode-timeout-performance",
860 				&cust_cfgs->lpmode_timeout_performance);
861 		of_property_read_u32(np_emif,
862 				"low-power-mode-timeout-power",
863 				&cust_cfgs->lpmode_timeout_power);
864 		of_property_read_u32(np_emif,
865 				"low-power-mode-freq-threshold",
866 				&cust_cfgs->lpmode_freq_threshold);
867 	}
868 
869 	if (poll_intvl) {
870 		cust_cfgs->mask |=
871 				EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL;
872 		cust_cfgs->temp_alert_poll_interval_ms =
873 						be32_to_cpup(poll_intvl);
874 	}
875 
876 	if (of_find_property(np_emif, "extended-temp-part", &len))
877 		cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART;
878 
879 	if (!is_custom_config_valid(cust_cfgs, emif->dev)) {
880 		devm_kfree(emif->dev, cust_cfgs);
881 		return;
882 	}
883 
884 	emif->plat_data->custom_configs = cust_cfgs;
885 }
886 
887 static void __init_or_module of_get_ddr_info(struct device_node *np_emif,
888 		struct device_node *np_ddr,
889 		struct ddr_device_info *dev_info)
890 {
891 	u32 density = 0, io_width = 0;
892 	int len;
893 
894 	if (of_find_property(np_emif, "cs1-used", &len))
895 		dev_info->cs1_used = true;
896 
897 	if (of_find_property(np_emif, "cal-resistor-per-cs", &len))
898 		dev_info->cal_resistors_per_cs = true;
899 
900 	if (of_device_is_compatible(np_ddr, "jedec,lpddr2-s4"))
901 		dev_info->type = DDR_TYPE_LPDDR2_S4;
902 	else if (of_device_is_compatible(np_ddr, "jedec,lpddr2-s2"))
903 		dev_info->type = DDR_TYPE_LPDDR2_S2;
904 
905 	of_property_read_u32(np_ddr, "density", &density);
906 	of_property_read_u32(np_ddr, "io-width", &io_width);
907 
908 	/* Convert from density in Mb to the density encoding in jedc_ddr.h */
909 	if (density & (density - 1))
910 		dev_info->density = 0;
911 	else
912 		dev_info->density = __fls(density) - 5;
913 
914 	/* Convert from io_width in bits to io_width encoding in jedc_ddr.h */
915 	if (io_width & (io_width - 1))
916 		dev_info->io_width = 0;
917 	else
918 		dev_info->io_width = __fls(io_width) - 1;
919 }
920 
921 static struct emif_data * __init_or_module of_get_memory_device_details(
922 		struct device_node *np_emif, struct device *dev)
923 {
924 	struct emif_data		*emif = NULL;
925 	struct ddr_device_info		*dev_info = NULL;
926 	struct emif_platform_data	*pd = NULL;
927 	struct device_node		*np_ddr;
928 	int				len;
929 
930 	np_ddr = of_parse_phandle(np_emif, "device-handle", 0);
931 	if (!np_ddr)
932 		goto error;
933 	emif	= devm_kzalloc(dev, sizeof(struct emif_data), GFP_KERNEL);
934 	pd	= devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
935 	dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
936 
937 	if (!emif || !pd || !dev_info) {
938 		dev_err(dev, "%s: Out of memory!!\n",
939 			__func__);
940 		goto error;
941 	}
942 
943 	emif->plat_data		= pd;
944 	pd->device_info		= dev_info;
945 	emif->dev		= dev;
946 	emif->np_ddr		= np_ddr;
947 	emif->temperature_level	= SDRAM_TEMP_NOMINAL;
948 
949 	if (of_device_is_compatible(np_emif, "ti,emif-4d"))
950 		emif->plat_data->ip_rev = EMIF_4D;
951 	else if (of_device_is_compatible(np_emif, "ti,emif-4d5"))
952 		emif->plat_data->ip_rev = EMIF_4D5;
953 
954 	of_property_read_u32(np_emif, "phy-type", &pd->phy_type);
955 
956 	if (of_find_property(np_emif, "hw-caps-ll-interface", &len))
957 		pd->hw_caps |= EMIF_HW_CAPS_LL_INTERFACE;
958 
959 	of_get_ddr_info(np_emif, np_ddr, dev_info);
960 	if (!is_dev_data_valid(pd->device_info->type, pd->device_info->density,
961 			pd->device_info->io_width, pd->phy_type, pd->ip_rev,
962 			emif->dev)) {
963 		dev_err(dev, "%s: invalid device data!!\n", __func__);
964 		goto error;
965 	}
966 	/*
967 	 * For EMIF instances other than EMIF1 see if the devices connected
968 	 * are exactly same as on EMIF1(which is typically the case). If so,
969 	 * mark it as a duplicate of EMIF1. This will save some memory and
970 	 * computation.
971 	 */
972 	if (emif1 && emif1->np_ddr == np_ddr) {
973 		emif->duplicate = true;
974 		goto out;
975 	} else if (emif1) {
976 		dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
977 			__func__);
978 	}
979 
980 	of_get_custom_configs(np_emif, emif);
981 	emif->plat_data->timings = of_get_ddr_timings(np_ddr, emif->dev,
982 					emif->plat_data->device_info->type,
983 					&emif->plat_data->timings_arr_size);
984 
985 	emif->plat_data->min_tck = of_get_min_tck(np_ddr, emif->dev);
986 	goto out;
987 
988 error:
989 	return NULL;
990 out:
991 	return emif;
992 }
993 
994 #else
995 
996 static struct emif_data * __init_or_module of_get_memory_device_details(
997 		struct device_node *np_emif, struct device *dev)
998 {
999 	return NULL;
1000 }
1001 #endif
1002 
1003 static struct emif_data *__init_or_module get_device_details(
1004 		struct platform_device *pdev)
1005 {
1006 	u32				size;
1007 	struct emif_data		*emif = NULL;
1008 	struct ddr_device_info		*dev_info;
1009 	struct emif_custom_configs	*cust_cfgs;
1010 	struct emif_platform_data	*pd;
1011 	struct device			*dev;
1012 	void				*temp;
1013 
1014 	pd = pdev->dev.platform_data;
1015 	dev = &pdev->dev;
1016 
1017 	if (!(pd && pd->device_info && is_dev_data_valid(pd->device_info->type,
1018 			pd->device_info->density, pd->device_info->io_width,
1019 			pd->phy_type, pd->ip_rev, dev))) {
1020 		dev_err(dev, "%s: invalid device data\n", __func__);
1021 		goto error;
1022 	}
1023 
1024 	emif	= devm_kzalloc(dev, sizeof(*emif), GFP_KERNEL);
1025 	temp	= devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
1026 	dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
1027 
1028 	if (!emif || !temp || !dev_info)
1029 		goto error;
1030 
1031 	memcpy(temp, pd, sizeof(*pd));
1032 	pd = temp;
1033 	memcpy(dev_info, pd->device_info, sizeof(*dev_info));
1034 
1035 	pd->device_info		= dev_info;
1036 	emif->plat_data		= pd;
1037 	emif->dev		= dev;
1038 	emif->temperature_level	= SDRAM_TEMP_NOMINAL;
1039 
1040 	/*
1041 	 * For EMIF instances other than EMIF1 see if the devices connected
1042 	 * are exactly same as on EMIF1(which is typically the case). If so,
1043 	 * mark it as a duplicate of EMIF1 and skip copying timings data.
1044 	 * This will save some memory and some computation later.
1045 	 */
1046 	emif->duplicate = emif1 && (memcmp(dev_info,
1047 		emif1->plat_data->device_info,
1048 		sizeof(struct ddr_device_info)) == 0);
1049 
1050 	if (emif->duplicate) {
1051 		pd->timings = NULL;
1052 		pd->min_tck = NULL;
1053 		goto out;
1054 	} else if (emif1) {
1055 		dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
1056 			__func__);
1057 	}
1058 
1059 	/*
1060 	 * Copy custom configs - ignore allocation error, if any, as
1061 	 * custom_configs is not very critical
1062 	 */
1063 	cust_cfgs = pd->custom_configs;
1064 	if (cust_cfgs && is_custom_config_valid(cust_cfgs, dev)) {
1065 		temp = devm_kzalloc(dev, sizeof(*cust_cfgs), GFP_KERNEL);
1066 		if (temp)
1067 			memcpy(temp, cust_cfgs, sizeof(*cust_cfgs));
1068 		pd->custom_configs = temp;
1069 	}
1070 
1071 	/*
1072 	 * Copy timings and min-tck values from platform data. If it is not
1073 	 * available or if memory allocation fails, use JEDEC defaults
1074 	 */
1075 	size = sizeof(struct lpddr2_timings) * pd->timings_arr_size;
1076 	if (pd->timings) {
1077 		temp = devm_kzalloc(dev, size, GFP_KERNEL);
1078 		if (temp) {
1079 			memcpy(temp, pd->timings, size);
1080 			pd->timings = temp;
1081 		} else {
1082 			get_default_timings(emif);
1083 		}
1084 	} else {
1085 		get_default_timings(emif);
1086 	}
1087 
1088 	if (pd->min_tck) {
1089 		temp = devm_kzalloc(dev, sizeof(*pd->min_tck), GFP_KERNEL);
1090 		if (temp) {
1091 			memcpy(temp, pd->min_tck, sizeof(*pd->min_tck));
1092 			pd->min_tck = temp;
1093 		} else {
1094 			pd->min_tck = &lpddr2_jedec_min_tck;
1095 		}
1096 	} else {
1097 		pd->min_tck = &lpddr2_jedec_min_tck;
1098 	}
1099 
1100 out:
1101 	return emif;
1102 
1103 error:
1104 	return NULL;
1105 }
1106 
1107 static int __init_or_module emif_probe(struct platform_device *pdev)
1108 {
1109 	struct emif_data	*emif;
1110 	int			irq, ret;
1111 
1112 	if (pdev->dev.of_node)
1113 		emif = of_get_memory_device_details(pdev->dev.of_node, &pdev->dev);
1114 	else
1115 		emif = get_device_details(pdev);
1116 
1117 	if (!emif) {
1118 		pr_err("%s: error getting device data\n", __func__);
1119 		goto error;
1120 	}
1121 
1122 	list_add(&emif->node, &device_list);
1123 
1124 	/* Save pointers to each other in emif and device structures */
1125 	emif->dev = &pdev->dev;
1126 	platform_set_drvdata(pdev, emif);
1127 
1128 	emif->base = devm_platform_ioremap_resource(pdev, 0);
1129 	if (IS_ERR(emif->base))
1130 		goto error;
1131 
1132 	irq = platform_get_irq(pdev, 0);
1133 	if (irq < 0)
1134 		goto error;
1135 
1136 	emif_onetime_settings(emif);
1137 	emif_debugfs_init(emif);
1138 	disable_and_clear_all_interrupts(emif);
1139 	ret = setup_interrupts(emif, irq);
1140 	if (ret)
1141 		goto error;
1142 
1143 	/* One-time actions taken on probing the first device */
1144 	if (!emif1) {
1145 		emif1 = emif;
1146 
1147 		/*
1148 		 * TODO: register notifiers for frequency and voltage
1149 		 * change here once the respective frameworks are
1150 		 * available
1151 		 */
1152 	}
1153 
1154 	dev_info(&pdev->dev, "%s: device configured with addr = %p and IRQ%d\n",
1155 		__func__, emif->base, irq);
1156 
1157 	return 0;
1158 error:
1159 	return -ENODEV;
1160 }
1161 
1162 static int __exit emif_remove(struct platform_device *pdev)
1163 {
1164 	struct emif_data *emif = platform_get_drvdata(pdev);
1165 
1166 	emif_debugfs_exit(emif);
1167 
1168 	return 0;
1169 }
1170 
1171 static void emif_shutdown(struct platform_device *pdev)
1172 {
1173 	struct emif_data	*emif = platform_get_drvdata(pdev);
1174 
1175 	disable_and_clear_all_interrupts(emif);
1176 }
1177 
1178 #if defined(CONFIG_OF)
1179 static const struct of_device_id emif_of_match[] = {
1180 		{ .compatible = "ti,emif-4d" },
1181 		{ .compatible = "ti,emif-4d5" },
1182 		{},
1183 };
1184 MODULE_DEVICE_TABLE(of, emif_of_match);
1185 #endif
1186 
1187 static struct platform_driver emif_driver = {
1188 	.remove		= __exit_p(emif_remove),
1189 	.shutdown	= emif_shutdown,
1190 	.driver = {
1191 		.name = "emif",
1192 		.of_match_table = of_match_ptr(emif_of_match),
1193 	},
1194 };
1195 
1196 module_platform_driver_probe(emif_driver, emif_probe);
1197 
1198 MODULE_DESCRIPTION("TI EMIF SDRAM Controller Driver");
1199 MODULE_LICENSE("GPL");
1200 MODULE_ALIAS("platform:emif");
1201 MODULE_AUTHOR("Texas Instruments Inc");
1202