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 */
55struct 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
70static struct emif_data *emif1;
71static DEFINE_SPINLOCK(emif_lock);
72static unsigned long irq_state;
73static LIST_HEAD(device_list);
74
75#ifdef CONFIG_DEBUG_FS
76static 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(m: s, fmt: "EMIF register cache dump for %dMHz\n",
83 regs->freq/1000000);
84
85 seq_printf(m: s, fmt: "ref_ctrl_shdw\t: 0x%08x\n", regs->ref_ctrl_shdw);
86 seq_printf(m: s, fmt: "sdram_tim1_shdw\t: 0x%08x\n", regs->sdram_tim1_shdw);
87 seq_printf(m: s, fmt: "sdram_tim2_shdw\t: 0x%08x\n", regs->sdram_tim2_shdw);
88 seq_printf(m: s, fmt: "sdram_tim3_shdw\t: 0x%08x\n", regs->sdram_tim3_shdw);
89
90 if (ip_rev == EMIF_4D) {
91 seq_printf(m: s, fmt: "read_idle_ctrl_shdw_normal\t: 0x%08x\n",
92 regs->read_idle_ctrl_shdw_normal);
93 seq_printf(m: s, fmt: "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(m: s, fmt: "dll_calib_ctrl_shdw_normal\t: 0x%08x\n",
97 regs->dll_calib_ctrl_shdw_normal);
98 seq_printf(m: s, fmt: "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(m: s, fmt: "ref_ctrl_shdw_derated\t: 0x%08x\n",
104 regs->ref_ctrl_shdw_derated);
105 seq_printf(m: s, fmt: "sdram_tim1_shdw_derated\t: 0x%08x\n",
106 regs->sdram_tim1_shdw_derated);
107 seq_printf(m: s, fmt: "sdram_tim3_shdw_derated\t: 0x%08x\n",
108 regs->sdram_tim3_shdw_derated);
109 }
110}
111
112static 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: regs_cache[i]);
125 seq_putc(m: s, c: '\n');
126 }
127
128 return 0;
129}
130
131DEFINE_SHOW_ATTRIBUTE(emif_regdump);
132
133static int emif_mr4_show(struct seq_file *s, void *unused)
134{
135 struct emif_data *emif = s->private;
136
137 seq_printf(m: s, fmt: "MR4=%d\n", emif->temperature_level);
138 return 0;
139}
140
141DEFINE_SHOW_ATTRIBUTE(emif_mr4);
142
143static int __init_or_module emif_debugfs_init(struct emif_data *emif)
144{
145 emif->debugfs_root = debugfs_create_dir(name: dev_name(dev: emif->dev), NULL);
146 debugfs_create_file(name: "regcache_dump", S_IRUGO, parent: emif->debugfs_root, data: emif,
147 fops: &emif_regdump_fops);
148 debugfs_create_file(name: "mr4", S_IRUGO, parent: emif->debugfs_root, data: emif,
149 fops: &emif_mr4_fops);
150 return 0;
151}
152
153static void __exit emif_debugfs_exit(struct emif_data *emif)
154{
155 debugfs_remove_recursive(dentry: emif->debugfs_root);
156 emif->debugfs_root = NULL;
157}
158#else
159static inline int __init_or_module emif_debugfs_init(struct emif_data *emif)
160{
161 return 0;
162}
163
164static 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 */
175static u32 get_emif_bus_width(struct emif_data *emif)
176{
177 u32 width;
178 void __iomem *base = emif->base;
179
180 width = (readl(addr: base + EMIF_SDRAM_CONFIG) & NARROW_MODE_MASK)
181 >> NARROW_MODE_SHIFT;
182 width = width == 0 ? 32 : 16;
183
184 return width;
185}
186
187static 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(addr: base + EMIF_POWER_MANAGEMENT_CONTROL);
227 temp &= ~LP_MODE_MASK;
228 temp |= (lpmode << LP_MODE_SHIFT);
229 writel(val: temp, addr: base + EMIF_POWER_MANAGEMENT_CONTROL);
230}
231
232static 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 */
277static 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
306static 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
335static 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(word: 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
370static 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(word: 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 */
461static 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, addr: base + EMIF_LPDDR2_MODE_REG_CONFIG);
470 temperature_level = readl(addr: 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, addr: base + EMIF_LPDDR2_MODE_REG_CONFIG);
476 temp = readl(addr: 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 */
499static 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
525out:
526 writel(val: tim1, addr: base + EMIF_SDRAM_TIMING_1_SHDW);
527 writel(val: tim3, addr: base + EMIF_SDRAM_TIMING_3_SHDW);
528 writel(val: ref_ctrl, addr: base + EMIF_SDRAM_REFRESH_CTRL_SHDW);
529}
530
531static 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, regs: emif->curr_regs);
581 do_freq_update();
582 }
583
584out:
585 spin_unlock_irqrestore(lock: &emif_lock, flags: irq_state);
586 return ret;
587}
588
589static 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(addr: base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
599 writel(val: interrupts, addr: 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(addr: base + EMIF_LL_OCP_INTERRUPT_STATUS);
615 writel(val: interrupts, addr: 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
625static 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(cmd: "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, regs: 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(lock: &emif_lock, flags: irq_state);
652
653 return IRQ_HANDLED;
654}
655
656static void clear_all_interrupts(struct emif_data *emif)
657{
658 void __iomem *base = emif->base;
659
660 writel(readl(addr: base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS),
661 addr: base + EMIF_SYSTEM_OCP_INTERRUPT_STATUS);
662 if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
663 writel(readl(addr: base + EMIF_LL_OCP_INTERRUPT_STATUS),
664 addr: base + EMIF_LL_OCP_INTERRUPT_STATUS);
665}
666
667static 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(addr: base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_SET),
673 addr: base + EMIF_SYSTEM_OCP_INTERRUPT_ENABLE_CLEAR);
674 if (emif->plat_data->hw_caps & EMIF_HW_CAPS_LL_INTERFACE)
675 writel(readl(addr: base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET),
676 addr: base + EMIF_LL_OCP_INTERRUPT_ENABLE_CLEAR);
677
678 /* Clear all interrupts */
679 clear_all_interrupts(emif);
680}
681
682static 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(val: interrupts, addr: 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(val: interrupts, addr: base + EMIF_LL_OCP_INTERRUPT_ENABLE_SET);
702 }
703
704 /* setup IRQ handlers */
705 return devm_request_threaded_irq(dev: emif->dev, irq,
706 handler: emif_interrupt_handler,
707 thread_fn: emif_threaded_isr,
708 irqflags: 0, devname: dev_name(dev: emif->dev),
709 dev_id: emif);
710
711}
712
713static 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(freq: 1000000000, emif,
729 ip_rev: emif->plat_data->ip_rev);
730 emif->lpmode = (pwr_mgmt_ctrl & LP_MODE_MASK) >> LP_MODE_SHIFT;
731 writel(val: pwr_mgmt_ctrl, addr: base + EMIF_POWER_MANAGEMENT_CONTROL);
732
733 /* Init ZQ calibration settings */
734 zq = get_zq_config_reg(addressing, cs1_used: device_info->cs1_used,
735 cal_resistors_per_cs: device_info->cal_resistors_per_cs);
736 writel(val: zq, addr: 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 custom_configs: emif->plat_data->custom_configs, cs1_used: device_info->cs1_used,
746 sdram_io_width: device_info->io_width, emif_bus_width: get_emif_bus_width(emif));
747 writel(val: temp_alert_cfg, addr: 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, addr: base + EMIF_EXT_PHY_CTRL_1_SHDW);
756 writel(EMIF_EXT_PHY_CTRL_5_VAL, addr: base + EMIF_EXT_PHY_CTRL_5_SHDW);
757 writel(EMIF_EXT_PHY_CTRL_6_VAL, addr: base + EMIF_EXT_PHY_CTRL_6_SHDW);
758 writel(EMIF_EXT_PHY_CTRL_7_VAL, addr: base + EMIF_EXT_PHY_CTRL_7_SHDW);
759 writel(EMIF_EXT_PHY_CTRL_8_VAL, addr: base + EMIF_EXT_PHY_CTRL_8_SHDW);
760 writel(EMIF_EXT_PHY_CTRL_9_VAL, addr: base + EMIF_EXT_PHY_CTRL_9_SHDW);
761 writel(EMIF_EXT_PHY_CTRL_10_VAL, addr: base + EMIF_EXT_PHY_CTRL_10_SHDW);
762 writel(EMIF_EXT_PHY_CTRL_11_VAL, addr: base + EMIF_EXT_PHY_CTRL_11_SHDW);
763 writel(EMIF_EXT_PHY_CTRL_12_VAL, addr: base + EMIF_EXT_PHY_CTRL_12_SHDW);
764 writel(EMIF_EXT_PHY_CTRL_13_VAL, addr: base + EMIF_EXT_PHY_CTRL_13_SHDW);
765 writel(EMIF_EXT_PHY_CTRL_14_VAL, addr: base + EMIF_EXT_PHY_CTRL_14_SHDW);
766 writel(EMIF_EXT_PHY_CTRL_15_VAL, addr: base + EMIF_EXT_PHY_CTRL_15_SHDW);
767 writel(EMIF_EXT_PHY_CTRL_16_VAL, addr: base + EMIF_EXT_PHY_CTRL_16_SHDW);
768 writel(EMIF_EXT_PHY_CTRL_17_VAL, addr: base + EMIF_EXT_PHY_CTRL_17_SHDW);
769 writel(EMIF_EXT_PHY_CTRL_18_VAL, addr: base + EMIF_EXT_PHY_CTRL_18_SHDW);
770 writel(EMIF_EXT_PHY_CTRL_19_VAL, addr: base + EMIF_EXT_PHY_CTRL_19_SHDW);
771 writel(EMIF_EXT_PHY_CTRL_20_VAL, addr: base + EMIF_EXT_PHY_CTRL_20_SHDW);
772 writel(EMIF_EXT_PHY_CTRL_21_VAL, addr: base + EMIF_EXT_PHY_CTRL_21_SHDW);
773 writel(EMIF_EXT_PHY_CTRL_22_VAL, addr: base + EMIF_EXT_PHY_CTRL_22_SHDW);
774 writel(EMIF_EXT_PHY_CTRL_23_VAL, addr: base + EMIF_EXT_PHY_CTRL_23_SHDW);
775 writel(EMIF_EXT_PHY_CTRL_24_VAL, addr: base + EMIF_EXT_PHY_CTRL_24_SHDW);
776}
777
778static 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
788static 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
817static 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)
838static 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(node: np_emif, name: "low-power-mode", lenp: &len);
846 poll_intvl = of_get_property(node: np_emif, name: "temp-alert-poll-interval", lenp: &len);
847
848 if (lpmode || poll_intvl)
849 cust_cfgs = devm_kzalloc(dev: emif->dev, size: 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(p: lpmode);
858 of_property_read_u32(np: np_emif,
859 propname: "low-power-mode-timeout-performance",
860 out_value: &cust_cfgs->lpmode_timeout_performance);
861 of_property_read_u32(np: np_emif,
862 propname: "low-power-mode-timeout-power",
863 out_value: &cust_cfgs->lpmode_timeout_power);
864 of_property_read_u32(np: np_emif,
865 propname: "low-power-mode-freq-threshold",
866 out_value: &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(p: poll_intvl);
874 }
875
876 if (of_find_property(np: np_emif, name: "extended-temp-part", lenp: &len))
877 cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART;
878
879 if (!is_custom_config_valid(cust_cfgs, dev: emif->dev)) {
880 devm_kfree(dev: emif->dev, p: cust_cfgs);
881 return;
882 }
883
884 emif->plat_data->custom_configs = cust_cfgs;
885}
886
887static 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: np_emif, name: "cs1-used", lenp: &len))
895 dev_info->cs1_used = true;
896
897 if (of_find_property(np: np_emif, name: "cal-resistor-per-cs", lenp: &len))
898 dev_info->cal_resistors_per_cs = true;
899
900 if (of_device_is_compatible(device: np_ddr, "jedec,lpddr2-s4"))
901 dev_info->type = DDR_TYPE_LPDDR2_S4;
902 else if (of_device_is_compatible(device: np_ddr, "jedec,lpddr2-s2"))
903 dev_info->type = DDR_TYPE_LPDDR2_S2;
904
905 of_property_read_u32(np: np_ddr, propname: "density", out_value: &density);
906 of_property_read_u32(np: np_ddr, propname: "io-width", out_value: &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(word: 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(word: io_width) - 1;
919}
920
921static 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: np_emif, phandle_name: "device-handle", index: 0);
931 if (!np_ddr)
932 goto error;
933 emif = devm_kzalloc(dev, size: sizeof(struct emif_data), GFP_KERNEL);
934 pd = devm_kzalloc(dev, size: sizeof(*pd), GFP_KERNEL);
935 dev_info = devm_kzalloc(dev, size: 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(device: np_emif, "ti,emif-4d"))
950 emif->plat_data->ip_rev = EMIF_4D;
951 else if (of_device_is_compatible(device: np_emif, "ti,emif-4d5"))
952 emif->plat_data->ip_rev = EMIF_4D5;
953
954 of_property_read_u32(np: np_emif, propname: "phy-type", out_value: &pd->phy_type);
955
956 if (of_find_property(np: np_emif, name: "hw-caps-ll-interface", lenp: &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(type: pd->device_info->type, density: pd->device_info->density,
961 io_width: pd->device_info->io_width, phy_type: pd->phy_type, ip_rev: pd->ip_rev,
962 dev: 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, dev: emif->dev,
982 device_type: emif->plat_data->device_info->type,
983 nr_frequencies: &emif->plat_data->timings_arr_size);
984
985 emif->plat_data->min_tck = of_get_min_tck(np: np_ddr, dev: emif->dev);
986 goto out;
987
988error:
989 return NULL;
990out:
991 return emif;
992}
993
994#else
995
996static 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
1003static 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(type: pd->device_info->type,
1018 density: pd->device_info->density, io_width: pd->device_info->io_width,
1019 phy_type: pd->phy_type, ip_rev: pd->ip_rev, dev))) {
1020 dev_err(dev, "%s: invalid device data\n", __func__);
1021 goto error;
1022 }
1023
1024 emif = devm_kzalloc(dev, size: sizeof(*emif), GFP_KERNEL);
1025 temp = devm_kzalloc(dev, size: sizeof(*pd), GFP_KERNEL);
1026 dev_info = devm_kzalloc(dev, size: 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(p: dev_info,
1047 q: emif1->plat_data->device_info,
1048 size: 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, size: 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, size: 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
1100out:
1101 return emif;
1102
1103error:
1104 return NULL;
1105}
1106
1107static 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(np_emif: pdev->dev.of_node, dev: &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(new: &emif->node, head: &device_list);
1123
1124 /* Save pointers to each other in emif and device structures */
1125 emif->dev = &pdev->dev;
1126 platform_set_drvdata(pdev, data: emif);
1127
1128 emif->base = devm_platform_ioremap_resource(pdev, index: 0);
1129 if (IS_ERR(ptr: 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;
1158error:
1159 return -ENODEV;
1160}
1161
1162static 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
1171static 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)
1179static const struct of_device_id emif_of_match[] = {
1180 { .compatible = "ti,emif-4d" },
1181 { .compatible = "ti,emif-4d5" },
1182 {},
1183};
1184MODULE_DEVICE_TABLE(of, emif_of_match);
1185#endif
1186
1187static 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
1196module_platform_driver_probe(emif_driver, emif_probe);
1197
1198MODULE_DESCRIPTION("TI EMIF SDRAM Controller Driver");
1199MODULE_LICENSE("GPL");
1200MODULE_ALIAS("platform:emif");
1201MODULE_AUTHOR("Texas Instruments Inc");
1202

source code of linux/drivers/memory/emif.c