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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2017 NXP
4 * Copyright 2011,2016 Freescale Semiconductor, Inc.
5 * Copyright 2011 Linaro Ltd.
6 */
7
8#include <linux/clk.h>
9#include <linux/hrtimer.h>
10#include <linux/init.h>
11#include <linux/interrupt.h>
12#include <linux/io.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16#include <linux/platform_device.h>
17#include <linux/property.h>
18#include <linux/perf_event.h>
19#include <linux/slab.h>
20
21#include "common.h"
22
23#define MMDC_MAPSR 0x404
24#define BP_MMDC_MAPSR_PSD 0
25#define BP_MMDC_MAPSR_PSS 4
26
27#define MMDC_MDMISC 0x18
28#define BM_MMDC_MDMISC_DDR_TYPE 0x18
29#define BP_MMDC_MDMISC_DDR_TYPE 0x3
30
31#define TOTAL_CYCLES 0x0
32#define BUSY_CYCLES 0x1
33#define READ_ACCESSES 0x2
34#define WRITE_ACCESSES 0x3
35#define READ_BYTES 0x4
36#define WRITE_BYTES 0x5
37
38/* Enables, resets, freezes, overflow profiling*/
39#define DBG_DIS 0x0
40#define DBG_EN 0x1
41#define DBG_RST 0x2
42#define PRF_FRZ 0x4
43#define CYC_OVF 0x8
44#define PROFILE_SEL 0x10
45
46#define MMDC_MADPCR0 0x410
47#define MMDC_MADPCR1 0x414
48#define MMDC_MADPSR0 0x418
49#define MMDC_MADPSR1 0x41C
50#define MMDC_MADPSR2 0x420
51#define MMDC_MADPSR3 0x424
52#define MMDC_MADPSR4 0x428
53#define MMDC_MADPSR5 0x42C
54
55#define MMDC_NUM_COUNTERS 6
56
57#define MMDC_FLAG_PROFILE_SEL 0x1
58#define MMDC_PRF_AXI_ID_CLEAR 0x0
59
60#define to_mmdc_pmu(p) container_of(p, struct mmdc_pmu, pmu)
61
62static int ddr_type;
63
64struct fsl_mmdc_devtype_data {
65 unsigned int flags;
66};
67
68static const struct fsl_mmdc_devtype_data imx6q_data = {
69};
70
71static const struct fsl_mmdc_devtype_data imx6qp_data = {
72 .flags = MMDC_FLAG_PROFILE_SEL,
73};
74
75static const struct of_device_id imx_mmdc_dt_ids[] = {
76 { .compatible = "fsl,imx6q-mmdc", .data = (void *)&imx6q_data},
77 { .compatible = "fsl,imx6qp-mmdc", .data = (void *)&imx6qp_data},
78 { /* sentinel */ }
79};
80
81#ifdef CONFIG_PERF_EVENTS
82
83static enum cpuhp_state cpuhp_mmdc_state;
84static DEFINE_IDA(mmdc_ida);
85
86PMU_EVENT_ATTR_STRING(total-cycles, mmdc_pmu_total_cycles, "event=0x00")
87PMU_EVENT_ATTR_STRING(busy-cycles, mmdc_pmu_busy_cycles, "event=0x01")
88PMU_EVENT_ATTR_STRING(read-accesses, mmdc_pmu_read_accesses, "event=0x02")
89PMU_EVENT_ATTR_STRING(write-accesses, mmdc_pmu_write_accesses, "event=0x03")
90PMU_EVENT_ATTR_STRING(read-bytes, mmdc_pmu_read_bytes, "event=0x04")
91PMU_EVENT_ATTR_STRING(read-bytes.unit, mmdc_pmu_read_bytes_unit, "MB");
92PMU_EVENT_ATTR_STRING(read-bytes.scale, mmdc_pmu_read_bytes_scale, "0.000001");
93PMU_EVENT_ATTR_STRING(write-bytes, mmdc_pmu_write_bytes, "event=0x05")
94PMU_EVENT_ATTR_STRING(write-bytes.unit, mmdc_pmu_write_bytes_unit, "MB");
95PMU_EVENT_ATTR_STRING(write-bytes.scale, mmdc_pmu_write_bytes_scale, "0.000001");
96
97struct mmdc_pmu {
98 struct pmu pmu;
99 void __iomem *mmdc_base;
100 cpumask_t cpu;
101 struct hrtimer hrtimer;
102 unsigned int active_events;
103 int id;
104 struct device *dev;
105 struct perf_event *mmdc_events[MMDC_NUM_COUNTERS];
106 struct hlist_node node;
107 const struct fsl_mmdc_devtype_data *devtype_data;
108 struct clk *mmdc_ipg_clk;
109};
110
111/*
112 * Polling period is set to one second, overflow of total-cycles (the fastest
113 * increasing counter) takes ten seconds so one second is safe
114 */
115static unsigned int mmdc_pmu_poll_period_us = 1000000;
116
117module_param_named(pmu_pmu_poll_period_us, mmdc_pmu_poll_period_us, uint,
118 S_IRUGO | S_IWUSR);
119
120static ktime_t mmdc_pmu_timer_period(void)
121{
122 return ns_to_ktime((u64)mmdc_pmu_poll_period_us * 1000);
123}
124
125static ssize_t mmdc_pmu_cpumask_show(struct device *dev,
126 struct device_attribute *attr, char *buf)
127{
128 struct mmdc_pmu *pmu_mmdc = dev_get_drvdata(dev);
129
130 return cpumap_print_to_pagebuf(true, buf, &pmu_mmdc->cpu);
131}
132
133static struct device_attribute mmdc_pmu_cpumask_attr =
134 __ATTR(cpumask, S_IRUGO, mmdc_pmu_cpumask_show, NULL);
135
136static struct attribute *mmdc_pmu_cpumask_attrs[] = {
137 &mmdc_pmu_cpumask_attr.attr,
138 NULL,
139};
140
141static struct attribute_group mmdc_pmu_cpumask_attr_group = {
142 .attrs = mmdc_pmu_cpumask_attrs,
143};
144
145static struct attribute *mmdc_pmu_events_attrs[] = {
146 &mmdc_pmu_total_cycles.attr.attr,
147 &mmdc_pmu_busy_cycles.attr.attr,
148 &mmdc_pmu_read_accesses.attr.attr,
149 &mmdc_pmu_write_accesses.attr.attr,
150 &mmdc_pmu_read_bytes.attr.attr,
151 &mmdc_pmu_read_bytes_unit.attr.attr,
152 &mmdc_pmu_read_bytes_scale.attr.attr,
153 &mmdc_pmu_write_bytes.attr.attr,
154 &mmdc_pmu_write_bytes_unit.attr.attr,
155 &mmdc_pmu_write_bytes_scale.attr.attr,
156 NULL,
157};
158
159static struct attribute_group mmdc_pmu_events_attr_group = {
160 .name = "events",
161 .attrs = mmdc_pmu_events_attrs,
162};
163
164PMU_FORMAT_ATTR(event, "config:0-63");
165PMU_FORMAT_ATTR(axi_id, "config1:0-63");
166
167static struct attribute *mmdc_pmu_format_attrs[] = {
168 &format_attr_event.attr,
169 &format_attr_axi_id.attr,
170 NULL,
171};
172
173static struct attribute_group mmdc_pmu_format_attr_group = {
174 .name = "format",
175 .attrs = mmdc_pmu_format_attrs,
176};
177
178static const struct attribute_group *attr_groups[] = {
179 &mmdc_pmu_events_attr_group,
180 &mmdc_pmu_format_attr_group,
181 &mmdc_pmu_cpumask_attr_group,
182 NULL,
183};
184
185static u32 mmdc_pmu_read_counter(struct mmdc_pmu *pmu_mmdc, int cfg)
186{
187 void __iomem *mmdc_base, *reg;
188
189 mmdc_base = pmu_mmdc->mmdc_base;
190
191 switch (cfg) {
192 case TOTAL_CYCLES:
193 reg = mmdc_base + MMDC_MADPSR0;
194 break;
195 case BUSY_CYCLES:
196 reg = mmdc_base + MMDC_MADPSR1;
197 break;
198 case READ_ACCESSES:
199 reg = mmdc_base + MMDC_MADPSR2;
200 break;
201 case WRITE_ACCESSES:
202 reg = mmdc_base + MMDC_MADPSR3;
203 break;
204 case READ_BYTES:
205 reg = mmdc_base + MMDC_MADPSR4;
206 break;
207 case WRITE_BYTES:
208 reg = mmdc_base + MMDC_MADPSR5;
209 break;
210 default:
211 return WARN_ONCE(1,
212 "invalid configuration %d for mmdc counter", cfg);
213 }
214 return readl(reg);
215}
216
217static int mmdc_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
218{
219 struct mmdc_pmu *pmu_mmdc = hlist_entry_safe(node, struct mmdc_pmu, node);
220 int target;
221
222 if (!cpumask_test_and_clear_cpu(cpu, &pmu_mmdc->cpu))
223 return 0;
224
225 target = cpumask_any_but(cpu_online_mask, cpu);
226 if (target >= nr_cpu_ids)
227 return 0;
228
229 perf_pmu_migrate_context(&pmu_mmdc->pmu, cpu, target);
230 cpumask_set_cpu(target, &pmu_mmdc->cpu);
231
232 return 0;
233}
234
235static bool mmdc_pmu_group_event_is_valid(struct perf_event *event,
236 struct pmu *pmu,
237 unsigned long *used_counters)
238{
239 int cfg = event->attr.config;
240
241 if (is_software_event(event))
242 return true;
243
244 if (event->pmu != pmu)
245 return false;
246
247 return !test_and_set_bit(cfg, used_counters);
248}
249
250/*
251 * Each event has a single fixed-purpose counter, so we can only have a
252 * single active event for each at any point in time. Here we just check
253 * for duplicates, and rely on mmdc_pmu_event_init to verify that the HW
254 * event numbers are valid.
255 */
256static bool mmdc_pmu_group_is_valid(struct perf_event *event)
257{
258 struct pmu *pmu = event->pmu;
259 struct perf_event *leader = event->group_leader;
260 struct perf_event *sibling;
261 unsigned long counter_mask = 0;
262
263 set_bit(leader->attr.config, &counter_mask);
264
265 if (event != leader) {
266 if (!mmdc_pmu_group_event_is_valid(event, pmu, &counter_mask))
267 return false;
268 }
269
270 for_each_sibling_event(sibling, leader) {
271 if (!mmdc_pmu_group_event_is_valid(sibling, pmu, &counter_mask))
272 return false;
273 }
274
275 return true;
276}
277
278static int mmdc_pmu_event_init(struct perf_event *event)
279{
280 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
281 int cfg = event->attr.config;
282
283 if (event->attr.type != event->pmu->type)
284 return -ENOENT;
285
286 if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
287 return -EOPNOTSUPP;
288
289 if (event->cpu < 0) {
290 dev_warn(pmu_mmdc->dev, "Can't provide per-task data!\n");
291 return -EOPNOTSUPP;
292 }
293
294 if (event->attr.sample_period)
295 return -EINVAL;
296
297 if (cfg < 0 || cfg >= MMDC_NUM_COUNTERS)
298 return -EINVAL;
299
300 if (!mmdc_pmu_group_is_valid(event))
301 return -EINVAL;
302
303 event->cpu = cpumask_first(&pmu_mmdc->cpu);
304 return 0;
305}
306
307static void mmdc_pmu_event_update(struct perf_event *event)
308{
309 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
310 struct hw_perf_event *hwc = &event->hw;
311 u64 delta, prev_raw_count, new_raw_count;
312
313 do {
314 prev_raw_count = local64_read(&hwc->prev_count);
315 new_raw_count = mmdc_pmu_read_counter(pmu_mmdc,
316 event->attr.config);
317 } while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
318 new_raw_count) != prev_raw_count);
319
320 delta = (new_raw_count - prev_raw_count) & 0xFFFFFFFF;
321
322 local64_add(delta, &event->count);
323}
324
325static void mmdc_pmu_event_start(struct perf_event *event, int flags)
326{
327 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
328 struct hw_perf_event *hwc = &event->hw;
329 void __iomem *mmdc_base, *reg;
330 u32 val;
331
332 mmdc_base = pmu_mmdc->mmdc_base;
333 reg = mmdc_base + MMDC_MADPCR0;
334
335 /*
336 * hrtimer is required because mmdc does not provide an interrupt so
337 * polling is necessary
338 */
339 hrtimer_start(&pmu_mmdc->hrtimer, mmdc_pmu_timer_period(),
340 HRTIMER_MODE_REL_PINNED);
341
342 local64_set(&hwc->prev_count, 0);
343
344 writel(DBG_RST, reg);
345
346 /*
347 * Write the AXI id parameter to MADPCR1.
348 */
349 val = event->attr.config1;
350 reg = mmdc_base + MMDC_MADPCR1;
351 writel(val, reg);
352
353 reg = mmdc_base + MMDC_MADPCR0;
354 val = DBG_EN;
355 if (pmu_mmdc->devtype_data->flags & MMDC_FLAG_PROFILE_SEL)
356 val |= PROFILE_SEL;
357
358 writel(val, reg);
359}
360
361static int mmdc_pmu_event_add(struct perf_event *event, int flags)
362{
363 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
364 struct hw_perf_event *hwc = &event->hw;
365
366 int cfg = event->attr.config;
367
368 if (flags & PERF_EF_START)
369 mmdc_pmu_event_start(event, flags);
370
371 if (pmu_mmdc->mmdc_events[cfg] != NULL)
372 return -EAGAIN;
373
374 pmu_mmdc->mmdc_events[cfg] = event;
375 pmu_mmdc->active_events++;
376
377 local64_set(&hwc->prev_count, mmdc_pmu_read_counter(pmu_mmdc, cfg));
378
379 return 0;
380}
381
382static void mmdc_pmu_event_stop(struct perf_event *event, int flags)
383{
384 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
385 void __iomem *mmdc_base, *reg;
386
387 mmdc_base = pmu_mmdc->mmdc_base;
388 reg = mmdc_base + MMDC_MADPCR0;
389
390 writel(PRF_FRZ, reg);
391
392 reg = mmdc_base + MMDC_MADPCR1;
393 writel(MMDC_PRF_AXI_ID_CLEAR, reg);
394
395 mmdc_pmu_event_update(event);
396}
397
398static void mmdc_pmu_event_del(struct perf_event *event, int flags)
399{
400 struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
401 int cfg = event->attr.config;
402
403 pmu_mmdc->mmdc_events[cfg] = NULL;
404 pmu_mmdc->active_events--;
405
406 if (pmu_mmdc->active_events == 0)
407 hrtimer_cancel(&pmu_mmdc->hrtimer);
408
409 mmdc_pmu_event_stop(event, PERF_EF_UPDATE);
410}
411
412static void mmdc_pmu_overflow_handler(struct mmdc_pmu *pmu_mmdc)
413{
414 int i;
415
416 for (i = 0; i < MMDC_NUM_COUNTERS; i++) {
417 struct perf_event *event = pmu_mmdc->mmdc_events[i];
418
419 if (event)
420 mmdc_pmu_event_update(event);
421 }
422}
423
424static enum hrtimer_restart mmdc_pmu_timer_handler(struct hrtimer *hrtimer)
425{
426 struct mmdc_pmu *pmu_mmdc = container_of(hrtimer, struct mmdc_pmu,
427 hrtimer);
428
429 mmdc_pmu_overflow_handler(pmu_mmdc);
430 hrtimer_forward_now(hrtimer, mmdc_pmu_timer_period());
431
432 return HRTIMER_RESTART;
433}
434
435static int mmdc_pmu_init(struct mmdc_pmu *pmu_mmdc,
436 void __iomem *mmdc_base, struct device *dev)
437{
438 *pmu_mmdc = (struct mmdc_pmu) {
439 .pmu = (struct pmu) {
440 .parent = dev,
441 .task_ctx_nr = perf_invalid_context,
442 .attr_groups = attr_groups,
443 .event_init = mmdc_pmu_event_init,
444 .add = mmdc_pmu_event_add,
445 .del = mmdc_pmu_event_del,
446 .start = mmdc_pmu_event_start,
447 .stop = mmdc_pmu_event_stop,
448 .read = mmdc_pmu_event_update,
449 .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
450 },
451 .mmdc_base = mmdc_base,
452 .dev = dev,
453 .active_events = 0,
454 };
455
456 pmu_mmdc->id = ida_alloc(&mmdc_ida, GFP_KERNEL);
457
458 return pmu_mmdc->id;
459}
460
461static void imx_mmdc_remove(struct platform_device *pdev)
462{
463 struct mmdc_pmu *pmu_mmdc = platform_get_drvdata(pdev);
464
465 ida_free(&mmdc_ida, pmu_mmdc->id);
466 cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
467 perf_pmu_unregister(&pmu_mmdc->pmu);
468 iounmap(pmu_mmdc->mmdc_base);
469 clk_disable_unprepare(pmu_mmdc->mmdc_ipg_clk);
470 kfree(pmu_mmdc);
471}
472
473static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_base,
474 struct clk *mmdc_ipg_clk)
475{
476 struct mmdc_pmu *pmu_mmdc;
477 char *name;
478 int ret;
479
480 pmu_mmdc = kzalloc(sizeof(*pmu_mmdc), GFP_KERNEL);
481 if (!pmu_mmdc) {
482 pr_err("failed to allocate PMU device!\n");
483 return -ENOMEM;
484 }
485
486 /* The first instance registers the hotplug state */
487 if (!cpuhp_mmdc_state) {
488 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
489 "perf/arm/mmdc:online", NULL,
490 mmdc_pmu_offline_cpu);
491 if (ret < 0) {
492 pr_err("cpuhp_setup_state_multi failed\n");
493 goto pmu_free;
494 }
495 cpuhp_mmdc_state = ret;
496 }
497
498 ret = mmdc_pmu_init(pmu_mmdc, mmdc_base, &pdev->dev);
499 if (ret < 0)
500 goto pmu_free;
501
502 name = devm_kasprintf(&pdev->dev,
503 GFP_KERNEL, "mmdc%d", ret);
504 if (!name) {
505 ret = -ENOMEM;
506 goto pmu_release_id;
507 }
508
509 pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
510 pmu_mmdc->devtype_data = device_get_match_data(&pdev->dev);
511
512 hrtimer_init(&pmu_mmdc->hrtimer, CLOCK_MONOTONIC,
513 HRTIMER_MODE_REL);
514 pmu_mmdc->hrtimer.function = mmdc_pmu_timer_handler;
515
516 cpumask_set_cpu(raw_smp_processor_id(), &pmu_mmdc->cpu);
517
518 /* Register the pmu instance for cpu hotplug */
519 cpuhp_state_add_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
520
521 ret = perf_pmu_register(&(pmu_mmdc->pmu), name, -1);
522 if (ret)
523 goto pmu_register_err;
524
525 platform_set_drvdata(pdev, pmu_mmdc);
526 return 0;
527
528pmu_register_err:
529 pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
530 cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
531 hrtimer_cancel(&pmu_mmdc->hrtimer);
532pmu_release_id:
533 ida_free(&mmdc_ida, pmu_mmdc->id);
534pmu_free:
535 kfree(pmu_mmdc);
536 return ret;
537}
538
539#else
540#define imx_mmdc_remove NULL
541#define imx_mmdc_perf_init(pdev, mmdc_base, mmdc_ipg_clk) 0
542#endif
543
544static int imx_mmdc_probe(struct platform_device *pdev)
545{
546 struct device_node *np = pdev->dev.of_node;
547 void __iomem *mmdc_base, *reg;
548 struct clk *mmdc_ipg_clk;
549 u32 val;
550 int err;
551
552 /* the ipg clock is optional */
553 mmdc_ipg_clk = devm_clk_get(&pdev->dev, NULL);
554 if (IS_ERR(mmdc_ipg_clk))
555 mmdc_ipg_clk = NULL;
556
557 err = clk_prepare_enable(mmdc_ipg_clk);
558 if (err) {
559 dev_err(&pdev->dev, "Unable to enable mmdc ipg clock.\n");
560 return err;
561 }
562
563 mmdc_base = of_iomap(np, 0);
564 WARN_ON(!mmdc_base);
565
566 reg = mmdc_base + MMDC_MDMISC;
567 /* Get ddr type */
568 val = readl_relaxed(reg);
569 ddr_type = (val & BM_MMDC_MDMISC_DDR_TYPE) >>
570 BP_MMDC_MDMISC_DDR_TYPE;
571
572 reg = mmdc_base + MMDC_MAPSR;
573
574 /* Enable automatic power saving */
575 val = readl_relaxed(reg);
576 val &= ~(1 << BP_MMDC_MAPSR_PSD);
577 writel_relaxed(val, reg);
578
579 err = imx_mmdc_perf_init(pdev, mmdc_base, mmdc_ipg_clk);
580 if (err) {
581 iounmap(mmdc_base);
582 clk_disable_unprepare(mmdc_ipg_clk);
583 }
584
585 return err;
586}
587
588int imx_mmdc_get_ddr_type(void)
589{
590 return ddr_type;
591}
592
593static struct platform_driver imx_mmdc_driver = {
594 .driver = {
595 .name = "imx-mmdc",
596 .of_match_table = imx_mmdc_dt_ids,
597 },
598 .probe = imx_mmdc_probe,
599 .remove = imx_mmdc_remove,
600};
601
602static int __init imx_mmdc_init(void)
603{
604 return platform_driver_register(&imx_mmdc_driver);
605}
606postcore_initcall(imx_mmdc_init);
1/*
2 * Copyright 2011 Freescale Semiconductor, Inc.
3 * Copyright 2011 Linaro Ltd.
4 *
5 * The code contained herein is licensed under the GNU General Public
6 * License. You may obtain a copy of the GNU General Public License
7 * Version 2 or later at the following locations:
8 *
9 * http://www.opensource.org/licenses/gpl-license.html
10 * http://www.gnu.org/copyleft/gpl.html
11 */
12
13#include <linux/init.h>
14#include <linux/io.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/of_device.h>
19
20#include "common.h"
21
22#define MMDC_MAPSR 0x404
23#define BP_MMDC_MAPSR_PSD 0
24#define BP_MMDC_MAPSR_PSS 4
25
26#define MMDC_MDMISC 0x18
27#define BM_MMDC_MDMISC_DDR_TYPE 0x18
28#define BP_MMDC_MDMISC_DDR_TYPE 0x3
29
30static int ddr_type;
31
32static int imx_mmdc_probe(struct platform_device *pdev)
33{
34 struct device_node *np = pdev->dev.of_node;
35 void __iomem *mmdc_base, *reg;
36 u32 val;
37 int timeout = 0x400;
38
39 mmdc_base = of_iomap(np, 0);
40 WARN_ON(!mmdc_base);
41
42 reg = mmdc_base + MMDC_MDMISC;
43 /* Get ddr type */
44 val = readl_relaxed(reg);
45 ddr_type = (val & BM_MMDC_MDMISC_DDR_TYPE) >>
46 BP_MMDC_MDMISC_DDR_TYPE;
47
48 reg = mmdc_base + MMDC_MAPSR;
49
50 /* Enable automatic power saving */
51 val = readl_relaxed(reg);
52 val &= ~(1 << BP_MMDC_MAPSR_PSD);
53 writel_relaxed(val, reg);
54
55 /* Ensure it's successfully enabled */
56 while (!(readl_relaxed(reg) & 1 << BP_MMDC_MAPSR_PSS) && --timeout)
57 cpu_relax();
58
59 if (unlikely(!timeout)) {
60 pr_warn("%s: failed to enable automatic power saving\n",
61 __func__);
62 return -EBUSY;
63 }
64
65 return 0;
66}
67
68int imx_mmdc_get_ddr_type(void)
69{
70 return ddr_type;
71}
72
73static const struct of_device_id imx_mmdc_dt_ids[] = {
74 { .compatible = "fsl,imx6q-mmdc", },
75 { /* sentinel */ }
76};
77
78static struct platform_driver imx_mmdc_driver = {
79 .driver = {
80 .name = "imx-mmdc",
81 .of_match_table = imx_mmdc_dt_ids,
82 },
83 .probe = imx_mmdc_probe,
84};
85
86static int __init imx_mmdc_init(void)
87{
88 return platform_driver_register(&imx_mmdc_driver);
89}
90postcore_initcall(imx_mmdc_init);