1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * AM33XX Power Management Routines
4 *
5 * Copyright (C) 2012-2018 Texas Instruments Incorporated - http://www.ti.com/
6 * Vaibhav Bedia, Dave Gerlach
7 */
8
9 #include <linux/clk.h>
10 #include <linux/cpu.h>
11 #include <linux/err.h>
12 #include <linux/genalloc.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/module.h>
17 #include <linux/nvmem-consumer.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/platform_data/pm33xx.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/rtc.h>
24 #include <linux/rtc/rtc-omap.h>
25 #include <linux/sizes.h>
26 #include <linux/sram.h>
27 #include <linux/suspend.h>
28 #include <linux/ti-emif-sram.h>
29 #include <linux/wkup_m3_ipc.h>
30
31 #include <asm/proc-fns.h>
32 #include <asm/suspend.h>
33 #include <asm/system_misc.h>
34
35 #define AMX3_PM_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
36 (unsigned long)pm_sram->do_wfi)
37
38 #define RTC_SCRATCH_RESUME_REG 0
39 #define RTC_SCRATCH_MAGIC_REG 1
40 #define RTC_REG_BOOT_MAGIC 0x8cd0 /* RTC */
41 #define GIC_INT_SET_PENDING_BASE 0x200
42 #define AM43XX_GIC_DIST_BASE 0x48241000
43
44 static void __iomem *rtc_base_virt;
45 static struct clk *rtc_fck;
46 static u32 rtc_magic_val;
47
48 static int (*am33xx_do_wfi_sram)(unsigned long unused);
49 static phys_addr_t am33xx_do_wfi_sram_phys;
50
51 static struct gen_pool *sram_pool, *sram_pool_data;
52 static unsigned long ocmcram_location, ocmcram_location_data;
53
54 static struct rtc_device *omap_rtc;
55 static void __iomem *gic_dist_base;
56
57 static struct am33xx_pm_platform_data *pm_ops;
58 static struct am33xx_pm_sram_addr *pm_sram;
59
60 static struct device *pm33xx_dev;
61 static struct wkup_m3_ipc *m3_ipc;
62
63 #ifdef CONFIG_SUSPEND
64 static int rtc_only_idle;
65 static int retrigger_irq;
66 static unsigned long suspend_wfi_flags;
67
68 static struct wkup_m3_wakeup_src wakeup_src = {.irq_nr = 0,
69 .src = "Unknown",
70 };
71
72 static struct wkup_m3_wakeup_src rtc_alarm_wakeup = {
73 .irq_nr = 108, .src = "RTC Alarm",
74 };
75
76 static struct wkup_m3_wakeup_src rtc_ext_wakeup = {
77 .irq_nr = 0, .src = "Ext wakeup",
78 };
79 #endif
80
sram_suspend_address(unsigned long addr)81 static u32 sram_suspend_address(unsigned long addr)
82 {
83 return ((unsigned long)am33xx_do_wfi_sram +
84 AMX3_PM_SRAM_SYMBOL_OFFSET(addr));
85 }
86
am33xx_push_sram_idle(void)87 static int am33xx_push_sram_idle(void)
88 {
89 struct am33xx_pm_ro_sram_data ro_sram_data;
90 int ret;
91 u32 table_addr, ro_data_addr;
92 void *copy_addr;
93
94 ro_sram_data.amx3_pm_sram_data_virt = ocmcram_location_data;
95 ro_sram_data.amx3_pm_sram_data_phys =
96 gen_pool_virt_to_phys(sram_pool_data, ocmcram_location_data);
97 ro_sram_data.rtc_base_virt = rtc_base_virt;
98
99 /* Save physical address to calculate resume offset during pm init */
100 am33xx_do_wfi_sram_phys = gen_pool_virt_to_phys(sram_pool,
101 ocmcram_location);
102
103 am33xx_do_wfi_sram = sram_exec_copy(sram_pool, (void *)ocmcram_location,
104 pm_sram->do_wfi,
105 *pm_sram->do_wfi_sz);
106 if (!am33xx_do_wfi_sram) {
107 dev_err(pm33xx_dev,
108 "PM: %s: am33xx_do_wfi copy to sram failed\n",
109 __func__);
110 return -ENODEV;
111 }
112
113 table_addr =
114 sram_suspend_address((unsigned long)pm_sram->emif_sram_table);
115 ret = ti_emif_copy_pm_function_table(sram_pool, (void *)table_addr);
116 if (ret) {
117 dev_dbg(pm33xx_dev,
118 "PM: %s: EMIF function copy failed\n", __func__);
119 return -EPROBE_DEFER;
120 }
121
122 ro_data_addr =
123 sram_suspend_address((unsigned long)pm_sram->ro_sram_data);
124 copy_addr = sram_exec_copy(sram_pool, (void *)ro_data_addr,
125 &ro_sram_data,
126 sizeof(ro_sram_data));
127 if (!copy_addr) {
128 dev_err(pm33xx_dev,
129 "PM: %s: ro_sram_data copy to sram failed\n",
130 __func__);
131 return -ENODEV;
132 }
133
134 return 0;
135 }
136
am33xx_do_sram_idle(u32 wfi_flags)137 static int am33xx_do_sram_idle(u32 wfi_flags)
138 {
139 if (!m3_ipc || !pm_ops)
140 return 0;
141
142 if (wfi_flags & WFI_FLAG_WAKE_M3)
143 m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_IDLE);
144
145 return pm_ops->cpu_suspend(am33xx_do_wfi_sram, wfi_flags);
146 }
147
am43xx_map_gic(void)148 static int __init am43xx_map_gic(void)
149 {
150 gic_dist_base = ioremap(AM43XX_GIC_DIST_BASE, SZ_4K);
151
152 if (!gic_dist_base)
153 return -ENOMEM;
154
155 return 0;
156 }
157
158 #ifdef CONFIG_SUSPEND
rtc_wake_src(void)159 static struct wkup_m3_wakeup_src rtc_wake_src(void)
160 {
161 u32 i;
162
163 i = __raw_readl(rtc_base_virt + 0x44) & 0x40;
164
165 if (i) {
166 retrigger_irq = rtc_alarm_wakeup.irq_nr;
167 return rtc_alarm_wakeup;
168 }
169
170 retrigger_irq = rtc_ext_wakeup.irq_nr;
171
172 return rtc_ext_wakeup;
173 }
174
am33xx_rtc_only_idle(unsigned long wfi_flags)175 static int am33xx_rtc_only_idle(unsigned long wfi_flags)
176 {
177 omap_rtc_power_off_program(&omap_rtc->dev);
178 am33xx_do_wfi_sram(wfi_flags);
179 return 0;
180 }
181
182 /*
183 * Note that the RTC module clock must be re-enabled only for rtc+ddr suspend.
184 * And looks like the module can stay in SYSC_IDLE_SMART_WKUP mode configured
185 * by the interconnect code just fine for both rtc+ddr suspend and retention
186 * suspend.
187 */
am33xx_pm_suspend(suspend_state_t suspend_state)188 static int am33xx_pm_suspend(suspend_state_t suspend_state)
189 {
190 int i, ret = 0;
191
192 if (suspend_state == PM_SUSPEND_MEM &&
193 pm_ops->check_off_mode_enable()) {
194 ret = clk_prepare_enable(rtc_fck);
195 if (ret) {
196 dev_err(pm33xx_dev, "Failed to enable clock: %i\n", ret);
197 return ret;
198 }
199
200 pm_ops->save_context();
201 suspend_wfi_flags |= WFI_FLAG_RTC_ONLY;
202 clk_save_context();
203 ret = pm_ops->soc_suspend(suspend_state, am33xx_rtc_only_idle,
204 suspend_wfi_flags);
205
206 suspend_wfi_flags &= ~WFI_FLAG_RTC_ONLY;
207 dev_info(pm33xx_dev, "Entering RTC Only mode with DDR in self-refresh\n");
208
209 if (!ret) {
210 clk_restore_context();
211 pm_ops->restore_context();
212 m3_ipc->ops->set_rtc_only(m3_ipc);
213 am33xx_push_sram_idle();
214 }
215 } else {
216 ret = pm_ops->soc_suspend(suspend_state, am33xx_do_wfi_sram,
217 suspend_wfi_flags);
218 }
219
220 if (ret) {
221 dev_err(pm33xx_dev, "PM: Kernel suspend failure\n");
222 } else {
223 i = m3_ipc->ops->request_pm_status(m3_ipc);
224
225 switch (i) {
226 case 0:
227 dev_info(pm33xx_dev,
228 "PM: Successfully put all powerdomains to target state\n");
229 break;
230 case 1:
231 dev_err(pm33xx_dev,
232 "PM: Could not transition all powerdomains to target state\n");
233 ret = -1;
234 break;
235 default:
236 dev_err(pm33xx_dev,
237 "PM: CM3 returned unknown result = %d\n", i);
238 ret = -1;
239 }
240
241 /* print the wakeup reason */
242 if (rtc_only_idle) {
243 wakeup_src = rtc_wake_src();
244 pr_info("PM: Wakeup source %s\n", wakeup_src.src);
245 } else {
246 pr_info("PM: Wakeup source %s\n",
247 m3_ipc->ops->request_wake_src(m3_ipc));
248 }
249 }
250
251 if (suspend_state == PM_SUSPEND_MEM && pm_ops->check_off_mode_enable())
252 clk_disable_unprepare(rtc_fck);
253
254 return ret;
255 }
256
am33xx_pm_enter(suspend_state_t suspend_state)257 static int am33xx_pm_enter(suspend_state_t suspend_state)
258 {
259 int ret = 0;
260
261 switch (suspend_state) {
262 case PM_SUSPEND_MEM:
263 case PM_SUSPEND_STANDBY:
264 ret = am33xx_pm_suspend(suspend_state);
265 break;
266 default:
267 ret = -EINVAL;
268 }
269
270 return ret;
271 }
272
am33xx_pm_begin(suspend_state_t state)273 static int am33xx_pm_begin(suspend_state_t state)
274 {
275 int ret = -EINVAL;
276 struct nvmem_device *nvmem;
277
278 if (state == PM_SUSPEND_MEM && pm_ops->check_off_mode_enable()) {
279 nvmem = devm_nvmem_device_get(&omap_rtc->dev,
280 "omap_rtc_scratch0");
281 if (!IS_ERR(nvmem))
282 nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4, 4,
283 (void *)&rtc_magic_val);
284 rtc_only_idle = 1;
285 } else {
286 rtc_only_idle = 0;
287 }
288
289 pm_ops->begin_suspend();
290
291 switch (state) {
292 case PM_SUSPEND_MEM:
293 ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_DEEPSLEEP);
294 break;
295 case PM_SUSPEND_STANDBY:
296 ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_STANDBY);
297 break;
298 }
299
300 return ret;
301 }
302
am33xx_pm_end(void)303 static void am33xx_pm_end(void)
304 {
305 u32 val = 0;
306 struct nvmem_device *nvmem;
307
308 nvmem = devm_nvmem_device_get(&omap_rtc->dev, "omap_rtc_scratch0");
309 if (IS_ERR(nvmem))
310 return;
311
312 m3_ipc->ops->finish_low_power(m3_ipc);
313 if (rtc_only_idle) {
314 if (retrigger_irq) {
315 /*
316 * 32 bits of Interrupt Set-Pending correspond to 32
317 * 32 interrupts. Compute the bit offset of the
318 * Interrupt and set that particular bit
319 * Compute the register offset by dividing interrupt
320 * number by 32 and mutiplying by 4
321 */
322 writel_relaxed(1 << (retrigger_irq & 31),
323 gic_dist_base + GIC_INT_SET_PENDING_BASE
324 + retrigger_irq / 32 * 4);
325 }
326
327 nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4, 4,
328 (void *)&val);
329 }
330
331 rtc_only_idle = 0;
332
333 pm_ops->finish_suspend();
334 }
335
am33xx_pm_valid(suspend_state_t state)336 static int am33xx_pm_valid(suspend_state_t state)
337 {
338 switch (state) {
339 case PM_SUSPEND_STANDBY:
340 case PM_SUSPEND_MEM:
341 return 1;
342 default:
343 return 0;
344 }
345 }
346
347 static const struct platform_suspend_ops am33xx_pm_ops = {
348 .begin = am33xx_pm_begin,
349 .end = am33xx_pm_end,
350 .enter = am33xx_pm_enter,
351 .valid = am33xx_pm_valid,
352 };
353 #endif /* CONFIG_SUSPEND */
354
am33xx_pm_set_ipc_ops(void)355 static void am33xx_pm_set_ipc_ops(void)
356 {
357 u32 resume_address;
358 int temp;
359
360 temp = ti_emif_get_mem_type();
361 if (temp < 0) {
362 dev_err(pm33xx_dev, "PM: Cannot determine memory type, no PM available\n");
363 return;
364 }
365 m3_ipc->ops->set_mem_type(m3_ipc, temp);
366
367 /* Physical resume address to be used by ROM code */
368 resume_address = am33xx_do_wfi_sram_phys +
369 *pm_sram->resume_offset + 0x4;
370
371 m3_ipc->ops->set_resume_address(m3_ipc, (void *)resume_address);
372 }
373
am33xx_pm_free_sram(void)374 static void am33xx_pm_free_sram(void)
375 {
376 gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
377 gen_pool_free(sram_pool_data, ocmcram_location_data,
378 sizeof(struct am33xx_pm_ro_sram_data));
379 }
380
381 /*
382 * Push the minimal suspend-resume code to SRAM
383 */
am33xx_pm_alloc_sram(void)384 static int am33xx_pm_alloc_sram(void)
385 {
386 struct device_node *np __free(device_node) =
387 of_find_compatible_node(NULL, NULL, "ti,omap3-mpu");
388
389 if (!np) {
390 np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
391 if (!np)
392 return dev_err_probe(pm33xx_dev, -ENODEV,
393 "PM: %s: Unable to find device node for mpu\n",
394 __func__);
395 }
396
397 sram_pool = of_gen_pool_get(np, "pm-sram", 0);
398 if (!sram_pool)
399 return dev_err_probe(pm33xx_dev, -ENODEV,
400 "PM: %s: Unable to get sram pool for ocmcram\n",
401 __func__);
402
403 sram_pool_data = of_gen_pool_get(np, "pm-sram", 1);
404 if (!sram_pool_data)
405 return dev_err_probe(pm33xx_dev, -ENODEV,
406 "PM: %s: Unable to get sram data pool for ocmcram\n",
407 __func__);
408
409 ocmcram_location = gen_pool_alloc(sram_pool, *pm_sram->do_wfi_sz);
410 if (!ocmcram_location)
411 return dev_err_probe(pm33xx_dev, -ENOMEM,
412 "PM: %s: Unable to allocate memory from ocmcram\n",
413 __func__);
414
415 ocmcram_location_data = gen_pool_alloc(sram_pool_data,
416 sizeof(struct emif_regs_amx3));
417 if (!ocmcram_location_data) {
418 gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
419 return dev_err_probe(pm33xx_dev, -ENOMEM,
420 "PM: Unable to allocate memory from ocmcram\n");
421 }
422
423 return 0;
424 }
425
am33xx_pm_rtc_setup(void)426 static int am33xx_pm_rtc_setup(void)
427 {
428 struct device_node *np;
429 unsigned long val = 0;
430 struct nvmem_device *nvmem;
431 int error;
432
433 np = of_find_node_by_name(NULL, "rtc");
434
435 if (of_device_is_available(np)) {
436 /* RTC interconnect target module clock */
437 rtc_fck = of_clk_get_by_name(np->parent, "fck");
438 if (IS_ERR(rtc_fck))
439 return PTR_ERR(rtc_fck);
440
441 rtc_base_virt = of_iomap(np, 0);
442 if (!rtc_base_virt) {
443 pr_warn("PM: could not iomap rtc\n");
444 error = -ENODEV;
445 goto err_clk_put;
446 }
447
448 omap_rtc = rtc_class_open("rtc0");
449 if (!omap_rtc) {
450 pr_warn("PM: rtc0 not available\n");
451 error = -EPROBE_DEFER;
452 goto err_iounmap;
453 }
454
455 nvmem = devm_nvmem_device_get(&omap_rtc->dev,
456 "omap_rtc_scratch0");
457 if (!IS_ERR(nvmem)) {
458 nvmem_device_read(nvmem, RTC_SCRATCH_MAGIC_REG * 4,
459 4, (void *)&rtc_magic_val);
460 if ((rtc_magic_val & 0xffff) != RTC_REG_BOOT_MAGIC)
461 pr_warn("PM: bootloader does not support rtc-only!\n");
462
463 nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4,
464 4, (void *)&val);
465 val = pm_sram->resume_address;
466 nvmem_device_write(nvmem, RTC_SCRATCH_RESUME_REG * 4,
467 4, (void *)&val);
468 }
469 } else {
470 pr_warn("PM: no-rtc available, rtc-only mode disabled.\n");
471 }
472
473 return 0;
474
475 err_iounmap:
476 iounmap(rtc_base_virt);
477 err_clk_put:
478 clk_put(rtc_fck);
479
480 return error;
481 }
482
am33xx_pm_probe(struct platform_device * pdev)483 static int am33xx_pm_probe(struct platform_device *pdev)
484 {
485 struct device *dev = &pdev->dev;
486 int ret;
487
488 if (!of_machine_is_compatible("ti,am33xx") &&
489 !of_machine_is_compatible("ti,am43"))
490 return -ENODEV;
491
492 pm_ops = dev->platform_data;
493 if (!pm_ops) {
494 dev_err(dev, "PM: Cannot get core PM ops!\n");
495 return -ENODEV;
496 }
497
498 ret = am43xx_map_gic();
499 if (ret) {
500 pr_err("PM: Could not ioremap GIC base\n");
501 return ret;
502 }
503
504 pm_sram = pm_ops->get_sram_addrs();
505 if (!pm_sram) {
506 dev_err(dev, "PM: Cannot get PM asm function addresses!!\n");
507 return -ENODEV;
508 }
509
510 m3_ipc = wkup_m3_ipc_get();
511 if (!m3_ipc) {
512 pr_err("PM: Cannot get wkup_m3_ipc handle\n");
513 return -EPROBE_DEFER;
514 }
515
516 pm33xx_dev = dev;
517
518 ret = am33xx_pm_alloc_sram();
519 if (ret)
520 goto err_wkup_m3_ipc_put;
521
522 ret = am33xx_pm_rtc_setup();
523 if (ret)
524 goto err_free_sram;
525
526 ret = am33xx_push_sram_idle();
527 if (ret)
528 goto err_unsetup_rtc;
529
530 am33xx_pm_set_ipc_ops();
531
532 #ifdef CONFIG_SUSPEND
533 suspend_set_ops(&am33xx_pm_ops);
534
535 /*
536 * For a system suspend we must flush the caches, we want
537 * the DDR in self-refresh, we want to save the context
538 * of the EMIF, and we want the wkup_m3 to handle low-power
539 * transition.
540 */
541 suspend_wfi_flags |= WFI_FLAG_FLUSH_CACHE;
542 suspend_wfi_flags |= WFI_FLAG_SELF_REFRESH;
543 suspend_wfi_flags |= WFI_FLAG_SAVE_EMIF;
544 suspend_wfi_flags |= WFI_FLAG_WAKE_M3;
545 #endif /* CONFIG_SUSPEND */
546
547 pm_runtime_enable(dev);
548 ret = pm_runtime_resume_and_get(dev);
549 if (ret < 0)
550 goto err_pm_runtime_disable;
551
552 ret = pm_ops->init(am33xx_do_sram_idle);
553 if (ret) {
554 dev_err(dev, "Unable to call core pm init!\n");
555 ret = -ENODEV;
556 goto err_pm_runtime_put;
557 }
558
559 return 0;
560
561 err_pm_runtime_put:
562 pm_runtime_put_sync(dev);
563 err_pm_runtime_disable:
564 pm_runtime_disable(dev);
565 err_unsetup_rtc:
566 iounmap(rtc_base_virt);
567 clk_put(rtc_fck);
568 err_free_sram:
569 am33xx_pm_free_sram();
570 pm33xx_dev = NULL;
571 err_wkup_m3_ipc_put:
572 wkup_m3_ipc_put(m3_ipc);
573 return ret;
574 }
575
am33xx_pm_remove(struct platform_device * pdev)576 static void am33xx_pm_remove(struct platform_device *pdev)
577 {
578 pm_runtime_put_sync(&pdev->dev);
579 pm_runtime_disable(&pdev->dev);
580 if (pm_ops->deinit)
581 pm_ops->deinit();
582 suspend_set_ops(NULL);
583 wkup_m3_ipc_put(m3_ipc);
584 am33xx_pm_free_sram();
585 iounmap(rtc_base_virt);
586 clk_put(rtc_fck);
587 }
588
589 static struct platform_driver am33xx_pm_driver = {
590 .driver = {
591 .name = "pm33xx",
592 },
593 .probe = am33xx_pm_probe,
594 .remove = am33xx_pm_remove,
595 };
596 module_platform_driver(am33xx_pm_driver);
597
598 MODULE_ALIAS("platform:pm33xx");
599 MODULE_LICENSE("GPL v2");
600 MODULE_DESCRIPTION("am33xx power management driver");
601