xref: /openbmc/linux/drivers/soc/ti/pm33xx.c (revision f519f0be)
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/platform_data/pm33xx.h>
20 #include <linux/platform_device.h>
21 #include <linux/rtc.h>
22 #include <linux/rtc/rtc-omap.h>
23 #include <linux/sizes.h>
24 #include <linux/sram.h>
25 #include <linux/suspend.h>
26 #include <linux/ti-emif-sram.h>
27 #include <linux/wkup_m3_ipc.h>
28 
29 #include <asm/proc-fns.h>
30 #include <asm/suspend.h>
31 #include <asm/system_misc.h>
32 
33 #define AMX3_PM_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
34 					 (unsigned long)pm_sram->do_wfi)
35 
36 #define RTC_SCRATCH_RESUME_REG	0
37 #define RTC_SCRATCH_MAGIC_REG	1
38 #define RTC_REG_BOOT_MAGIC	0x8cd0 /* RTC */
39 #define GIC_INT_SET_PENDING_BASE 0x200
40 #define AM43XX_GIC_DIST_BASE	0x48241000
41 
42 static u32 rtc_magic_val;
43 
44 static int (*am33xx_do_wfi_sram)(unsigned long unused);
45 static phys_addr_t am33xx_do_wfi_sram_phys;
46 
47 static struct gen_pool *sram_pool, *sram_pool_data;
48 static unsigned long ocmcram_location, ocmcram_location_data;
49 
50 static struct rtc_device *omap_rtc;
51 static void __iomem *gic_dist_base;
52 
53 static struct am33xx_pm_platform_data *pm_ops;
54 static struct am33xx_pm_sram_addr *pm_sram;
55 
56 static struct device *pm33xx_dev;
57 static struct wkup_m3_ipc *m3_ipc;
58 
59 #ifdef CONFIG_SUSPEND
60 static int rtc_only_idle;
61 static int retrigger_irq;
62 static unsigned long suspend_wfi_flags;
63 
64 static struct wkup_m3_wakeup_src wakeup_src = {.irq_nr = 0,
65 	.src = "Unknown",
66 };
67 
68 static struct wkup_m3_wakeup_src rtc_alarm_wakeup = {
69 	.irq_nr = 108, .src = "RTC Alarm",
70 };
71 
72 static struct wkup_m3_wakeup_src rtc_ext_wakeup = {
73 	.irq_nr = 0, .src = "Ext wakeup",
74 };
75 #endif
76 
77 static u32 sram_suspend_address(unsigned long addr)
78 {
79 	return ((unsigned long)am33xx_do_wfi_sram +
80 		AMX3_PM_SRAM_SYMBOL_OFFSET(addr));
81 }
82 
83 static int am33xx_push_sram_idle(void)
84 {
85 	struct am33xx_pm_ro_sram_data ro_sram_data;
86 	int ret;
87 	u32 table_addr, ro_data_addr;
88 	void *copy_addr;
89 
90 	ro_sram_data.amx3_pm_sram_data_virt = ocmcram_location_data;
91 	ro_sram_data.amx3_pm_sram_data_phys =
92 		gen_pool_virt_to_phys(sram_pool_data, ocmcram_location_data);
93 	ro_sram_data.rtc_base_virt = pm_ops->get_rtc_base_addr();
94 
95 	/* Save physical address to calculate resume offset during pm init */
96 	am33xx_do_wfi_sram_phys = gen_pool_virt_to_phys(sram_pool,
97 							ocmcram_location);
98 
99 	am33xx_do_wfi_sram = sram_exec_copy(sram_pool, (void *)ocmcram_location,
100 					    pm_sram->do_wfi,
101 					    *pm_sram->do_wfi_sz);
102 	if (!am33xx_do_wfi_sram) {
103 		dev_err(pm33xx_dev,
104 			"PM: %s: am33xx_do_wfi copy to sram failed\n",
105 			__func__);
106 		return -ENODEV;
107 	}
108 
109 	table_addr =
110 		sram_suspend_address((unsigned long)pm_sram->emif_sram_table);
111 	ret = ti_emif_copy_pm_function_table(sram_pool, (void *)table_addr);
112 	if (ret) {
113 		dev_dbg(pm33xx_dev,
114 			"PM: %s: EMIF function copy failed\n", __func__);
115 		return -EPROBE_DEFER;
116 	}
117 
118 	ro_data_addr =
119 		sram_suspend_address((unsigned long)pm_sram->ro_sram_data);
120 	copy_addr = sram_exec_copy(sram_pool, (void *)ro_data_addr,
121 				   &ro_sram_data,
122 				   sizeof(ro_sram_data));
123 	if (!copy_addr) {
124 		dev_err(pm33xx_dev,
125 			"PM: %s: ro_sram_data copy to sram failed\n",
126 			__func__);
127 		return -ENODEV;
128 	}
129 
130 	return 0;
131 }
132 
133 static int __init am43xx_map_gic(void)
134 {
135 	gic_dist_base = ioremap(AM43XX_GIC_DIST_BASE, SZ_4K);
136 
137 	if (!gic_dist_base)
138 		return -ENOMEM;
139 
140 	return 0;
141 }
142 
143 #ifdef CONFIG_SUSPEND
144 struct wkup_m3_wakeup_src rtc_wake_src(void)
145 {
146 	u32 i;
147 
148 	i = __raw_readl(pm_ops->get_rtc_base_addr() + 0x44) & 0x40;
149 
150 	if (i) {
151 		retrigger_irq = rtc_alarm_wakeup.irq_nr;
152 		return rtc_alarm_wakeup;
153 	}
154 
155 	retrigger_irq = rtc_ext_wakeup.irq_nr;
156 
157 	return rtc_ext_wakeup;
158 }
159 
160 int am33xx_rtc_only_idle(unsigned long wfi_flags)
161 {
162 	omap_rtc_power_off_program(&omap_rtc->dev);
163 	am33xx_do_wfi_sram(wfi_flags);
164 	return 0;
165 }
166 
167 static int am33xx_pm_suspend(suspend_state_t suspend_state)
168 {
169 	int i, ret = 0;
170 
171 	if (suspend_state == PM_SUSPEND_MEM &&
172 	    pm_ops->check_off_mode_enable()) {
173 		pm_ops->prepare_rtc_suspend();
174 		pm_ops->save_context();
175 		suspend_wfi_flags |= WFI_FLAG_RTC_ONLY;
176 		clk_save_context();
177 		ret = pm_ops->soc_suspend(suspend_state, am33xx_rtc_only_idle,
178 					  suspend_wfi_flags);
179 
180 		suspend_wfi_flags &= ~WFI_FLAG_RTC_ONLY;
181 
182 		if (!ret) {
183 			clk_restore_context();
184 			pm_ops->restore_context();
185 			m3_ipc->ops->set_rtc_only(m3_ipc);
186 			am33xx_push_sram_idle();
187 		}
188 	} else {
189 		ret = pm_ops->soc_suspend(suspend_state, am33xx_do_wfi_sram,
190 					  suspend_wfi_flags);
191 	}
192 
193 	if (ret) {
194 		dev_err(pm33xx_dev, "PM: Kernel suspend failure\n");
195 	} else {
196 		i = m3_ipc->ops->request_pm_status(m3_ipc);
197 
198 		switch (i) {
199 		case 0:
200 			dev_info(pm33xx_dev,
201 				 "PM: Successfully put all powerdomains to target state\n");
202 			break;
203 		case 1:
204 			dev_err(pm33xx_dev,
205 				"PM: Could not transition all powerdomains to target state\n");
206 			ret = -1;
207 			break;
208 		default:
209 			dev_err(pm33xx_dev,
210 				"PM: CM3 returned unknown result = %d\n", i);
211 			ret = -1;
212 		}
213 
214 		/* print the wakeup reason */
215 		if (rtc_only_idle) {
216 			wakeup_src = rtc_wake_src();
217 			pr_info("PM: Wakeup source %s\n", wakeup_src.src);
218 		} else {
219 			pr_info("PM: Wakeup source %s\n",
220 				m3_ipc->ops->request_wake_src(m3_ipc));
221 		}
222 	}
223 
224 	if (suspend_state == PM_SUSPEND_MEM && pm_ops->check_off_mode_enable())
225 		pm_ops->prepare_rtc_resume();
226 
227 	return ret;
228 }
229 
230 static int am33xx_pm_enter(suspend_state_t suspend_state)
231 {
232 	int ret = 0;
233 
234 	switch (suspend_state) {
235 	case PM_SUSPEND_MEM:
236 	case PM_SUSPEND_STANDBY:
237 		ret = am33xx_pm_suspend(suspend_state);
238 		break;
239 	default:
240 		ret = -EINVAL;
241 	}
242 
243 	return ret;
244 }
245 
246 static int am33xx_pm_begin(suspend_state_t state)
247 {
248 	int ret = -EINVAL;
249 	struct nvmem_device *nvmem;
250 
251 	if (state == PM_SUSPEND_MEM && pm_ops->check_off_mode_enable()) {
252 		nvmem = devm_nvmem_device_get(&omap_rtc->dev,
253 					      "omap_rtc_scratch0");
254 		if (nvmem)
255 			nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4, 4,
256 					   (void *)&rtc_magic_val);
257 		rtc_only_idle = 1;
258 	} else {
259 		rtc_only_idle = 0;
260 	}
261 
262 	switch (state) {
263 	case PM_SUSPEND_MEM:
264 		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_DEEPSLEEP);
265 		break;
266 	case PM_SUSPEND_STANDBY:
267 		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_STANDBY);
268 		break;
269 	}
270 
271 	return ret;
272 }
273 
274 static void am33xx_pm_end(void)
275 {
276 	u32 val = 0;
277 	struct nvmem_device *nvmem;
278 
279 	nvmem = devm_nvmem_device_get(&omap_rtc->dev, "omap_rtc_scratch0");
280 	m3_ipc->ops->finish_low_power(m3_ipc);
281 	if (rtc_only_idle) {
282 		if (retrigger_irq)
283 			/*
284 			 * 32 bits of Interrupt Set-Pending correspond to 32
285 			 * 32 interrupts. Compute the bit offset of the
286 			 * Interrupt and set that particular bit
287 			 * Compute the register offset by dividing interrupt
288 			 * number by 32 and mutiplying by 4
289 			 */
290 			writel_relaxed(1 << (retrigger_irq & 31),
291 				       gic_dist_base + GIC_INT_SET_PENDING_BASE
292 				       + retrigger_irq / 32 * 4);
293 			nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4, 4,
294 					   (void *)&val);
295 	}
296 
297 	rtc_only_idle = 0;
298 }
299 
300 static int am33xx_pm_valid(suspend_state_t state)
301 {
302 	switch (state) {
303 	case PM_SUSPEND_STANDBY:
304 	case PM_SUSPEND_MEM:
305 		return 1;
306 	default:
307 		return 0;
308 	}
309 }
310 
311 static const struct platform_suspend_ops am33xx_pm_ops = {
312 	.begin		= am33xx_pm_begin,
313 	.end		= am33xx_pm_end,
314 	.enter		= am33xx_pm_enter,
315 	.valid		= am33xx_pm_valid,
316 };
317 #endif /* CONFIG_SUSPEND */
318 
319 static void am33xx_pm_set_ipc_ops(void)
320 {
321 	u32 resume_address;
322 	int temp;
323 
324 	temp = ti_emif_get_mem_type();
325 	if (temp < 0) {
326 		dev_err(pm33xx_dev, "PM: Cannot determine memory type, no PM available\n");
327 		return;
328 	}
329 	m3_ipc->ops->set_mem_type(m3_ipc, temp);
330 
331 	/* Physical resume address to be used by ROM code */
332 	resume_address = am33xx_do_wfi_sram_phys +
333 			 *pm_sram->resume_offset + 0x4;
334 
335 	m3_ipc->ops->set_resume_address(m3_ipc, (void *)resume_address);
336 }
337 
338 static void am33xx_pm_free_sram(void)
339 {
340 	gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
341 	gen_pool_free(sram_pool_data, ocmcram_location_data,
342 		      sizeof(struct am33xx_pm_ro_sram_data));
343 }
344 
345 /*
346  * Push the minimal suspend-resume code to SRAM
347  */
348 static int am33xx_pm_alloc_sram(void)
349 {
350 	struct device_node *np;
351 	int ret = 0;
352 
353 	np = of_find_compatible_node(NULL, NULL, "ti,omap3-mpu");
354 	if (!np) {
355 		np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
356 		if (!np) {
357 			dev_err(pm33xx_dev, "PM: %s: Unable to find device node for mpu\n",
358 				__func__);
359 			return -ENODEV;
360 		}
361 	}
362 
363 	sram_pool = of_gen_pool_get(np, "pm-sram", 0);
364 	if (!sram_pool) {
365 		dev_err(pm33xx_dev, "PM: %s: Unable to get sram pool for ocmcram\n",
366 			__func__);
367 		ret = -ENODEV;
368 		goto mpu_put_node;
369 	}
370 
371 	sram_pool_data = of_gen_pool_get(np, "pm-sram", 1);
372 	if (!sram_pool_data) {
373 		dev_err(pm33xx_dev, "PM: %s: Unable to get sram data pool for ocmcram\n",
374 			__func__);
375 		ret = -ENODEV;
376 		goto mpu_put_node;
377 	}
378 
379 	ocmcram_location = gen_pool_alloc(sram_pool, *pm_sram->do_wfi_sz);
380 	if (!ocmcram_location) {
381 		dev_err(pm33xx_dev, "PM: %s: Unable to allocate memory from ocmcram\n",
382 			__func__);
383 		ret = -ENOMEM;
384 		goto mpu_put_node;
385 	}
386 
387 	ocmcram_location_data = gen_pool_alloc(sram_pool_data,
388 					       sizeof(struct emif_regs_amx3));
389 	if (!ocmcram_location_data) {
390 		dev_err(pm33xx_dev, "PM: Unable to allocate memory from ocmcram\n");
391 		gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
392 		ret = -ENOMEM;
393 	}
394 
395 mpu_put_node:
396 	of_node_put(np);
397 	return ret;
398 }
399 
400 static int am33xx_pm_rtc_setup(void)
401 {
402 	struct device_node *np;
403 	unsigned long val = 0;
404 	struct nvmem_device *nvmem;
405 
406 	np = of_find_node_by_name(NULL, "rtc");
407 
408 	if (of_device_is_available(np)) {
409 		omap_rtc = rtc_class_open("rtc0");
410 		if (!omap_rtc) {
411 			pr_warn("PM: rtc0 not available");
412 			return -EPROBE_DEFER;
413 		}
414 
415 		nvmem = devm_nvmem_device_get(&omap_rtc->dev,
416 					      "omap_rtc_scratch0");
417 		if (nvmem) {
418 			nvmem_device_read(nvmem, RTC_SCRATCH_MAGIC_REG * 4,
419 					  4, (void *)&rtc_magic_val);
420 			if ((rtc_magic_val & 0xffff) != RTC_REG_BOOT_MAGIC)
421 				pr_warn("PM: bootloader does not support rtc-only!\n");
422 
423 			nvmem_device_write(nvmem, RTC_SCRATCH_MAGIC_REG * 4,
424 					   4, (void *)&val);
425 			val = pm_sram->resume_address;
426 			nvmem_device_write(nvmem, RTC_SCRATCH_RESUME_REG * 4,
427 					   4, (void *)&val);
428 		}
429 	} else {
430 		pr_warn("PM: no-rtc available, rtc-only mode disabled.\n");
431 	}
432 
433 	return 0;
434 }
435 
436 static int am33xx_pm_probe(struct platform_device *pdev)
437 {
438 	struct device *dev = &pdev->dev;
439 	int ret;
440 
441 	if (!of_machine_is_compatible("ti,am33xx") &&
442 	    !of_machine_is_compatible("ti,am43"))
443 		return -ENODEV;
444 
445 	pm_ops = dev->platform_data;
446 	if (!pm_ops) {
447 		dev_err(dev, "PM: Cannot get core PM ops!\n");
448 		return -ENODEV;
449 	}
450 
451 	ret = am43xx_map_gic();
452 	if (ret) {
453 		pr_err("PM: Could not ioremap GIC base\n");
454 		return ret;
455 	}
456 
457 	pm_sram = pm_ops->get_sram_addrs();
458 	if (!pm_sram) {
459 		dev_err(dev, "PM: Cannot get PM asm function addresses!!\n");
460 		return -ENODEV;
461 	}
462 
463 	m3_ipc = wkup_m3_ipc_get();
464 	if (!m3_ipc) {
465 		pr_err("PM: Cannot get wkup_m3_ipc handle\n");
466 		return -EPROBE_DEFER;
467 	}
468 
469 	pm33xx_dev = dev;
470 
471 	ret = am33xx_pm_alloc_sram();
472 	if (ret)
473 		return ret;
474 
475 	ret = am33xx_pm_rtc_setup();
476 	if (ret)
477 		goto err_free_sram;
478 
479 	ret = am33xx_push_sram_idle();
480 	if (ret)
481 		goto err_free_sram;
482 
483 	am33xx_pm_set_ipc_ops();
484 
485 #ifdef CONFIG_SUSPEND
486 	suspend_set_ops(&am33xx_pm_ops);
487 
488 	/*
489 	 * For a system suspend we must flush the caches, we want
490 	 * the DDR in self-refresh, we want to save the context
491 	 * of the EMIF, and we want the wkup_m3 to handle low-power
492 	 * transition.
493 	 */
494 	suspend_wfi_flags |= WFI_FLAG_FLUSH_CACHE;
495 	suspend_wfi_flags |= WFI_FLAG_SELF_REFRESH;
496 	suspend_wfi_flags |= WFI_FLAG_SAVE_EMIF;
497 	suspend_wfi_flags |= WFI_FLAG_WAKE_M3;
498 #endif /* CONFIG_SUSPEND */
499 
500 	ret = pm_ops->init();
501 	if (ret) {
502 		dev_err(dev, "Unable to call core pm init!\n");
503 		ret = -ENODEV;
504 		goto err_put_wkup_m3_ipc;
505 	}
506 
507 	return 0;
508 
509 err_put_wkup_m3_ipc:
510 	wkup_m3_ipc_put(m3_ipc);
511 err_free_sram:
512 	am33xx_pm_free_sram();
513 	pm33xx_dev = NULL;
514 	return ret;
515 }
516 
517 static int am33xx_pm_remove(struct platform_device *pdev)
518 {
519 	suspend_set_ops(NULL);
520 	wkup_m3_ipc_put(m3_ipc);
521 	am33xx_pm_free_sram();
522 	return 0;
523 }
524 
525 static struct platform_driver am33xx_pm_driver = {
526 	.driver = {
527 		.name   = "pm33xx",
528 	},
529 	.probe = am33xx_pm_probe,
530 	.remove = am33xx_pm_remove,
531 };
532 module_platform_driver(am33xx_pm_driver);
533 
534 MODULE_ALIAS("platform:pm33xx");
535 MODULE_LICENSE("GPL v2");
536 MODULE_DESCRIPTION("am33xx power management driver");
537