1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * MPC83xx suspend support
4  *
5  * Author: Scott Wood <scottwood@freescale.com>
6  *
7  * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
8  */
9 
10 #include <linux/pm.h>
11 #include <linux/types.h>
12 #include <linux/ioport.h>
13 #include <linux/interrupt.h>
14 #include <linux/wait.h>
15 #include <linux/sched/signal.h>
16 #include <linux/kthread.h>
17 #include <linux/freezer.h>
18 #include <linux/suspend.h>
19 #include <linux/fsl_devices.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_platform.h>
23 #include <linux/export.h>
24 
25 #include <asm/reg.h>
26 #include <asm/io.h>
27 #include <asm/time.h>
28 #include <asm/mpc6xx.h>
29 #include <asm/switch_to.h>
30 
31 #include <sysdev/fsl_soc.h>
32 
33 #define PMCCR1_NEXT_STATE       0x0C /* Next state for power management */
34 #define PMCCR1_NEXT_STATE_SHIFT 2
35 #define PMCCR1_CURR_STATE       0x03 /* Current state for power management*/
36 #define IMMR_SYSCR_OFFSET       0x100
37 #define IMMR_RCW_OFFSET         0x900
38 #define RCW_PCI_HOST            0x80000000
39 
40 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
41 
42 struct mpc83xx_pmc {
43 	u32 config;
44 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
45 #define PMCCR_SLPEN 1 /* System low power enable */
46 
47 	u32 event;
48 	u32 mask;
49 /* All but PMCI are deep-sleep only */
50 #define PMCER_GPIO   0x100
51 #define PMCER_PCI    0x080
52 #define PMCER_USB    0x040
53 #define PMCER_ETSEC1 0x020
54 #define PMCER_ETSEC2 0x010
55 #define PMCER_TIMER  0x008
56 #define PMCER_INT1   0x004
57 #define PMCER_INT2   0x002
58 #define PMCER_PMCI   0x001
59 #define PMCER_ALL    0x1FF
60 
61 	/* deep-sleep only */
62 	u32 config1;
63 #define PMCCR1_USE_STATE  0x80000000
64 #define PMCCR1_PME_EN     0x00000080
65 #define PMCCR1_ASSERT_PME 0x00000040
66 #define PMCCR1_POWER_OFF  0x00000020
67 
68 	/* deep-sleep only */
69 	u32 config2;
70 };
71 
72 struct mpc83xx_rcw {
73 	u32 rcwlr;
74 	u32 rcwhr;
75 };
76 
77 struct mpc83xx_clock {
78 	u32 spmr;
79 	u32 occr;
80 	u32 sccr;
81 };
82 
83 struct mpc83xx_syscr {
84 	__be32 sgprl;
85 	__be32 sgprh;
86 	__be32 spridr;
87 	__be32 :32;
88 	__be32 spcr;
89 	__be32 sicrl;
90 	__be32 sicrh;
91 };
92 
93 struct mpc83xx_saved {
94 	u32 sicrl;
95 	u32 sicrh;
96 	u32 sccr;
97 };
98 
99 struct pmc_type {
100 	int has_deep_sleep;
101 };
102 
103 static struct platform_device *pmc_dev;
104 static int has_deep_sleep, deep_sleeping;
105 static int pmc_irq;
106 static struct mpc83xx_pmc __iomem *pmc_regs;
107 static struct mpc83xx_clock __iomem *clock_regs;
108 static struct mpc83xx_syscr __iomem *syscr_regs;
109 static struct mpc83xx_saved saved_regs;
110 static int is_pci_agent, wake_from_pci;
111 static phys_addr_t immrbase;
112 static int pci_pm_state;
113 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
114 
115 int fsl_deep_sleep(void)
116 {
117 	return deep_sleeping;
118 }
119 EXPORT_SYMBOL(fsl_deep_sleep);
120 
121 static int mpc83xx_change_state(void)
122 {
123 	u32 curr_state;
124 	u32 reg_cfg1 = in_be32(&pmc_regs->config1);
125 
126 	if (is_pci_agent) {
127 		pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
128 		               PMCCR1_NEXT_STATE_SHIFT;
129 		curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
130 
131 		if (curr_state != pci_pm_state) {
132 			reg_cfg1 &= ~PMCCR1_CURR_STATE;
133 			reg_cfg1 |= pci_pm_state;
134 			out_be32(&pmc_regs->config1, reg_cfg1);
135 
136 			wake_up(&agent_wq);
137 			return 1;
138 		}
139 	}
140 
141 	return 0;
142 }
143 
144 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
145 {
146 	u32 event = in_be32(&pmc_regs->event);
147 	int ret = IRQ_NONE;
148 
149 	if (mpc83xx_change_state())
150 		ret = IRQ_HANDLED;
151 
152 	if (event) {
153 		out_be32(&pmc_regs->event, event);
154 		ret = IRQ_HANDLED;
155 	}
156 
157 	return ret;
158 }
159 
160 static void mpc83xx_suspend_restore_regs(void)
161 {
162 	out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
163 	out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
164 	out_be32(&clock_regs->sccr, saved_regs.sccr);
165 }
166 
167 static void mpc83xx_suspend_save_regs(void)
168 {
169 	saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
170 	saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
171 	saved_regs.sccr = in_be32(&clock_regs->sccr);
172 }
173 
174 static int mpc83xx_suspend_enter(suspend_state_t state)
175 {
176 	int ret = -EAGAIN;
177 
178 	/* Don't go to sleep if there's a race where pci_pm_state changes
179 	 * between the agent thread checking it and the PM code disabling
180 	 * interrupts.
181 	 */
182 	if (wake_from_pci) {
183 		if (pci_pm_state != (deep_sleeping ? 3 : 2))
184 			goto out;
185 
186 		out_be32(&pmc_regs->config1,
187 		         in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
188 	}
189 
190 	/* Put the system into low-power mode and the RAM
191 	 * into self-refresh mode once the core goes to
192 	 * sleep.
193 	 */
194 
195 	out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
196 
197 	/* If it has deep sleep (i.e. it's an 831x or compatible),
198 	 * disable power to the core upon entering sleep mode.  This will
199 	 * require going through the boot firmware upon a wakeup event.
200 	 */
201 
202 	if (deep_sleeping) {
203 		mpc83xx_suspend_save_regs();
204 
205 		out_be32(&pmc_regs->mask, PMCER_ALL);
206 
207 		out_be32(&pmc_regs->config1,
208 		         in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
209 
210 		enable_kernel_fp();
211 
212 		mpc83xx_enter_deep_sleep(immrbase);
213 
214 		out_be32(&pmc_regs->config1,
215 		         in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
216 
217 		out_be32(&pmc_regs->mask, PMCER_PMCI);
218 
219 		mpc83xx_suspend_restore_regs();
220 	} else {
221 		out_be32(&pmc_regs->mask, PMCER_PMCI);
222 
223 		mpc6xx_enter_standby();
224 	}
225 
226 	ret = 0;
227 
228 out:
229 	out_be32(&pmc_regs->config1,
230 	         in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
231 
232 	return ret;
233 }
234 
235 static void mpc83xx_suspend_end(void)
236 {
237 	deep_sleeping = 0;
238 }
239 
240 static int mpc83xx_suspend_valid(suspend_state_t state)
241 {
242 	return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
243 }
244 
245 static int mpc83xx_suspend_begin(suspend_state_t state)
246 {
247 	switch (state) {
248 		case PM_SUSPEND_STANDBY:
249 			deep_sleeping = 0;
250 			return 0;
251 
252 		case PM_SUSPEND_MEM:
253 			if (has_deep_sleep)
254 				deep_sleeping = 1;
255 
256 			return 0;
257 
258 		default:
259 			return -EINVAL;
260 	}
261 }
262 
263 static int agent_thread_fn(void *data)
264 {
265 	while (1) {
266 		wait_event_interruptible(agent_wq, pci_pm_state >= 2);
267 		try_to_freeze();
268 
269 		if (signal_pending(current) || pci_pm_state < 2)
270 			continue;
271 
272 		/* With a preemptible kernel (or SMP), this could race with
273 		 * a userspace-driven suspend request.  It's probably best
274 		 * to avoid mixing the two with such a configuration (or
275 		 * else fix it by adding a mutex to state_store that we can
276 		 * synchronize with).
277 		 */
278 
279 		wake_from_pci = 1;
280 
281 		pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
282 		                               PM_SUSPEND_STANDBY);
283 
284 		wake_from_pci = 0;
285 	}
286 
287 	return 0;
288 }
289 
290 static void mpc83xx_set_agent(void)
291 {
292 	out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
293 	out_be32(&pmc_regs->mask, PMCER_PMCI);
294 
295 	kthread_run(agent_thread_fn, NULL, "PCI power mgt");
296 }
297 
298 static int mpc83xx_is_pci_agent(void)
299 {
300 	struct mpc83xx_rcw __iomem *rcw_regs;
301 	int ret;
302 
303 	rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
304 	                   sizeof(struct mpc83xx_rcw));
305 
306 	if (!rcw_regs)
307 		return -ENOMEM;
308 
309 	ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
310 
311 	iounmap(rcw_regs);
312 	return ret;
313 }
314 
315 static const struct platform_suspend_ops mpc83xx_suspend_ops = {
316 	.valid = mpc83xx_suspend_valid,
317 	.begin = mpc83xx_suspend_begin,
318 	.enter = mpc83xx_suspend_enter,
319 	.end = mpc83xx_suspend_end,
320 };
321 
322 static const struct of_device_id pmc_match[];
323 static int pmc_probe(struct platform_device *ofdev)
324 {
325 	const struct of_device_id *match;
326 	struct device_node *np = ofdev->dev.of_node;
327 	struct resource res;
328 	const struct pmc_type *type;
329 	int ret = 0;
330 
331 	match = of_match_device(pmc_match, &ofdev->dev);
332 	if (!match)
333 		return -EINVAL;
334 
335 	type = match->data;
336 
337 	if (!of_device_is_available(np))
338 		return -ENODEV;
339 
340 	has_deep_sleep = type->has_deep_sleep;
341 	immrbase = get_immrbase();
342 	pmc_dev = ofdev;
343 
344 	is_pci_agent = mpc83xx_is_pci_agent();
345 	if (is_pci_agent < 0)
346 		return is_pci_agent;
347 
348 	ret = of_address_to_resource(np, 0, &res);
349 	if (ret)
350 		return -ENODEV;
351 
352 	pmc_irq = irq_of_parse_and_map(np, 0);
353 	if (pmc_irq) {
354 		ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
355 		                  "pmc", ofdev);
356 
357 		if (ret)
358 			return -EBUSY;
359 	}
360 
361 	pmc_regs = ioremap(res.start, sizeof(*pmc_regs));
362 
363 	if (!pmc_regs) {
364 		ret = -ENOMEM;
365 		goto out;
366 	}
367 
368 	ret = of_address_to_resource(np, 1, &res);
369 	if (ret) {
370 		ret = -ENODEV;
371 		goto out_pmc;
372 	}
373 
374 	clock_regs = ioremap(res.start, sizeof(*clock_regs));
375 
376 	if (!clock_regs) {
377 		ret = -ENOMEM;
378 		goto out_pmc;
379 	}
380 
381 	if (has_deep_sleep) {
382 		syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
383 				     sizeof(*syscr_regs));
384 		if (!syscr_regs) {
385 			ret = -ENOMEM;
386 			goto out_syscr;
387 		}
388 	}
389 
390 	if (is_pci_agent)
391 		mpc83xx_set_agent();
392 
393 	suspend_set_ops(&mpc83xx_suspend_ops);
394 	return 0;
395 
396 out_syscr:
397 	iounmap(clock_regs);
398 out_pmc:
399 	iounmap(pmc_regs);
400 out:
401 	if (pmc_irq)
402 		free_irq(pmc_irq, ofdev);
403 
404 	return ret;
405 }
406 
407 static int pmc_remove(struct platform_device *ofdev)
408 {
409 	return -EPERM;
410 };
411 
412 static struct pmc_type pmc_types[] = {
413 	{
414 		.has_deep_sleep = 1,
415 	},
416 	{
417 		.has_deep_sleep = 0,
418 	}
419 };
420 
421 static const struct of_device_id pmc_match[] = {
422 	{
423 		.compatible = "fsl,mpc8313-pmc",
424 		.data = &pmc_types[0],
425 	},
426 	{
427 		.compatible = "fsl,mpc8349-pmc",
428 		.data = &pmc_types[1],
429 	},
430 	{}
431 };
432 
433 static struct platform_driver pmc_driver = {
434 	.driver = {
435 		.name = "mpc83xx-pmc",
436 		.of_match_table = pmc_match,
437 	},
438 	.probe = pmc_probe,
439 	.remove = pmc_remove
440 };
441 
442 builtin_platform_driver(pmc_driver);
443