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/platform_device.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 int has_deep_sleep, deep_sleeping;
104 static int pmc_irq;
105 static struct mpc83xx_pmc __iomem *pmc_regs;
106 static struct mpc83xx_clock __iomem *clock_regs;
107 static struct mpc83xx_syscr __iomem *syscr_regs;
108 static struct mpc83xx_saved saved_regs;
109 static int is_pci_agent, wake_from_pci;
110 static phys_addr_t immrbase;
111 static int pci_pm_state;
112 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
113 
114 int fsl_deep_sleep(void)
115 {
116 	return deep_sleeping;
117 }
118 EXPORT_SYMBOL(fsl_deep_sleep);
119 
120 static int mpc83xx_change_state(void)
121 {
122 	u32 curr_state;
123 	u32 reg_cfg1 = in_be32(&pmc_regs->config1);
124 
125 	if (is_pci_agent) {
126 		pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
127 		               PMCCR1_NEXT_STATE_SHIFT;
128 		curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
129 
130 		if (curr_state != pci_pm_state) {
131 			reg_cfg1 &= ~PMCCR1_CURR_STATE;
132 			reg_cfg1 |= pci_pm_state;
133 			out_be32(&pmc_regs->config1, reg_cfg1);
134 
135 			wake_up(&agent_wq);
136 			return 1;
137 		}
138 	}
139 
140 	return 0;
141 }
142 
143 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
144 {
145 	u32 event = in_be32(&pmc_regs->event);
146 	int ret = IRQ_NONE;
147 
148 	if (mpc83xx_change_state())
149 		ret = IRQ_HANDLED;
150 
151 	if (event) {
152 		out_be32(&pmc_regs->event, event);
153 		ret = IRQ_HANDLED;
154 	}
155 
156 	return ret;
157 }
158 
159 static void mpc83xx_suspend_restore_regs(void)
160 {
161 	out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
162 	out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
163 	out_be32(&clock_regs->sccr, saved_regs.sccr);
164 }
165 
166 static void mpc83xx_suspend_save_regs(void)
167 {
168 	saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
169 	saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
170 	saved_regs.sccr = in_be32(&clock_regs->sccr);
171 }
172 
173 static int mpc83xx_suspend_enter(suspend_state_t state)
174 {
175 	int ret = -EAGAIN;
176 
177 	/* Don't go to sleep if there's a race where pci_pm_state changes
178 	 * between the agent thread checking it and the PM code disabling
179 	 * interrupts.
180 	 */
181 	if (wake_from_pci) {
182 		if (pci_pm_state != (deep_sleeping ? 3 : 2))
183 			goto out;
184 
185 		out_be32(&pmc_regs->config1,
186 		         in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
187 	}
188 
189 	/* Put the system into low-power mode and the RAM
190 	 * into self-refresh mode once the core goes to
191 	 * sleep.
192 	 */
193 
194 	out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
195 
196 	/* If it has deep sleep (i.e. it's an 831x or compatible),
197 	 * disable power to the core upon entering sleep mode.  This will
198 	 * require going through the boot firmware upon a wakeup event.
199 	 */
200 
201 	if (deep_sleeping) {
202 		mpc83xx_suspend_save_regs();
203 
204 		out_be32(&pmc_regs->mask, PMCER_ALL);
205 
206 		out_be32(&pmc_regs->config1,
207 		         in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
208 
209 		enable_kernel_fp();
210 
211 		mpc83xx_enter_deep_sleep(immrbase);
212 
213 		out_be32(&pmc_regs->config1,
214 		         in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
215 
216 		out_be32(&pmc_regs->mask, PMCER_PMCI);
217 
218 		mpc83xx_suspend_restore_regs();
219 	} else {
220 		out_be32(&pmc_regs->mask, PMCER_PMCI);
221 
222 		mpc6xx_enter_standby();
223 	}
224 
225 	ret = 0;
226 
227 out:
228 	out_be32(&pmc_regs->config1,
229 	         in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
230 
231 	return ret;
232 }
233 
234 static void mpc83xx_suspend_end(void)
235 {
236 	deep_sleeping = 0;
237 }
238 
239 static int mpc83xx_suspend_valid(suspend_state_t state)
240 {
241 	return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
242 }
243 
244 static int mpc83xx_suspend_begin(suspend_state_t state)
245 {
246 	switch (state) {
247 		case PM_SUSPEND_STANDBY:
248 			deep_sleeping = 0;
249 			return 0;
250 
251 		case PM_SUSPEND_MEM:
252 			if (has_deep_sleep)
253 				deep_sleeping = 1;
254 
255 			return 0;
256 
257 		default:
258 			return -EINVAL;
259 	}
260 }
261 
262 static int agent_thread_fn(void *data)
263 {
264 	while (1) {
265 		wait_event_interruptible(agent_wq, pci_pm_state >= 2);
266 		try_to_freeze();
267 
268 		if (signal_pending(current) || pci_pm_state < 2)
269 			continue;
270 
271 		/* With a preemptible kernel (or SMP), this could race with
272 		 * a userspace-driven suspend request.  It's probably best
273 		 * to avoid mixing the two with such a configuration (or
274 		 * else fix it by adding a mutex to state_store that we can
275 		 * synchronize with).
276 		 */
277 
278 		wake_from_pci = 1;
279 
280 		pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
281 		                               PM_SUSPEND_STANDBY);
282 
283 		wake_from_pci = 0;
284 	}
285 
286 	return 0;
287 }
288 
289 static void mpc83xx_set_agent(void)
290 {
291 	out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
292 	out_be32(&pmc_regs->mask, PMCER_PMCI);
293 
294 	kthread_run(agent_thread_fn, NULL, "PCI power mgt");
295 }
296 
297 static int mpc83xx_is_pci_agent(void)
298 {
299 	struct mpc83xx_rcw __iomem *rcw_regs;
300 	int ret;
301 
302 	rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
303 	                   sizeof(struct mpc83xx_rcw));
304 
305 	if (!rcw_regs)
306 		return -ENOMEM;
307 
308 	ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
309 
310 	iounmap(rcw_regs);
311 	return ret;
312 }
313 
314 static const struct platform_suspend_ops mpc83xx_suspend_ops = {
315 	.valid = mpc83xx_suspend_valid,
316 	.begin = mpc83xx_suspend_begin,
317 	.enter = mpc83xx_suspend_enter,
318 	.end = mpc83xx_suspend_end,
319 };
320 
321 static struct pmc_type pmc_types[] = {
322 	{
323 		.has_deep_sleep = 1,
324 	},
325 	{
326 		.has_deep_sleep = 0,
327 	}
328 };
329 
330 static const struct of_device_id pmc_match[] = {
331 	{
332 		.compatible = "fsl,mpc8313-pmc",
333 		.data = &pmc_types[0],
334 	},
335 	{
336 		.compatible = "fsl,mpc8349-pmc",
337 		.data = &pmc_types[1],
338 	},
339 	{}
340 };
341 
342 static int pmc_probe(struct platform_device *ofdev)
343 {
344 	struct device_node *np = ofdev->dev.of_node;
345 	struct resource res;
346 	const struct pmc_type *type;
347 	int ret = 0;
348 
349 	type = of_device_get_match_data(&ofdev->dev);
350 	if (!type)
351 		return -EINVAL;
352 
353 	if (!of_device_is_available(np))
354 		return -ENODEV;
355 
356 	has_deep_sleep = type->has_deep_sleep;
357 	immrbase = get_immrbase();
358 
359 	is_pci_agent = mpc83xx_is_pci_agent();
360 	if (is_pci_agent < 0)
361 		return is_pci_agent;
362 
363 	ret = of_address_to_resource(np, 0, &res);
364 	if (ret)
365 		return -ENODEV;
366 
367 	pmc_irq = irq_of_parse_and_map(np, 0);
368 	if (pmc_irq) {
369 		ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
370 		                  "pmc", ofdev);
371 
372 		if (ret)
373 			return -EBUSY;
374 	}
375 
376 	pmc_regs = ioremap(res.start, sizeof(*pmc_regs));
377 
378 	if (!pmc_regs) {
379 		ret = -ENOMEM;
380 		goto out;
381 	}
382 
383 	ret = of_address_to_resource(np, 1, &res);
384 	if (ret) {
385 		ret = -ENODEV;
386 		goto out_pmc;
387 	}
388 
389 	clock_regs = ioremap(res.start, sizeof(*clock_regs));
390 
391 	if (!clock_regs) {
392 		ret = -ENOMEM;
393 		goto out_pmc;
394 	}
395 
396 	if (has_deep_sleep) {
397 		syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
398 				     sizeof(*syscr_regs));
399 		if (!syscr_regs) {
400 			ret = -ENOMEM;
401 			goto out_syscr;
402 		}
403 	}
404 
405 	if (is_pci_agent)
406 		mpc83xx_set_agent();
407 
408 	suspend_set_ops(&mpc83xx_suspend_ops);
409 	return 0;
410 
411 out_syscr:
412 	iounmap(clock_regs);
413 out_pmc:
414 	iounmap(pmc_regs);
415 out:
416 	if (pmc_irq)
417 		free_irq(pmc_irq, ofdev);
418 
419 	return ret;
420 }
421 
422 static struct platform_driver pmc_driver = {
423 	.driver = {
424 		.name = "mpc83xx-pmc",
425 		.of_match_table = pmc_match,
426 		.suppress_bind_attrs = true,
427 	},
428 	.probe = pmc_probe,
429 };
430 
431 builtin_platform_driver(pmc_driver);
432