1 /*
2  * MPC83xx suspend support
3  *
4  * Author: Scott Wood <scottwood@freescale.com>
5  *
6  * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published
10  * by the Free Software Foundation.
11  */
12 
13 #include <linux/pm.h>
14 #include <linux/types.h>
15 #include <linux/ioport.h>
16 #include <linux/interrupt.h>
17 #include <linux/wait.h>
18 #include <linux/kthread.h>
19 #include <linux/freezer.h>
20 #include <linux/suspend.h>
21 #include <linux/fsl_devices.h>
22 #include <linux/of_address.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_platform.h>
25 #include <linux/export.h>
26 
27 #include <asm/reg.h>
28 #include <asm/io.h>
29 #include <asm/time.h>
30 #include <asm/mpc6xx.h>
31 #include <asm/switch_to.h>
32 
33 #include <sysdev/fsl_soc.h>
34 
35 #define PMCCR1_NEXT_STATE       0x0C /* Next state for power management */
36 #define PMCCR1_NEXT_STATE_SHIFT 2
37 #define PMCCR1_CURR_STATE       0x03 /* Current state for power management*/
38 #define IMMR_SYSCR_OFFSET       0x100
39 #define IMMR_RCW_OFFSET         0x900
40 #define RCW_PCI_HOST            0x80000000
41 
42 void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
43 
44 struct mpc83xx_pmc {
45 	u32 config;
46 #define PMCCR_DLPEN 2 /* DDR SDRAM low power enable */
47 #define PMCCR_SLPEN 1 /* System low power enable */
48 
49 	u32 event;
50 	u32 mask;
51 /* All but PMCI are deep-sleep only */
52 #define PMCER_GPIO   0x100
53 #define PMCER_PCI    0x080
54 #define PMCER_USB    0x040
55 #define PMCER_ETSEC1 0x020
56 #define PMCER_ETSEC2 0x010
57 #define PMCER_TIMER  0x008
58 #define PMCER_INT1   0x004
59 #define PMCER_INT2   0x002
60 #define PMCER_PMCI   0x001
61 #define PMCER_ALL    0x1FF
62 
63 	/* deep-sleep only */
64 	u32 config1;
65 #define PMCCR1_USE_STATE  0x80000000
66 #define PMCCR1_PME_EN     0x00000080
67 #define PMCCR1_ASSERT_PME 0x00000040
68 #define PMCCR1_POWER_OFF  0x00000020
69 
70 	/* deep-sleep only */
71 	u32 config2;
72 };
73 
74 struct mpc83xx_rcw {
75 	u32 rcwlr;
76 	u32 rcwhr;
77 };
78 
79 struct mpc83xx_clock {
80 	u32 spmr;
81 	u32 occr;
82 	u32 sccr;
83 };
84 
85 struct mpc83xx_syscr {
86 	__be32 sgprl;
87 	__be32 sgprh;
88 	__be32 spridr;
89 	__be32 :32;
90 	__be32 spcr;
91 	__be32 sicrl;
92 	__be32 sicrh;
93 };
94 
95 struct mpc83xx_saved {
96 	u32 sicrl;
97 	u32 sicrh;
98 	u32 sccr;
99 };
100 
101 struct pmc_type {
102 	int has_deep_sleep;
103 };
104 
105 static struct platform_device *pmc_dev;
106 static int has_deep_sleep, deep_sleeping;
107 static int pmc_irq;
108 static struct mpc83xx_pmc __iomem *pmc_regs;
109 static struct mpc83xx_clock __iomem *clock_regs;
110 static struct mpc83xx_syscr __iomem *syscr_regs;
111 static struct mpc83xx_saved saved_regs;
112 static int is_pci_agent, wake_from_pci;
113 static phys_addr_t immrbase;
114 static int pci_pm_state;
115 static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
116 
117 int fsl_deep_sleep(void)
118 {
119 	return deep_sleeping;
120 }
121 EXPORT_SYMBOL(fsl_deep_sleep);
122 
123 static int mpc83xx_change_state(void)
124 {
125 	u32 curr_state;
126 	u32 reg_cfg1 = in_be32(&pmc_regs->config1);
127 
128 	if (is_pci_agent) {
129 		pci_pm_state = (reg_cfg1 & PMCCR1_NEXT_STATE) >>
130 		               PMCCR1_NEXT_STATE_SHIFT;
131 		curr_state = reg_cfg1 & PMCCR1_CURR_STATE;
132 
133 		if (curr_state != pci_pm_state) {
134 			reg_cfg1 &= ~PMCCR1_CURR_STATE;
135 			reg_cfg1 |= pci_pm_state;
136 			out_be32(&pmc_regs->config1, reg_cfg1);
137 
138 			wake_up(&agent_wq);
139 			return 1;
140 		}
141 	}
142 
143 	return 0;
144 }
145 
146 static irqreturn_t pmc_irq_handler(int irq, void *dev_id)
147 {
148 	u32 event = in_be32(&pmc_regs->event);
149 	int ret = IRQ_NONE;
150 
151 	if (mpc83xx_change_state())
152 		ret = IRQ_HANDLED;
153 
154 	if (event) {
155 		out_be32(&pmc_regs->event, event);
156 		ret = IRQ_HANDLED;
157 	}
158 
159 	return ret;
160 }
161 
162 static void mpc83xx_suspend_restore_regs(void)
163 {
164 	out_be32(&syscr_regs->sicrl, saved_regs.sicrl);
165 	out_be32(&syscr_regs->sicrh, saved_regs.sicrh);
166 	out_be32(&clock_regs->sccr, saved_regs.sccr);
167 }
168 
169 static void mpc83xx_suspend_save_regs(void)
170 {
171 	saved_regs.sicrl = in_be32(&syscr_regs->sicrl);
172 	saved_regs.sicrh = in_be32(&syscr_regs->sicrh);
173 	saved_regs.sccr = in_be32(&clock_regs->sccr);
174 }
175 
176 static int mpc83xx_suspend_enter(suspend_state_t state)
177 {
178 	int ret = -EAGAIN;
179 
180 	/* Don't go to sleep if there's a race where pci_pm_state changes
181 	 * between the agent thread checking it and the PM code disabling
182 	 * interrupts.
183 	 */
184 	if (wake_from_pci) {
185 		if (pci_pm_state != (deep_sleeping ? 3 : 2))
186 			goto out;
187 
188 		out_be32(&pmc_regs->config1,
189 		         in_be32(&pmc_regs->config1) | PMCCR1_PME_EN);
190 	}
191 
192 	/* Put the system into low-power mode and the RAM
193 	 * into self-refresh mode once the core goes to
194 	 * sleep.
195 	 */
196 
197 	out_be32(&pmc_regs->config, PMCCR_SLPEN | PMCCR_DLPEN);
198 
199 	/* If it has deep sleep (i.e. it's an 831x or compatible),
200 	 * disable power to the core upon entering sleep mode.  This will
201 	 * require going through the boot firmware upon a wakeup event.
202 	 */
203 
204 	if (deep_sleeping) {
205 		mpc83xx_suspend_save_regs();
206 
207 		out_be32(&pmc_regs->mask, PMCER_ALL);
208 
209 		out_be32(&pmc_regs->config1,
210 		         in_be32(&pmc_regs->config1) | PMCCR1_POWER_OFF);
211 
212 		enable_kernel_fp();
213 
214 		mpc83xx_enter_deep_sleep(immrbase);
215 
216 		out_be32(&pmc_regs->config1,
217 		         in_be32(&pmc_regs->config1) & ~PMCCR1_POWER_OFF);
218 
219 		out_be32(&pmc_regs->mask, PMCER_PMCI);
220 
221 		mpc83xx_suspend_restore_regs();
222 	} else {
223 		out_be32(&pmc_regs->mask, PMCER_PMCI);
224 
225 		mpc6xx_enter_standby();
226 	}
227 
228 	ret = 0;
229 
230 out:
231 	out_be32(&pmc_regs->config1,
232 	         in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
233 
234 	return ret;
235 }
236 
237 static void mpc83xx_suspend_end(void)
238 {
239 	deep_sleeping = 0;
240 }
241 
242 static int mpc83xx_suspend_valid(suspend_state_t state)
243 {
244 	return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
245 }
246 
247 static int mpc83xx_suspend_begin(suspend_state_t state)
248 {
249 	switch (state) {
250 		case PM_SUSPEND_STANDBY:
251 			deep_sleeping = 0;
252 			return 0;
253 
254 		case PM_SUSPEND_MEM:
255 			if (has_deep_sleep)
256 				deep_sleeping = 1;
257 
258 			return 0;
259 
260 		default:
261 			return -EINVAL;
262 	}
263 }
264 
265 static int agent_thread_fn(void *data)
266 {
267 	while (1) {
268 		wait_event_interruptible(agent_wq, pci_pm_state >= 2);
269 		try_to_freeze();
270 
271 		if (signal_pending(current) || pci_pm_state < 2)
272 			continue;
273 
274 		/* With a preemptible kernel (or SMP), this could race with
275 		 * a userspace-driven suspend request.  It's probably best
276 		 * to avoid mixing the two with such a configuration (or
277 		 * else fix it by adding a mutex to state_store that we can
278 		 * synchronize with).
279 		 */
280 
281 		wake_from_pci = 1;
282 
283 		pm_suspend(pci_pm_state == 3 ? PM_SUSPEND_MEM :
284 		                               PM_SUSPEND_STANDBY);
285 
286 		wake_from_pci = 0;
287 	}
288 
289 	return 0;
290 }
291 
292 static void mpc83xx_set_agent(void)
293 {
294 	out_be32(&pmc_regs->config1, PMCCR1_USE_STATE);
295 	out_be32(&pmc_regs->mask, PMCER_PMCI);
296 
297 	kthread_run(agent_thread_fn, NULL, "PCI power mgt");
298 }
299 
300 static int mpc83xx_is_pci_agent(void)
301 {
302 	struct mpc83xx_rcw __iomem *rcw_regs;
303 	int ret;
304 
305 	rcw_regs = ioremap(get_immrbase() + IMMR_RCW_OFFSET,
306 	                   sizeof(struct mpc83xx_rcw));
307 
308 	if (!rcw_regs)
309 		return -ENOMEM;
310 
311 	ret = !(in_be32(&rcw_regs->rcwhr) & RCW_PCI_HOST);
312 
313 	iounmap(rcw_regs);
314 	return ret;
315 }
316 
317 static const struct platform_suspend_ops mpc83xx_suspend_ops = {
318 	.valid = mpc83xx_suspend_valid,
319 	.begin = mpc83xx_suspend_begin,
320 	.enter = mpc83xx_suspend_enter,
321 	.end = mpc83xx_suspend_end,
322 };
323 
324 static const struct of_device_id pmc_match[];
325 static int pmc_probe(struct platform_device *ofdev)
326 {
327 	const struct of_device_id *match;
328 	struct device_node *np = ofdev->dev.of_node;
329 	struct resource res;
330 	const struct pmc_type *type;
331 	int ret = 0;
332 
333 	match = of_match_device(pmc_match, &ofdev->dev);
334 	if (!match)
335 		return -EINVAL;
336 
337 	type = match->data;
338 
339 	if (!of_device_is_available(np))
340 		return -ENODEV;
341 
342 	has_deep_sleep = type->has_deep_sleep;
343 	immrbase = get_immrbase();
344 	pmc_dev = ofdev;
345 
346 	is_pci_agent = mpc83xx_is_pci_agent();
347 	if (is_pci_agent < 0)
348 		return is_pci_agent;
349 
350 	ret = of_address_to_resource(np, 0, &res);
351 	if (ret)
352 		return -ENODEV;
353 
354 	pmc_irq = irq_of_parse_and_map(np, 0);
355 	if (pmc_irq != NO_IRQ) {
356 		ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
357 		                  "pmc", ofdev);
358 
359 		if (ret)
360 			return -EBUSY;
361 	}
362 
363 	pmc_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
364 
365 	if (!pmc_regs) {
366 		ret = -ENOMEM;
367 		goto out;
368 	}
369 
370 	ret = of_address_to_resource(np, 1, &res);
371 	if (ret) {
372 		ret = -ENODEV;
373 		goto out_pmc;
374 	}
375 
376 	clock_regs = ioremap(res.start, sizeof(struct mpc83xx_pmc));
377 
378 	if (!clock_regs) {
379 		ret = -ENOMEM;
380 		goto out_pmc;
381 	}
382 
383 	if (has_deep_sleep) {
384 		syscr_regs = ioremap(immrbase + IMMR_SYSCR_OFFSET,
385 				     sizeof(*syscr_regs));
386 		if (!syscr_regs) {
387 			ret = -ENOMEM;
388 			goto out_syscr;
389 		}
390 	}
391 
392 	if (is_pci_agent)
393 		mpc83xx_set_agent();
394 
395 	suspend_set_ops(&mpc83xx_suspend_ops);
396 	return 0;
397 
398 out_syscr:
399 	iounmap(clock_regs);
400 out_pmc:
401 	iounmap(pmc_regs);
402 out:
403 	if (pmc_irq != NO_IRQ)
404 		free_irq(pmc_irq, ofdev);
405 
406 	return ret;
407 }
408 
409 static int pmc_remove(struct platform_device *ofdev)
410 {
411 	return -EPERM;
412 };
413 
414 static struct pmc_type pmc_types[] = {
415 	{
416 		.has_deep_sleep = 1,
417 	},
418 	{
419 		.has_deep_sleep = 0,
420 	}
421 };
422 
423 static const struct of_device_id pmc_match[] = {
424 	{
425 		.compatible = "fsl,mpc8313-pmc",
426 		.data = &pmc_types[0],
427 	},
428 	{
429 		.compatible = "fsl,mpc8349-pmc",
430 		.data = &pmc_types[1],
431 	},
432 	{}
433 };
434 
435 static struct platform_driver pmc_driver = {
436 	.driver = {
437 		.name = "mpc83xx-pmc",
438 		.owner = THIS_MODULE,
439 		.of_match_table = pmc_match,
440 	},
441 	.probe = pmc_probe,
442 	.remove = pmc_remove
443 };
444 
445 static int pmc_init(void)
446 {
447 	return platform_driver_register(&pmc_driver);
448 }
449 
450 module_init(pmc_init);
451