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
42void mpc83xx_enter_deep_sleep(phys_addr_t immrbase);
43
44struct 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
74struct mpc83xx_rcw {
75	u32 rcwlr;
76	u32 rcwhr;
77};
78
79struct mpc83xx_clock {
80	u32 spmr;
81	u32 occr;
82	u32 sccr;
83};
84
85struct 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
95struct mpc83xx_saved {
96	u32 sicrl;
97	u32 sicrh;
98	u32 sccr;
99};
100
101struct pmc_type {
102	int has_deep_sleep;
103};
104
105static struct platform_device *pmc_dev;
106static int has_deep_sleep, deep_sleeping;
107static int pmc_irq;
108static struct mpc83xx_pmc __iomem *pmc_regs;
109static struct mpc83xx_clock __iomem *clock_regs;
110static struct mpc83xx_syscr __iomem *syscr_regs;
111static struct mpc83xx_saved saved_regs;
112static int is_pci_agent, wake_from_pci;
113static phys_addr_t immrbase;
114static int pci_pm_state;
115static DECLARE_WAIT_QUEUE_HEAD(agent_wq);
116
117int fsl_deep_sleep(void)
118{
119	return deep_sleeping;
120}
121EXPORT_SYMBOL(fsl_deep_sleep);
122
123static 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
146static 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
162static 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
169static 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
176static 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
230out:
231	out_be32(&pmc_regs->config1,
232	         in_be32(&pmc_regs->config1) & ~PMCCR1_PME_EN);
233
234	return ret;
235}
236
237static void mpc83xx_suspend_end(void)
238{
239	deep_sleeping = 0;
240}
241
242static int mpc83xx_suspend_valid(suspend_state_t state)
243{
244	return state == PM_SUSPEND_STANDBY || state == PM_SUSPEND_MEM;
245}
246
247static 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
265static 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
292static 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
300static 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
317static 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
324static const struct of_device_id pmc_match[];
325static 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
398out_syscr:
399	iounmap(clock_regs);
400out_pmc:
401	iounmap(pmc_regs);
402out:
403	if (pmc_irq != NO_IRQ)
404		free_irq(pmc_irq, ofdev);
405
406	return ret;
407}
408
409static int pmc_remove(struct platform_device *ofdev)
410{
411	return -EPERM;
412};
413
414static struct pmc_type pmc_types[] = {
415	{
416		.has_deep_sleep = 1,
417	},
418	{
419		.has_deep_sleep = 0,
420	}
421};
422
423static 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
435static struct platform_driver pmc_driver = {
436	.driver = {
437		.name = "mpc83xx-pmc",
438		.of_match_table = pmc_match,
439	},
440	.probe = pmc_probe,
441	.remove = pmc_remove
442};
443
444static int pmc_init(void)
445{
446	return platform_driver_register(&pmc_driver);
447}
448
449module_init(pmc_init);
450