pm.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Alchemy Development Board example suspend userspace interface.
  4 *
  5 * (c) 2008 Manuel Lauss <mano@roarinelk.homelinux.net>
  6 */
  7
  8#include <linux/init.h>
  9#include <linux/kobject.h>
 10#include <linux/suspend.h>
 11#include <linux/sysfs.h>
 12#include <asm/mach-au1x00/au1000.h>
 13#include <asm/mach-au1x00/gpio-au1000.h>
 14#include <asm/mach-db1x00/bcsr.h>
 15
 16/*
 17 * Generic suspend userspace interface for Alchemy development boards.
 18 * This code exports a few sysfs nodes under /sys/power/db1x/ which
 19 * can be used by userspace to en/disable all au1x-provided wakeup
 20 * sources and configure the timeout after which the TOYMATCH2 irq
 21 * is to trigger a wakeup.
 22 */
 23
 24
 25static unsigned long db1x_pm_sleep_secs;
 26static unsigned long db1x_pm_wakemsk;
 27static unsigned long db1x_pm_last_wakesrc;
 28
 29static int db1x_pm_enter(suspend_state_t state)
 30{
 31	unsigned short bcsrs[16];
 32	int i, j, hasint;
 33
 34	/* save CPLD regs */
 35	hasint = bcsr_read(BCSR_WHOAMI);
 36	hasint = BCSR_WHOAMI_BOARD(hasint) >= BCSR_WHOAMI_DB1200;
 37	j = (hasint) ? BCSR_MASKSET : BCSR_SYSTEM;
 38
 39	for (i = BCSR_STATUS; i <= j; i++)
 40		bcsrs[i] = bcsr_read(i);
 41
 42	/* shut off hexleds */
 43	bcsr_write(BCSR_HEXCLEAR, 3);
 44
 45	/* enable GPIO based wakeup */
 46	alchemy_gpio1_input_enable();
 47
 48	/* clear and setup wake cause and source */
 49	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
 50	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
 51
 52	alchemy_wrsys(db1x_pm_wakemsk, AU1000_SYS_WAKEMSK);
 53
 54	/* setup 1Hz-timer-based wakeup: wait for reg access */
 55	while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
 56		asm volatile ("nop");
 57
 58	alchemy_wrsys(alchemy_rdsys(AU1000_SYS_TOYREAD) + db1x_pm_sleep_secs,
 59		      AU1000_SYS_TOYMATCH2);
 60
 61	/* wait for value to really hit the register */
 62	while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
 63		asm volatile ("nop");
 64
 65	/* ...and now the sandman can come! */
 66	au_sleep();
 67
 68
 69	/* restore CPLD regs */
 70	for (i = BCSR_STATUS; i <= BCSR_SYSTEM; i++)
 71		bcsr_write(i, bcsrs[i]);
 72
 73	/* restore CPLD int registers */
 74	if (hasint) {
 75		bcsr_write(BCSR_INTCLR, 0xffff);
 76		bcsr_write(BCSR_MASKCLR, 0xffff);
 77		bcsr_write(BCSR_INTSTAT, 0xffff);
 78		bcsr_write(BCSR_INTSET, bcsrs[BCSR_INTSET]);
 79		bcsr_write(BCSR_MASKSET, bcsrs[BCSR_MASKSET]);
 80	}
 81
 82	/* light up hexleds */
 83	bcsr_write(BCSR_HEXCLEAR, 0);
 84
 85	return 0;
 86}
 87
 88static int db1x_pm_begin(suspend_state_t state)
 89{
 90	if (!db1x_pm_wakemsk) {
 91		printk(KERN_ERR "db1x: no wakeup source activated!\n");
 92		return -EINVAL;
 93	}
 94
 95	return 0;
 96}
 97
 98static void db1x_pm_end(void)
 99{
100	/* read and store wakeup source, the clear the register. To
101	 * be able to clear it, WAKEMSK must be cleared first.
102	 */
103	db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);
104
105	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
106	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
107}
108
109static const struct platform_suspend_ops db1x_pm_ops = {
110	.valid		= suspend_valid_only_mem,
111	.begin		= db1x_pm_begin,
112	.enter		= db1x_pm_enter,
113	.end		= db1x_pm_end,
114};
115
116#define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
117
118static ssize_t db1x_pmattr_show(struct kobject *kobj,
119				struct kobj_attribute *attr,
120				char *buf)
121{
122	int idx;
123
124	if (ATTRCMP(timer_timeout))
125		return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
126
127	else if (ATTRCMP(timer))
128		return sprintf(buf, "%u\n",
129				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
130
131	else if (ATTRCMP(wakesrc))
132		return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
133
134	else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
135		 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
136		 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
137		idx = (attr->attr.name)[4] - '0';
138		return sprintf(buf, "%d\n",
139			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
140
141	} else if (ATTRCMP(wakemsk)) {
142		return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
143	}
144
145	return -ENOENT;
146}
147
148static ssize_t db1x_pmattr_store(struct kobject *kobj,
149				 struct kobj_attribute *attr,
150				 const char *instr,
151				 size_t bytes)
152{
153	unsigned long l;
154	int tmp;
155
156	if (ATTRCMP(timer_timeout)) {
157		tmp = kstrtoul(instr, 0, &l);
158		if (tmp)
159			return tmp;
160
161		db1x_pm_sleep_secs = l;
162
163	} else if (ATTRCMP(timer)) {
164		if (instr[0] != '0')
165			db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
166		else
167			db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
168
169	} else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
170		   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
171		   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
172		tmp = (attr->attr.name)[4] - '0';
173		if (instr[0] != '0') {
174			db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
175		} else {
176			db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
177		}
178
179	} else if (ATTRCMP(wakemsk)) {
180		tmp = kstrtoul(instr, 0, &l);
181		if (tmp)
182			return tmp;
183
184		db1x_pm_wakemsk = l & 0x0000003f;
185
186	} else
187		bytes = -ENOENT;
188
189	return bytes;
190}
191
192#define ATTR(x)							\
193	static struct kobj_attribute x##_attribute =		\
194		__ATTR(x, 0664, db1x_pmattr_show,		\
195				db1x_pmattr_store);
196
197ATTR(gpio0)		/* GPIO-based wakeup enable */
198ATTR(gpio1)
199ATTR(gpio2)
200ATTR(gpio3)
201ATTR(gpio4)
202ATTR(gpio5)
203ATTR(gpio6)
204ATTR(gpio7)
205ATTR(timer)		/* TOYMATCH2-based wakeup enable */
206ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
207ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
208ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
209
210#define ATTR_LIST(x)	& x ## _attribute.attr
211static struct attribute *db1x_pmattrs[] = {
212	ATTR_LIST(gpio0),
213	ATTR_LIST(gpio1),
214	ATTR_LIST(gpio2),
215	ATTR_LIST(gpio3),
216	ATTR_LIST(gpio4),
217	ATTR_LIST(gpio5),
218	ATTR_LIST(gpio6),
219	ATTR_LIST(gpio7),
220	ATTR_LIST(timer),
221	ATTR_LIST(timer_timeout),
222	ATTR_LIST(wakesrc),
223	ATTR_LIST(wakemsk),
224	NULL,		/* terminator */
225};
226
227static struct attribute_group db1x_pmattr_group = {
228	.name	= "db1x",
229	.attrs	= db1x_pmattrs,
230};
231
232/*
233 * Initialize suspend interface
234 */
235static int __init pm_init(void)
236{
237	/* init TOY to tick at 1Hz if not already done. No need to wait
238	 * for confirmation since there's plenty of time from here to
239	 * the next suspend cycle.
240	 */
241	if (alchemy_rdsys(AU1000_SYS_TOYTRIM) != 32767)
242		alchemy_wrsys(32767, AU1000_SYS_TOYTRIM);
243
244	db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);
245
246	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
247	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
248
249	suspend_set_ops(&db1x_pm_ops);
250
251	return sysfs_create_group(power_kobj, &db1x_pmattr_group);
252}
253
254late_initcall(pm_init);