xref: /openbmc/linux/arch/mips/alchemy/devboards/pm.c (revision 82ced6fd)
1 /*
2  * Alchemy Development Board example suspend userspace interface.
3  *
4  * (c) 2008 Manuel Lauss <mano@roarinelk.homelinux.net>
5  */
6 
7 #include <linux/init.h>
8 #include <linux/kobject.h>
9 #include <linux/suspend.h>
10 #include <linux/sysfs.h>
11 #include <asm/mach-au1x00/au1000.h>
12 
13 /*
14  * Generic suspend userspace interface for Alchemy development boards.
15  * This code exports a few sysfs nodes under /sys/power/db1x/ which
16  * can be used by userspace to en/disable all au1x-provided wakeup
17  * sources and configure the timeout after which the the TOYMATCH2 irq
18  * is to trigger a wakeup.
19  */
20 
21 
22 static unsigned long db1x_pm_sleep_secs;
23 static unsigned long db1x_pm_wakemsk;
24 static unsigned long db1x_pm_last_wakesrc;
25 
26 static int db1x_pm_enter(suspend_state_t state)
27 {
28 	/* enable GPIO based wakeup */
29 	au_writel(1, SYS_PININPUTEN);
30 
31 	/* clear and setup wake cause and source */
32 	au_writel(0, SYS_WAKEMSK);
33 	au_sync();
34 	au_writel(0, SYS_WAKESRC);
35 	au_sync();
36 
37 	au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
38 	au_sync();
39 
40 	/* setup 1Hz-timer-based wakeup: wait for reg access */
41 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
42 		asm volatile ("nop");
43 
44 	au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
45 	au_sync();
46 
47 	/* wait for value to really hit the register */
48 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
49 		asm volatile ("nop");
50 
51 	/* ...and now the sandman can come! */
52 	au_sleep();
53 
54 	return 0;
55 }
56 
57 static int db1x_pm_begin(suspend_state_t state)
58 {
59 	if (!db1x_pm_wakemsk) {
60 		printk(KERN_ERR "db1x: no wakeup source activated!\n");
61 		return -EINVAL;
62 	}
63 
64 	return 0;
65 }
66 
67 static void db1x_pm_end(void)
68 {
69 	/* read and store wakeup source, the clear the register. To
70 	 * be able to clear it, WAKEMSK must be cleared first.
71 	 */
72 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
73 
74 	au_writel(0, SYS_WAKEMSK);
75 	au_writel(0, SYS_WAKESRC);
76 	au_sync();
77 
78 }
79 
80 static struct platform_suspend_ops db1x_pm_ops = {
81 	.valid		= suspend_valid_only_mem,
82 	.begin		= db1x_pm_begin,
83 	.enter		= db1x_pm_enter,
84 	.end		= db1x_pm_end,
85 };
86 
87 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
88 
89 static ssize_t db1x_pmattr_show(struct kobject *kobj,
90 				struct kobj_attribute *attr,
91 				char *buf)
92 {
93 	int idx;
94 
95 	if (ATTRCMP(timer_timeout))
96 		return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
97 
98 	else if (ATTRCMP(timer))
99 		return sprintf(buf, "%u\n",
100 				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
101 
102 	else if (ATTRCMP(wakesrc))
103 		return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
104 
105 	else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
106 		 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
107 		 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
108 		idx = (attr->attr.name)[4] - '0';
109 		return sprintf(buf, "%d\n",
110 			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
111 
112 	} else if (ATTRCMP(wakemsk)) {
113 		return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
114 	}
115 
116 	return -ENOENT;
117 }
118 
119 static ssize_t db1x_pmattr_store(struct kobject *kobj,
120 				 struct kobj_attribute *attr,
121 				 const char *instr,
122 				 size_t bytes)
123 {
124 	unsigned long l;
125 	int tmp;
126 
127 	if (ATTRCMP(timer_timeout)) {
128 		tmp = strict_strtoul(instr, 0, &l);
129 		if (tmp)
130 			return tmp;
131 
132 		db1x_pm_sleep_secs = l;
133 
134 	} else if (ATTRCMP(timer)) {
135 		if (instr[0] != '0')
136 			db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
137 		else
138 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
139 
140 	} else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
141 		   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
142 		   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
143 		tmp = (attr->attr.name)[4] - '0';
144 		if (instr[0] != '0') {
145 			db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
146 		} else {
147 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
148 		}
149 
150 	} else if (ATTRCMP(wakemsk)) {
151 		tmp = strict_strtoul(instr, 0, &l);
152 		if (tmp)
153 			return tmp;
154 
155 		db1x_pm_wakemsk = l & 0x0000003f;
156 
157 	} else
158 		bytes = -ENOENT;
159 
160 	return bytes;
161 }
162 
163 #define ATTR(x)							\
164 	static struct kobj_attribute x##_attribute = 		\
165 		__ATTR(x, 0664, db1x_pmattr_show,		\
166 				db1x_pmattr_store);
167 
168 ATTR(gpio0)		/* GPIO-based wakeup enable */
169 ATTR(gpio1)
170 ATTR(gpio2)
171 ATTR(gpio3)
172 ATTR(gpio4)
173 ATTR(gpio5)
174 ATTR(gpio6)
175 ATTR(gpio7)
176 ATTR(timer)		/* TOYMATCH2-based wakeup enable */
177 ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
178 ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
179 ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
180 
181 #define ATTR_LIST(x)	& x ## _attribute.attr
182 static struct attribute *db1x_pmattrs[] = {
183 	ATTR_LIST(gpio0),
184 	ATTR_LIST(gpio1),
185 	ATTR_LIST(gpio2),
186 	ATTR_LIST(gpio3),
187 	ATTR_LIST(gpio4),
188 	ATTR_LIST(gpio5),
189 	ATTR_LIST(gpio6),
190 	ATTR_LIST(gpio7),
191 	ATTR_LIST(timer),
192 	ATTR_LIST(timer_timeout),
193 	ATTR_LIST(wakesrc),
194 	ATTR_LIST(wakemsk),
195 	NULL,		/* terminator */
196 };
197 
198 static struct attribute_group db1x_pmattr_group = {
199 	.name	= "db1x",
200 	.attrs	= db1x_pmattrs,
201 };
202 
203 /*
204  * Initialize suspend interface
205  */
206 static int __init pm_init(void)
207 {
208 	/* init TOY to tick at 1Hz if not already done. No need to wait
209 	 * for confirmation since there's plenty of time from here to
210 	 * the next suspend cycle.
211 	 */
212 	if (au_readl(SYS_TOYTRIM) != 32767) {
213 		au_writel(32767, SYS_TOYTRIM);
214 		au_sync();
215 	}
216 
217 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
218 
219 	au_writel(0, SYS_WAKESRC);
220 	au_sync();
221 	au_writel(0, SYS_WAKEMSK);
222 	au_sync();
223 
224 	suspend_set_ops(&db1x_pm_ops);
225 
226 	return sysfs_create_group(power_kobj, &db1x_pmattr_group);
227 }
228 
229 late_initcall(pm_init);
230