xref: /openbmc/linux/arch/mips/alchemy/devboards/pm.c (revision 7dd65feb)
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 #include <asm/mach-au1x00/gpio.h>
13 
14 /*
15  * Generic suspend userspace interface for Alchemy development boards.
16  * This code exports a few sysfs nodes under /sys/power/db1x/ which
17  * can be used by userspace to en/disable all au1x-provided wakeup
18  * sources and configure the timeout after which the the TOYMATCH2 irq
19  * is to trigger a wakeup.
20  */
21 
22 
23 static unsigned long db1x_pm_sleep_secs;
24 static unsigned long db1x_pm_wakemsk;
25 static unsigned long db1x_pm_last_wakesrc;
26 
27 static int db1x_pm_enter(suspend_state_t state)
28 {
29 	/* enable GPIO based wakeup */
30 	alchemy_gpio1_input_enable();
31 
32 	/* clear and setup wake cause and source */
33 	au_writel(0, SYS_WAKEMSK);
34 	au_sync();
35 	au_writel(0, SYS_WAKESRC);
36 	au_sync();
37 
38 	au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
39 	au_sync();
40 
41 	/* setup 1Hz-timer-based wakeup: wait for reg access */
42 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
43 		asm volatile ("nop");
44 
45 	au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
46 	au_sync();
47 
48 	/* wait for value to really hit the register */
49 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
50 		asm volatile ("nop");
51 
52 	/* ...and now the sandman can come! */
53 	au_sleep();
54 
55 	return 0;
56 }
57 
58 static int db1x_pm_begin(suspend_state_t state)
59 {
60 	if (!db1x_pm_wakemsk) {
61 		printk(KERN_ERR "db1x: no wakeup source activated!\n");
62 		return -EINVAL;
63 	}
64 
65 	return 0;
66 }
67 
68 static void db1x_pm_end(void)
69 {
70 	/* read and store wakeup source, the clear the register. To
71 	 * be able to clear it, WAKEMSK must be cleared first.
72 	 */
73 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
74 
75 	au_writel(0, SYS_WAKEMSK);
76 	au_writel(0, SYS_WAKESRC);
77 	au_sync();
78 
79 }
80 
81 static struct platform_suspend_ops db1x_pm_ops = {
82 	.valid		= suspend_valid_only_mem,
83 	.begin		= db1x_pm_begin,
84 	.enter		= db1x_pm_enter,
85 	.end		= db1x_pm_end,
86 };
87 
88 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
89 
90 static ssize_t db1x_pmattr_show(struct kobject *kobj,
91 				struct kobj_attribute *attr,
92 				char *buf)
93 {
94 	int idx;
95 
96 	if (ATTRCMP(timer_timeout))
97 		return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
98 
99 	else if (ATTRCMP(timer))
100 		return sprintf(buf, "%u\n",
101 				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
102 
103 	else if (ATTRCMP(wakesrc))
104 		return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
105 
106 	else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
107 		 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
108 		 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
109 		idx = (attr->attr.name)[4] - '0';
110 		return sprintf(buf, "%d\n",
111 			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
112 
113 	} else if (ATTRCMP(wakemsk)) {
114 		return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
115 	}
116 
117 	return -ENOENT;
118 }
119 
120 static ssize_t db1x_pmattr_store(struct kobject *kobj,
121 				 struct kobj_attribute *attr,
122 				 const char *instr,
123 				 size_t bytes)
124 {
125 	unsigned long l;
126 	int tmp;
127 
128 	if (ATTRCMP(timer_timeout)) {
129 		tmp = strict_strtoul(instr, 0, &l);
130 		if (tmp)
131 			return tmp;
132 
133 		db1x_pm_sleep_secs = l;
134 
135 	} else if (ATTRCMP(timer)) {
136 		if (instr[0] != '0')
137 			db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
138 		else
139 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
140 
141 	} else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
142 		   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
143 		   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
144 		tmp = (attr->attr.name)[4] - '0';
145 		if (instr[0] != '0') {
146 			db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
147 		} else {
148 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
149 		}
150 
151 	} else if (ATTRCMP(wakemsk)) {
152 		tmp = strict_strtoul(instr, 0, &l);
153 		if (tmp)
154 			return tmp;
155 
156 		db1x_pm_wakemsk = l & 0x0000003f;
157 
158 	} else
159 		bytes = -ENOENT;
160 
161 	return bytes;
162 }
163 
164 #define ATTR(x)							\
165 	static struct kobj_attribute x##_attribute = 		\
166 		__ATTR(x, 0664, db1x_pmattr_show,		\
167 				db1x_pmattr_store);
168 
169 ATTR(gpio0)		/* GPIO-based wakeup enable */
170 ATTR(gpio1)
171 ATTR(gpio2)
172 ATTR(gpio3)
173 ATTR(gpio4)
174 ATTR(gpio5)
175 ATTR(gpio6)
176 ATTR(gpio7)
177 ATTR(timer)		/* TOYMATCH2-based wakeup enable */
178 ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
179 ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
180 ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
181 
182 #define ATTR_LIST(x)	& x ## _attribute.attr
183 static struct attribute *db1x_pmattrs[] = {
184 	ATTR_LIST(gpio0),
185 	ATTR_LIST(gpio1),
186 	ATTR_LIST(gpio2),
187 	ATTR_LIST(gpio3),
188 	ATTR_LIST(gpio4),
189 	ATTR_LIST(gpio5),
190 	ATTR_LIST(gpio6),
191 	ATTR_LIST(gpio7),
192 	ATTR_LIST(timer),
193 	ATTR_LIST(timer_timeout),
194 	ATTR_LIST(wakesrc),
195 	ATTR_LIST(wakemsk),
196 	NULL,		/* terminator */
197 };
198 
199 static struct attribute_group db1x_pmattr_group = {
200 	.name	= "db1x",
201 	.attrs	= db1x_pmattrs,
202 };
203 
204 /*
205  * Initialize suspend interface
206  */
207 static int __init pm_init(void)
208 {
209 	/* init TOY to tick at 1Hz if not already done. No need to wait
210 	 * for confirmation since there's plenty of time from here to
211 	 * the next suspend cycle.
212 	 */
213 	if (au_readl(SYS_TOYTRIM) != 32767) {
214 		au_writel(32767, SYS_TOYTRIM);
215 		au_sync();
216 	}
217 
218 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
219 
220 	au_writel(0, SYS_WAKESRC);
221 	au_sync();
222 	au_writel(0, SYS_WAKEMSK);
223 	au_sync();
224 
225 	suspend_set_ops(&db1x_pm_ops);
226 
227 	return sysfs_create_group(power_kobj, &db1x_pmattr_group);
228 }
229 
230 late_initcall(pm_init);
231