xref: /openbmc/linux/arch/mips/alchemy/devboards/pm.c (revision d0b73b48)
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 #include <asm/mach-db1x00/bcsr.h>
14 
15 /*
16  * Generic suspend userspace interface for Alchemy development boards.
17  * This code exports a few sysfs nodes under /sys/power/db1x/ which
18  * can be used by userspace to en/disable all au1x-provided wakeup
19  * sources and configure the timeout after which the the TOYMATCH2 irq
20  * is to trigger a wakeup.
21  */
22 
23 
24 static unsigned long db1x_pm_sleep_secs;
25 static unsigned long db1x_pm_wakemsk;
26 static unsigned long db1x_pm_last_wakesrc;
27 
28 static int db1x_pm_enter(suspend_state_t state)
29 {
30 	unsigned short bcsrs[16];
31 	int i, j, hasint;
32 
33 	/* save CPLD regs */
34 	hasint = bcsr_read(BCSR_WHOAMI);
35 	hasint = BCSR_WHOAMI_BOARD(hasint) >= BCSR_WHOAMI_DB1200;
36 	j = (hasint) ? BCSR_MASKSET : BCSR_SYSTEM;
37 
38 	for (i = BCSR_STATUS; i <= j; i++)
39 		bcsrs[i] = bcsr_read(i);
40 
41 	/* shut off hexleds */
42 	bcsr_write(BCSR_HEXCLEAR, 3);
43 
44 	/* enable GPIO based wakeup */
45 	alchemy_gpio1_input_enable();
46 
47 	/* clear and setup wake cause and source */
48 	au_writel(0, SYS_WAKEMSK);
49 	au_sync();
50 	au_writel(0, SYS_WAKESRC);
51 	au_sync();
52 
53 	au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
54 	au_sync();
55 
56 	/* setup 1Hz-timer-based wakeup: wait for reg access */
57 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
58 		asm volatile ("nop");
59 
60 	au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
61 	au_sync();
62 
63 	/* wait for value to really hit the register */
64 	while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
65 		asm volatile ("nop");
66 
67 	/* ...and now the sandman can come! */
68 	au_sleep();
69 
70 
71 	/* restore CPLD regs */
72 	for (i = BCSR_STATUS; i <= BCSR_SYSTEM; i++)
73 		bcsr_write(i, bcsrs[i]);
74 
75 	/* restore CPLD int registers */
76 	if (hasint) {
77 		bcsr_write(BCSR_INTCLR, 0xffff);
78 		bcsr_write(BCSR_MASKCLR, 0xffff);
79 		bcsr_write(BCSR_INTSTAT, 0xffff);
80 		bcsr_write(BCSR_INTSET, bcsrs[BCSR_INTSET]);
81 		bcsr_write(BCSR_MASKSET, bcsrs[BCSR_MASKSET]);
82 	}
83 
84 	/* light up hexleds */
85 	bcsr_write(BCSR_HEXCLEAR, 0);
86 
87 	return 0;
88 }
89 
90 static int db1x_pm_begin(suspend_state_t state)
91 {
92 	if (!db1x_pm_wakemsk) {
93 		printk(KERN_ERR "db1x: no wakeup source activated!\n");
94 		return -EINVAL;
95 	}
96 
97 	return 0;
98 }
99 
100 static void db1x_pm_end(void)
101 {
102 	/* read and store wakeup source, the clear the register. To
103 	 * be able to clear it, WAKEMSK must be cleared first.
104 	 */
105 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
106 
107 	au_writel(0, SYS_WAKEMSK);
108 	au_writel(0, SYS_WAKESRC);
109 	au_sync();
110 
111 }
112 
113 static const struct platform_suspend_ops db1x_pm_ops = {
114 	.valid		= suspend_valid_only_mem,
115 	.begin		= db1x_pm_begin,
116 	.enter		= db1x_pm_enter,
117 	.end		= db1x_pm_end,
118 };
119 
120 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
121 
122 static ssize_t db1x_pmattr_show(struct kobject *kobj,
123 				struct kobj_attribute *attr,
124 				char *buf)
125 {
126 	int idx;
127 
128 	if (ATTRCMP(timer_timeout))
129 		return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
130 
131 	else if (ATTRCMP(timer))
132 		return sprintf(buf, "%u\n",
133 				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
134 
135 	else if (ATTRCMP(wakesrc))
136 		return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
137 
138 	else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
139 		 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
140 		 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
141 		idx = (attr->attr.name)[4] - '0';
142 		return sprintf(buf, "%d\n",
143 			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
144 
145 	} else if (ATTRCMP(wakemsk)) {
146 		return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
147 	}
148 
149 	return -ENOENT;
150 }
151 
152 static ssize_t db1x_pmattr_store(struct kobject *kobj,
153 				 struct kobj_attribute *attr,
154 				 const char *instr,
155 				 size_t bytes)
156 {
157 	unsigned long l;
158 	int tmp;
159 
160 	if (ATTRCMP(timer_timeout)) {
161 		tmp = strict_strtoul(instr, 0, &l);
162 		if (tmp)
163 			return tmp;
164 
165 		db1x_pm_sleep_secs = l;
166 
167 	} else if (ATTRCMP(timer)) {
168 		if (instr[0] != '0')
169 			db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
170 		else
171 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
172 
173 	} else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
174 		   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
175 		   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
176 		tmp = (attr->attr.name)[4] - '0';
177 		if (instr[0] != '0') {
178 			db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
179 		} else {
180 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
181 		}
182 
183 	} else if (ATTRCMP(wakemsk)) {
184 		tmp = strict_strtoul(instr, 0, &l);
185 		if (tmp)
186 			return tmp;
187 
188 		db1x_pm_wakemsk = l & 0x0000003f;
189 
190 	} else
191 		bytes = -ENOENT;
192 
193 	return bytes;
194 }
195 
196 #define ATTR(x)							\
197 	static struct kobj_attribute x##_attribute = 		\
198 		__ATTR(x, 0664, db1x_pmattr_show,		\
199 				db1x_pmattr_store);
200 
201 ATTR(gpio0)		/* GPIO-based wakeup enable */
202 ATTR(gpio1)
203 ATTR(gpio2)
204 ATTR(gpio3)
205 ATTR(gpio4)
206 ATTR(gpio5)
207 ATTR(gpio6)
208 ATTR(gpio7)
209 ATTR(timer)		/* TOYMATCH2-based wakeup enable */
210 ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
211 ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
212 ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
213 
214 #define ATTR_LIST(x)	& x ## _attribute.attr
215 static struct attribute *db1x_pmattrs[] = {
216 	ATTR_LIST(gpio0),
217 	ATTR_LIST(gpio1),
218 	ATTR_LIST(gpio2),
219 	ATTR_LIST(gpio3),
220 	ATTR_LIST(gpio4),
221 	ATTR_LIST(gpio5),
222 	ATTR_LIST(gpio6),
223 	ATTR_LIST(gpio7),
224 	ATTR_LIST(timer),
225 	ATTR_LIST(timer_timeout),
226 	ATTR_LIST(wakesrc),
227 	ATTR_LIST(wakemsk),
228 	NULL,		/* terminator */
229 };
230 
231 static struct attribute_group db1x_pmattr_group = {
232 	.name	= "db1x",
233 	.attrs	= db1x_pmattrs,
234 };
235 
236 /*
237  * Initialize suspend interface
238  */
239 static int __init pm_init(void)
240 {
241 	/* init TOY to tick at 1Hz if not already done. No need to wait
242 	 * for confirmation since there's plenty of time from here to
243 	 * the next suspend cycle.
244 	 */
245 	if (au_readl(SYS_TOYTRIM) != 32767) {
246 		au_writel(32767, SYS_TOYTRIM);
247 		au_sync();
248 	}
249 
250 	db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
251 
252 	au_writel(0, SYS_WAKESRC);
253 	au_sync();
254 	au_writel(0, SYS_WAKEMSK);
255 	au_sync();
256 
257 	suspend_set_ops(&db1x_pm_ops);
258 
259 	return sysfs_create_group(power_kobj, &db1x_pmattr_group);
260 }
261 
262 late_initcall(pm_init);
263