xref: /openbmc/linux/arch/mips/alchemy/devboards/pm.c (revision 9cfc5c90)
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-au1000.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 	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
49 	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
50 
51 	alchemy_wrsys(db1x_pm_wakemsk, AU1000_SYS_WAKEMSK);
52 
53 	/* setup 1Hz-timer-based wakeup: wait for reg access */
54 	while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
55 		asm volatile ("nop");
56 
57 	alchemy_wrsys(alchemy_rdsys(AU1000_SYS_TOYREAD) + db1x_pm_sleep_secs,
58 		      AU1000_SYS_TOYMATCH2);
59 
60 	/* wait for value to really hit the register */
61 	while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
62 		asm volatile ("nop");
63 
64 	/* ...and now the sandman can come! */
65 	au_sleep();
66 
67 
68 	/* restore CPLD regs */
69 	for (i = BCSR_STATUS; i <= BCSR_SYSTEM; i++)
70 		bcsr_write(i, bcsrs[i]);
71 
72 	/* restore CPLD int registers */
73 	if (hasint) {
74 		bcsr_write(BCSR_INTCLR, 0xffff);
75 		bcsr_write(BCSR_MASKCLR, 0xffff);
76 		bcsr_write(BCSR_INTSTAT, 0xffff);
77 		bcsr_write(BCSR_INTSET, bcsrs[BCSR_INTSET]);
78 		bcsr_write(BCSR_MASKSET, bcsrs[BCSR_MASKSET]);
79 	}
80 
81 	/* light up hexleds */
82 	bcsr_write(BCSR_HEXCLEAR, 0);
83 
84 	return 0;
85 }
86 
87 static int db1x_pm_begin(suspend_state_t state)
88 {
89 	if (!db1x_pm_wakemsk) {
90 		printk(KERN_ERR "db1x: no wakeup source activated!\n");
91 		return -EINVAL;
92 	}
93 
94 	return 0;
95 }
96 
97 static void db1x_pm_end(void)
98 {
99 	/* read and store wakeup source, the clear the register. To
100 	 * be able to clear it, WAKEMSK must be cleared first.
101 	 */
102 	db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);
103 
104 	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
105 	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
106 }
107 
108 static const struct platform_suspend_ops db1x_pm_ops = {
109 	.valid		= suspend_valid_only_mem,
110 	.begin		= db1x_pm_begin,
111 	.enter		= db1x_pm_enter,
112 	.end		= db1x_pm_end,
113 };
114 
115 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
116 
117 static ssize_t db1x_pmattr_show(struct kobject *kobj,
118 				struct kobj_attribute *attr,
119 				char *buf)
120 {
121 	int idx;
122 
123 	if (ATTRCMP(timer_timeout))
124 		return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
125 
126 	else if (ATTRCMP(timer))
127 		return sprintf(buf, "%u\n",
128 				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
129 
130 	else if (ATTRCMP(wakesrc))
131 		return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
132 
133 	else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
134 		 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
135 		 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
136 		idx = (attr->attr.name)[4] - '0';
137 		return sprintf(buf, "%d\n",
138 			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
139 
140 	} else if (ATTRCMP(wakemsk)) {
141 		return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
142 	}
143 
144 	return -ENOENT;
145 }
146 
147 static ssize_t db1x_pmattr_store(struct kobject *kobj,
148 				 struct kobj_attribute *attr,
149 				 const char *instr,
150 				 size_t bytes)
151 {
152 	unsigned long l;
153 	int tmp;
154 
155 	if (ATTRCMP(timer_timeout)) {
156 		tmp = kstrtoul(instr, 0, &l);
157 		if (tmp)
158 			return tmp;
159 
160 		db1x_pm_sleep_secs = l;
161 
162 	} else if (ATTRCMP(timer)) {
163 		if (instr[0] != '0')
164 			db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
165 		else
166 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
167 
168 	} else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
169 		   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
170 		   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
171 		tmp = (attr->attr.name)[4] - '0';
172 		if (instr[0] != '0') {
173 			db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
174 		} else {
175 			db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
176 		}
177 
178 	} else if (ATTRCMP(wakemsk)) {
179 		tmp = kstrtoul(instr, 0, &l);
180 		if (tmp)
181 			return tmp;
182 
183 		db1x_pm_wakemsk = l & 0x0000003f;
184 
185 	} else
186 		bytes = -ENOENT;
187 
188 	return bytes;
189 }
190 
191 #define ATTR(x)							\
192 	static struct kobj_attribute x##_attribute =		\
193 		__ATTR(x, 0664, db1x_pmattr_show,		\
194 				db1x_pmattr_store);
195 
196 ATTR(gpio0)		/* GPIO-based wakeup enable */
197 ATTR(gpio1)
198 ATTR(gpio2)
199 ATTR(gpio3)
200 ATTR(gpio4)
201 ATTR(gpio5)
202 ATTR(gpio6)
203 ATTR(gpio7)
204 ATTR(timer)		/* TOYMATCH2-based wakeup enable */
205 ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
206 ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
207 ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
208 
209 #define ATTR_LIST(x)	& x ## _attribute.attr
210 static struct attribute *db1x_pmattrs[] = {
211 	ATTR_LIST(gpio0),
212 	ATTR_LIST(gpio1),
213 	ATTR_LIST(gpio2),
214 	ATTR_LIST(gpio3),
215 	ATTR_LIST(gpio4),
216 	ATTR_LIST(gpio5),
217 	ATTR_LIST(gpio6),
218 	ATTR_LIST(gpio7),
219 	ATTR_LIST(timer),
220 	ATTR_LIST(timer_timeout),
221 	ATTR_LIST(wakesrc),
222 	ATTR_LIST(wakemsk),
223 	NULL,		/* terminator */
224 };
225 
226 static struct attribute_group db1x_pmattr_group = {
227 	.name	= "db1x",
228 	.attrs	= db1x_pmattrs,
229 };
230 
231 /*
232  * Initialize suspend interface
233  */
234 static int __init pm_init(void)
235 {
236 	/* init TOY to tick at 1Hz if not already done. No need to wait
237 	 * for confirmation since there's plenty of time from here to
238 	 * the next suspend cycle.
239 	 */
240 	if (alchemy_rdsys(AU1000_SYS_TOYTRIM) != 32767)
241 		alchemy_wrsys(32767, AU1000_SYS_TOYTRIM);
242 
243 	db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);
244 
245 	alchemy_wrsys(0, AU1000_SYS_WAKESRC);
246 	alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
247 
248 	suspend_set_ops(&db1x_pm_ops);
249 
250 	return sysfs_create_group(power_kobj, &db1x_pmattr_group);
251 }
252 
253 late_initcall(pm_init);
254