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 
25 static unsigned long db1x_pm_sleep_secs;
26 static unsigned long db1x_pm_wakemsk;
27 static unsigned long db1x_pm_last_wakesrc;
28 
db1x_pm_enter(suspend_state_t state)29 static 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 
db1x_pm_begin(suspend_state_t state)88 static 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 
db1x_pm_end(void)98 static 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 
109 static 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 
db1x_pmattr_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)118 static 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 
db1x_pmattr_store(struct kobject * kobj,struct kobj_attribute * attr,const char * instr,size_t bytes)148 static 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 
197 ATTR(gpio0)		/* GPIO-based wakeup enable */
198 ATTR(gpio1)
199 ATTR(gpio2)
200 ATTR(gpio3)
201 ATTR(gpio4)
202 ATTR(gpio5)
203 ATTR(gpio6)
204 ATTR(gpio7)
205 ATTR(timer)		/* TOYMATCH2-based wakeup enable */
206 ATTR(timer_timeout)	/* timer-based wakeup timeout value, in seconds */
207 ATTR(wakesrc)		/* contents of SYS_WAKESRC after last wakeup */
208 ATTR(wakemsk)		/* direct access to SYS_WAKEMSK */
209 
210 #define ATTR_LIST(x)	& x ## _attribute.attr
211 static 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 
227 static struct attribute_group db1x_pmattr_group = {
228 	.name	= "db1x",
229 	.attrs	= db1x_pmattrs,
230 };
231 
232 /*
233  * Initialize suspend interface
234  */
pm_init(void)235 static 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 
254 late_initcall(pm_init);
255