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
25static unsigned long db1x_pm_sleep_secs;
26static unsigned long db1x_pm_wakemsk;
27static unsigned long db1x_pm_last_wakesrc;
28
29static 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
88static 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
98static 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
109static 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
118static 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, fmt: "%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, fmt: "%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, fmt: "%d\n",
139 !!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
140
141 } else if (ATTRCMP(wakemsk)) {
142 return sprintf(buf, fmt: "%08lx\n", db1x_pm_wakemsk);
143 }
144
145 return -ENOENT;
146}
147
148static 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(s: instr, base: 0, res: &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(s: instr, base: 0, res: &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
197ATTR(gpio0) /* GPIO-based wakeup enable */
198ATTR(gpio1)
199ATTR(gpio2)
200ATTR(gpio3)
201ATTR(gpio4)
202ATTR(gpio5)
203ATTR(gpio6)
204ATTR(gpio7)
205ATTR(timer) /* TOYMATCH2-based wakeup enable */
206ATTR(timer_timeout) /* timer-based wakeup timeout value, in seconds */
207ATTR(wakesrc) /* contents of SYS_WAKESRC after last wakeup */
208ATTR(wakemsk) /* direct access to SYS_WAKEMSK */
209
210#define ATTR_LIST(x) & x ## _attribute.attr
211static 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
227static struct attribute_group db1x_pmattr_group = {
228 .name = "db1x",
229 .attrs = db1x_pmattrs,
230};
231
232/*
233 * Initialize suspend interface
234 */
235static 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(ops: &db1x_pm_ops);
250
251 return sysfs_create_group(kobj: power_kobj, grp: &db1x_pmattr_group);
252}
253
254late_initcall(pm_init);
255

source code of linux/arch/mips/alchemy/devboards/pm.c