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pm.c
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1 /*
2  * Alchemy Development Board example suspend userspace interface.
3  *
4  * (c) 2008 Manuel Lauss <[email protected]>
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);
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