arch/mips/alchemy/devboards/pm.c

   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
  13 /*
  14  * Generic suspend userspace interface for Alchemy development boards.
  15  * This code exports a few sysfs nodes under /sys/power/db1x/ which
  16  * can be used by userspace to en/disable all au1x-provided wakeup
  17  * sources and configure the timeout after which the the TOYMATCH2 irq
  18  * is to trigger a wakeup.
  19  */
  20
  21
  22 static unsigned long db1x_pm_sleep_secs;
  23 static unsigned long db1x_pm_wakemsk;
  24 static unsigned long db1x_pm_last_wakesrc;
  25
  26 static int db1x_pm_enter(suspend_state_t state)
  27 {
  28         /* enable GPIO based wakeup */
  29         au_writel(1, SYS_PININPUTEN);
  30
  31         /* clear and setup wake cause and source */
  32         au_writel(0, SYS_WAKEMSK);
  33         au_sync();
  34         au_writel(0, SYS_WAKESRC);
  35         au_sync();
  36
  37         au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
  38         au_sync();
  39
  40         /* setup 1Hz-timer-based wakeup: wait for reg access */
  41         while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
  42                 asm volatile ("nop");
  43
  44         au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
  45         au_sync();
  46
  47         /* wait for value to really hit the register */
  48         while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
  49                 asm volatile ("nop");
  50
  51         /* ...and now the sandman can come! */
  52         au_sleep();
  53
  54         return 0;
  55 }
  56
  57 static int db1x_pm_begin(suspend_state_t state)
  58 {
  59         if (!db1x_pm_wakemsk) {
  60                 printk(KERN_ERR "db1x: no wakeup source activated!\n");
  61                 return -EINVAL;
  62         }
  63
  64         return 0;
  65 }
  66
  67 static void db1x_pm_end(void)
  68 {
  69         /* read and store wakeup source, the clear the register. To
  70          * be able to clear it, WAKEMSK must be cleared first.
  71          */
  72         db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
  73
  74         au_writel(0, SYS_WAKEMSK);
  75         au_writel(0, SYS_WAKESRC);
  76         au_sync();
  77
  78 }
  79
  80 static struct platform_suspend_ops db1x_pm_ops = {
  81         .valid          = suspend_valid_only_mem,
  82         .begin          = db1x_pm_begin,
  83         .enter          = db1x_pm_enter,
  84         .end            = db1x_pm_end,
  85 };
  86
  87 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
  88
  89 static ssize_t db1x_pmattr_show(struct kobject *kobj,
  90                                 struct kobj_attribute *attr,
  91                                 char *buf)
  92 {
  93         int idx;
  94
  95         if (ATTRCMP(timer_timeout))
  96                 return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
  97
  98         else if (ATTRCMP(timer))
  99                 return sprintf(buf, "%u\n",
 100                                 !!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
 101
 102         else if (ATTRCMP(wakesrc))
 103                 return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
 104
 105         else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
 106                  ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
 107                  ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
 108                 idx = (attr->attr.name)[4] - '0';
 109                 return sprintf(buf, "%d\n",
 110                         !!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
 111
 112         } else if (ATTRCMP(wakemsk)) {
 113                 return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
 114         }
 115
 116         return -ENOENT;
 117 }
 118
 119 static ssize_t db1x_pmattr_store(struct kobject *kobj,
 120                                  struct kobj_attribute *attr,
 121                                  const char *instr,
 122                                  size_t bytes)
 123 {
 124         unsigned long l;
 125         int tmp;
 126
 127         if (ATTRCMP(timer_timeout)) {
 128                 tmp = strict_strtoul(instr, 0, &l);
 129                 if (tmp)
 130                         return tmp;
 131
 132                 db1x_pm_sleep_secs = l;
 133
 134         } else if (ATTRCMP(timer)) {
 135                 if (instr[0] != '0')
 136                         db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
 137                 else
 138                         db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
 139
 140         } else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
 141                    ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
 142                    ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
 143                 tmp = (attr->attr.name)[4] - '0';
 144                 if (instr[0] != '0') {
 145                         db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
 146                 } else {
 147                         db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
 148                 }
 149
 150         } else if (ATTRCMP(wakemsk)) {
 151                 tmp = strict_strtoul(instr, 0, &l);
 152                 if (tmp)
 153                         return tmp;
 154
 155                 db1x_pm_wakemsk = l & 0x0000003f;
 156
 157         } else
 158                 bytes = -ENOENT;
 159
 160         return bytes;
 161 }
 162
 163 #define ATTR(x)                                                 \
 164         static struct kobj_attribute x##_attribute =            \
 165                 __ATTR(x, 0664, db1x_pmattr_show,               \
 166                                 db1x_pmattr_store);
 167
 168 ATTR(gpio0)             /* GPIO-based wakeup enable */
 169 ATTR(gpio1)
 170 ATTR(gpio2)
 171 ATTR(gpio3)
 172 ATTR(gpio4)
 173 ATTR(gpio5)
 174 ATTR(gpio6)
 175 ATTR(gpio7)
 176 ATTR(timer)             /* TOYMATCH2-based wakeup enable */
 177 ATTR(timer_timeout)     /* timer-based wakeup timeout value, in seconds */
 178 ATTR(wakesrc)           /* contents of SYS_WAKESRC after last wakeup */
 179 ATTR(wakemsk)           /* direct access to SYS_WAKEMSK */
 180
 181 #define ATTR_LIST(x)    & x ## _attribute.attr
 182 static struct attribute *db1x_pmattrs[] = {
 183         ATTR_LIST(gpio0),
 184         ATTR_LIST(gpio1),
 185         ATTR_LIST(gpio2),
 186         ATTR_LIST(gpio3),
 187         ATTR_LIST(gpio4),
 188         ATTR_LIST(gpio5),
 189         ATTR_LIST(gpio6),
 190         ATTR_LIST(gpio7),
 191         ATTR_LIST(timer),
 192         ATTR_LIST(timer_timeout),
 193         ATTR_LIST(wakesrc),
 194         ATTR_LIST(wakemsk),
 195         NULL,           /* terminator */
 196 };
 197
 198 static struct attribute_group db1x_pmattr_group = {
 199         .name   = "db1x",
 200         .attrs  = db1x_pmattrs,
 201 };
 202
 203 /*
 204  * Initialize suspend interface
 205  */
 206 static int __init pm_init(void)
 207 {
 208         /* init TOY to tick at 1Hz if not already done. No need to wait
 209          * for confirmation since there's plenty of time from here to
 210          * the next suspend cycle.
 211          */
 212         if (au_readl(SYS_TOYTRIM) != 32767) {
 213                 au_writel(32767, SYS_TOYTRIM);
 214                 au_sync();
 215         }
 216
 217         db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
 218
 219         au_writel(0, SYS_WAKESRC);
 220         au_sync();
 221         au_writel(0, SYS_WAKEMSK);
 222         au_sync();
 223
 224         suspend_set_ops(&db1x_pm_ops);
 225
 226         return sysfs_create_group(power_kobj, &db1x_pmattr_group);
 227 }
 228
 229 late_initcall(pm_init);