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 #include <asm/mach-au1x00/gpio.h>
  13
  14 /*
  15  * Generic suspend userspace interface for Alchemy development boards.
  16  * This code exports a few sysfs nodes under /sys/power/db1x/ which
  17  * can be used by userspace to en/disable all au1x-provided wakeup
  18  * sources and configure the timeout after which the the TOYMATCH2 irq
  19  * is to trigger a wakeup.
  20  */
  21
  22
  23 static unsigned long db1x_pm_sleep_secs;
  24 static unsigned long db1x_pm_wakemsk;
  25 static unsigned long db1x_pm_last_wakesrc;
  26
  27 static int db1x_pm_enter(suspend_state_t state)
  28 {
  29         /* enable GPIO based wakeup */
  30         alchemy_gpio1_input_enable();
  31
  32         /* clear and setup wake cause and source */
  33         au_writel(0, SYS_WAKEMSK);
  34         au_sync();
  35         au_writel(0, SYS_WAKESRC);
  36         au_sync();
  37
  38         au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
  39         au_sync();
  40
  41         /* setup 1Hz-timer-based wakeup: wait for reg access */
  42         while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
  43                 asm volatile ("nop");
  44
  45         au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
  46         au_sync();
  47
  48         /* wait for value to really hit the register */
  49         while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
  50                 asm volatile ("nop");
  51
  52         /* ...and now the sandman can come! */
  53         au_sleep();
  54
  55         return 0;
  56 }
  57
  58 static int db1x_pm_begin(suspend_state_t state)
  59 {
  60         if (!db1x_pm_wakemsk) {
  61                 printk(KERN_ERR "db1x: no wakeup source activated!\n");
  62                 return -EINVAL;
  63         }
  64
  65         return 0;
  66 }
  67
  68 static void db1x_pm_end(void)
  69 {
  70         /* read and store wakeup source, the clear the register. To
  71          * be able to clear it, WAKEMSK must be cleared first.
  72          */
  73         db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
  74
  75         au_writel(0, SYS_WAKEMSK);
  76         au_writel(0, SYS_WAKESRC);
  77         au_sync();
  78
  79 }
  80
  81 static struct platform_suspend_ops db1x_pm_ops = {
  82         .valid          = suspend_valid_only_mem,
  83         .begin          = db1x_pm_begin,
  84         .enter          = db1x_pm_enter,
  85         .end            = db1x_pm_end,
  86 };
  87
  88 #define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
  89
  90 static ssize_t db1x_pmattr_show(struct kobject *kobj,
  91                                 struct kobj_attribute *attr,
  92                                 char *buf)
  93 {
  94         int idx;
  95
  96         if (ATTRCMP(timer_timeout))
  97                 return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
  98
  99         else if (ATTRCMP(timer))
 100                 return sprintf(buf, "%u\n",
 101                                 !!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
 102
 103         else if (ATTRCMP(wakesrc))
 104                 return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
 105
 106         else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
 107                  ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
 108                  ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
 109                 idx = (attr->attr.name)[4] - '0';
 110                 return sprintf(buf, "%d\n",
 111                         !!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
 112
 113         } else if (ATTRCMP(wakemsk)) {
 114                 return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
 115         }
 116
 117         return -ENOENT;
 118 }
 119
 120 static ssize_t db1x_pmattr_store(struct kobject *kobj,
 121                                  struct kobj_attribute *attr,
 122                                  const char *instr,
 123                                  size_t bytes)
 124 {
 125         unsigned long l;
 126         int tmp;
 127
 128         if (ATTRCMP(timer_timeout)) {
 129                 tmp = strict_strtoul(instr, 0, &l);
 130                 if (tmp)
 131                         return tmp;
 132
 133                 db1x_pm_sleep_secs = l;
 134
 135         } else if (ATTRCMP(timer)) {
 136                 if (instr[0] != '0')
 137                         db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
 138                 else
 139                         db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
 140
 141         } else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
 142                    ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
 143                    ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
 144                 tmp = (attr->attr.name)[4] - '0';
 145                 if (instr[0] != '0') {
 146                         db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
 147                 } else {
 148                         db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
 149                 }
 150
 151         } else if (ATTRCMP(wakemsk)) {
 152                 tmp = strict_strtoul(instr, 0, &l);
 153                 if (tmp)
 154                         return tmp;
 155
 156                 db1x_pm_wakemsk = l & 0x0000003f;
 157
 158         } else
 159                 bytes = -ENOENT;
 160
 161         return bytes;
 162 }
 163
 164 #define ATTR(x)                                                 \
 165         static struct kobj_attribute x##_attribute =            \
 166                 __ATTR(x, 0664, db1x_pmattr_show,               \
 167                                 db1x_pmattr_store);
 168
 169 ATTR(gpio0)             /* GPIO-based wakeup enable */
 170 ATTR(gpio1)
 171 ATTR(gpio2)
 172 ATTR(gpio3)
 173 ATTR(gpio4)
 174 ATTR(gpio5)
 175 ATTR(gpio6)
 176 ATTR(gpio7)
 177 ATTR(timer)             /* TOYMATCH2-based wakeup enable */
 178 ATTR(timer_timeout)     /* timer-based wakeup timeout value, in seconds */
 179 ATTR(wakesrc)           /* contents of SYS_WAKESRC after last wakeup */
 180 ATTR(wakemsk)           /* direct access to SYS_WAKEMSK */
 181
 182 #define ATTR_LIST(x)    & x ## _attribute.attr
 183 static struct attribute *db1x_pmattrs[] = {
 184         ATTR_LIST(gpio0),
 185         ATTR_LIST(gpio1),
 186         ATTR_LIST(gpio2),
 187         ATTR_LIST(gpio3),
 188         ATTR_LIST(gpio4),
 189         ATTR_LIST(gpio5),
 190         ATTR_LIST(gpio6),
 191         ATTR_LIST(gpio7),
 192         ATTR_LIST(timer),
 193         ATTR_LIST(timer_timeout),
 194         ATTR_LIST(wakesrc),
 195         ATTR_LIST(wakemsk),
 196         NULL,           /* terminator */
 197 };
 198
 199 static struct attribute_group db1x_pmattr_group = {
 200         .name   = "db1x",
 201         .attrs  = db1x_pmattrs,
 202 };
 203
 204 /*
 205  * Initialize suspend interface
 206  */
 207 static int __init pm_init(void)
 208 {
 209         /* init TOY to tick at 1Hz if not already done. No need to wait
 210          * for confirmation since there's plenty of time from here to
 211          * the next suspend cycle.
 212          */
 213         if (au_readl(SYS_TOYTRIM) != 32767) {
 214                 au_writel(32767, SYS_TOYTRIM);
 215                 au_sync();
 216         }
 217
 218         db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
 219
 220         au_writel(0, SYS_WAKESRC);
 221         au_sync();
 222         au_writel(0, SYS_WAKEMSK);
 223         au_sync();
 224
 225         suspend_set_ops(&db1x_pm_ops);
 226
 227         return sysfs_create_group(power_kobj, &db1x_pmattr_group);
 228 }
 229
 230 late_initcall(pm_init);