arch/mips/alchemy/devboards/pm.c

   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 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
  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
  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
  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
 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
 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  */
 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);