LXR linux/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
  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, "%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
 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(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
 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(&db1x_pm_ops);
 250
 251        return sysfs_create_group(power_kobj, &db1x_pmattr_group);
 252}
 253
 254late_initcall(pm_init);
 255