// SPDX-License-Identifier: GPL-2.0
/*
 * Alchemy Development Board example suspend userspace interface.
 *
 * (c) 2008 Manuel Lauss <mano@roarinelk.homelinux.net>
 */

#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/suspend.h>
#include <linux/sysfs.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/gpio-au1000.h>
#include <asm/mach-db1x00/bcsr.h>

/*
 * Generic suspend userspace interface for Alchemy development boards.
 * This code exports a few sysfs nodes under /sys/power/db1x/ which
 * can be used by userspace to en/disable all au1x-provided wakeup
 * sources and configure the timeout after which the TOYMATCH2 irq
 * is to trigger a wakeup.
 */


static unsigned long db1x_pm_sleep_secs;
static unsigned long db1x_pm_wakemsk;
static unsigned long db1x_pm_last_wakesrc;

static int db1x_pm_enter(suspend_state_t state)
{
        unsigned short bcsrs[16];
        int i, j, hasint;

        /* save CPLD regs */
        hasint = bcsr_read(BCSR_WHOAMI);
        hasint = BCSR_WHOAMI_BOARD(hasint) >= BCSR_WHOAMI_DB1200;
        j = (hasint) ? BCSR_MASKSET : BCSR_SYSTEM;

        for (i = BCSR_STATUS; i <= j; i++)
                bcsrs[i] = bcsr_read(i);

        /* shut off hexleds */
        bcsr_write(BCSR_HEXCLEAR, 3);

        /* enable GPIO based wakeup */
        alchemy_gpio1_input_enable();

        /* clear and setup wake cause and source */
        alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
        alchemy_wrsys(0, AU1000_SYS_WAKESRC);

        alchemy_wrsys(db1x_pm_wakemsk, AU1000_SYS_WAKEMSK);

        /* setup 1Hz-timer-based wakeup: wait for reg access */
        while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
                asm volatile ("nop");

        alchemy_wrsys(alchemy_rdsys(AU1000_SYS_TOYREAD) + db1x_pm_sleep_secs,
                      AU1000_SYS_TOYMATCH2);

        /* wait for value to really hit the register */
        while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M20)
                asm volatile ("nop");

        /* ...and now the sandman can come! */
        au_sleep();


        /* restore CPLD regs */
        for (i = BCSR_STATUS; i <= BCSR_SYSTEM; i++)
                bcsr_write(i, bcsrs[i]);

        /* restore CPLD int registers */
        if (hasint) {
                bcsr_write(BCSR_INTCLR, 0xffff);
                bcsr_write(BCSR_MASKCLR, 0xffff);
                bcsr_write(BCSR_INTSTAT, 0xffff);
                bcsr_write(BCSR_INTSET, bcsrs[BCSR_INTSET]);
                bcsr_write(BCSR_MASKSET, bcsrs[BCSR_MASKSET]);
        }

        /* light up hexleds */
        bcsr_write(BCSR_HEXCLEAR, 0);

        return 0;
}

static int db1x_pm_begin(suspend_state_t state)
{
        if (!db1x_pm_wakemsk) {
                printk(KERN_ERR "db1x: no wakeup source activated!\n");
                return -EINVAL;
        }

        return 0;
}

static void db1x_pm_end(void)
{
        /* read and store wakeup source, the clear the register. To
         * be able to clear it, WAKEMSK must be cleared first.
         */
        db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);

        alchemy_wrsys(0, AU1000_SYS_WAKEMSK);
        alchemy_wrsys(0, AU1000_SYS_WAKESRC);
}

static const struct platform_suspend_ops db1x_pm_ops = {
        .valid          = suspend_valid_only_mem,
        .begin          = db1x_pm_begin,
        .enter          = db1x_pm_enter,
        .end            = db1x_pm_end,
};

#define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))

static ssize_t db1x_pmattr_show(struct kobject *kobj,
                                struct kobj_attribute *attr,
                                char *buf)
{
        int idx;

        if (ATTRCMP(timer_timeout))
                return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);

        else if (ATTRCMP(timer))
                return sprintf(buf, "%u\n",
                                !!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));

        else if (ATTRCMP(wakesrc))
                return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);

        else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
                 ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
                 ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
                idx = (attr->attr.name)[4] - '0';
                return sprintf(buf, "%d\n",
                        !!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));

        } else if (ATTRCMP(wakemsk)) {
                return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
        }

        return -ENOENT;
}

static ssize_t db1x_pmattr_store(struct kobject *kobj,
                                 struct kobj_attribute *attr,
                                 const char *instr,
                                 size_t bytes)
{
        unsigned long l;
        int tmp;

        if (ATTRCMP(timer_timeout)) {
                tmp = kstrtoul(instr, 0, &l);
                if (tmp)
                        return tmp;

                db1x_pm_sleep_secs = l;

        } else if (ATTRCMP(timer)) {
                if (instr[0] != '0')
                        db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
                else
                        db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;

        } else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
                   ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
                   ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
                tmp = (attr->attr.name)[4] - '0';
                if (instr[0] != '0') {
                        db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
                } else {
                        db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
                }

        } else if (ATTRCMP(wakemsk)) {
                tmp = kstrtoul(instr, 0, &l);
                if (tmp)
                        return tmp;

                db1x_pm_wakemsk = l & 0x0000003f;

        } else
                bytes = -ENOENT;

        return bytes;
}

#define ATTR(x)                                                 \
        static struct kobj_attribute x##_attribute =            \
                __ATTR(x, 0664, db1x_pmattr_show,               \
                                db1x_pmattr_store);

ATTR(gpio0)             /* GPIO-based wakeup enable */
ATTR(gpio1)
ATTR(gpio2)
ATTR(gpio3)
ATTR(gpio4)
ATTR(gpio5)
ATTR(gpio6)
ATTR(gpio7)
ATTR(timer)             /* TOYMATCH2-based wakeup enable */
ATTR(timer_timeout)     /* timer-based wakeup timeout value, in seconds */
ATTR(wakesrc)           /* contents of SYS_WAKESRC after last wakeup */
ATTR(wakemsk)           /* direct access to SYS_WAKEMSK */

#define ATTR_LIST(x)    & x ## _attribute.attr
static struct attribute *db1x_pmattrs[] = {
        ATTR_LIST(gpio0),
        ATTR_LIST(gpio1),
        ATTR_LIST(gpio2),
        ATTR_LIST(gpio3),
        ATTR_LIST(gpio4),
        ATTR_LIST(gpio5),
        ATTR_LIST(gpio6),
        ATTR_LIST(gpio7),
        ATTR_LIST(timer),
        ATTR_LIST(timer_timeout),
        ATTR_LIST(wakesrc),
        ATTR_LIST(wakemsk),
        NULL,           /* terminator */
};

static struct attribute_group db1x_pmattr_group = {
        .name   = "db1x",
        .attrs  = db1x_pmattrs,
};

/*
 * Initialize suspend interface
 */
static int __init pm_init(void)
{
        /* init TOY to tick at 1Hz if not already done. No need to wait
         * for confirmation since there's plenty of time from here to
         * the next suspend cycle.
         */
        if (alchemy_rdsys(AU1000_SYS_TOYTRIM) != 32767)
                alchemy_wrsys(32767, AU1000_SYS_TOYTRIM);

        db1x_pm_last_wakesrc = alchemy_rdsys(AU1000_SYS_WAKESRC);

        alchemy_wrsys(0, AU1000_SYS_WAKESRC);
        alchemy_wrsys(0, AU1000_SYS_WAKEMSK);

        suspend_set_ops(&db1x_pm_ops);

        return sysfs_create_group(power_kobj, &db1x_pmattr_group);
}

late_initcall(pm_init);