/*
   * 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 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!
  ");
  		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
  ", db1x_pm_sleep_secs);
  
  	else if (ATTRCMP(timer))
  		return sprintf(buf, "%u
  ",
  				!!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
  
  	else if (ATTRCMP(wakesrc))
  		return sprintf(buf, "%lu
  ", 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
  ",
  			!!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
  
  	} else if (ATTRCMP(wakemsk)) {
  		return sprintf(buf, "%08lx
  ", 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);