/* NXP PCF50633 Power Management Unit (PMU) driver
   *
   * (C) 2006-2008 by Openmoko, Inc.
   * Author: Harald Welte <laforge@openmoko.org>
   * 	   Balaji Rao <balajirrao@openmoko.org>
   * All rights reserved.
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   *
   */
  
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/mutex.h>
  #include <linux/export.h>
  #include <linux/slab.h>
  
  #include <linux/mfd/pcf50633/core.h>
  #include <linux/mfd/pcf50633/mbc.h>
  
  int pcf50633_register_irq(struct pcf50633 *pcf, int irq,
  			void (*handler) (int, void *), void *data)
  {
  	if (irq < 0 || irq >= PCF50633_NUM_IRQ || !handler)
  		return -EINVAL;
  
  	if (WARN_ON(pcf->irq_handler[irq].handler))
  		return -EBUSY;
  
  	mutex_lock(&pcf->lock);
  	pcf->irq_handler[irq].handler = handler;
  	pcf->irq_handler[irq].data = data;
  	mutex_unlock(&pcf->lock);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(pcf50633_register_irq);
  
  int pcf50633_free_irq(struct pcf50633 *pcf, int irq)
  {
  	if (irq < 0 || irq >= PCF50633_NUM_IRQ)
  		return -EINVAL;
  
  	mutex_lock(&pcf->lock);
  	pcf->irq_handler[irq].handler = NULL;
  	mutex_unlock(&pcf->lock);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(pcf50633_free_irq);
  
  static int __pcf50633_irq_mask_set(struct pcf50633 *pcf, int irq, u8 mask)
  {
  	u8 reg, bit;
  	int ret = 0, idx;
  
  	idx = irq >> 3;
  	reg = PCF50633_REG_INT1M + idx;
  	bit = 1 << (irq & 0x07);
  
  	pcf50633_reg_set_bit_mask(pcf, reg, bit, mask ? bit : 0);
  
  	mutex_lock(&pcf->lock);
  
  	if (mask)
  		pcf->mask_regs[idx] |= bit;
  	else
  		pcf->mask_regs[idx] &= ~bit;
  
  	mutex_unlock(&pcf->lock);
  
  	return ret;
  }
  
  int pcf50633_irq_mask(struct pcf50633 *pcf, int irq)
  {
  	dev_dbg(pcf->dev, "Masking IRQ %d
  ", irq);
  
  	return __pcf50633_irq_mask_set(pcf, irq, 1);
  }
  EXPORT_SYMBOL_GPL(pcf50633_irq_mask);
  
  int pcf50633_irq_unmask(struct pcf50633 *pcf, int irq)
  {
  	dev_dbg(pcf->dev, "Unmasking IRQ %d
  ", irq);
  
  	return __pcf50633_irq_mask_set(pcf, irq, 0);
  }
  EXPORT_SYMBOL_GPL(pcf50633_irq_unmask);
  
  int pcf50633_irq_mask_get(struct pcf50633 *pcf, int irq)
  {
  	u8 reg, bits;
  
  	reg =  irq >> 3;
  	bits = 1 << (irq & 0x07);
  
  	return pcf->mask_regs[reg] & bits;
  }
  EXPORT_SYMBOL_GPL(pcf50633_irq_mask_get);
  
  static void pcf50633_irq_call_handler(struct pcf50633 *pcf, int irq)
  {
  	if (pcf->irq_handler[irq].handler)
  		pcf->irq_handler[irq].handler(irq, pcf->irq_handler[irq].data);
  }
  
  /* Maximum amount of time ONKEY is held before emergency action is taken */
  #define PCF50633_ONKEY1S_TIMEOUT 8
  
  static irqreturn_t pcf50633_irq(int irq, void *data)
  {
  	struct pcf50633 *pcf = data;
  	int ret, i, j;
  	u8 pcf_int[5], chgstat;
  
  	/* Read the 5 INT regs in one transaction */
  	ret = pcf50633_read_block(pcf, PCF50633_REG_INT1,
  						ARRAY_SIZE(pcf_int), pcf_int);
  	if (ret != ARRAY_SIZE(pcf_int)) {
  		dev_err(pcf->dev, "Error reading INT registers
  ");
  
  		/*
  		 * If this doesn't ACK the interrupt to the chip, we'll be
  		 * called once again as we're level triggered.
  		 */
  		goto out;
  	}
  
  	/* defeat 8s death from lowsys on A5 */
  	pcf50633_reg_write(pcf, PCF50633_REG_OOCSHDWN,  0x04);
  
  	/* We immediately read the usb and adapter status. We thus make sure
  	 * only of USBINS/USBREM IRQ handlers are called */
  	if (pcf_int[0] & (PCF50633_INT1_USBINS | PCF50633_INT1_USBREM)) {
  		chgstat = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2);
  		if (chgstat & (0x3 << 4))
  			pcf_int[0] &= ~PCF50633_INT1_USBREM;
  		else
  			pcf_int[0] &= ~PCF50633_INT1_USBINS;
  	}
  
  	/* Make sure only one of ADPINS or ADPREM is set */
  	if (pcf_int[0] & (PCF50633_INT1_ADPINS | PCF50633_INT1_ADPREM)) {
  		chgstat = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2);
  		if (chgstat & (0x3 << 4))
  			pcf_int[0] &= ~PCF50633_INT1_ADPREM;
  		else
  			pcf_int[0] &= ~PCF50633_INT1_ADPINS;
  	}
  
  	dev_dbg(pcf->dev, "INT1=0x%02x INT2=0x%02x INT3=0x%02x "
  			"INT4=0x%02x INT5=0x%02x
  ", pcf_int[0],
  			pcf_int[1], pcf_int[2], pcf_int[3], pcf_int[4]);
  
  	/* Some revisions of the chip don't have a 8s standby mode on
  	 * ONKEY1S press. We try to manually do it in such cases. */
  	if ((pcf_int[0] & PCF50633_INT1_SECOND) && pcf->onkey1s_held) {
  		dev_info(pcf->dev, "ONKEY1S held for %d secs
  ",
  							pcf->onkey1s_held);
  		if (pcf->onkey1s_held++ == PCF50633_ONKEY1S_TIMEOUT)
  			if (pcf->pdata->force_shutdown)
  				pcf->pdata->force_shutdown(pcf);
  	}
  
  	if (pcf_int[2] & PCF50633_INT3_ONKEY1S) {
  		dev_info(pcf->dev, "ONKEY1S held
  ");
  		pcf->onkey1s_held = 1 ;
  
  		/* Unmask IRQ_SECOND */
  		pcf50633_reg_clear_bits(pcf, PCF50633_REG_INT1M,
  						PCF50633_INT1_SECOND);
  
  		/* Unmask IRQ_ONKEYR */
  		pcf50633_reg_clear_bits(pcf, PCF50633_REG_INT2M,
  						PCF50633_INT2_ONKEYR);
  	}
  
  	if ((pcf_int[1] & PCF50633_INT2_ONKEYR) && pcf->onkey1s_held) {
  		pcf->onkey1s_held = 0;
  
  		/* Mask SECOND and ONKEYR interrupts */
  		if (pcf->mask_regs[0] & PCF50633_INT1_SECOND)
  			pcf50633_reg_set_bit_mask(pcf,
  					PCF50633_REG_INT1M,
  					PCF50633_INT1_SECOND,
  					PCF50633_INT1_SECOND);
  
  		if (pcf->mask_regs[1] & PCF50633_INT2_ONKEYR)
  			pcf50633_reg_set_bit_mask(pcf,
  					PCF50633_REG_INT2M,
  					PCF50633_INT2_ONKEYR,
  					PCF50633_INT2_ONKEYR);
  	}
  
  	/* Have we just resumed ? */
  	if (pcf->is_suspended) {
  		pcf->is_suspended = 0;
  
  		/* Set the resume reason filtering out non resumers */
  		for (i = 0; i < ARRAY_SIZE(pcf_int); i++)
  			pcf->resume_reason[i] = pcf_int[i] &
  						pcf->pdata->resumers[i];
  
  		/* Make sure we don't pass on any ONKEY events to
  		 * userspace now */
  		pcf_int[1] &= ~(PCF50633_INT2_ONKEYR | PCF50633_INT2_ONKEYF);
  	}
  
  	for (i = 0; i < ARRAY_SIZE(pcf_int); i++) {
  		/* Unset masked interrupts */
  		pcf_int[i] &= ~pcf->mask_regs[i];
  
  		for (j = 0; j < 8 ; j++)
  			if (pcf_int[i] & (1 << j))
  				pcf50633_irq_call_handler(pcf, (i * 8) + j);
  	}
  
  out:
  	return IRQ_HANDLED;
  }
  
  #ifdef CONFIG_PM
  
  int pcf50633_irq_suspend(struct pcf50633 *pcf)
  {
  	int ret;
  	int i;
  	u8 res[5];
  
  
  	/* Make sure our interrupt handlers are not called
  	 * henceforth */
  	disable_irq(pcf->irq);
  
  	/* Save the masks */
  	ret = pcf50633_read_block(pcf, PCF50633_REG_INT1M,
  				ARRAY_SIZE(pcf->suspend_irq_masks),
  					pcf->suspend_irq_masks);
  	if (ret < 0) {
  		dev_err(pcf->dev, "error saving irq masks
  ");
  		goto out;
  	}
  
  	/* Write wakeup irq masks */
  	for (i = 0; i < ARRAY_SIZE(res); i++)
  		res[i] = ~pcf->pdata->resumers[i];
  
  	ret = pcf50633_write_block(pcf, PCF50633_REG_INT1M,
  					ARRAY_SIZE(res), &res[0]);
  	if (ret < 0) {
  		dev_err(pcf->dev, "error writing wakeup irq masks
  ");
  		goto out;
  	}
  
  	pcf->is_suspended = 1;
  
  out:
  	return ret;
  }
  
  int pcf50633_irq_resume(struct pcf50633 *pcf)
  {
  	int ret;
  
  	/* Write the saved mask registers */
  	ret = pcf50633_write_block(pcf, PCF50633_REG_INT1M,
  				ARRAY_SIZE(pcf->suspend_irq_masks),
  					pcf->suspend_irq_masks);
  	if (ret < 0)
  		dev_err(pcf->dev, "Error restoring saved suspend masks
  ");
  
  	enable_irq(pcf->irq);
  
  	return ret;
  }
  
  #endif
  
  int pcf50633_irq_init(struct pcf50633 *pcf, int irq)
  {
  	int ret;
  
  	pcf->irq = irq;
  
  	/* Enable all interrupts except RTC SECOND */
  	pcf->mask_regs[0] = 0x80;
  	pcf50633_reg_write(pcf, PCF50633_REG_INT1M, pcf->mask_regs[0]);
  	pcf50633_reg_write(pcf, PCF50633_REG_INT2M, 0x00);
  	pcf50633_reg_write(pcf, PCF50633_REG_INT3M, 0x00);
  	pcf50633_reg_write(pcf, PCF50633_REG_INT4M, 0x00);
  	pcf50633_reg_write(pcf, PCF50633_REG_INT5M, 0x00);
  
  	ret = request_threaded_irq(irq, NULL, pcf50633_irq,
  					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
  					"pcf50633", pcf);
  
  	if (ret)
  		dev_err(pcf->dev, "Failed to request IRQ %d
  ", ret);
  
  	if (enable_irq_wake(irq) < 0)
  		dev_err(pcf->dev, "IRQ %u cannot be enabled as wake-up source"
  			"in this hardware revision", irq);
  
  	return ret;
  }
  
  void pcf50633_irq_free(struct pcf50633 *pcf)
  {
  	free_irq(pcf->irq, pcf);
  }