/*
   * Apple Motion Sensor driver
   *
   * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
   * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/init.h>

  #include <linux/of_platform.h>

  #include <asm/pmac_pfunc.h>

  
  #include "ams.h"
  
  /* There is only one motion sensor per machine */
  struct ams ams_info;

  static bool verbose;

  module_param(verbose, bool, 0644);
  MODULE_PARM_DESC(verbose, "Show free falls and shocks in kernel output");
  
  /* Call with ams_info.lock held! */
  void ams_sensors(s8 *x, s8 *y, s8 *z)
  {
  	u32 orient = ams_info.vflag? ams_info.orient1 : ams_info.orient2;
  
  	if (orient & 0x80)
  		/* X and Y swapped */
  		ams_info.get_xyz(y, x, z);
  	else
  		ams_info.get_xyz(x, y, z);
  
  	if (orient & 0x04)
  		*z = ~(*z);
  	if (orient & 0x02)
  		*y = ~(*y);
  	if (orient & 0x01)
  		*x = ~(*x);
  }
  
  static ssize_t ams_show_current(struct device *dev,
  	struct device_attribute *attr, char *buf)
  {
  	s8 x, y, z;
  
  	mutex_lock(&ams_info.lock);
  	ams_sensors(&x, &y, &z);
  	mutex_unlock(&ams_info.lock);
  
  	return snprintf(buf, PAGE_SIZE, "%d %d %d
  ", x, y, z);
  }
  
  static DEVICE_ATTR(current, S_IRUGO, ams_show_current, NULL);
  
  static void ams_handle_irq(void *data)
  {
  	enum ams_irq irq = *((enum ams_irq *)data);
  
  	spin_lock(&ams_info.irq_lock);
  
  	ams_info.worker_irqs |= irq;
  	schedule_work(&ams_info.worker);
  
  	spin_unlock(&ams_info.irq_lock);
  }
  
  static enum ams_irq ams_freefall_irq_data = AMS_IRQ_FREEFALL;
  static struct pmf_irq_client ams_freefall_client = {
  	.owner = THIS_MODULE,
  	.handler = ams_handle_irq,
  	.data = &ams_freefall_irq_data,
  };
  
  static enum ams_irq ams_shock_irq_data = AMS_IRQ_SHOCK;
  static struct pmf_irq_client ams_shock_client = {
  	.owner = THIS_MODULE,
  	.handler = ams_handle_irq,
  	.data = &ams_shock_irq_data,
  };
  
  /* Once hard disk parking is implemented in the kernel, this function can
   * trigger it.
   */
  static void ams_worker(struct work_struct *work)
  {

  	unsigned long flags;
  	u8 irqs_to_clear;

  	mutex_lock(&ams_info.lock);

  	spin_lock_irqsave(&ams_info.irq_lock, flags);
  	irqs_to_clear = ams_info.worker_irqs;

  	if (ams_info.worker_irqs & AMS_IRQ_FREEFALL) {
  		if (verbose)
  			printk(KERN_INFO "ams: freefall detected!
  ");

  		ams_info.worker_irqs &= ~AMS_IRQ_FREEFALL;
  	}

  	if (ams_info.worker_irqs & AMS_IRQ_SHOCK) {
  		if (verbose)
  			printk(KERN_INFO "ams: shock detected!
  ");

  		ams_info.worker_irqs &= ~AMS_IRQ_SHOCK;
  	}

  	spin_unlock_irqrestore(&ams_info.irq_lock, flags);

  	ams_info.clear_irq(irqs_to_clear);

  
  	mutex_unlock(&ams_info.lock);
  }
  
  /* Call with ams_info.lock held! */
  int ams_sensor_attach(void)
  {
  	int result;

  	const u32 *prop;

  
  	/* Get orientation */

  	prop = of_get_property(ams_info.of_node, "orientation", NULL);

  	if (!prop)
  		return -ENODEV;
  	ams_info.orient1 = *prop;
  	ams_info.orient2 = *(prop + 1);
  
  	/* Register freefall interrupt handler */
  	result = pmf_register_irq_client(ams_info.of_node,
  			"accel-int-1",
  			&ams_freefall_client);
  	if (result < 0)
  		return -ENODEV;
  
  	/* Reset saved irqs */
  	ams_info.worker_irqs = 0;
  
  	/* Register shock interrupt handler */
  	result = pmf_register_irq_client(ams_info.of_node,
  			"accel-int-2",
  			&ams_shock_client);
  	if (result < 0)
  		goto release_freefall;
  
  	/* Create device */
  	ams_info.of_dev = of_platform_device_create(ams_info.of_node, "ams", NULL);
  	if (!ams_info.of_dev) {
  		result = -ENODEV;
  		goto release_shock;
  	}
  
  	/* Create attributes */
  	result = device_create_file(&ams_info.of_dev->dev, &dev_attr_current);
  	if (result)
  		goto release_of;
  
  	ams_info.vflag = !!(ams_info.get_vendor() & 0x10);
  
  	/* Init input device */
  	result = ams_input_init();
  	if (result)
  		goto release_device_file;
  
  	return result;
  release_device_file:
  	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
  release_of:
  	of_device_unregister(ams_info.of_dev);
  release_shock:
  	pmf_unregister_irq_client(&ams_shock_client);
  release_freefall:
  	pmf_unregister_irq_client(&ams_freefall_client);
  	return result;
  }
  
  int __init ams_init(void)
  {
  	struct device_node *np;
  
  	spin_lock_init(&ams_info.irq_lock);
  	mutex_init(&ams_info.lock);
  	INIT_WORK(&ams_info.worker, ams_worker);
  
  #ifdef CONFIG_SENSORS_AMS_I2C
  	np = of_find_node_by_name(NULL, "accelerometer");

  	if (np && of_device_is_compatible(np, "AAPL,accelerometer_1"))

  		/* Found I2C motion sensor */
  		return ams_i2c_init(np);
  #endif
  
  #ifdef CONFIG_SENSORS_AMS_PMU
  	np = of_find_node_by_name(NULL, "sms");

  	if (np && of_device_is_compatible(np, "sms"))

  		/* Found PMU motion sensor */
  		return ams_pmu_init(np);
  #endif

  	return -ENODEV;
  }

  void ams_sensor_detach(void)

  {

  	/* Remove input device */
  	ams_input_exit();

  	/* Remove attributes */
  	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);

  	/* Flush interrupt worker
  	 *
  	 * We do this after ams_info.exit(), because an interrupt might
  	 * have arrived before disabling them.
  	 */

  	flush_work_sync(&ams_info.worker);

  	/* Remove device */
  	of_device_unregister(ams_info.of_dev);

  	/* Remove handler */
  	pmf_unregister_irq_client(&ams_shock_client);
  	pmf_unregister_irq_client(&ams_freefall_client);

  }

  static void __exit ams_exit(void)
  {
  	/* Shut down implementation */
  	ams_info.exit();
  }

  MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
  MODULE_DESCRIPTION("Apple Motion Sensor driver");
  MODULE_LICENSE("GPL");
  
  module_init(ams_init);
  module_exit(ams_exit);