/*
   *  Fujitsu Lifebook Application Panel button drive
   *
   *  Copyright (C) 2007 Stephen Hemminger <shemminger@linux-foundation.org>
   *  Copyright (C) 2001-2003 Jochen Eisinger <jochen@penguin-breeder.org>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * Many Fujitsu Lifebook laptops have a small panel of buttons that are
   * accessible via the i2c/smbus interface. This driver polls those
   * buttons and generates input events.
   *
   * For more details see:
   *	http://apanel.sourceforge.net/tech.php
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/ioport.h>
  #include <linux/io.h>
  #include <linux/input-polldev.h>
  #include <linux/i2c.h>
  #include <linux/workqueue.h>
  #include <linux/leds.h>
  
  #define APANEL_NAME	"Fujitsu Application Panel"
  #define APANEL_VERSION	"1.3.1"
  #define APANEL		"apanel"
  
  /* How often we poll keys - msecs */
  #define POLL_INTERVAL_DEFAULT	1000
  
  /* Magic constants in BIOS that tell about buttons */
  enum apanel_devid {
  	APANEL_DEV_NONE	  = 0,
  	APANEL_DEV_APPBTN = 1,
  	APANEL_DEV_CDBTN  = 2,
  	APANEL_DEV_LCD	  = 3,
  	APANEL_DEV_LED	  = 4,
  
  	APANEL_DEV_MAX,
  };
  
  enum apanel_chip {
  	CHIP_NONE    = 0,
  	CHIP_OZ992C  = 1,
  	CHIP_OZ163T  = 2,
  	CHIP_OZ711M3 = 4,
  };
  
  /* Result of BIOS snooping/probing -- what features are supported */
  static enum apanel_chip device_chip[APANEL_DEV_MAX];
  
  #define MAX_PANEL_KEYS	12
  
  struct apanel {
  	struct input_polled_dev *ipdev;
  	struct i2c_client *client;
  	unsigned short keymap[MAX_PANEL_KEYS];
  	u16    nkeys;
  	u16    led_bits;
  	struct work_struct led_work;
  	struct led_classdev mail_led;
  };
  
  
  static int apanel_probe(struct i2c_client *, const struct i2c_device_id *);
  
  static void report_key(struct input_dev *input, unsigned keycode)
  {
  	pr_debug(APANEL ": report key %#x
  ", keycode);
  	input_report_key(input, keycode, 1);
  	input_sync(input);
  
  	input_report_key(input, keycode, 0);
  	input_sync(input);
  }
  
  /* Poll for key changes
   *
   * Read Application keys via SMI
   *  A (0x4), B (0x8), Internet (0x2), Email (0x1).
   *
   * CD keys:
   * Forward (0x100), Rewind (0x200), Stop (0x400), Pause (0x800)
   */
  static void apanel_poll(struct input_polled_dev *ipdev)
  {
  	struct apanel *ap = ipdev->private;
  	struct input_dev *idev = ipdev->input;
  	u8 cmd = device_chip[APANEL_DEV_APPBTN] == CHIP_OZ992C ? 0 : 8;
  	s32 data;
  	int i;
  
  	data = i2c_smbus_read_word_data(ap->client, cmd);
  	if (data < 0)
  		return;	/* ignore errors (due to ACPI??) */
  
  	/* write back to clear latch */
  	i2c_smbus_write_word_data(ap->client, cmd, 0);
  
  	if (!data)
  		return;
  
  	dev_dbg(&idev->dev, APANEL ": data %#x
  ", data);
  	for (i = 0; i < idev->keycodemax; i++)
  		if ((1u << i) & data)
  			report_key(idev, ap->keymap[i]);
  }
  
  /* Track state changes of LED */
  static void led_update(struct work_struct *work)
  {
  	struct apanel *ap = container_of(work, struct apanel, led_work);
  
  	i2c_smbus_write_word_data(ap->client, 0x10, ap->led_bits);
  }
  
  static void mail_led_set(struct led_classdev *led,
  			 enum led_brightness value)
  {
  	struct apanel *ap = container_of(led, struct apanel, mail_led);
  
  	if (value != LED_OFF)
  		ap->led_bits |= 0x8000;
  	else
  		ap->led_bits &= ~0x8000;
  
  	schedule_work(&ap->led_work);
  }
  
  static int apanel_remove(struct i2c_client *client)
  {
  	struct apanel *ap = i2c_get_clientdata(client);
  
  	if (device_chip[APANEL_DEV_LED] != CHIP_NONE)
  		led_classdev_unregister(&ap->mail_led);
  
  	input_unregister_polled_device(ap->ipdev);
  	input_free_polled_device(ap->ipdev);
  
  	return 0;
  }
  
  static void apanel_shutdown(struct i2c_client *client)
  {
  	apanel_remove(client);
  }
  
  static const struct i2c_device_id apanel_id[] = {
  	{ "fujitsu_apanel", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, apanel_id);
  
  static struct i2c_driver apanel_driver = {
  	.driver = {
  		.name = APANEL,
  	},
  	.probe		= &apanel_probe,
  	.remove		= &apanel_remove,
  	.shutdown	= &apanel_shutdown,
  	.id_table	= apanel_id,
  };
  
  static struct apanel apanel = {
  	.keymap = {
  		[0] = KEY_MAIL,
  		[1] = KEY_WWW,
  		[2] = KEY_PROG2,
  		[3] = KEY_PROG1,
  
  		[8] = KEY_FORWARD,
  		[9] = KEY_REWIND,
  		[10] = KEY_STOPCD,
  		[11] = KEY_PLAYPAUSE,
  
  	},
  	.mail_led = {
  		.name = "mail:blue",
  		.brightness_set = mail_led_set,
  	},
  };
  
  /* NB: Only one panel on the i2c. */
  static int apanel_probe(struct i2c_client *client,
  			const struct i2c_device_id *id)
  {
  	struct apanel *ap;
  	struct input_polled_dev *ipdev;
  	struct input_dev *idev;
  	u8 cmd = device_chip[APANEL_DEV_APPBTN] == CHIP_OZ992C ? 0 : 8;
  	int i, err = -ENOMEM;
  
  	ap = &apanel;
  
  	ipdev = input_allocate_polled_device();
  	if (!ipdev)
  		goto out1;
  
  	ap->ipdev = ipdev;
  	ap->client = client;
  
  	i2c_set_clientdata(client, ap);
  
  	err = i2c_smbus_write_word_data(client, cmd, 0);
  	if (err) {
  		dev_warn(&client->dev, APANEL ": smbus write error %d
  ",
  			 err);
  		goto out3;
  	}
  
  	ipdev->poll = apanel_poll;
  	ipdev->poll_interval = POLL_INTERVAL_DEFAULT;
  	ipdev->private = ap;
  
  	idev = ipdev->input;
  	idev->name = APANEL_NAME " buttons";
  	idev->phys = "apanel/input0";
  	idev->id.bustype = BUS_HOST;
  	idev->dev.parent = &client->dev;
  
  	set_bit(EV_KEY, idev->evbit);
  
  	idev->keycode = ap->keymap;
  	idev->keycodesize = sizeof(ap->keymap[0]);
  	idev->keycodemax = (device_chip[APANEL_DEV_CDBTN] != CHIP_NONE) ? 12 : 4;
  
  	for (i = 0; i < idev->keycodemax; i++)
  		if (ap->keymap[i])
  			set_bit(ap->keymap[i], idev->keybit);
  
  	err = input_register_polled_device(ipdev);
  	if (err)
  		goto out3;
  
  	INIT_WORK(&ap->led_work, led_update);
  	if (device_chip[APANEL_DEV_LED] != CHIP_NONE) {
  		err = led_classdev_register(&client->dev, &ap->mail_led);
  		if (err)
  			goto out4;
  	}
  
  	return 0;
  out4:
  	input_unregister_polled_device(ipdev);
  out3:
  	input_free_polled_device(ipdev);
  out1:
  	return err;
  }
  
  /* Scan the system ROM for the signature "FJKEYINF" */
  static __init const void __iomem *bios_signature(const void __iomem *bios)
  {
  	ssize_t offset;
  	const unsigned char signature[] = "FJKEYINF";
  
  	for (offset = 0; offset < 0x10000; offset += 0x10) {
  		if (check_signature(bios + offset, signature,
  				    sizeof(signature)-1))
  			return bios + offset;
  	}
  	pr_notice(APANEL ": Fujitsu BIOS signature '%s' not found...
  ",
  		  signature);
  	return NULL;
  }
  
  static int __init apanel_init(void)
  {
  	void __iomem *bios;
  	const void __iomem *p;
  	u8 devno;
  	unsigned char i2c_addr;
  	int found = 0;
  
  	bios = ioremap(0xF0000, 0x10000); /* Can't fail */
  
  	p = bios_signature(bios);
  	if (!p) {
  		iounmap(bios);
  		return -ENODEV;
  	}
  
  	/* just use the first address */
  	p += 8;
  	i2c_addr = readb(p + 3) >> 1;
  
  	for ( ; (devno = readb(p)) & 0x7f; p += 4) {
  		unsigned char method, slave, chip;
  
  		method = readb(p + 1);
  		chip = readb(p + 2);
  		slave = readb(p + 3) >> 1;
  
  		if (slave != i2c_addr) {
  			pr_notice(APANEL ": only one SMBus slave "
  				  "address supported, skiping device...
  ");
  			continue;
  		}
  
  		/* translate alternative device numbers */
  		switch (devno) {
  		case 6:
  			devno = APANEL_DEV_APPBTN;
  			break;
  		case 7:
  			devno = APANEL_DEV_LED;
  			break;
  		}
  
  		if (devno >= APANEL_DEV_MAX)
  			pr_notice(APANEL ": unknown device %u found
  ", devno);
  		else if (device_chip[devno] != CHIP_NONE)
  			pr_warning(APANEL ": duplicate entry for devno %u
  ", devno);
  
  		else if (method != 1 && method != 2 && method != 4) {
  			pr_notice(APANEL ": unknown method %u for devno %u
  ",
  				  method, devno);
  		} else {
  			device_chip[devno] = (enum apanel_chip) chip;
  			++found;
  		}
  	}
  	iounmap(bios);
  
  	if (found == 0) {
  		pr_info(APANEL ": no input devices reported by BIOS
  ");
  		return -EIO;
  	}
  
  	return i2c_add_driver(&apanel_driver);
  }
  module_init(apanel_init);
  
  static void __exit apanel_cleanup(void)
  {
  	i2c_del_driver(&apanel_driver);
  }
  module_exit(apanel_cleanup);
  
  MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
  MODULE_DESCRIPTION(APANEL_NAME " driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(APANEL_VERSION);
  
  MODULE_ALIAS("dmi:*:svnFUJITSU:pnLifeBook*:pvr*:rvnFUJITSU:*");
  MODULE_ALIAS("dmi:*:svnFUJITSU:pnLifebook*:pvr*:rvnFUJITSU:*");