drivers/hwmon/hdaps.c - kernel/msm-4.9 - Gitiles

 /*
  * drivers/hwmon/hdaps.c - driver for IBM's Hard Drive Active Protection System
  *
  * Copyright (C) 2005 Robert Love <rml@novell.com>
  * Copyright (C) 2005 Jesper Juhl <jesper.juhl@gmail.com>
  *
  * The HardDisk Active Protection System (hdaps) is present in the IBM ThinkPad
  * T41, T42, T43, R51, and X40, at least.  It provides a basic two-axis
  * accelerometer and other data, such as the device's temperature.
  *
  * Based on the document by Mark A. Smith available at
  * http://www.almaden.ibm.com/cs/people/marksmith/tpaps.html and a lot of trial
  * and error.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License v2 as published by the
  * Free Software Foundation.
  *
  * 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/delay.h>
 #include <linux/device.h>
 #include <linux/input.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/dmi.h>
 #include <asm/io.h>

 #define HDAPS_LOW_PORT		0x1600	/* first port used by hdaps */
 #define HDAPS_NR_PORTS		0x30	/* 0x1600 - 0x162f */

 #define STATE_FRESH		0x50	/* accelerometer data is fresh */

 #define REFRESH_ASYNC		0x00	/* do asynchronous refresh */
 #define REFRESH_SYNC		0x01	/* do synchronous refresh */

 #define HDAPS_PORT_STATE	0x1611	/* device state */
 #define HDAPS_PORT_YPOS		0x1612	/* y-axis position */
 #define	HDAPS_PORT_XPOS		0x1614	/* x-axis position */
 #define HDAPS_PORT_TEMP1	0x1616	/* device temperature, in celcius */
 #define HDAPS_PORT_YVAR		0x1617	/* y-axis variance (what is this?) */
 #define HDAPS_PORT_XVAR		0x1619	/* x-axis variance (what is this?) */
 #define HDAPS_PORT_TEMP2	0x161b	/* device temperature (again?) */
 #define HDAPS_PORT_UNKNOWN	0x161c	/* what is this? */
 #define HDAPS_PORT_KMACT	0x161d	/* keyboard or mouse activity */

 #define HDAPS_READ_MASK		0xff	/* some reads have the low 8 bits set */

 #define KEYBD_MASK		0x20	/* set if keyboard activity */
 #define MOUSE_MASK		0x40	/* set if mouse activity */
 #define KEYBD_ISSET(n)		(!! (n & KEYBD_MASK))	/* keyboard used? */
 #define MOUSE_ISSET(n)		(!! (n & MOUSE_MASK))	/* mouse used? */

 #define INIT_TIMEOUT_MSECS	4000	/* wait up to 4s for device init ... */
 #define INIT_WAIT_MSECS		200	/* ... in 200ms increments */

 static struct platform_device *pdev;
 static struct input_dev hdaps_idev;
 static struct timer_list hdaps_timer;
 static unsigned int hdaps_mousedev_threshold = 4;
 static unsigned long hdaps_poll_ms = 50;
 static unsigned int hdaps_mousedev;
 static unsigned int hdaps_invert;
 static u8 km_activity;
 static int rest_x;
 static int rest_y;

 static DECLARE_MUTEX(hdaps_sem);

 /*
  * __get_latch - Get the value from a given port.  Callers must hold hdaps_sem.
  */
 static inline u8 __get_latch(u16 port)
 {
 	return inb(port) & HDAPS_READ_MASK;
 }

 /*
  * __check_latch - Check a port latch for a given value.  Callers must hold
  * hdaps_sem.  Returns zero if the port contains the given value.
  */
 static inline unsigned int __check_latch(u16 port, u8 val)
 {
 	if (__get_latch(port) == val)
 		return 0;
 	return -EINVAL;
 }

 /*
  * __wait_latch - Wait up to 100us for a port latch to get a certain value,
  * returning zero if the value is obtained.  Callers must hold hdaps_sem.
  */
 static unsigned int __wait_latch(u16 port, u8 val)
 {
 	unsigned int i;

 	for (i = 0; i < 20; i++) {
 		if (!__check_latch(port, val))
 			return 0;
 		udelay(5);
 	}

 	return -EINVAL;
 }

 /*
  * __device_refresh - Request a refresh from the accelerometer.
  *
  * If sync is REFRESH_SYNC, we perform a synchronous refresh and will wait.
  * Returns zero if successful and nonzero on error.
  *
  * If sync is REFRESH_ASYNC, we merely kick off a new refresh if the device is
  * not up-to-date.  Always returns zero.
  *
  * Callers must hold hdaps_sem.
  */
 static int __device_refresh(unsigned int sync)
 {
 	u8 state;

 	udelay(100);

 	state = inb(0x1604);
 	if (state == STATE_FRESH)
 		return 0;

 	outb(0x11, 0x1610);
 	outb(0x01, 0x161f);
 	if (sync == REFRESH_ASYNC)
 		return 0;

 	return __wait_latch(0x1604, STATE_FRESH);
 }

 /*
  * __device_complete - Indicate to the accelerometer that we are done reading
  * data, and then initiate an async refresh.  Callers must hold hdaps_sem.
  */
 static inline void __device_complete(void)
 {
 	inb(0x161f);
 	inb(0x1604);
 	__device_refresh(REFRESH_ASYNC);
 }

 static int __hdaps_readb_one(unsigned int port, u8 *val)
 {
 	/* do a sync refresh -- we need to be sure that we read fresh data */
 	if (__device_refresh(REFRESH_SYNC))
 		return -EIO;

 	*val = inb(port);
 	__device_complete();

 	return 0;
 }

 /*
  * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
  * the given pointer.  Returns zero on success or a negative error on failure.
  * Can sleep.
  */
 static int hdaps_readb_one(unsigned int port, u8 *val)
 {
 	int ret;

 	down(&hdaps_sem);
 	ret = __hdaps_readb_one(port, val);
 	up(&hdaps_sem);

 	return ret;
 }

 static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
 			     int *x, int *y)
 {
 	/* do a sync refresh -- we need to be sure that we read fresh data */
 	if (__device_refresh(REFRESH_SYNC))
 		return -EIO;

 	*y = inw(port2);
 	*x = inw(port1);
 	km_activity = inb(HDAPS_PORT_KMACT);
 	__device_complete();

 	/* if hdaps_invert is set, negate the two values */
 	if (hdaps_invert) {
 		*x = -*x;
 		*y = -*y;
 	}

 	return 0;
 }

 /*
  * hdaps_read_pair - reads the values from a pair of ports, placing the values
  * in the given pointers.  Returns zero on success.  Can sleep.
  */
 static int hdaps_read_pair(unsigned int port1, unsigned int port2,
 			   int *val1, int *val2)
 {
 	int ret;

 	down(&hdaps_sem);
 	ret = __hdaps_read_pair(port1, port2, val1, val2);
 	up(&hdaps_sem);

 	return ret;
 }

 /* initialize the accelerometer */
 static int hdaps_device_init(void)
 {
 	unsigned int total_msecs = INIT_TIMEOUT_MSECS;
 	int ret = -ENXIO;

 	down(&hdaps_sem);

 	outb(0x13, 0x1610);
 	outb(0x01, 0x161f);
 	if (__wait_latch(0x161f, 0x00))
 		goto out;

 	/*
 	 * The 0x03 value appears to only work on some thinkpads, such as the
 	 * T42p.  Others return 0x01.
 	 *
 	 * The 0x02 value occurs when the chip has been previously initialized.
 	 */
 	if (__check_latch(0x1611, 0x03) &&
 		     __check_latch(0x1611, 0x02) &&
 		     __check_latch(0x1611, 0x01))
 		goto out;

 	printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
 	       __get_latch(0x1611));

 	outb(0x17, 0x1610);
 	outb(0x81, 0x1611);
 	outb(0x01, 0x161f);
 	if (__wait_latch(0x161f, 0x00))
 		goto out;
 	if (__wait_latch(0x1611, 0x00))
 		goto out;
 	if (__wait_latch(0x1612, 0x60))
 		goto out;
 	if (__wait_latch(0x1613, 0x00))
 		goto out;
 	outb(0x14, 0x1610);
 	outb(0x01, 0x1611);
 	outb(0x01, 0x161f);
 	if (__wait_latch(0x161f, 0x00))
 		goto out;
 	outb(0x10, 0x1610);
 	outb(0xc8, 0x1611);
 	outb(0x00, 0x1612);
 	outb(0x02, 0x1613);
 	outb(0x01, 0x161f);
 	if (__wait_latch(0x161f, 0x00))
 		goto out;
 	if (__device_refresh(REFRESH_SYNC))
 		goto out;
 	if (__wait_latch(0x1611, 0x00))
 		goto out;

 	/* we have done our dance, now let's wait for the applause */
 	while (total_msecs > 0) {
 		u8 ignored;

 		/* a read of the device helps push it into action */
 		__hdaps_readb_one(HDAPS_PORT_UNKNOWN, &ignored);
 		if (!__wait_latch(0x1611, 0x02)) {
 			ret = 0;
 			break;
 		}

 		msleep(INIT_WAIT_MSECS);
 		total_msecs -= INIT_WAIT_MSECS;
 	}

 out:
 	up(&hdaps_sem);
 	return ret;
 }


 /* Input class stuff */

 /*
  * hdaps_calibrate - Zero out our "resting" values. Callers must hold hdaps_sem.
  */
 static void hdaps_calibrate(void)
 {
 	int x, y;

 	if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
 		return;

 	rest_x = x;
 	rest_y = y;
 }

 static void hdaps_mousedev_poll(unsigned long unused)
 {
 	int x, y;

 	/* Cannot sleep.  Try nonblockingly.  If we fail, try again later. */
 	if (down_trylock(&hdaps_sem)) {
 		mod_timer(&hdaps_timer,jiffies+msecs_to_jiffies(hdaps_poll_ms));
 		return;
 	}

 	if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
 		goto out;

 	x -= rest_x;
 	y -= rest_y;
 	if (abs(x) > hdaps_mousedev_threshold)
 		input_report_rel(&hdaps_idev, REL_X, x);
 	if (abs(y) > hdaps_mousedev_threshold)
 		input_report_rel(&hdaps_idev, REL_Y, y);
 	input_sync(&hdaps_idev);

 	mod_timer(&hdaps_timer, jiffies + msecs_to_jiffies(hdaps_poll_ms));

 out:
 	up(&hdaps_sem);
 }

 /*
  * hdaps_mousedev_enable - enable the input class device.  Can sleep.
  */
 static void hdaps_mousedev_enable(void)
 {
 	down(&hdaps_sem);

 	/* calibrate the device before enabling */
 	hdaps_calibrate();

 	/* initialize the input class */
 	init_input_dev(&hdaps_idev);
 	hdaps_idev.dev = &pdev->dev;
 	hdaps_idev.evbit[0] = BIT(EV_KEY) | BIT(EV_REL);
 	hdaps_idev.relbit[0] = BIT(REL_X) | BIT(REL_Y);
 	hdaps_idev.keybit[LONG(BTN_LEFT)] = BIT(BTN_LEFT);
 	input_register_device(&hdaps_idev);

 	/* start up our timer */
 	init_timer(&hdaps_timer);
 	hdaps_timer.function = hdaps_mousedev_poll;
 	hdaps_timer.expires = jiffies + msecs_to_jiffies(hdaps_poll_ms);
 	add_timer(&hdaps_timer);

 	hdaps_mousedev = 1;

 	up(&hdaps_sem);

 	printk(KERN_INFO "hdaps: input device enabled.\n");
 }

 /*
  * hdaps_mousedev_disable - disable the input class device.  Caller must hold
  * hdaps_sem.
  */
 static void hdaps_mousedev_disable(void)
 {
 	down(&hdaps_sem);
 	if (hdaps_mousedev) {
 		hdaps_mousedev = 0;
 		del_timer_sync(&hdaps_timer);
 		input_unregister_device(&hdaps_idev);
 	}
 	up(&hdaps_sem);
 }


 /* Device model stuff */

 static int hdaps_probe(struct device *dev)
 {
 	int ret;

 	ret = hdaps_device_init();
 	if (ret)
 		return ret;

 	printk(KERN_INFO "hdaps: device successfully initialized.\n");
 	return 0;
 }

 static int hdaps_resume(struct device *dev, u32 level)
 {
 	if (level == RESUME_ENABLE)
 		return hdaps_device_init();
 	return 0;
 }

 static struct device_driver hdaps_driver = {
 	.name = "hdaps",
 	.bus = &platform_bus_type,
 	.owner = THIS_MODULE,
 	.probe = hdaps_probe,
 	.resume = hdaps_resume
 };


 /* Sysfs Files */

 static ssize_t hdaps_position_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	int ret, x, y;

 	ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
 	if (ret)
 		return ret;

 	return sprintf(buf, "(%d,%d)\n", x, y);
 }

 static ssize_t hdaps_variance_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	int ret, x, y;

 	ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
 	if (ret)
 		return ret;

 	return sprintf(buf, "(%d,%d)\n", x, y);
 }

 static ssize_t hdaps_temp1_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	u8 temp;
 	int ret;

 	ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%u\n", temp);
 }

 static ssize_t hdaps_temp2_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	u8 temp;
 	int ret;

 	ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%u\n", temp);
 }

 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
 					    struct device_attribute *attr,
 					    char *buf)
 {
 	return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
 }

 static ssize_t hdaps_mouse_activity_show(struct device *dev,
 					 struct device_attribute *attr,
 					 char *buf)
 {
 	return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
 }

 static ssize_t hdaps_calibrate_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
 }

 static ssize_t hdaps_calibrate_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
 {
 	down(&hdaps_sem);
 	hdaps_calibrate();
 	up(&hdaps_sem);

 	return count;
 }

 static ssize_t hdaps_invert_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%u\n", hdaps_invert);
 }

 static ssize_t hdaps_invert_store(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buf, size_t count)
 {
 	int invert;

 	if (sscanf(buf, "%d", &invert) != 1 || (invert != 1 && invert != 0))
 		return -EINVAL;

 	hdaps_invert = invert;
 	hdaps_calibrate();

 	return count;
 }

 static ssize_t hdaps_mousedev_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", hdaps_mousedev);
 }

 static ssize_t hdaps_mousedev_store(struct device *dev,
 				    struct device_attribute *attr,
 				    const char *buf, size_t count)
 {
 	int enable;

 	if (sscanf(buf, "%d", &enable) != 1)
 		return -EINVAL;

 	if (enable == 1)
 		hdaps_mousedev_enable();
 	else if (enable == 0)
 		hdaps_mousedev_disable();
 	else
 		return -EINVAL;

 	return count;
 }

 static ssize_t hdaps_poll_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%lu\n", hdaps_poll_ms);
 }

 static ssize_t hdaps_poll_store(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t count)
 {
 	unsigned int poll;

 	if (sscanf(buf, "%u", &poll) != 1 || poll == 0)
 		return -EINVAL;
 	hdaps_poll_ms = poll;

 	return count;
 }

 static ssize_t hdaps_threshold_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%u\n", hdaps_mousedev_threshold);
 }

 static ssize_t hdaps_threshold_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
 {
 	unsigned int threshold;

 	if (sscanf(buf, "%u", &threshold) != 1 || threshold == 0)
 		return -EINVAL;
 	hdaps_mousedev_threshold = threshold;

 	return count;
 }

 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
 static DEVICE_ATTR(mousedev, 0644, hdaps_mousedev_show, hdaps_mousedev_store);
 static DEVICE_ATTR(mousedev_poll_ms, 0644, hdaps_poll_show, hdaps_poll_store);
 static DEVICE_ATTR(mousedev_threshold, 0644, hdaps_threshold_show,
 		   hdaps_threshold_store);

 static struct attribute *hdaps_attributes[] = {
 	&dev_attr_position.attr,
 	&dev_attr_variance.attr,
 	&dev_attr_temp1.attr,
 	&dev_attr_temp2.attr,
 	&dev_attr_keyboard_activity.attr,
 	&dev_attr_mouse_activity.attr,
 	&dev_attr_calibrate.attr,
 	&dev_attr_mousedev.attr,
 	&dev_attr_mousedev_threshold.attr,
 	&dev_attr_mousedev_poll_ms.attr,
 	&dev_attr_invert.attr,
 	NULL,
 };

 static struct attribute_group hdaps_attribute_group = {
 	.attrs = hdaps_attributes,
 };


 /* Module stuff */

 /*
  * XXX: We should be able to return nonzero and halt the detection process.
  * But there is a bug in dmi_check_system() where a nonzero return from the
  * first match will result in a return of failure from dmi_check_system().
  * I fixed this; the patch is in 2.6-mm.  Once in Linus's tree we can make
  * hdaps_dmi_match_invert() return hdaps_dmi_match(), which in turn returns 1.
  */
 static int hdaps_dmi_match(struct dmi_system_id *id)
 {
 	printk(KERN_INFO "hdaps: %s detected.\n", id->ident);
 	return 0;
 }

 static int hdaps_dmi_match_invert(struct dmi_system_id *id)
 {
 	hdaps_invert = 1;
 	printk(KERN_INFO "hdaps: inverting axis readings.\n");
 	return 0;
 }

 #define HDAPS_DMI_MATCH_NORMAL(model)	{		\
 	.ident = "IBM " model,				\
 	.callback = hdaps_dmi_match,			\
 	.matches = {					\
 		DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),	\
 		DMI_MATCH(DMI_PRODUCT_VERSION, model)	\
 	}						\
 }

 #define HDAPS_DMI_MATCH_INVERT(model)	{		\
 	.ident = "IBM " model,				\
 	.callback = hdaps_dmi_match_invert,		\
 	.matches = {					\
 		DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),	\
 		DMI_MATCH(DMI_PRODUCT_VERSION, model)	\
 	}						\
 }

 static int __init hdaps_init(void)
 {
 	int ret;

 	/* Note that DMI_MATCH(...,"ThinkPad T42") will match "ThinkPad T42p" */
 	struct dmi_system_id hdaps_whitelist[] = {
 		HDAPS_DMI_MATCH_INVERT("ThinkPad R50p"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad R50"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad R51"),
 		HDAPS_DMI_MATCH_INVERT("ThinkPad T41p"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad T41"),
 		HDAPS_DMI_MATCH_INVERT("ThinkPad T42p"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad T42"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad T43"),
 		HDAPS_DMI_MATCH_NORMAL("ThinkPad X40"),
 		{ .ident = NULL }
 	};

 	if (!dmi_check_system(hdaps_whitelist)) {
 		printk(KERN_WARNING "hdaps: supported laptop not found!\n");
 		ret = -ENXIO;
 		goto out;
 	}

 	if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
 		ret = -ENXIO;
 		goto out;
 	}

 	ret = driver_register(&hdaps_driver);
 	if (ret)
 		goto out_region;

 	pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
 	if (IS_ERR(pdev)) {
 		ret = PTR_ERR(pdev);
 		goto out_driver;
 	}

 	ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
 	if (ret)
 		goto out_device;

 	if (hdaps_mousedev)
 		hdaps_mousedev_enable();

 	printk(KERN_INFO "hdaps: driver successfully loaded.\n");
 	return 0;

 out_device:
 	platform_device_unregister(pdev);
 out_driver:
 	driver_unregister(&hdaps_driver);
 out_region:
 	release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
 out:
 	printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret);
 	return ret;
 }

 static void __exit hdaps_exit(void)
 {
 	hdaps_mousedev_disable();

 	sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
 	platform_device_unregister(pdev);
 	driver_unregister(&hdaps_driver);
 	release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);

 	printk(KERN_INFO "hdaps: driver unloaded.\n");
 }

 module_init(hdaps_init);
 module_exit(hdaps_exit);

 module_param_named(mousedev, hdaps_mousedev, bool, 0);
 MODULE_PARM_DESC(mousedev, "enable the input class device");

 module_param_named(invert, hdaps_invert, bool, 0);
 MODULE_PARM_DESC(invert, "invert data along each axis");

 MODULE_AUTHOR("Robert Love");
 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
 MODULE_LICENSE("GPL v2");
	/*
	* drivers/hwmon/hdaps.c - driver for IBM's Hard Drive Active Protection System
	*
	* Copyright (C) 2005 Robert Love <rml@novell.com>
	* Copyright (C) 2005 Jesper Juhl <jesper.juhl@gmail.com>
	*
	* The HardDisk Active Protection System (hdaps) is present in the IBM ThinkPad
	* T41, T42, T43, R51, and X40, at least. It provides a basic two-axis
	* accelerometer and other data, such as the device's temperature.
	*
	* Based on the document by Mark A. Smith available at
	* http://www.almaden.ibm.com/cs/people/marksmith/tpaps.html and a lot of trial
	* and error.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License v2 as published by the
	* Free Software Foundation.
	*
	* 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/delay.h>
	#include <linux/device.h>
	#include <linux/input.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/timer.h>
	#include <linux/dmi.h>
	#include <asm/io.h>

	#define HDAPS_LOW_PORT 0x1600 /* first port used by hdaps */
	#define HDAPS_NR_PORTS 0x30 /* 0x1600 - 0x162f */

	#define STATE_FRESH 0x50 /* accelerometer data is fresh */

	#define REFRESH_ASYNC 0x00 /* do asynchronous refresh */
	#define REFRESH_SYNC 0x01 /* do synchronous refresh */

	#define HDAPS_PORT_STATE 0x1611 /* device state */
	#define HDAPS_PORT_YPOS 0x1612 /* y-axis position */
	#define HDAPS_PORT_XPOS 0x1614 /* x-axis position */
	#define HDAPS_PORT_TEMP1 0x1616 /* device temperature, in celcius */
	#define HDAPS_PORT_YVAR 0x1617 /* y-axis variance (what is this?) */
	#define HDAPS_PORT_XVAR 0x1619 /* x-axis variance (what is this?) */
	#define HDAPS_PORT_TEMP2 0x161b /* device temperature (again?) */
	#define HDAPS_PORT_UNKNOWN 0x161c /* what is this? */
	#define HDAPS_PORT_KMACT 0x161d /* keyboard or mouse activity */

	#define HDAPS_READ_MASK 0xff /* some reads have the low 8 bits set */

	#define KEYBD_MASK 0x20 /* set if keyboard activity */
	#define MOUSE_MASK 0x40 /* set if mouse activity */
	#define KEYBD_ISSET(n) (!! (n & KEYBD_MASK)) /* keyboard used? */
	#define MOUSE_ISSET(n) (!! (n & MOUSE_MASK)) /* mouse used? */

	#define INIT_TIMEOUT_MSECS 4000 /* wait up to 4s for device init ... */
	#define INIT_WAIT_MSECS 200 /* ... in 200ms increments */

	static struct platform_device *pdev;
	static struct input_dev hdaps_idev;
	static struct timer_list hdaps_timer;
	static unsigned int hdaps_mousedev_threshold = 4;
	static unsigned long hdaps_poll_ms = 50;
	static unsigned int hdaps_mousedev;
	static unsigned int hdaps_invert;
	static u8 km_activity;
	static int rest_x;
	static int rest_y;

	static DECLARE_MUTEX(hdaps_sem);

	/*
	* __get_latch - Get the value from a given port. Callers must hold hdaps_sem.
	*/
	static inline u8 __get_latch(u16 port)
	{
	return inb(port) & HDAPS_READ_MASK;
	}

	/*
	* __check_latch - Check a port latch for a given value. Callers must hold
	* hdaps_sem. Returns zero if the port contains the given value.
	*/
	static inline unsigned int __check_latch(u16 port, u8 val)
	{
	if (__get_latch(port) == val)
	return 0;
	return -EINVAL;
	}

	/*
	* __wait_latch - Wait up to 100us for a port latch to get a certain value,
	* returning zero if the value is obtained. Callers must hold hdaps_sem.
	*/
	static unsigned int __wait_latch(u16 port, u8 val)
	{
	unsigned int i;

	for (i = 0; i < 20; i++) {
	if (!__check_latch(port, val))
	return 0;
	udelay(5);
	}

	return -EINVAL;
	}

	/*
	* __device_refresh - Request a refresh from the accelerometer.
	*
	* If sync is REFRESH_SYNC, we perform a synchronous refresh and will wait.
	* Returns zero if successful and nonzero on error.
	*
	* If sync is REFRESH_ASYNC, we merely kick off a new refresh if the device is
	* not up-to-date. Always returns zero.
	*
	* Callers must hold hdaps_sem.
	*/
	static int __device_refresh(unsigned int sync)
	{
	u8 state;

	udelay(100);

	state = inb(0x1604);
	if (state == STATE_FRESH)
	return 0;

	outb(0x11, 0x1610);
	outb(0x01, 0x161f);
	if (sync == REFRESH_ASYNC)
	return 0;

	return __wait_latch(0x1604, STATE_FRESH);
	}

	/*
	* __device_complete - Indicate to the accelerometer that we are done reading
	* data, and then initiate an async refresh. Callers must hold hdaps_sem.
	*/
	static inline void __device_complete(void)
	{
	inb(0x161f);
	inb(0x1604);
	__device_refresh(REFRESH_ASYNC);
	}

	static int __hdaps_readb_one(unsigned int port, u8 *val)
	{
	/* do a sync refresh -- we need to be sure that we read fresh data */
	if (__device_refresh(REFRESH_SYNC))
	return -EIO;

	*val = inb(port);
	__device_complete();

	return 0;
	}

	/*
	* hdaps_readb_one - reads a byte from a single I/O port, placing the value in
	* the given pointer. Returns zero on success or a negative error on failure.
	* Can sleep.
	*/
	static int hdaps_readb_one(unsigned int port, u8 *val)
	{
	int ret;

	down(&hdaps_sem);
	ret = __hdaps_readb_one(port, val);
	up(&hdaps_sem);

	return ret;
	}

	static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
	int x, int y)
	{
	/* do a sync refresh -- we need to be sure that we read fresh data */
	if (__device_refresh(REFRESH_SYNC))
	return -EIO;

	*y = inw(port2);
	*x = inw(port1);
	km_activity = inb(HDAPS_PORT_KMACT);
	__device_complete();

	/* if hdaps_invert is set, negate the two values */
	if (hdaps_invert) {
	x = -x;
	y = -y;
	}

	return 0;
	}

	/*
	* hdaps_read_pair - reads the values from a pair of ports, placing the values
	* in the given pointers. Returns zero on success. Can sleep.
	*/
	static int hdaps_read_pair(unsigned int port1, unsigned int port2,
	int val1, int val2)
	{
	int ret;

	down(&hdaps_sem);
	ret = __hdaps_read_pair(port1, port2, val1, val2);
	up(&hdaps_sem);

	return ret;
	}

	/* initialize the accelerometer */
	static int hdaps_device_init(void)
	{
	unsigned int total_msecs = INIT_TIMEOUT_MSECS;
	int ret = -ENXIO;

	down(&hdaps_sem);

	outb(0x13, 0x1610);
	outb(0x01, 0x161f);
	if (__wait_latch(0x161f, 0x00))
	goto out;

	/*
	* The 0x03 value appears to only work on some thinkpads, such as the
	* T42p. Others return 0x01.
	*
	* The 0x02 value occurs when the chip has been previously initialized.
	*/
	if (__check_latch(0x1611, 0x03) &&
	__check_latch(0x1611, 0x02) &&
	__check_latch(0x1611, 0x01))
	goto out;

	printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
	__get_latch(0x1611));

	outb(0x17, 0x1610);
	outb(0x81, 0x1611);
	outb(0x01, 0x161f);
	if (__wait_latch(0x161f, 0x00))
	goto out;
	if (__wait_latch(0x1611, 0x00))
	goto out;
	if (__wait_latch(0x1612, 0x60))
	goto out;
	if (__wait_latch(0x1613, 0x00))
	goto out;
	outb(0x14, 0x1610);
	outb(0x01, 0x1611);
	outb(0x01, 0x161f);
	if (__wait_latch(0x161f, 0x00))
	goto out;
	outb(0x10, 0x1610);
	outb(0xc8, 0x1611);
	outb(0x00, 0x1612);
	outb(0x02, 0x1613);
	outb(0x01, 0x161f);
	if (__wait_latch(0x161f, 0x00))
	goto out;
	if (__device_refresh(REFRESH_SYNC))
	goto out;
	if (__wait_latch(0x1611, 0x00))
	goto out;

	/* we have done our dance, now let's wait for the applause */
	while (total_msecs > 0) {
	u8 ignored;

	/* a read of the device helps push it into action */
	__hdaps_readb_one(HDAPS_PORT_UNKNOWN, &ignored);
	if (!__wait_latch(0x1611, 0x02)) {
	ret = 0;
	break;
	}

	msleep(INIT_WAIT_MSECS);
	total_msecs -= INIT_WAIT_MSECS;
	}

	out:
	up(&hdaps_sem);
	return ret;
	}


	/* Input class stuff */

	/*
	* hdaps_calibrate - Zero out our "resting" values. Callers must hold hdaps_sem.
	*/
	static void hdaps_calibrate(void)
	{
	int x, y;

	if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
	return;

	rest_x = x;
	rest_y = y;
	}

	static void hdaps_mousedev_poll(unsigned long unused)
	{
	int x, y;

	/* Cannot sleep. Try nonblockingly. If we fail, try again later. */
	if (down_trylock(&hdaps_sem)) {
	mod_timer(&hdaps_timer,jiffies+msecs_to_jiffies(hdaps_poll_ms));
	return;
	}

	if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
	goto out;

	x -= rest_x;
	y -= rest_y;
	if (abs(x) > hdaps_mousedev_threshold)
	input_report_rel(&hdaps_idev, REL_X, x);
	if (abs(y) > hdaps_mousedev_threshold)
	input_report_rel(&hdaps_idev, REL_Y, y);
	input_sync(&hdaps_idev);

	mod_timer(&hdaps_timer, jiffies + msecs_to_jiffies(hdaps_poll_ms));

	out:
	up(&hdaps_sem);
	}

	/*
	* hdaps_mousedev_enable - enable the input class device. Can sleep.
	*/
	static void hdaps_mousedev_enable(void)
	{
	down(&hdaps_sem);

	/* calibrate the device before enabling */
	hdaps_calibrate();

	/* initialize the input class */
	init_input_dev(&hdaps_idev);
	hdaps_idev.dev = &pdev->dev;
	hdaps_idev.evbit[0] = BIT(EV_KEY) \| BIT(EV_REL);
	hdaps_idev.relbit[0] = BIT(REL_X) \| BIT(REL_Y);
	hdaps_idev.keybit[LONG(BTN_LEFT)] = BIT(BTN_LEFT);
	input_register_device(&hdaps_idev);

	/* start up our timer */
	init_timer(&hdaps_timer);
	hdaps_timer.function = hdaps_mousedev_poll;
	hdaps_timer.expires = jiffies + msecs_to_jiffies(hdaps_poll_ms);
	add_timer(&hdaps_timer);

	hdaps_mousedev = 1;

	up(&hdaps_sem);

	printk(KERN_INFO "hdaps: input device enabled.\n");
	}

	/*
	* hdaps_mousedev_disable - disable the input class device. Caller must hold
	* hdaps_sem.
	*/
	static void hdaps_mousedev_disable(void)
	{
	down(&hdaps_sem);
	if (hdaps_mousedev) {
	hdaps_mousedev = 0;
	del_timer_sync(&hdaps_timer);
	input_unregister_device(&hdaps_idev);
	}
	up(&hdaps_sem);
	}


	/* Device model stuff */

	static int hdaps_probe(struct device *dev)
	{
	int ret;

	ret = hdaps_device_init();
	if (ret)
	return ret;

	printk(KERN_INFO "hdaps: device successfully initialized.\n");
	return 0;
	}

	static int hdaps_resume(struct device *dev, u32 level)
	{
	if (level == RESUME_ENABLE)
	return hdaps_device_init();
	return 0;
	}

	static struct device_driver hdaps_driver = {
	.name = "hdaps",
	.bus = &platform_bus_type,
	.owner = THIS_MODULE,
	.probe = hdaps_probe,
	.resume = hdaps_resume
	};


	/* Sysfs Files */

	static ssize_t hdaps_position_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int ret, x, y;

	ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
	if (ret)
	return ret;

	return sprintf(buf, "(%d,%d)\n", x, y);
	}

	static ssize_t hdaps_variance_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int ret, x, y;

	ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
	if (ret)
	return ret;

	return sprintf(buf, "(%d,%d)\n", x, y);
	}

	static ssize_t hdaps_temp1_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	u8 temp;
	int ret;

	ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%u\n", temp);
	}

	static ssize_t hdaps_temp2_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	u8 temp;
	int ret;

	ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%u\n", temp);
	}

	static ssize_t hdaps_keyboard_activity_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
	}

	static ssize_t hdaps_mouse_activity_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
	}

	static ssize_t hdaps_calibrate_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
	}

	static ssize_t hdaps_calibrate_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	down(&hdaps_sem);
	hdaps_calibrate();
	up(&hdaps_sem);

	return count;
	}

	static ssize_t hdaps_invert_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return sprintf(buf, "%u\n", hdaps_invert);
	}

	static ssize_t hdaps_invert_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	int invert;

	if (sscanf(buf, "%d", &invert) != 1 \|\| (invert != 1 && invert != 0))
	return -EINVAL;

	hdaps_invert = invert;
	hdaps_calibrate();

	return count;
	}

	static ssize_t hdaps_mousedev_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return sprintf(buf, "%d\n", hdaps_mousedev);
	}

	static ssize_t hdaps_mousedev_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	int enable;

	if (sscanf(buf, "%d", &enable) != 1)
	return -EINVAL;

	if (enable == 1)
	hdaps_mousedev_enable();
	else if (enable == 0)
	hdaps_mousedev_disable();
	else
	return -EINVAL;

	return count;
	}

	static ssize_t hdaps_poll_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return sprintf(buf, "%lu\n", hdaps_poll_ms);
	}

	static ssize_t hdaps_poll_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	unsigned int poll;

	if (sscanf(buf, "%u", &poll) != 1 \|\| poll == 0)
	return -EINVAL;
	hdaps_poll_ms = poll;

	return count;
	}

	static ssize_t hdaps_threshold_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return sprintf(buf, "%u\n", hdaps_mousedev_threshold);
	}

	static ssize_t hdaps_threshold_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	unsigned int threshold;

	if (sscanf(buf, "%u", &threshold) != 1 \|\| threshold == 0)
	return -EINVAL;
	hdaps_mousedev_threshold = threshold;

	return count;
	}

	static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
	static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
	static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
	static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
	static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
	static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
	static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
	static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
	static DEVICE_ATTR(mousedev, 0644, hdaps_mousedev_show, hdaps_mousedev_store);
	static DEVICE_ATTR(mousedev_poll_ms, 0644, hdaps_poll_show, hdaps_poll_store);
	static DEVICE_ATTR(mousedev_threshold, 0644, hdaps_threshold_show,
	hdaps_threshold_store);

	static struct attribute *hdaps_attributes[] = {
	&dev_attr_position.attr,
	&dev_attr_variance.attr,
	&dev_attr_temp1.attr,
	&dev_attr_temp2.attr,
	&dev_attr_keyboard_activity.attr,
	&dev_attr_mouse_activity.attr,
	&dev_attr_calibrate.attr,
	&dev_attr_mousedev.attr,
	&dev_attr_mousedev_threshold.attr,
	&dev_attr_mousedev_poll_ms.attr,
	&dev_attr_invert.attr,
	NULL,
	};

	static struct attribute_group hdaps_attribute_group = {
	.attrs = hdaps_attributes,
	};


	/* Module stuff */

	/*
	* XXX: We should be able to return nonzero and halt the detection process.
	* But there is a bug in dmi_check_system() where a nonzero return from the
	* first match will result in a return of failure from dmi_check_system().
	* I fixed this; the patch is in 2.6-mm. Once in Linus's tree we can make
	* hdaps_dmi_match_invert() return hdaps_dmi_match(), which in turn returns 1.
	*/
	static int hdaps_dmi_match(struct dmi_system_id *id)
	{
	printk(KERN_INFO "hdaps: %s detected.\n", id->ident);
	return 0;
	}

	static int hdaps_dmi_match_invert(struct dmi_system_id *id)
	{
	hdaps_invert = 1;
	printk(KERN_INFO "hdaps: inverting axis readings.\n");
	return 0;
	}

	#define HDAPS_DMI_MATCH_NORMAL(model) { \
	.ident = "IBM " model, \
	.callback = hdaps_dmi_match, \
	.matches = { \
	DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
	DMI_MATCH(DMI_PRODUCT_VERSION, model) \
	} \
	}

	#define HDAPS_DMI_MATCH_INVERT(model) { \
	.ident = "IBM " model, \
	.callback = hdaps_dmi_match_invert, \
	.matches = { \
	DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
	DMI_MATCH(DMI_PRODUCT_VERSION, model) \
	} \
	}

	static int __init hdaps_init(void)
	{
	int ret;

	/* Note that DMI_MATCH(...,"ThinkPad T42") will match "ThinkPad T42p" */
	struct dmi_system_id hdaps_whitelist[] = {
	HDAPS_DMI_MATCH_INVERT("ThinkPad R50p"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad R50"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad R51"),
	HDAPS_DMI_MATCH_INVERT("ThinkPad T41p"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad T41"),
	HDAPS_DMI_MATCH_INVERT("ThinkPad T42p"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad T42"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad T43"),
	HDAPS_DMI_MATCH_NORMAL("ThinkPad X40"),
	{ .ident = NULL }
	};

	if (!dmi_check_system(hdaps_whitelist)) {
	printk(KERN_WARNING "hdaps: supported laptop not found!\n");
	ret = -ENXIO;
	goto out;
	}

	if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
	ret = -ENXIO;
	goto out;
	}

	ret = driver_register(&hdaps_driver);
	if (ret)
	goto out_region;

	pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
	if (IS_ERR(pdev)) {
	ret = PTR_ERR(pdev);
	goto out_driver;
	}

	ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
	if (ret)
	goto out_device;

	if (hdaps_mousedev)
	hdaps_mousedev_enable();

	printk(KERN_INFO "hdaps: driver successfully loaded.\n");
	return 0;

	out_device:
	platform_device_unregister(pdev);
	out_driver:
	driver_unregister(&hdaps_driver);
	out_region:
	release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
	out:
	printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret);
	return ret;
	}

	static void __exit hdaps_exit(void)
	{
	hdaps_mousedev_disable();

	sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
	platform_device_unregister(pdev);
	driver_unregister(&hdaps_driver);
	release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);

	printk(KERN_INFO "hdaps: driver unloaded.\n");
	}

	module_init(hdaps_init);
	module_exit(hdaps_exit);

	module_param_named(mousedev, hdaps_mousedev, bool, 0);
	MODULE_PARM_DESC(mousedev, "enable the input class device");

	module_param_named(invert, hdaps_invert, bool, 0);
	MODULE_PARM_DESC(invert, "invert data along each axis");

	MODULE_AUTHOR("Robert Love");
	MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
	MODULE_LICENSE("GPL v2");