[PATCH] hdaps driver update

 * 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.

 * T41, T42, T43, R50, R50p, 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

 * This driver is 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.

 *

#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_NR_PORTS		0x30	/* number of ports: 0x1600 - 0x162f */

#define HDAPS_PORT_STATE	0x1611	/* device state */

#define HDAPS_PORT_YPOS		0x1612	/* y-axis position */

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

#define KEYBD_MASK		0x20	/* set if keyboard activity */

#define MOUSE_MASK		0x40	/* set if mouse activity */

#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;

#define HDAPS_POLL_PERIOD	(HZ/20)	/* poll for input every 1/20s */

#define HDAPS_INPUT_FUZZ	4	/* input event threshold */

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 struct platform_device *pdev;

static unsigned int hdaps_invert;

static u8 km_activity;

static int rest_x;

 */

static inline u8 __get_latch(u16 port)

{

	return inb(port) & HDAPS_READ_MASK;

	return inb(port) & 0xff;

}

/*

 * __check_latch - Check a port latch for a given value.  Callers must hold

 * hdaps_sem.  Returns zero if the port contains the given value.

 * __check_latch - Check a port latch for a given value.  Returns zero if the

 * port contains the given value.  Callers must hold hdaps_sem.

 */

static inline unsigned int __check_latch(u16 port, u8 val)

static inline int __check_latch(u16 port, u8 val)

{

	if (__get_latch(port) == val)

		return 0;

 * __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)

static int __wait_latch(u16 port, u8 val)

{

	unsigned int i;

		udelay(5);

	}

	return -EINVAL;

	return -EIO;

}

/*

 * __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.

 * __device_refresh - request a refresh from the accelerometer.  Does not wait

 * for refresh to complete.  Callers must hold hdaps_sem.

 */

static int __device_refresh(unsigned int sync)

static void __device_refresh(void)

{

	u8 state;

	udelay(100);

	state = inb(0x1604);

	if (state == STATE_FRESH)

		return 0;

	udelay(200);

	if (inb(0x1604) != STATE_FRESH) {

		outb(0x11, 0x1610);

		outb(0x01, 0x161f);

	if (sync == REFRESH_ASYNC)

		return 0;

	}

}

/*

 * __device_refresh_sync - request a synchronous refresh from the

 * accelerometer.  We wait for the refresh to complete.  Returns zero if

 * successful and nonzero on error.  Callers must hold hdaps_sem.

 */

static int __device_refresh_sync(void)

{

	__device_refresh();

	return __wait_latch(0x1604, STATE_FRESH);

}

/*

 * __device_complete - Indicate to the accelerometer that we are done reading

 * __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;

	__device_refresh();

}

/*

	int ret;

	down(&hdaps_sem);

	ret = __hdaps_readb_one(port, val);

	up(&hdaps_sem);

	/* do a sync refresh -- we need to be sure that we read fresh data */

	ret = __device_refresh_sync();

	if (ret)

		goto out;

	*val = inb(port);

	__device_complete();

out:

	up(&hdaps_sem);

	return ret;

}

/* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */

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))

	if (__device_refresh_sync())

		return -EIO;

	*y = inw(port2);

	return ret;

}

/* initialize the accelerometer */

/*

 * hdaps_device_init - initialize the accelerometer.  Returns zero on success

 * and negative error code on failure.  Can sleep.

 */

static int hdaps_device_init(void)

{

	unsigned int total_msecs = INIT_TIMEOUT_MSECS;

	int ret = -ENXIO;

	int total, ret = -ENXIO;

	down(&hdaps_sem);

		goto out;

	/*

	 * The 0x03 value appears to only work on some thinkpads, such as the

	 * T42p.  Others return 0x01.

	 * Most ThinkPads return 0x01.

	 *

	 * Others--namely the R50p, T41p, and T42p--return 0x03.  These laptops

	 * have "inverted" axises.

	 *

	 * The 0x02 value occurs when the chip has been previously initialized.

	 */

	outb(0x01, 0x161f);

	if (__wait_latch(0x161f, 0x00))

		goto out;

	if (__device_refresh(REFRESH_SYNC))

	if (__device_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;

	for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {

		int x, y;

		/* a read of the device helps push it into action */

		__hdaps_readb_one(HDAPS_PORT_UNKNOWN, &ignored);

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

		if (!__wait_latch(0x1611, 0x02)) {

			ret = 0;

			break;

		}

		msleep(INIT_WAIT_MSECS);

		total_msecs -= INIT_WAIT_MSECS;

	}

out:

}

/* 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)

	.resume = hdaps_resume

};

/* Input class stuff */

static struct input_dev hdaps_idev = {

	.name = "hdaps",

	.evbit = { BIT(EV_ABS) },

	.absbit = { BIT(ABS_X) | BIT(ABS_Y) },

	.absmin  = { [ABS_X] = -256, [ABS_Y] = -256 },

	.absmax  = { [ABS_X] = 256, [ABS_Y] = 256 },

	.absfuzz = { [ABS_X] = HDAPS_INPUT_FUZZ, [ABS_Y] = HDAPS_INPUT_FUZZ },

	.absflat = { [ABS_X] = HDAPS_INPUT_FUZZ, [ABS_Y] = HDAPS_INPUT_FUZZ },

};

/*

 * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_sem.

 */

static void hdaps_calibrate(void)

{

	__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_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 + HDAPS_POLL_PERIOD);

		return;

	}

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

		goto out;

	input_report_abs(&hdaps_idev, ABS_X, x - rest_x);

	input_report_abs(&hdaps_idev, ABS_Y, y - rest_y);

	input_sync(&hdaps_idev);

	mod_timer(&hdaps_timer, jiffies + HDAPS_POLL_PERIOD);

out:

	up(&hdaps_sem);

}

/* Sysfs Files */

	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(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_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,

};

 * 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

 * I fixed this; the patch is 2.6-git.  Once in a released 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)

		HDAPS_DMI_MATCH_NORMAL("ThinkPad T42"),

		HDAPS_DMI_MATCH_NORMAL("ThinkPad T43"),

		HDAPS_DMI_MATCH_NORMAL("ThinkPad X40"),

		HDAPS_DMI_MATCH_NORMAL("ThinkPad X41 Tablet"),

		{ .ident = NULL }

	};

	if (ret)

		goto out_device;

	if (hdaps_mousedev)

		hdaps_mousedev_enable();

	/* initial calibrate for the input device */

	hdaps_calibrate();

	/* initialize the input class */

	hdaps_idev.dev = &pdev->dev;

	input_register_device(&hdaps_idev);

	/* start up our timer for the input device */

	init_timer(&hdaps_timer);

	hdaps_timer.function = hdaps_mousedev_poll;

	hdaps_timer.expires = jiffies + HDAPS_POLL_PERIOD;

	add_timer(&hdaps_timer);

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

	return 0;

static void __exit hdaps_exit(void)

{

	hdaps_mousedev_disable();

	del_timer_sync(&hdaps_timer);

	input_unregister_device(&hdaps_idev);

	sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);

	platform_device_unregister(pdev);

	driver_unregister(&hdaps_driver);

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");