1 // SPDX-License-Identifier: GPL-2.0-only
3  * hdaps.c - driver for IBM's Hard Drive Active Protection System
9  * starting with the R40, T41, and X40.  It provides a basic two-axis
31 #define HDAPS_NR_PORTS		0x30	/* number of ports: 0x1600 - 0x162f */
34 #define HDAPS_PORT_YPOS		0x1612	/* y-axis position */
35 #define	HDAPS_PORT_XPOS		0x1614	/* x-axis position */
37 #define HDAPS_PORT_YVAR		0x1617	/* y-axis variance (what is this?) */
38 #define HDAPS_PORT_XVAR		0x1619	/* x-axis variance (what is this?) */
71  * __get_latch - Get the value from a given port.  Callers must hold hdaps_mtx.
79  * __check_latch - Check a port latch for a given value.  Returns zero if the
86 	return -EINVAL;  in __check_latch()
90  * __wait_latch - Wait up to 100us for a port latch to get a certain value,
103 	return -EIO;  in __wait_latch()
107  * __device_refresh - request a refresh from the accelerometer.  Does not wait
120  * __device_refresh_sync - request a synchronous refresh from the
131  * __device_complete - indicate to the accelerometer that we are done reading
142  * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
152 	/* do a sync refresh -- we need to be sure that we read fresh data */  in hdaps_readb_one()
165 /* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
167 			     int *x, int *y)  in __hdaps_read_pair()  argument
169 	/* do a sync refresh -- we need to be sure that we read fresh data */  in __hdaps_read_pair()
171 		return -EIO;  in __hdaps_read_pair()
174 	*x = inw(port1);  in __hdaps_read_pair()
180 		*x = -*x;  in __hdaps_read_pair()
182 		*y = -*y;  in __hdaps_read_pair()
188  * hdaps_read_pair - reads the values from a pair of ports, placing the values
204  * hdaps_device_init - initialize the accelerometer.  Returns zero on success
209 	int total, ret = -ENXIO;  in hdaps_device_init()
221 	 * Others--namely the R50p, T41p, and T42p--return 0x03.  These laptops  in hdaps_device_init()
231 	printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x)\n",  in hdaps_device_init()
263 	for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {  in hdaps_device_init()
264 		int x, y;  in hdaps_device_init()  local
267 		__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);  in hdaps_device_init()
314  * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mtx.
323 	int x, y;  in hdaps_mousedev_poll()  local
327 	if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))  in hdaps_mousedev_poll()
330 	input_report_abs(input_dev, ABS_X, x - rest_x);  in hdaps_mousedev_poll()
331 	input_report_abs(input_dev, ABS_Y, y - rest_y);  in hdaps_mousedev_poll()
344 	int ret, x, y;  in hdaps_position_show()  local
346 	ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);  in hdaps_position_show()
350 	return sprintf(buf, "(%d,%d)\n", x, y);  in hdaps_position_show()
356 	int ret, x, y;  in hdaps_variance_show()  local
358 	ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);  in hdaps_variance_show()
362 	return sprintf(buf, "(%d,%d)\n", x, y);  in hdaps_variance_show()
436 		return -EINVAL;  in hdaps_invert_store()
472 /* hdaps_dmi_match - found a match.  return one, short-circuiting the hunt. */
475 	pr_info("%s detected\n", id->ident);  in hdaps_dmi_match()
479 /* hdaps_dmi_match_invert - found an inverted match. */
482 	hdaps_invert = (unsigned long)id->driver_data;  in hdaps_dmi_match_invert()
483 	pr_info("inverting axis (%u) readings\n", hdaps_invert);  in hdaps_dmi_match_invert()
537 		ret = -ENODEV;  in hdaps_init()
542 		ret = -ENXIO;  in hdaps_init()
556 	ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);  in hdaps_init()
562 		ret = -ENOMEM;  in hdaps_init()
570 	hdaps_idev->name = "hdaps";  in hdaps_init()
571 	hdaps_idev->phys = "isa1600/input0";  in hdaps_init()
572 	hdaps_idev->id.bustype = BUS_ISA;  in hdaps_init()
573 	hdaps_idev->dev.parent = &pdev->dev;  in hdaps_init()
575 			-256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);  in hdaps_init()
577 			-256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);  in hdaps_init()
595 	sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);  in hdaps_init()
610 	sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);  in hdaps_exit()
622 MODULE_PARM_DESC(invert, "invert data along each axis. 1 invert x-axis, "
623 		 "2 invert y-axis, 3 invert both axes.");