[PATCH 18/47] Updates to the tsdev driver (raw protocol, calib ioctls, ...)

From: Vojtech Pavlik
Date: Thu Jul 29 2004 - 13:25:04 EST

You can pull this changeset from:
bk://kernel.bkbits.net/vojtech/input

===================================================================

ChangeSet@xxxxxxxxxxxx, 2004-06-06 11:56:42+02:00, zap@xxxxxxxxxxx
input:

From: Andrew Zabolotny <zap@xxxxxxxxxxx>

- Implement the 'raw' touchscreen protocol for backward compatibility
(/dev/input/ts[0-7] now speaks the protocol of the old /dev/h3600_ts, and
the /dev/input/tsraw[0-7] speaks the protocol of the old /dev/h3600_tsraw
device).

- Support the ioctls for setting the calibration parameters. The default
calibration matrix is computed from the xres,yres parameters (duplicate the
old behaviour), however this is not enough for a good translation from
touchscreen space to screen space.

- Fixed a old bug in tsdev: on a pen motion event X1,Y1 -> X2,Y2 the driver
would output three events with coordinates: X1,Y1, X2,Y1, X2,Y2. This
happened not only with coordinates, but with pressure too.

- Update James's email address

- Remove mention of Transvirtual Technologies: they no longer exist.

Signed-off-by: Vojtech Pavlik <vojtech@xxxxxxx>


tsdev.c | 291 ++++++++++++++++++++++++++++++++++++++++------------------------
1 files changed, 186 insertions(+), 105 deletions(-)

===================================================================

diff -Nru a/drivers/input/tsdev.c b/drivers/input/tsdev.c
--- a/drivers/input/tsdev.c Thu Jul 29 14:40:58 2004
+++ b/drivers/input/tsdev.c Thu Jul 29 14:40:58 2004
@@ -3,9 +3,17 @@
*
* Copyright (c) 2001 "Crazy" james Simmons
*
- * Input driver to Touchscreen device driver module.
+ * Compaq touchscreen protocol driver. The protocol emulated by this driver
+ * is obsolete; for new programs use the tslib library which can read directly
+ * from evdev and perform dejittering, variance filtering and calibration -
+ * all in user space, not at kernel level. The meaning of this driver is
+ * to allow usage of newer input drivers with old applications that use the
+ * old /dev/h3600_ts and /dev/h3600_tsraw devices.
*
- * Sponsored by Transvirtual Technology
+ * 09-Apr-2004: Andrew Zabolotny <zap@xxxxxxxxxxx>
+ * Fixed to actually work, not just output random numbers.
+ * Added support for both h3600_ts and h3600_tsraw protocol
+ * emulation.
*/

/*
@@ -24,11 +32,13 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so either by
- * e-mail - mail your message to <jsimmons@xxxxxxxxxxxxxxxx>.
+ * e-mail - mail your message to <jsimmons@xxxxxxxxxxxxx>.
*/

#define TSDEV_MINOR_BASE 128
#define TSDEV_MINORS 32
+/* First 16 devices are h3600_ts compatible; second 16 are h3600_tsraw */
+#define TSDEV_MINOR_MASK 15
#define TSDEV_BUFFER_SIZE 64

#include <linux/slab.h>
@@ -52,48 +62,84 @@
#define CONFIG_INPUT_TSDEV_SCREEN_Y 320
#endif

+/* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
+ * devices. The first one must output X/Y data in 'cooked' format, e.g.
+ * filtered, dejittered and calibrated. Second device just outputs raw
+ * data received from the hardware.
+ *
+ * This driver doesn't support filtering and dejittering; it supports only
+ * calibration. Filtering and dejittering must be done in the low-level
+ * driver, if needed, because it may gain additional benefits from knowing
+ * the low-level details, the nature of noise and so on.
+ *
+ * The driver precomputes a calibration matrix given the initial xres and
+ * yres values (quite innacurate for most touchscreens) that will result
+ * in a more or less expected range of output values. The driver supports
+ * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
+ * new one, supposedly generated from the values taken from the raw device.
+ */
+
MODULE_AUTHOR("James Simmons <jsimmons@xxxxxxxxxxxxxxxx>");
MODULE_DESCRIPTION("Input driver to touchscreen converter");
MODULE_LICENSE("GPL");

static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
module_param(xres, uint, 0);
-MODULE_PARM_DESC(xres, "Horizontal screen resolution");
+MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");

static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
module_param(yres, uint, 0);
-MODULE_PARM_DESC(yres, "Vertical screen resolution");
+MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");
+
+/* From Compaq's Touch Screen Specification version 0.2 (draft) */
+struct ts_event {
+ short pressure;
+ short x;
+ short y;
+ short millisecs;
+};
+
+struct ts_calibration {
+ int xscale;
+ int xtrans;
+ int yscale;
+ int ytrans;
+ int xyswap;
+};

struct tsdev {
int exist;
int open;
int minor;
- char name[16];
+ char name[8];
wait_queue_head_t wait;
struct list_head list;
struct input_handle handle;
+ int x, y, pressure;
+ struct ts_calibration cal;
};

-/* From Compaq's Touch Screen Specification version 0.2 (draft) */
-typedef struct {
- short pressure;
- short x;
- short y;
- short millisecs;
-} TS_EVENT;
-
struct tsdev_list {
struct fasync_struct *fasync;
struct list_head node;
struct tsdev *tsdev;
int head, tail;
- int oldx, oldy, pendown;
- TS_EVENT event[TSDEV_BUFFER_SIZE];
+ struct ts_event event[TSDEV_BUFFER_SIZE];
+ int raw;
};

+/* The following ioctl codes are defined ONLY for backward compatibility.
+ * Don't use tsdev for new developement; use the tslib library instead.
+ * Touchscreen calibration is a fully userspace task.
+ */
+/* Use 'f' as magic number */
+#define IOC_H3600_TS_MAGIC 'f'
+#define TS_GET_CAL _IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
+#define TS_SET_CAL _IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)
+
static struct input_handler tsdev_handler;

-static struct tsdev *tsdev_table[TSDEV_MINORS];
+static struct tsdev *tsdev_table[TSDEV_MINORS/2];

static int tsdev_fasync(int fd, struct file *file, int on)
{
@@ -109,13 +155,16 @@
int i = iminor(inode) - TSDEV_MINOR_BASE;
struct tsdev_list *list;

- if (i >= TSDEV_MINORS || !tsdev_table[i])
+ if (i >= TSDEV_MINORS || !tsdev_table[i & TSDEV_MINOR_MASK])
return -ENODEV;

if (!(list = kmalloc(sizeof(struct tsdev_list), GFP_KERNEL)))
return -ENOMEM;
memset(list, 0, sizeof(struct tsdev_list));

+ list->raw = (i >= TSDEV_MINORS/2) ? 1 : 0;
+
+ i &= TSDEV_MINOR_MASK;
list->tsdev = tsdev_table[i];
list_add_tail(&list->node, &tsdev_table[i]->list);
file->private_data = list;
@@ -169,11 +218,13 @@
if (!list->tsdev->exist)
return -ENODEV;

- while (list->head != list->tail && retval + sizeof(TS_EVENT) <= count) {
- if (copy_to_user (buffer + retval, list->event + list->tail, sizeof(TS_EVENT)))
+ while (list->head != list->tail &&
+ retval + sizeof (struct ts_event) <= count) {
+ if (copy_to_user (buffer + retval, list->event + list->tail,
+ sizeof (struct ts_event)))
return -EFAULT;
list->tail = (list->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
- retval += sizeof(TS_EVENT);
+ retval += sizeof (struct ts_event);
}

return retval;
@@ -193,22 +244,27 @@
static int tsdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
-/*
struct tsdev_list *list = file->private_data;
- struct tsdev *evdev = list->tsdev;
- struct input_dev *dev = tsdev->handle.dev;
- int retval;
-
+ struct tsdev *tsdev = list->tsdev;
+ int retval = 0;
+
switch (cmd) {
- case HHEHE:
- return 0;
- case hjff:
- return 0;
- default:
- return 0;
+ case TS_GET_CAL:
+ if (copy_to_user ((void *)arg, &tsdev->cal,
+ sizeof (struct ts_calibration)))
+ retval = -EFAULT;
+ break;
+ case TS_SET_CAL:
+ if (copy_from_user (&tsdev->cal, (void *)arg,
+ sizeof (struct ts_calibration)))
+ retval = -EFAULT;
+ break;
+ default:
+ retval = -EINVAL;
+ break;
}
-*/
- return -EINVAL;
+
+ return retval;
}

struct file_operations tsdev_fops = {
@@ -227,82 +283,85 @@
struct tsdev *tsdev = handle->private;
struct tsdev_list *list;
struct timeval time;
- int size;

- list_for_each_entry(list, &tsdev->list, node) {
- switch (type) {
- case EV_ABS:
- switch (code) {
- case ABS_X:
- if (!list->pendown)
- return;
- size = handle->dev->absmax[ABS_X] - handle->dev->absmin[ABS_X];
- if (size > 0)
- list->oldx = ((value - handle->dev->absmin[ABS_X]) * xres / size);
- else
- list->oldx = ((value - handle->dev->absmin[ABS_X]));
- break;
- case ABS_Y:
- if (!list->pendown)
- return;
- size = handle->dev->absmax[ABS_Y] - handle->dev->absmin[ABS_Y];
- if (size > 0)
- list->oldy = ((value - handle->dev->absmin[ABS_Y]) * yres / size);
- else
- list->oldy = ((value - handle->dev->absmin[ABS_Y]));
- break;
- case ABS_PRESSURE:
- list->pendown = ((value > handle->dev-> absmin[ABS_PRESSURE])) ?
- value - handle->dev->absmin[ABS_PRESSURE] : 0;
- break;
- }
+ switch (type) {
+ case EV_ABS:
+ switch (code) {
+ case ABS_X:
+ tsdev->x = value;
+ break;
+ case ABS_Y:
+ tsdev->y = value;
+ break;
+ case ABS_PRESSURE:
+ if (value > handle->dev->absmax[ABS_PRESSURE])
+ value = handle->dev->absmax[ABS_PRESSURE];
+ value -= handle->dev->absmin[ABS_PRESSURE];
+ if (value < 0)
+ value = 0;
+ tsdev->pressure = value;
+ break;
+ }
+ break;
+
+ case EV_REL:
+ switch (code) {
+ case REL_X:
+ tsdev->x += value;
+ if (tsdev->x < 0)
+ tsdev->x = 0;
+ else if (tsdev->x > xres)
+ tsdev->x = xres;
+ break;
+ case REL_Y:
+ tsdev->y += value;
+ if (tsdev->y < 0)
+ tsdev->y = 0;
+ else if (tsdev->y > yres)
+ tsdev->y = yres;
break;
+ }
+ break;

- case EV_REL:
- switch (code) {
- case REL_X:
- if (!list->pendown)
- return;
- list->oldx += value;
- if (list->oldx < 0)
- list->oldx = 0;
- else if (list->oldx > xres)
- list->oldx = xres;
+ case EV_KEY:
+ if (code == BTN_TOUCH || code == BTN_MOUSE) {
+ switch (value) {
+ case 0:
+ tsdev->pressure = 0;
break;
- case REL_Y:
- if (!list->pendown)
- return;
- list->oldy += value;
- if (list->oldy < 0)
- list->oldy = 0;
- else if (list->oldy > xres)
- list->oldy = xres;
+ case 1:
+ if (!tsdev->pressure)
+ tsdev->pressure = 1;
break;
}
- break;
-
- case EV_KEY:
- if (code == BTN_TOUCH || code == BTN_MOUSE) {
- switch (value) {
- case 0:
- list->pendown = 0;
- break;
- case 1:
- if (!list->pendown)
- list->pendown = 1;
- break;
- case 2:
- return;
- }
- } else
- return;
- break;
}
+ break;
+ }
+
+ if (type != EV_SYN || code != SYN_REPORT)
+ return;
+
+ list_for_each_entry(list, &tsdev->list, node) {
+ int x, y, tmp;
+
do_gettimeofday(&time);
list->event[list->head].millisecs = time.tv_usec / 100;
- list->event[list->head].pressure = list->pendown;
- list->event[list->head].x = list->oldx;
- list->event[list->head].y = list->oldy;
+ list->event[list->head].pressure = tsdev->pressure;
+
+ x = tsdev->x;
+ y = tsdev->y;
+
+ /* Calibration */
+ if (!list->raw) {
+ x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
+ y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
+ if (tsdev->cal.xyswap) {
+ tmp = x; x = y; y = tmp;
+ }
+ }
+
+ list->event[list->head].x = x;
+ list->event[list->head].y = y;
list->head = (list->head + 1) & (TSDEV_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
}
@@ -314,11 +373,11 @@
struct input_device_id *id)
{
struct tsdev *tsdev;
- int minor;
+ int minor, delta;

- for (minor = 0; minor < TSDEV_MINORS && tsdev_table[minor];
+ for (minor = 0; minor < TSDEV_MINORS/2 && tsdev_table[minor];
minor++);
- if (minor == TSDEV_MINORS) {
+ if (minor >= TSDEV_MINORS/2) {
printk(KERN_ERR
"tsdev: You have way too many touchscreens\n");
return NULL;
@@ -340,10 +399,25 @@
tsdev->handle.handler = handler;
tsdev->handle.private = tsdev;

+ /* Precompute the rough calibration matrix */
+ delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
+ if (delta == 0)
+ delta = 1;
+ tsdev->cal.xscale = (xres << 8) / delta;
+ tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
+
+ delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
+ if (delta == 0)
+ delta = 1;
+ tsdev->cal.yscale = (yres << 8) / delta;
+ tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
+
tsdev_table[minor] = tsdev;
-
+
devfs_mk_cdev(MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
S_IFCHR|S_IRUGO|S_IWUSR, "input/ts%d", minor);
+ devfs_mk_cdev(MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor + TSDEV_MINORS/2),
+ S_IFCHR|S_IRUGO|S_IWUSR, "input/tsraw%d", minor);
class_simple_device_add(input_class,
MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
dev->dev, "ts%d", minor);
@@ -362,6 +436,7 @@
wake_up_interruptible(&tsdev->wait);
} else
tsdev_free(tsdev);
+ devfs_remove("input/tsraw%d", tsdev->minor);
}

static struct input_device_id tsdev_ids[] = {
@@ -378,6 +453,12 @@
.keybit = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
.absbit = { BIT(ABS_X) | BIT(ABS_Y) },
},/* A tablet like device, at least touch detection, two absolute axes */
+
+ {
+ .flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
+ .evbit = { BIT(EV_ABS) },
+ .absbit = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
+ },/* A tablet like device with several gradations of pressure */

{},/* Terminating entry */
};

-
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