Input: elo - fix checksum calculation

Fix 10-byte protocol checksum calculation and do not discard packet early
unless it is missing lead in byte.

Signed-off-by: Shaun Jackman <sjackman@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Shaun Jackman 2006-08-05 00:27:59 -04:00 коммит произвёл Dmitry Torokhov
Родитель 6b50d8b862
Коммит 1ce316efb5
1 изменённых файлов: 29 добавлений и 26 удалений

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@ -34,7 +34,11 @@ MODULE_LICENSE("GPL");
* Definitions & global arrays. * Definitions & global arrays.
*/ */
#define ELO_MAX_LENGTH 10 #define ELO_MAX_LENGTH 10
#define ELO10_LEAD_BYTE 'U'
#define ELO10_TOUCH_PACKET 'T'
/* /*
* Per-touchscreen data. * Per-touchscreen data.
@ -50,44 +54,43 @@ struct elo {
char phys[32]; char phys[32];
}; };
static void elo_process_data_10(struct elo* elo, unsigned char data, struct pt_regs *regs) static void elo_process_data_10(struct elo *elo, unsigned char data, struct pt_regs *regs)
{ {
struct input_dev *dev = elo->dev; struct input_dev *dev = elo->dev;
elo->csum += elo->data[elo->idx] = data; elo->data[elo->idx] = data;
switch (elo->idx++) { switch (elo->idx++) {
case 0: case 0:
if (data != 'U') { elo->csum = 0xaa;
if (data != ELO10_LEAD_BYTE) {
pr_debug("elo: unsynchronized data: 0x%02x\n", data);
elo->idx = 0; elo->idx = 0;
elo->csum = 0;
}
break;
case 1:
if (data != 'T') {
elo->idx = 0;
elo->csum = 0;
} }
break; break;
case 9: case 9:
if (elo->csum) {
input_regs(dev, regs);
input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
input_report_abs(dev, ABS_PRESSURE, (elo->data[8] << 8) | elo->data[7]);
input_report_key(dev, BTN_TOUCH, elo->data[8] || elo->data[7]);
input_sync(dev);
}
elo->idx = 0; elo->idx = 0;
elo->csum = 0; if (data != elo->csum) {
pr_debug("elo: bad checksum: 0x%02x, expected 0x%02x\n",
data, elo->csum);
break;
}
if (elo->data[1] != ELO10_TOUCH_PACKET) {
pr_debug(elo: "unexpected packet: 0x%02x\n", elo->data[1]);
break;
}
input_regs(dev, regs);
input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
input_report_abs(dev, ABS_PRESSURE, (elo->data[8] << 8) | elo->data[7]);
input_report_key(dev, BTN_TOUCH, elo->data[8] || elo->data[7]);
input_sync(dev);
break; break;
} }
elo->csum += data;
} }
static void elo_process_data_6(struct elo* elo, unsigned char data, struct pt_regs *regs) static void elo_process_data_6(struct elo *elo, unsigned char data, struct pt_regs *regs)
{ {
struct input_dev *dev = elo->dev; struct input_dev *dev = elo->dev;
@ -135,7 +138,7 @@ static void elo_process_data_6(struct elo* elo, unsigned char data, struct pt_re
} }
} }
static void elo_process_data_3(struct elo* elo, unsigned char data, struct pt_regs *regs) static void elo_process_data_3(struct elo *elo, unsigned char data, struct pt_regs *regs)
{ {
struct input_dev *dev = elo->dev; struct input_dev *dev = elo->dev;
@ -161,7 +164,7 @@ static void elo_process_data_3(struct elo* elo, unsigned char data, struct pt_re
static irqreturn_t elo_interrupt(struct serio *serio, static irqreturn_t elo_interrupt(struct serio *serio,
unsigned char data, unsigned int flags, struct pt_regs *regs) unsigned char data, unsigned int flags, struct pt_regs *regs)
{ {
struct elo* elo = serio_get_drvdata(serio); struct elo *elo = serio_get_drvdata(serio);
switch(elo->id) { switch(elo->id) {
case 0: case 0: