diff options
| author | Shaun Jackman <sjackman@gmail.com> | 2006-08-05 00:27:59 -0400 |
|---|---|---|
| committer | Dmitry Torokhov <dtor@insightbb.com> | 2006-08-05 00:27:59 -0400 |
| commit | 1ce316efb55a1497d07d518853e60a4356abceb6 (patch) | |
| tree | 5b80f90e5ddc7ff36b1ce30bdbf796d8741d7bc2 /drivers/input | |
| parent | 6b50d8b862284929314e9ff09e5b1cce2c43d32b (diff) | |
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>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/touchscreen/elo.c | 55 |
1 files changed, 29 insertions, 26 deletions
diff --git a/drivers/input/touchscreen/elo.c b/drivers/input/touchscreen/elo.c index b7ac016219d..fe6e1a42867 100644 --- a/drivers/input/touchscreen/elo.c +++ b/drivers/input/touchscreen/elo.c @@ -34,7 +34,11 @@ MODULE_LICENSE("GPL"); * 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. @@ -50,44 +54,43 @@ struct elo { 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; - elo->csum += elo->data[elo->idx] = data; - + elo->data[elo->idx] = data; switch (elo->idx++) { - case 0: - if (data != 'U') { - elo->idx = 0; - elo->csum = 0; - } - break; - - case 1: - if (data != 'T') { + elo->csum = 0xaa; + if (data != ELO10_LEAD_BYTE) { + pr_debug("elo: unsynchronized data: 0x%02x\n", data); elo->idx = 0; - elo->csum = 0; } break; 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->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; } + 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; @@ -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; @@ -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, 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) { case 0: |