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| author | Philipp Zabel <p.zabel@pengutronix.de> | 2020-01-09 17:03:21 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-24 08:34:46 +0100 |
| commit | 45a6f48eebf8a4ae1419de0e9c52365a490b787a (patch) | |
| tree | dfc6ce882150e26b356fb1c560ac164c20d97e90 | |
| parent | 60a449170552a9ee35840342888a53e61e1253b2 (diff) | |
| download | linux-rt-45a6f48eebf8a4ae1419de0e9c52365a490b787a.tar.gz | |
Input: edt-ft5x06 - work around first register access error
[ Upstream commit e112324cc0422c046f1cf54c56f333d34fa20885 ]
The EP0700MLP1 returns bogus data on the first register read access
(reading the threshold parameter from register 0x00):
edt_ft5x06 2-0038: crc error: 0xfc expected, got 0x40
It ignores writes until then. This patch adds a dummy read after which
the number of sensors and parameter read/writes work correctly.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/input/touchscreen/edt-ft5x06.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c index 1e18ca0d1b4e..3fdaa644a82c 100644 --- a/drivers/input/touchscreen/edt-ft5x06.c +++ b/drivers/input/touchscreen/edt-ft5x06.c @@ -968,6 +968,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client, { const struct edt_i2c_chip_data *chip_data; struct edt_ft5x06_ts_data *tsdata; + u8 buf[2] = { 0xfc, 0x00 }; struct input_dev *input; unsigned long irq_flags; int error; @@ -1037,6 +1038,12 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client, return error; } + /* + * Dummy read access. EP0700MLP1 returns bogus data on the first + * register read access and ignores writes. + */ + edt_ft5x06_ts_readwrite(tsdata->client, 2, buf, 2, buf); + edt_ft5x06_ts_set_regs(tsdata); edt_ft5x06_ts_get_defaults(&client->dev, tsdata); edt_ft5x06_ts_get_parameters(tsdata); |