| From d949722b0857bc2165927cda77fd67d9759eca53 Mon Sep 17 00:00:00 2001 |
| From: Philipp Zabel <p.zabel@pengutronix.de> |
| Date: Thu, 9 Jan 2020 17:03:21 -0800 |
| Subject: [PATCH] Input: edt-ft5x06 - work around first register access error |
| |
| commit e112324cc0422c046f1cf54c56f333d34fa20885 upstream. |
| |
| 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c |
| index c639ebce914c..522f0f04c61e 100644 |
| --- a/drivers/input/touchscreen/edt-ft5x06.c |
| +++ b/drivers/input/touchscreen/edt-ft5x06.c |
| @@ -1047,6 +1047,7 @@ 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; |
| @@ -1116,6 +1117,12 @@ 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); |
| -- |
| 2.7.4 |
| |
