[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20200227132241.932215524@linuxfoundation.org>
Date: Thu, 27 Feb 2020 14:35:46 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Philipp Zabel <p.zabel@...gutronix.de>,
Marco Felsch <m.felsch@...gutronix.de>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 072/165] Input: edt-ft5x06 - work around first register access error
From: Philipp Zabel <p.zabel@...gutronix.de>
[ 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@...gutronix.de>
Signed-off-by: Marco Felsch <m.felsch@...gutronix.de>
Tested-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/input/touchscreen/edt-ft5x06.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 28466e358fee1..22c8d2070faac 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -887,6 +887,7 @@ 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;
@@ -956,6 +957,12 @@ 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);
--
2.20.1
Powered by blists - more mailing lists