blob: 416fca097a867d4d3a137cd86783dafe5197a26d [file] [log] [blame]
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