From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Nikolaus Schaller" Subject: [PATCH v9 2/8] drivers:input:tsc2007: check for presence and power down tsc2007 during probe Date: Wed, 28 Dec 2016 15:53:17 +0100 Message-ID: References: Return-path: In-Reply-To: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org To: Sebastian Reichel , Dmitry Torokhov , Mark Rutland , =?UTF-8?q?Beno=C3=AEt=20Cousson?= , Tony Lindgren , Russell King , Arnd Bergmann , Michael Welling , =?UTF-8?q?Mika=20Penttil=C3=A4?= , Javier Martinez Canillas , Igor Grinberg , "Andrew F. Davis" , Mark Brown , Jonathan Cameron , Rob Herring , "H. Nikolaus Schaller" , Alexander Stein , Eric Engestrom Cc: linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, letux-kernel@openphoenux.org, linux-iio@vger.kernel.org, kernel@pyra-handheld.com List-Id: linux-input@vger.kernel.org 1. check if chip is really present and don't succeed if it isn't. 2. if it succeeds, power down the chip until accessed Signed-off-by: H. Nikolaus Schaller --- drivers/input/touchscreen/tsc2007.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c index c1d9593..76b462b 100644 --- a/drivers/input/touchscreen/tsc2007.c +++ b/drivers/input/touchscreen/tsc2007.c @@ -529,6 +529,14 @@ static int tsc2007_probe(struct i2c_client *client, tsc2007_stop(ts); + /* power down the chip (TSC2007_SETUP does not ACK on I2C) */ + err = tsc2007_xfer(ts, PWRDOWN); + if (err < 0) { + dev_err(&client->dev, + "Failed to setup chip: %d\n", err); + return err; /* usually, chip does not respond */ + } + err = input_register_device(input_dev); if (err) { dev_err(&client->dev, -- 2.7.3