From mboxrd@z Thu Jan 1 00:00:00 1970 From: crag0715@gmail.com Subject: [PATCH] input: touchscreen: add delay time to device power on Date: Wed, 10 Jul 2019 10:58:59 +0800 Message-ID: <20190710025859.6025-1-crag0715@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org Cc: mario_limonciello@dell.com, chrome.os.engineering@dell.com, "Crag.Wang" , Sangwon Jee , Dmitry Torokhov , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org From: "Crag.Wang" Delay time for MELFAS MIP4 controller is required at power on stage regardless the existence of GPIO consumer lookup from devicetree or ACPI device table. There is an issue if GPIO ce is undefined in the ACPI results no delay time for deive power on, the controller ended up in an abnormal state. TEST=echo i2c-MLFS0000:00 > /sys/bus/i2c/drivers/mip4_ts/unbind verify the touch function is off echo i2c-MLFS0000:00 > /sys/bus/i2c/drivers/mip4_ts/bind verify the touch function is on Signed-off-by: Crag.Wang --- drivers/input/touchscreen/melfas_mip4.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/input/touchscreen/melfas_mip4.c b/drivers/input/touchscreen/melfas_mip4.c index 430a2bc5f7ca..8e803658fb43 100644 --- a/drivers/input/touchscreen/melfas_mip4.c +++ b/drivers/input/touchscreen/melfas_mip4.c @@ -374,12 +374,11 @@ static int mip4_query_device(struct mip4_ts *ts) static int mip4_power_on(struct mip4_ts *ts) { - if (ts->gpio_ce) { + if (ts->gpio_ce) gpiod_set_value_cansleep(ts->gpio_ce, 1); - /* Booting delay : 200~300ms */ - usleep_range(200 * 1000, 300 * 1000); - } + /* Booting delay : 200~300ms */ + usleep_range(200 * 1000, 300 * 1000); return 0; } -- 2.20.1