From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Leitner Subject: [RESEND PATCH v2 2/8] Input: sx8654 - add reset-gpio support Date: Tue, 18 Dec 2018 09:36:00 +0100 Message-ID: <20181218083606.25795-3-richard.leitner@skidata.com> References: <20181218083606.25795-1-richard.leitner@skidata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181218083606.25795-1-richard.leitner@skidata.com> Sender: linux-kernel-owner@vger.kernel.org To: dmitry.torokhov@gmail.com, mark.rutland@arm.com Cc: robh+dt@kernel.org, linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, richard.leitner@skidata.com List-Id: linux-input@vger.kernel.org The sx8654 features a NRST input which may be connected to a GPIO. Therefore add support for hard-resetting the sx8654 via this NRST. If the reset-gpio property is provided the sx8654 is resetted via NRST instead of the soft-reset via I2C. Signed-off-by: Richard Leitner --- drivers/input/touchscreen/sx8654.c | 40 +++++++++++++++++++++++++++++++++++--- 1 file changed, 37 insertions(+), 3 deletions(-) diff --git a/drivers/input/touchscreen/sx8654.c b/drivers/input/touchscreen/sx8654.c index ed29db3ec731..238f56b1581b 100644 --- a/drivers/input/touchscreen/sx8654.c +++ b/drivers/input/touchscreen/sx8654.c @@ -33,6 +33,8 @@ #include #include #include +#include +#include /* register addresses */ #define I2C_REG_TOUCH0 0x00 @@ -74,6 +76,7 @@ struct sx8654 { struct input_dev *input; struct i2c_client *client; + struct gpio_desc *gpio_reset; }; static irqreturn_t sx8654_irq(int irq, void *handle) @@ -124,6 +127,27 @@ static irqreturn_t sx8654_irq(int irq, void *handle) return IRQ_HANDLED; } +static int sx8654_reset(struct sx8654 *ts) +{ + int err; + + if (ts->gpio_reset) { + gpiod_set_value_cansleep(ts->gpio_reset, 1); + udelay(2); /* Tpulse > 1µs */ + gpiod_set_value_cansleep(ts->gpio_reset, 0); + + return 0; + } + + dev_dbg(&ts->client->dev, "NRST unavailable, try softreset\n"); + err = i2c_smbus_write_byte_data(ts->client, I2C_REG_SOFTRESET, + SOFTRESET_VALUE); + if (err) + return err; + else + return 0; +} + static int sx8654_open(struct input_dev *dev) { struct sx8654 *sx8654 = input_get_drvdata(dev); @@ -186,6 +210,17 @@ static int sx8654_probe(struct i2c_client *client, if (!sx8654) return -ENOMEM; + sx8654->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(sx8654->gpio_reset)) { + error = PTR_ERR(sx8654->gpio_reset); + if (error != -EPROBE_DEFER) + dev_err(&client->dev, "unable to get reset-gpio: %d\n", + error); + return error; + } + dev_dbg(&client->dev, "got GPIO reset pin\n"); + input = devm_input_allocate_device(&client->dev); if (!input) return -ENOMEM; @@ -206,10 +241,9 @@ static int sx8654_probe(struct i2c_client *client, input_set_drvdata(sx8654->input, sx8654); - error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET, - SOFTRESET_VALUE); + error = sx8654_reset(sx8654); if (error) { - dev_err(&client->dev, "writing softreset value failed"); + dev_err(&client->dev, "reset failed"); return error; } -- 2.11.0