Commit c3a39380 authored by Richard Leitner's avatar Richard Leitner Committed by Dmitry Torokhov

Input: sx8654 - add reset-gpio support

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: default avatarRichard Leitner <richard.leitner@skidata.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 4dbb7119
...@@ -5,6 +5,9 @@ Required properties: ...@@ -5,6 +5,9 @@ Required properties:
- reg: i2c slave address - reg: i2c slave address
- interrupts: touch controller interrupt - interrupts: touch controller interrupt
Optional properties:
- reset-gpios: GPIO specification for the NRST input
Example: Example:
sx8654@48 { sx8654@48 {
...@@ -12,4 +15,5 @@ Example: ...@@ -12,4 +15,5 @@ Example:
reg = <0x48>; reg = <0x48>;
interrupt-parent = <&gpio6>; interrupt-parent = <&gpio6>;
interrupts = <3 IRQ_TYPE_EDGE_FALLING>; interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
reset-gpios = <&gpio4 2 GPIO_ACTIVE_LOW>;
}; };
...@@ -27,12 +27,14 @@ ...@@ -27,12 +27,14 @@
* published by the Free Software Foundation. * published by the Free Software Foundation.
*/ */
#include <linux/input.h> #include <linux/delay.h>
#include <linux/module.h> #include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/i2c.h> #include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/irq.h> #include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
/* register addresses */ /* register addresses */
#define I2C_REG_TOUCH0 0x00 #define I2C_REG_TOUCH0 0x00
...@@ -74,6 +76,7 @@ ...@@ -74,6 +76,7 @@
struct sx8654 { struct sx8654 {
struct input_dev *input; struct input_dev *input;
struct i2c_client *client; struct i2c_client *client;
struct gpio_desc *gpio_reset;
}; };
static irqreturn_t sx8654_irq(int irq, void *handle) static irqreturn_t sx8654_irq(int irq, void *handle)
...@@ -124,6 +127,25 @@ static irqreturn_t sx8654_irq(int irq, void *handle) ...@@ -124,6 +127,25 @@ static irqreturn_t sx8654_irq(int irq, void *handle)
return IRQ_HANDLED; 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);
} else {
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;
}
return 0;
}
static int sx8654_open(struct input_dev *dev) static int sx8654_open(struct input_dev *dev)
{ {
struct sx8654 *sx8654 = input_get_drvdata(dev); struct sx8654 *sx8654 = input_get_drvdata(dev);
...@@ -186,6 +208,17 @@ static int sx8654_probe(struct i2c_client *client, ...@@ -186,6 +208,17 @@ static int sx8654_probe(struct i2c_client *client,
if (!sx8654) if (!sx8654)
return -ENOMEM; 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); input = devm_input_allocate_device(&client->dev);
if (!input) if (!input)
return -ENOMEM; return -ENOMEM;
...@@ -206,10 +239,9 @@ static int sx8654_probe(struct i2c_client *client, ...@@ -206,10 +239,9 @@ static int sx8654_probe(struct i2c_client *client,
input_set_drvdata(sx8654->input, sx8654); input_set_drvdata(sx8654->input, sx8654);
error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET, error = sx8654_reset(sx8654);
SOFTRESET_VALUE);
if (error) { if (error) {
dev_err(&client->dev, "writing softreset value failed"); dev_err(&client->dev, "reset failed");
return error; return error;
} }
......
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