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    Subject[PATCH] Input: egalax_ts - do not release gpio if probe successful
    Date
    Thus preventing anyone to later modify the interrupt GPIO direction
    and/or state without the driver knowing.

    Also checking if device is present before allocating the input device.

    Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
    ---
    drivers/input/touchscreen/egalax_ts.c | 56 ++++++++++++++++-------------------
    1 file changed, 25 insertions(+), 31 deletions(-)

    diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
    index 1afc08b08155..f6b94bb19bd8 100644
    --- a/drivers/input/touchscreen/egalax_ts.c
    +++ b/drivers/input/touchscreen/egalax_ts.c
    @@ -62,6 +62,7 @@
    struct egalax_ts {
    struct i2c_client *client;
    struct input_dev *input_dev;
    + struct gpio_desc *wakeup_gpio;
    };

    static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
    @@ -120,36 +121,21 @@ static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
    }

    /* wake up controller by an falling edge of interrupt gpio. */
    -static int egalax_wake_up_device(struct i2c_client *client)
    +static int egalax_wake_up_device(struct gpio_desc *wakeup_gpio)
    {
    - struct device_node *np = client->dev.of_node;
    - int gpio;
    int ret;

    - if (!np)
    - return -ENODEV;
    -
    - gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
    - if (!gpio_is_valid(gpio))
    - return -ENODEV;
    -
    - ret = gpio_request(gpio, "egalax_irq");
    - if (ret < 0) {
    - dev_err(&client->dev,
    - "request gpio failed, cannot wake up controller: %d\n",
    - ret);
    + /* wake up controller via an falling edge on IRQ gpio. */
    + ret = gpiod_direction_output(wakeup_gpio, 0);
    + if (ret < 0)
    return ret;
    - }

    - /* wake up controller via an falling edge on IRQ gpio. */
    - gpio_direction_output(gpio, 0);
    - gpio_set_value(gpio, 1);
    + gpiod_set_value(wakeup_gpio, 1);

    /* controller should be waken up, return irq. */
    - gpio_direction_input(gpio);
    - gpio_free(gpio);
    + ret = gpiod_direction_input(wakeup_gpio);

    - return 0;
    + return ret;
    }

    static int egalax_firmware_version(struct i2c_client *client)
    @@ -177,17 +163,15 @@ static int egalax_ts_probe(struct i2c_client *client,
    return -ENOMEM;
    }

    - input_dev = devm_input_allocate_device(&client->dev);
    - if (!input_dev) {
    - dev_err(&client->dev, "Failed to allocate memory\n");
    - return -ENOMEM;
    + ts->wakeup_gpio = devm_gpiod_get_index(&client->dev, "wakeup",
    + 0, GPIOD_ASIS);
    + if (IS_ERR(ts->wakeup_gpio)) {
    + dev_err(&client->dev, "Failed to get wakeup gpio");
    + return -ENODEV;
    }

    - ts->client = client;
    - ts->input_dev = input_dev;
    -
    /* controller may be in sleep, wake it up. */
    - error = egalax_wake_up_device(client);
    + error = egalax_wake_up_device(ts->wakeup_gpio);
    if (error) {
    dev_err(&client->dev, "Failed to wake up the controller\n");
    return error;
    @@ -199,6 +183,15 @@ static int egalax_ts_probe(struct i2c_client *client,
    return error;
    }

    + input_dev = devm_input_allocate_device(&client->dev);
    + if (!input_dev) {
    + dev_err(&client->dev, "Failed to allocate memory\n");
    + return -ENOMEM;
    + }
    +
    + ts->client = client;
    + ts->input_dev = input_dev;
    +
    input_dev->name = "EETI eGalax Touch Screen";
    input_dev->id.bustype = BUS_I2C;

    @@ -254,8 +247,9 @@ static int __maybe_unused egalax_ts_suspend(struct device *dev)
    static int __maybe_unused egalax_ts_resume(struct device *dev)
    {
    struct i2c_client *client = to_i2c_client(dev);
    + struct egalax_ts *ts = i2c_get_clientdata(client);

    - return egalax_wake_up_device(client);
    + return egalax_wake_up_device(ts->wakeup_gpio);
    }

    static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
    --
    2.11.0
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