Re: [PATCH 5/9] input: goodix: reset device at init

Mark Rutland
2015-05-28T13:19:50Z

Hi,

On Thu, May 28, 2015 at 01:47:41PM +0100, Irina Tirdea wrote:
> After power on, it is recommended that the driver resets the device.
> For reset the driver needs to control the interrupt and
> reset gpio pins (configured through ACPI/device tree).

Why is it necessary to mess with the GPIO the interrupts is wired up to?
What exactly does the device expect at reset w.r.t. the interrupt line?

>
> Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
> Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
> ---
> .../bindings/input/touchscreen/goodix.txt | 5 ++
> drivers/input/touchscreen/goodix.c | 99 ++++++++++++++++++++++
> 2 files changed, 104 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> index 8ba98ee..7137881 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> @@ -12,6 +12,8 @@ Required properties:
> - reg : I2C address of the chip. Should be 0x5d or 0x14
> - interrupt-parent : Interrupt controller to which the chip is connected
> - interrupts : Interrupt to which the chip is connected
> + - irq-gpio : GPIO pin used for IRQ
> + - reset-gpio : GPIO pin used for reset
>
> Example:
>
> @@ -23,6 +25,9 @@ Example:
> reg = <0x5d>;
> interrupt-parent = <&gpio>;
> interrupts = <0 0>;
> +
> + irq-gpio = <&gpio1 0 0>;
> + reset-gpio = <&gpio1 1 0>;
> };
>
> /* ... */
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index 9e7d215..4405c55 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -26,6 +26,7 @@
> #include <linux/acpi.h>
> #include <linux/of.h>
> #include <asm/unaligned.h>
> +#include <linux/gpio.h>

Nit: weird include ordering.

Mark.