Re: [PATCH] USB: serial: cp210x: Make the CP210x driver work with GPIOs of CP2108

From: Johan Hovold
Date: Fri Mar 05 2021 - 05:00:12 EST


On Thu, Mar 04, 2021 at 09:50:47AM +0000, Pho Tran wrote:
> Similar to other CP210x devices, GPIO interfaces (gpiochip) should be
> supported for CP2108.
>
> CP2108 has 4 serial interfaces but only 1 set of GPIO pins are shared
> to all of those interfaces. So, just need to initialize GPIOs of CP2108
> with only one interface (I use interface 0). It means just only 1 gpiochip
> device file will be created for CP2108.
>
> CP2108 has 16 GPIOs, So data types of several variables need to be is u16
> instead of u8(in struct cp210x_serial_private). This doesn't affect other
> CP210x devices.
>
> Because CP2108 has 16 GPIO pins, the parameter passed by cp210x functions
> will be different from other CP210x devices. So need to check part number
> of the device to use correct data format before sending commands to
> devices.
>
> Like CP2104, CP2108 have GPIO pins with configurable options. Therefore,
> should be mask all pins which are not in GPIO mode in cp2108_gpio_init()
> function.
>
> Signed-off-by: Pho Tran <pho.tran@xxxxxxxxxx>
> ---

Which version is this and what changed since the previous one? Always
include a patch revision in the Subject when resending (e.g.
"[PATCH v3]: USB: ...") and add a short changelog here.

I tried not to look at the code but I still see some overly long lines
(e.g. comments beyond 80 cols).

Johan