lkml.org 
[lkml]   [2023]   [May]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v3 08/11] serial: sc16is7xx: fix regression with GPIO configuration
Thu, May 25, 2023 at 12:03:22AM -0400, Hugo Villeneuve kirjoitti:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
>
> Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> changed the function of the GPIOs pins to act as modem control
> lines without any possibility of selecting GPIO function.
>
> As a consequence, applications that depends on GPIO lines configured
> by default as GPIO pins no longer work as expected.
>
> Also, the change to select modem control lines function was done only
> for channel A of dual UART variants (752/762). This was not documented
> in the log message.

> This new patch allows to specify GPIO or modem control line function
> in the device tree, and for each of the ports (A or B).

Imperative mood as stated in documentation, please.
Like "Allow to specify...".

> This is done by using the new device-tree property named
> "modem-control-line-ports" (property added in separate patch).
>
> We also now reduce the number of exported GPIOs according to the
> modem-status-line-port DT property.
>
> Boards that need to have GPIOS configured as modem control lines
> should add that property to their device tree. Here is a list of
> boards using the sc16is7xx driver in their device tree and that may
> need to be modified:
> arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
> mips/boot/dts/ingenic/cu1830-neo.dts
> mips/boot/dts/ingenic/cu1000-neo.dts

...

> +#ifdef CONFIG_GPIOLIB

I'm wondering if we can avoid adding new ifdefferies...

> + s->gpio_configured = devtype->nr_gpio;

The name of the variable is a bit vague WRT its content.
Shouldn't be as simple as the rvalue, i.e. s->nr_gpio?

> +#endif /* CONFIG_GPIOLIB */

...

> + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> + prop, p, u)

The driver so far is agnostic to property provider. Please keep it that way,
i.e. no of_ APIs.

> + if (u < devtype->nr_uart) {

Hmm... What other can it be?

> + /* Use GPIO lines as modem control lines */
> + if (u == 0)
> + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> + else if (u == 1)
> + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> +
> +#ifdef CONFIG_GPIOLIB
> + if (s->gpio_configured >=
> + SC16IS7XX_GPIOS_PER_BANK)

On one line it will be better to read. Esp. taking into account the above remark.

> + s->gpio_configured -=
> + SC16IS7XX_GPIOS_PER_BANK;

Ditto.

> +#endif /* CONFIG_GPIOLIB */
> + }

--
With Best Regards,
Andy Shevchenko


\
 
 \ /
  Last update: 2023-05-25 13:21    [W:0.402 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site