From: Linus Walleij <linus.walleij@linaro.org>
To: Sander Vanheule <sander@svanheule.net>
Cc: "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Rob Herring <robh+dt@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Marc Zyngier <maz@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Bert Vermeulen <bert@biot.com>
Subject: Re: [PATCH 2/2] gpio: Add Realtek Otto GPIO support
Date: Mon, 15 Mar 2021 16:10:27 +0100 [thread overview]
Message-ID: <CACRpkdZ7zWQPBgQ+AjFM7up8x8HJES2EDfBKGmPU9LJwWzB8EA@mail.gmail.com> (raw)
In-Reply-To: <20210315082339.9787-3-sander@svanheule.net>
On Mon, Mar 15, 2021 at 9:26 AM Sander Vanheule <sander@svanheule.net> wrote:
> Realtek MIPS SoCs (platform name Otto) have GPIO controllers with up to
> 64 GPIOs, divided over two banks. Each bank has a set of registers for
> 32 GPIOs, with support for edge-triggered interrupts.
>
> Each GPIO bank consists of four 8-bit GPIO ports (ABCD and EFGH). Most
> registers pack one bit per GPIO, except for the IMR register, which
> packs two bits per GPIO (AB-CD).
>
> Although the byte order is currently assumed to have port A..D at offset
> 0x0..0x3, this has been observed to be reversed on other, Lexra-based,
> SoCs (e.g. RTL8196E/97D/97F).
>
> Interrupt support is disabled for the fallback devicetree-compatible
> 'realtek,otto-gpio'. This allows for quick support of GPIO banks in
> which the byte order would be unknown. In this case, the port ordering
> in the IMR registers may not match the reversed order in the other
> registers (DCBA, and BA-DC or DC-BA).
>
> Signed-off-by: Sander Vanheule <sander@svanheule.net>
Overall this is a beautiful driver and it makes use of all the generic
frameworks I can think of. I don't see any reason not to merge
it so:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
The following is some notes and nitpicks, nothing blocking any
merge, more like discussion.
> +enum realtek_gpio_flags {
> + GPIO_INTERRUPTS = BIT(0),
> +};
I suppose this looks like this because more flags will be introduced
when you add more functionality to the driver. Otherwise it seems
like overkill so a bool would suffice.
I would add a comment /* TODO: this will be expanded */
> +static inline u32 realtek_gpio_imr_bits(unsigned int pin, u32 value)
> +{
> + return ((value & 0x3) << 2*(pin % 16));
> +}
I would explain a bit about this, obviouslt it is two bit per
line, but it took me some time to parse, so a comment
about the bit layout would be nice.
> + unsigned int offset = pin/16;
Here that number appears again.
The use of GPIO_GENERIC and GPIO irqchip is flawless
and first class.
Thanks!
Linus Walleij
next prev parent reply other threads:[~2021-03-15 15:11 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 8:23 [PATCH 0/2] Add Realtek Otto GPIO support Sander Vanheule
2021-03-15 8:23 ` [PATCH 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-15 15:01 ` Linus Walleij
2021-03-15 8:23 ` [PATCH 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-15 15:10 ` Linus Walleij [this message]
2021-03-15 19:09 ` Sander Vanheule
2021-03-15 19:08 ` [PATCH v2 0/2] " Sander Vanheule
2021-03-15 19:08 ` [PATCH v2 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-24 18:29 ` Rob Herring
2021-03-15 19:08 ` [PATCH v2 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-17 13:08 ` Andy Shevchenko
2021-03-19 15:51 ` Sander Vanheule
2021-03-19 17:57 ` Andy Shevchenko
2021-03-19 21:20 ` Sander Vanheule
2021-03-19 21:24 ` Andy Shevchenko
2021-03-19 21:48 ` Sander Vanheule
2021-03-22 13:16 ` Andy Shevchenko
2021-03-24 21:22 ` [PATCH v3 0/2] " Sander Vanheule
2021-03-24 21:22 ` [PATCH v3 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-24 21:22 ` [PATCH v3 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-24 21:29 ` Sander Vanheule
2021-03-26 12:03 ` [PATCH v4 0/2] " Sander Vanheule
2021-03-26 12:03 ` [PATCH v4 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-27 18:16 ` Rob Herring
2021-03-26 12:03 ` [PATCH v4 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-26 18:19 ` Andy Shevchenko
2021-03-26 21:11 ` Sander Vanheule
2021-03-29 10:26 ` Andy Shevchenko
2021-03-29 17:28 ` Sander Vanheule
2021-03-30 10:14 ` Andy Shevchenko
2021-03-30 15:26 ` [PATCH v5 0/2] " Sander Vanheule
2021-03-30 15:26 ` [PATCH v5 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-30 15:26 ` [PATCH v5 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-30 16:43 ` Andy Shevchenko
2021-03-30 17:48 ` [PATCH v6 0/2] " Sander Vanheule
2021-03-30 17:48 ` [PATCH v6 1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO Sander Vanheule
2021-03-30 17:48 ` [PATCH v6 2/2] gpio: Add Realtek Otto GPIO support Sander Vanheule
2021-03-31 7:49 ` [PATCH v6 0/2] " Bartosz Golaszewski
2021-03-31 8:11 ` Sander Vanheule
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