Re: [PATCH 08/20] pinctrl: Assume map table entries can't have a NULL name field

From: Linus Walleij <linus.walleij@linaro.org>
To: Stephen Warren <swarren@nvidia.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>,
	B29396@freescale.com, s.hauer@pengutronix.de, dongas86@gmail.com,
	shawn.guo@linaro.org, thomas.abraham@linaro.org,
	tony@atomide.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/20] pinctrl: Assume map table entries can't have a NULL name field
Date: Mon, 20 Feb 2012 22:42:04 +0100	[thread overview]
Message-ID: <CACRpkdYK1epBfxPCu+cc3Edmd_9aZf4nvNyBx8O0sns5V+gNWw@mail.gmail.com> (raw)
In-Reply-To: <1329720360-23227-9-git-send-email-swarren@nvidia.com>

On Mon, Feb 20, 2012 at 7:45 AM, Stephen Warren <swarren@nvidia.com> wrote:

> pinctrl_register_mappings() already requires that every mapping table
> entry have a non-NULL name field.
>
> Logically, this makes sense too; drivers should always request a specific
> named state so they know what they're getting. Relying on getting the
> first mentioned state in the mapping table is error-prone, and a nasty
> special case to implement, given that a given the mapping table may define
> multiple states for a device.
>
> Update a few places in the code and documentation that still allowed for
> NULL name fields.
>
> Signed-off-by: Stephen Warren <swarren@nvidia.com>

This causes a regression on U300 and most certainly on the Sirf Prima II
as well. The U300 can be fixed up as per below:

diff --git a/arch/arm/mach-u300/core.c b/arch/arm/mach-u300/core.c
index bb1034f..66555d7 100644
--- a/arch/arm/mach-u300/core.c
+++ b/arch/arm/mach-u300/core.c
@@ -1645,7 +1645,7 @@ static int __init u300_pinctrl_fetch(void)
                struct pinctrl *p;
                int ret;

-               p = pinctrl_get(u300_mux_hogs[i].dev, NULL);
+               p = pinctrl_get(u300_mux_hogs[i].dev, u300_mux_hogs[i].name);
                if (IS_ERR(p)) {
                        pr_err("u300: could not get pinmux hog %s\n",
                               u300_mux_hogs[i].name);


The drivers/tty/serial/sirfsoc_uart.c asks for it's UART pinctrl like
this:

sirfport->p = pinctrl_get(&pdev->dev, NULL);

I don't know quite what to encode in there, if "deafult" is sensible
we might just

#define PIN_MAP_NAME_DEFAULT "default"
In <linux/pinctrl/consumer.h> and <linux/pinctrl/machine.h> alike,
maybe in some <linux/pinctrl/mapnames.h> that both of these
include?

the have the driver ask for:

sirfport->p = pinctrl_get(&pdev->dev, PIN_MAP_NAME_DEFAULT);

(Similar changes can be done for U300, naming all its map
"default".)

Yours,
Linus Walleij
