linux-kernel - [PATCH 0/2] pinctrl: sx150x: set multiple pins at once

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Message-ID: <1479830762-1839-1-git-send-email-peda@axentia.se>
Date:   Tue, 22 Nov 2016 17:06:00 +0100
From:   Peter Rosin <peda@...ntia.se>
To:     <linux-kernel@...r.kernel.org>
CC:     Peter Rosin <peda@...ntia.se>,
        Linus Walleij <linus.walleij@...aro.org>,
        Andrey Smirnov <andrew.smirnov@...il.com>,
        Neil Armstrong <narmstrong@...libre.com>,
        <linux-gpio@...r.kernel.org>
Subject: [PATCH 0/2] pinctrl: sx150x: set multiple pins at once

Hi!

I have only tested this on an 8-bit sx1502, so I'm uncertain if
the there needs to be locking for this to work as intended for
the bigger chips with an oscio pin? Probably.

So, I didn't add (or rather, removed) these lines at the end of
sx150x_gpio_set_multiple() and made the op optional instead.

	if (*mask & pctl->oscio_mask)
		sx150x_gpio_oscio_set(pctl, *bits & pctl->oscio_mask);

I mean, what happens if there are two users writing multiple pins
where one of the pins is the oscio pin, and this happens concurrently?
I get the feeling that there is nothing stopping interleaving in that
case, and you could end up with the desired values from user 1 for the
normal pins, and the desired value for the oscio pin from user 2.

But for the easy case (no oscio) where the existing regmap locking
holds, this is a nice speedup and desired behaviour without a lot
of individual pin changes.

Cheers,
Peter

Peter Rosin (2):
  pinctrl: sx150x: various spelling fixes and some white-space cleanup
  pinctrl: sx150x: support setting multiple pins at once

 drivers/pinctrl/pinctrl-sx150x.c | 50 ++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 15 deletions(-)

-- 
2.1.4