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pinctrl: rockchip: enable clock when reading pin direction register

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[ Upstream commit 5c9d8c4f6b ]

We generally leave the GPIO clock disabled, unless an interrupt is
requested or we're accessing IO registers. We forgot to do this for the
->get_direction() callback, which means we can sometimes [1] get
incorrect results [2] from, e.g., /sys/kernel/debug/gpio.

Enable the clock, so we get the right results!

[1] Sometimes, because many systems have 1 or mor interrupt requested on
each GPIO bank, so they always leave their clock on.

[2] Incorrect, meaning the register returns 0, and so we interpret that
as "input".

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Brian Norris 2017-12-12 09:43:43 -08:00 committed by Greg Kroah-Hartman
parent 130e535210
commit 915bd53d68
1 changed files with 8 additions and 0 deletions
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8
drivers/pinctrl/pinctrl-rockchip.c
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@ -1989,8 +1989,16 @@ static int rockchip_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
u32 data;
int ret;
ret = clk_enable(bank->clk);
if (ret < 0) {
dev_err(bank->drvdata->dev,
"failed to enable clock for bank %s\n", bank->name);
return ret;
}
data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
clk_disable(bank->clk);
return !(data & BIT(offset));
}