This is a note to let you know that I've just added the patch titled
pinctrl: rockchip: enable clock when reading pin direction register
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pinctrl-rockchip-enable-clock-when-reading-pin-direction-register.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Mar 22 14:26:48 CET 2018
From: Brian Norris <briannorris@xxxxxxxxxxxx>
Date: Tue, 12 Dec 2017 09:43:43 -0800
Subject: pinctrl: rockchip: enable clock when reading pin direction register
From: Brian Norris <briannorris@xxxxxxxxxxxx>
[ Upstream commit 5c9d8c4f6b8168738a26bcf288516cc3a0886810 ]
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@xxxxxxxxxxxx>
Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pinctrl/pinctrl-rockchip.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/pinctrl/pinctrl-rockchip.c
+++ b/drivers/pinctrl/pinctrl-rockchip.c
@@ -1989,8 +1989,16 @@ static int rockchip_gpio_get_direction(s
{
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));
}
Patches currently in stable-queue which might be from briannorris@xxxxxxxxxxxx are
queue-4.14/pinctrl-rockchip-enable-clock-when-reading-pin-direction-register.patch
queue-4.14/platform-chrome-use-proper-protocol-transfer-function.patch