4.9-stable review patch. If anyone has any objections, please let me know.
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From: Brian Norris briannorris@chromium.org
[ 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@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 --- drivers/pinctrl/pinctrl-rockchip.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/pinctrl/pinctrl-rockchip.c +++ b/drivers/pinctrl/pinctrl-rockchip.c @@ -1278,8 +1278,16 @@ 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)); }