[PATCH RFC/RFT] pinctrl: qcom: make the pinmuxing strict

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

The strict flag in struct pinmux_ops disallows the usage of the same pin
as a GPIO and for another function. Without it, a rouge user-space
process with enough privileges (or even a buggy driver) can request a
used pin as GPIO and drive it, potentially confusing devices or even
crashing the system. Set it globally for all pinctrl-msm users.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
Having discussed this with Bjorn and Konrad - it seems the consensus is
that it makes sense to set this flag in pinctrl-msm. I'm marking this
patch as an RFC/RFT as I'm a bit afraid existing use-cases could break
with it but I suggest we give it a shot and see what happens.

 drivers/pinctrl/qcom/pinctrl-msm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index f713c80d7f3ed..b78492dc05adc 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -293,6 +293,7 @@ static const struct pinmux_ops msm_pinmux_ops = {
 	.get_function_groups	= msm_get_function_groups,
 	.gpio_request_enable	= msm_pinmux_request_gpio,
 	.set_mux		= msm_pinmux_set_mux,
+	.strict			= true,
 };
 
 static int msm_config_reg(struct msm_pinctrl *pctrl,
-- 
2.48.1