pinctrl: allow exlusive GPIO/mux pin allocation
Disallow simultaneous use of the the GPIO and peripheral mux
functions by setting a flag "strict" in struct pinctrl_desc.
The blackfin pinmux and gpio controller doesn't allow user to
set up a pin for both GPIO and peripheral function. So, add flag
strict in struct pinctrl_desc to check both gpio_owner and
mux_owner before approving the pin request.
v2-changes:
- if strict flag is set, check gpio_owner and mux_onwer in if and
else clause
v3-changes:
- add kerneldoc for this struct
- augment Documentation/pinctrl.txt
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index b874458..2546fa7 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -107,6 +107,13 @@
desc->name, desc->gpio_owner, owner);
goto out;
}
+ if (pctldev->desc->strict && desc->mux_usecount &&
+ strcmp(desc->mux_owner, owner)) {
+ dev_err(pctldev->dev,
+ "pin %s already requested by %s; cannot claim for %s\n",
+ desc->name, desc->mux_owner, owner);
+ goto out;
+ }
desc->gpio_owner = owner;
} else {
@@ -116,6 +123,12 @@
desc->name, desc->mux_owner, owner);
goto out;
}
+ if (pctldev->desc->strict && desc->gpio_owner) {
+ dev_err(pctldev->dev,
+ "pin %s already requested by %s; cannot claim for %s\n",
+ desc->name, desc->gpio_owner, owner);
+ goto out;
+ }
desc->mux_usecount++;
if (desc->mux_usecount > 1)