pinctrl: Don't copy function name when requesting a pin

Instead, store a pointer to the currently assigned function.

This allows us to delete the mux_requested variable from pin_desc; a pin
is requested if its currently assigned function is non-NULL.

When a pin is requested as a GPIO rather than a regular function, the
assigned function name is dynamically constructed. In this case, we have
to kstrdup() the dynamically constructed name, so that mux_function doesn't
pointed at stack data. This requires pin_free to be told whether to free
the mux_function pointer or not.

This removes the hard-coded maximum function name length.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index e431aa537287..472fa1341cc0 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -59,8 +59,7 @@ struct pin_desc {
         spinlock_t lock;
         /* These fields only added when supporting pinmux drivers */
 #ifdef CONFIG_PINMUX
-        bool    mux_requested;
-        char    mux_function[16];
+        const char *mux_function;
 #endif
 };