diff options
author | Linus Walleij <linus.walleij@linaro.org> | 2011-11-14 10:06:22 +0100 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2012-01-03 09:10:01 +0100 |
commit | 542e704f3ffee1dc4539c9e8191e4dc215220f5e (patch) | |
tree | da2f8aae8bedb6e3216b4808dc743eb94c3270e3 /include/linux/pinctrl | |
parent | 75d6642a3ee1dfe2552028997cdcc2c4207bec8f (diff) |
pinctrl: GPIO direction support for muxing
When requesting a single GPIO pin to be muxed in, some controllers
will need to poke a different value into the control register
depending on whether the pin will be used for GPIO output or GPIO
input. So create pinmux counterparts to gpio_direction_[input|output]
in the pinctrl framework.
ChangeLog v1->v2:
- This also amends the documentation to make it clear the this
function and associated machinery is *ONLY* intended as a backend
to gpiolib machinery, not for everyone and his dog to start playing
around with pins.
ChangeLog v2->v3:
- Don't pass an argument to the common request function, instead
provide pinmux_* counterparts to the gpio_direction_[input|output]
calls, simpler and anyone can understand it.
ChangeLog v3->v4:
- Fix numerous spelling mistakes and dangling text in documentation.
Add Ack and Rewewed-by.
Cc: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'include/linux/pinctrl')
-rw-r--r-- | include/linux/pinctrl/pinmux.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h index bb7a9792f1e..937b3e2fa36 100644 --- a/include/linux/pinctrl/pinmux.h +++ b/include/linux/pinctrl/pinmux.h @@ -54,7 +54,13 @@ struct pinctrl_dev; * Implement this only if you can mux every pin individually as GPIO. The * affected GPIO range is passed along with an offset(pin number) into that * specific GPIO range - function selectors and pin groups are orthogonal - * to this, the core will however make sure the pins do not collide + * to this, the core will however make sure the pins do not collide. + * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of + * @gpio_request_enable + * @gpio_set_direction: Since controllers may need different configurations + * depending on whether the GPIO is configured as input or output, + * a direction selector function may be implemented as a backing + * to the GPIO controllers that need pin muxing. */ struct pinmux_ops { int (*request) (struct pinctrl_dev *pctldev, unsigned offset); @@ -76,11 +82,17 @@ struct pinmux_ops { void (*gpio_disable_free) (struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned offset); + int (*gpio_set_direction) (struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range, + unsigned offset, + bool input); }; /* External interface to pinmux */ extern int pinmux_request_gpio(unsigned gpio); extern void pinmux_free_gpio(unsigned gpio); +extern int pinmux_gpio_direction_input(unsigned gpio); +extern int pinmux_gpio_direction_output(unsigned gpio); extern struct pinmux * __must_check pinmux_get(struct device *dev, const char *name); extern void pinmux_put(struct pinmux *pmx); extern int pinmux_enable(struct pinmux *pmx); @@ -97,6 +109,16 @@ static inline void pinmux_free_gpio(unsigned gpio) { } +static inline int pinmux_gpio_direction_input(unsigned gpio) +{ + return 0; +} + +static inline int pinmux_gpio_direction_output(unsigned gpio) +{ + return 0; +} + static inline struct pinmux * __must_check pinmux_get(struct device *dev, const char *name) { return NULL; |