Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free.
So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate.
When doing this, I noticed that when calling pin_request():
!!gpio == (gpio_range != NULL)
... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free().
Also, for pin_free():
!!free_func == (gpio_range != NULL)
However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio().
Signed-off-by: Stephen Warren swarren@nvidia.com --- drivers/pinctrl/pinmux.c | 39 +++++++++++++++++++++++++-------------- include/linux/pinctrl/pinmux.h | 3 +++ 2 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index a5467f8..8a95e45 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -98,12 +98,11 @@ struct pinmux_hog { * @function: a functional name to give to this pin, passed to the driver * so it knows what function to mux in, e.g. the string "gpioNN" * means that you want to mux in the pin for use as GPIO number NN - * @gpio: if this request concerns a single GPIO pin * @gpio_range: the range matching the GPIO pin if this is a request for a * single GPIO pin */ static int pin_request(struct pinctrl_dev *pctldev, - int pin, const char *function, bool gpio, + int pin, const char *function, struct pinctrl_gpio_range *gpio_range) { struct pin_desc *desc; @@ -152,7 +151,7 @@ static int pin_request(struct pinctrl_dev *pctldev, * If there is no kind of request function for the pin we just assume * we got it by default and proceed. */ - if (gpio && ops->gpio_request_enable) + if (gpio_range && ops->gpio_request_enable) /* This requests and enables a single GPIO pin */ status = ops->gpio_request_enable(pctldev, gpio_range, pin); else if (ops->request) @@ -182,29 +181,39 @@ out: * pin_free() - release a single muxed in pin so something else can be muxed * @pctldev: pin controller device handling this pin * @pin: the pin to free - * @free_func: whether to free the pin's assigned function name string + * @gpio_range: the range matching the GPIO pin if this is a request for a + * single GPIO pin */ -static void pin_free(struct pinctrl_dev *pctldev, int pin, int free_func) +static const char *pin_free(struct pinctrl_dev *pctldev, int pin, + struct pinctrl_gpio_range *gpio_range) { const struct pinmux_ops *ops = pctldev->desc->pmxops; struct pin_desc *desc; + const char *func;
desc = pin_desc_get(pctldev, pin); if (desc == NULL) { dev_err(&pctldev->dev, "pin is not registered so it cannot be freed\n"); - return; + return NULL; }
- if (ops->free) + /* + * If there is no kind of request function for the pin we just assume + * we got it by default and proceed. + */ + if (gpio_range && ops->gpio_disable_free) + ops->gpio_disable_free(pctldev, gpio_range, pin); + else if (ops->free) ops->free(pctldev, pin);
spin_lock(&desc->lock); - if (free_func) - kfree(desc->mux_function); + func = desc->mux_function; desc->mux_function = NULL; spin_unlock(&desc->lock); module_put(pctldev->owner); + + return func; }
/** @@ -234,7 +243,7 @@ int pinmux_request_gpio(unsigned gpio) if (!function) return -EINVAL;
- ret = pin_request(pctldev, pin, function, true, range); + ret = pin_request(pctldev, pin, function, range); if (ret < 0) kfree(function);
@@ -252,6 +261,7 @@ void pinmux_free_gpio(unsigned gpio) struct pinctrl_gpio_range *range; int ret; int pin; + const char *func;
ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range); if (ret) @@ -260,7 +270,8 @@ void pinmux_free_gpio(unsigned gpio) /* Convert to the pin controllers number space */ pin = gpio - range->base;
- pin_free(pctldev, pin, true); + func = pin_free(pctldev, pin, range); + kfree(func); } EXPORT_SYMBOL_GPL(pinmux_free_gpio);
@@ -350,7 +361,7 @@ static int acquire_pins(struct pinctrl_dev *pctldev,
/* Try to allocate all pins in this group, one by one */ for (i = 0; i < num_pins; i++) { - ret = pin_request(pctldev, pins[i], func, false, NULL); + ret = pin_request(pctldev, pins[i], func, NULL); if (ret) { dev_err(&pctldev->dev, "could not get pin %d for function %s " @@ -360,7 +371,7 @@ static int acquire_pins(struct pinctrl_dev *pctldev, /* On error release all taken pins */ i--; /* this pin just failed */ for (; i >= 0; i--) - pin_free(pctldev, pins[i], false); + pin_free(pctldev, pins[i], NULL); return -ENODEV; } } @@ -390,7 +401,7 @@ static void release_pins(struct pinctrl_dev *pctldev, return; } for (i = 0; i < num_pins; i++) - pin_free(pctldev, pins[i], false); + pin_free(pctldev, pins[i], NULL); }
/** diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h index 3c430e7..350e32a 100644 --- a/include/linux/pinctrl/pinmux.h +++ b/include/linux/pinctrl/pinmux.h @@ -73,6 +73,9 @@ struct pinmux_ops { int (*gpio_request_enable) (struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned offset); + void (*gpio_disable_free) (struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range, + unsigned offset); };
/* External interface to pinmux */