pinctrl: add explicit gpio_disable_free pinmux_op
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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index 17c3931..c77aee5 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -94,12 +94,11 @@
* @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;
@@ -143,7 +142,7 @@
* 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)
@@ -173,29 +172,39 @@
* 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;
}
/**
@@ -225,7 +234,7 @@
if (!function)
return -EINVAL;
- ret = pin_request(pctldev, pin, function, true, range);
+ ret = pin_request(pctldev, pin, function, range);
if (ret < 0)
kfree(function);
@@ -243,6 +252,7 @@
struct pinctrl_gpio_range *range;
int ret;
int pin;
+ const char *func;
ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
if (ret)
@@ -251,7 +261,8 @@
/* 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);
@@ -341,7 +352,7 @@
/* 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 "
@@ -351,7 +362,7 @@
/* 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;
}
}
@@ -381,7 +392,7 @@
return;
}
for (i = 0; i < num_pins; i++)
- pin_free(pctldev, pins[i], false);
+ pin_free(pctldev, pins[i], NULL);
}
/**