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Commit 5d2eaf80 authored by Stephen Warren's avatar Stephen Warren Committed by Linus Walleij
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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: default avatarStephen Warren <swarren@nvidia.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 9af1e44f

drivers/pinctrl/core.h

+1 −2
Original line number Diff line number Diff line
@@ -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

};

drivers/pinctrl/pinmux.c

+23 −13
Original line number Diff line number Diff line
@@ -130,14 +130,13 @@ static int pin_request(struct pinctrl_dev *pctldev, 
	}



	spin_lock(&desc->lock);

	if (desc->mux_requested) {

	if (desc->mux_function) {

		spin_unlock(&desc->lock);

		dev_err(&pctldev->dev,

			"pin already requested\n");

		goto out;

	}

	desc->mux_requested = true;

	strncpy(desc->mux_function, function, sizeof(desc->mux_function));

	desc->mux_function = function;

	spin_unlock(&desc->lock);



	/* Let each pin increase references to this module */
@@ -168,8 +167,7 @@ static int pin_request(struct pinctrl_dev *pctldev, 
out_free_pin:

	if (status) {

		spin_lock(&desc->lock);

		desc->mux_requested = false;

		desc->mux_function[0] = '\0';

		desc->mux_function = NULL;

		spin_unlock(&desc->lock);

	}

out:
@@ -184,8 +182,9 @@ static int pin_request(struct pinctrl_dev *pctldev, 
 * 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

 */

static void pin_free(struct pinctrl_dev *pctldev, int pin)

static void pin_free(struct pinctrl_dev *pctldev, int pin, int free_func)

{

	const struct pinmux_ops *ops = pctldev->desc->pmxops;

	struct pin_desc *desc;
@@ -201,8 +200,9 @@ static void pin_free(struct pinctrl_dev *pctldev, int pin) 
		ops->free(pctldev, pin);



	spin_lock(&desc->lock);

	desc->mux_requested = false;

	desc->mux_function[0] = '\0';

	if (free_func)

		kfree(desc->mux_function);

	desc->mux_function = NULL;

	spin_unlock(&desc->lock);

	module_put(pctldev->owner);

}
@@ -214,6 +214,7 @@ static void pin_free(struct pinctrl_dev *pctldev, int pin) 
int pinmux_request_gpio(unsigned gpio)

{

	char gpiostr[16];

	const char *function;

	struct pinctrl_dev *pctldev;

	struct pinctrl_gpio_range *range;

	int ret;
@@ -229,7 +230,15 @@ int pinmux_request_gpio(unsigned gpio) 
	/* Conjure some name stating what chip and pin this is taken by */

	snprintf(gpiostr, 15, "%s:%d", range->name, gpio);



	return pin_request(pctldev, pin, gpiostr, true, range);

	function = kstrdup(gpiostr, GFP_KERNEL);

	if (!function)

		return -EINVAL;



	ret = pin_request(pctldev, pin, function, true, range);

	if (ret < 0)

		kfree(function);



	return ret;

}

EXPORT_SYMBOL_GPL(pinmux_request_gpio);
@@ -251,7 +260,7 @@ void pinmux_free_gpio(unsigned gpio) 
	/* Convert to the pin controllers number space */

	pin = gpio - range->base;



	pin_free(pctldev, pin);

	pin_free(pctldev, pin, true);

}

EXPORT_SYMBOL_GPL(pinmux_free_gpio);
@@ -351,7 +360,7 @@ 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]);

				pin_free(pctldev, pins[i], false);

			return -ENODEV;

		}

	}
@@ -381,7 +390,7 @@ static void release_pins(struct pinctrl_dev *pctldev, 
		return;

	}

	for (i = 0; i < num_pins; i++)

		pin_free(pctldev, pins[i]);

		pin_free(pctldev, pins[i], false);

}



/**
@@ -1013,7 +1022,8 @@ static int pinmux_pins_show(struct seq_file *s, void *what) 


		seq_printf(s, "pin %d (%s): %s\n", pin,

			   desc->name ? desc->name : "unnamed",

			   desc->mux_requested ? desc->mux_function : "UNCLAIMED");

			   desc->mux_function ? desc->mux_function

					      : "UNCLAIMED");

	}



	return 0;