From 5d2eaf8090874f8e65388e82f7e91f9cef74885e Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 19 Oct 2011 16:19:28 -0600 Subject: [PATCH] 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 Signed-off-by: Linus Walleij --- drivers/pinctrl/core.h | 3 +-- drivers/pinctrl/pinmux.c | 36 +++++++++++++++++++++++------------- 2 files changed, 24 insertions(+), 15 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 }; diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 90fb00d9a8a2..a5467f8709e9 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -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 @@ 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 */ -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; -- 2.34.1