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Date: Wed, 19 Oct 2011 16:19:28 -0600
From: Stephen Warren <swarren@...dia.com>
To: Linus Walleij <linus.walleij@...ricsson.com>,
Linus Walleij <linus.walleij@...aro.org>
Cc: linux-kernel@...r.kernel.org, Barry Song <21cnbao@...il.com>,
Shawn Guo <shawn.guo@...escale.com>,
Sascha Hauer <s.hauer@...gutronix.de>,
David Brown <davidb@...eaurora.org>,
Grant Likely <grant.likely@...retlab.ca>,
Rongjun Ying <Rongjun.Ying@....com>,
Linaro Dev <linaro-dev@...ts.linaro.org>,
Stephen Warren <swarren@...dia.com>
Subject: [PATCH 4/4] 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 <swarren@...dia.com>
---
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 a493ba6..783c075 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 4679ae6..f139609 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;
--
1.7.0.4
--
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