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Date: Mon, 20 Apr 2009 15:00:56 -0400
From: "H Hartley Sweeten" <hartleys@...ionengravers.com>
To: <linux-kernel@...r.kernel.org>
Cc: <dbrownell@...rs.sourceforge.net>
Subject: [PATCH] gpiolib: Introduce a GPIO "port" concept
gpiolib: Introduce a GPIO "port" concept.
Some drivers will use all the GPIOs in a given GPIOLIB chip as
a port. Allow them to request/free these GPIOs with a single
call. For both functions any valid GPIO in the chip needs to
be passed.
Signed-off-by: H Hartley Sweeten <hsweeten@...ionengravers.com>
---
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 51a8d41..cd16e83 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -49,6 +49,7 @@ struct gpio_desc {
#define FLAG_RESERVED 2
#define FLAG_EXPORT 3 /* protected by sysfs_lock */
#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control
*/
+#define FLAG_IS_PORT 5
#ifdef CONFIG_DEBUG_FS
const char *label;
@@ -859,6 +860,84 @@ void gpio_free(unsigned gpio)
}
EXPORT_SYMBOL_GPL(gpio_free);
+int gpio_port_request(unsigned gpio, const char *label)
+{
+ struct gpio_desc *desc;
+ struct gpio_chip *chip;
+ int status = -EINVAL;
+ unsigned long flags;
+ unsigned _gpio;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (!gpio_is_valid(gpio))
+ goto done;
+ desc = &gpio_desc[gpio];
+ chip = desc->chip;
+ if (chip == NULL)
+ goto done;
+
+ for (_gpio = chip->base; _gpio < chip->base + chip->ngpio;
_gpio++) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ status = gpio_request(_gpio, label);
+ if (status < 0)
+ goto err;
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ desc = &gpio_desc[_gpio];
+ set_bit(FLAG_IS_PORT, &desc->flags);
+ }
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return 0;
+
+err:
+ /* free any GPIOs that may have been successfully requested */
+ for ( ; _gpio >= chip->base; _gpio--)
+ gpio_free(_gpio);
+ spin_lock_irqsave(&gpio_lock, flags);
+done:
+ pr_debug("gpio_port_request: gpio-%d (%s) status %d\n",
+ gpio, label ? : "?", status);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ return status;
+}
+EXPORT_SYMBOL_GPL(gpio_port_request);
+
+void gpio_port_free(unsigned gpio)
+{
+ unsigned long flags;
+ struct gpio_desc *desc;
+ struct gpio_chip *chip;
+ unsigned _gpio;
+
+ might_sleep();
+
+ if (!gpio_is_valid(gpio)) {
+ WARN_ON(extra_checks);
+ return;
+ }
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ desc = &gpio_desc[gpio];
+ chip = desc->chip;
+
+ for (_gpio = chip->base; _gpio < chip->base + chip->ngpio;
_gpio++) {
+ desc = &gpio_desc[_gpio];
+ if (!test_bit(FLAG_IS_PORT, &desc->flags))
+ WARN_ON(extra_checks);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ gpio_free(_gpio);
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ clear_bit(FLAG_IS_PORT, &desc->flags);
+ }
+ spin_unlock_irqrestore(&gpio_lock, flags);
+}
+EXPORT_SYMBOL_GPL(gpio_port_free);
+
/**
* gpiochip_is_requested - return string iff signal was requested
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d6c379d..9f7ebd5 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -116,6 +116,9 @@ extern int __must_check gpiochip_remove(struct
gpio_chip *chip);
extern int gpio_request(unsigned gpio, const char *label);
extern void gpio_free(unsigned gpio);
+extern int gpio_port_request(unsigned gpio, const char *label);
+extern void gpio_port_free(unsigned gpio);
+
extern int gpio_direction_input(unsigned gpio);
extern int gpio_direction_output(unsigned gpio, int value);
Download attachment "gpiolib_ports.patch" of type "application/octet-stream" (2969 bytes)
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