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Message-ID: <f17812d70711131704l6b0562ffmec6e7e1981130898@mail.gmail.com>
Date: Wed, 14 Nov 2007 09:04:41 +0800
From: "eric miao" <eric.y.miao@...il.com>
To: "David Brownell" <david-b@...bell.net>
Cc: "Linux Kernel list" <linux-kernel@...r.kernel.org>,
"Felipe Balbi" <felipebalbi@...rs.sourceforge.net>,
"Bill Gatliff" <bgat@...lgatliff.com>,
"Haavard Skinnemoen" <hskinnemoen@...el.com>,
"Andrew Victor" <andrew@...people.com>,
"Tony Lindgren" <tony@...mide.com>,
"Jean Delvare" <khali@...ux-fr.org>,
"Kevin Hilman" <khilman@...sta.com>,
"Paul Mundt" <lethal@...ux-sh.org>,
"Ben Dooks" <ben@...nity.fluff.org>
Subject: Re: [patch/rfc 1/4] GPIO implementation framework
Subject: [PATCH 5/5] move per GPIO "requested" to "struct gpio_desc"
---
include/asm-generic/gpio.h | 17 +++---------
lib/gpiolib.c | 62 ++++++++++++++++++++++++-------------------
2 files changed, 39 insertions(+), 40 deletions(-)
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index da67038..7e70c67 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -28,6 +28,10 @@ struct gpio_chip;
struct gpio_desc {
struct gpio_chip *chip;
unsigned is_out:1;
+ unsigned requested:1;
+#ifdef CONFIG_DEBUG_FS
+ const char *requested_str;
+#endif
};
/**
@@ -76,24 +80,11 @@ struct gpio_chip {
u16 ngpio;
unsigned can_sleep:1;
- /* other fields are modified by the gpio library only */
- DECLARE_BITMAP(requested, ARCH_GPIOS_PER_CHIP);
-
#ifdef CONFIG_DEBUG_FS
struct list_head node;
- const char *requested_str[ARCH_GPIOS_PER_CHIP];
#endif
};
-/* returns true iff a given gpio signal has been requested;
- * primarily for code dumping gpio_chip state.
- */
-static inline int
-gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
-{
- return test_bit(offset, chip->requested);
-}
-
/* add/remove chips */
extern int gpiochip_add(struct gpio_chip *chip);
extern int __must_check gpiochip_remove(struct gpio_chip *chip);
diff --git a/lib/gpiolib.c b/lib/gpiolib.c
index a089597..f9e1c88 100644
--- a/lib/gpiolib.c
+++ b/lib/gpiolib.c
@@ -43,20 +43,19 @@ static inline int gpio_is_onchip(unsigned gpio,
struct gpio_chip *chip)
/* Warn when drivers omit gpio_request() calls -- legal but
* ill-advised when setting direction, and otherwise illegal.
*/
-static void gpio_ensure_requested(struct gpio_chip *chip, unsigned offset)
+static void gpio_ensure_requested(unsigned gpio)
{
- int requested;
+ int requested;
- requested = test_and_set_bit(offset, chip->requested);
+ requested = gpio_desc[gpio].requested;
#ifdef CONFIG_DEBUG_FS
if (!requested)
- chip->requested_str[offset] = "(auto)";
+ gpio_desc[gpio].requested_str = "(auto)";
#endif
if (!requested)
- printk(KERN_DEBUG "GPIO-%d autorequested\n",
- chip->base + offset);
+ pr_debug("GPIO-%d autorequested\n", gpio);
}
/* caller holds gpio_lock */
@@ -114,13 +113,12 @@ EXPORT_SYMBOL_GPL(gpiochip_add);
int gpiochip_remove(struct gpio_chip *chip)
{
unsigned long flags;
- int offset;
unsigned id;
spin_lock_irqsave(&gpio_lock, flags);
- for (offset = 0; offset < chip->ngpio; offset++)
- if (gpiochip_is_requested(chip, offset)) {
+ for (id = chip->base; id < chip->base + chip->ngpio; id++)
+ if (gpio_desc[id].requested) {
spin_unlock_irqrestore(&gpio_lock, flags);
return -EBUSY;
}
@@ -145,11 +143,14 @@ EXPORT_SYMBOL_GPL(gpiochip_remove);
int gpio_request(unsigned gpio, const char *label)
{
struct gpio_chip *chip;
+ struct gpio_desc *desc;
int status = -EINVAL;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
- chip = gpio_to_chip(gpio);
+
+ desc = &gpio_desc[gpio];
+ chip = desc->chip;
if (!gpio_is_onchip(gpio, chip))
goto done;
@@ -162,12 +163,14 @@ int gpio_request(unsigned gpio, const char *label)
status = 0;
- if (test_and_set_bit(gpio, chip->requested))
+ if (desc->requested == 0)
+ desc->requested = 1;
+ else
status = -EBUSY;
#ifdef CONFIG_DEBUG_FS
if (status == 0)
- chip->requested_str[gpio] = (label == NULL) ? "?" : label;
+ desc->requested_str = (label == NULL) ? "?" : label;
#endif
done:
@@ -180,9 +183,11 @@ void gpio_free(unsigned gpio)
{
unsigned long flags;
struct gpio_chip *chip;
+ struct gpio_desc *desc;
spin_lock_irqsave(&gpio_lock, flags);
+ desc = &gpio_desc[gpio];
chip = gpio_to_chip(gpio);
if (!gpio_is_onchip(gpio, chip))
@@ -190,12 +195,13 @@ void gpio_free(unsigned gpio)
gpio -= chip->base;
- if (!test_and_clear_bit(gpio, chip->requested))
+ if (desc->requested == 0)
+ desc->requested = 1;
+ else
chip = NULL;
#ifdef CONFIG_DEBUG_FS
- if (chip != NULL)
- chip->requested_str[gpio] = NULL;
+ desc->requested_str = NULL;
#endif
WARN_ON(extra_checks && chip == NULL);
done:
@@ -231,8 +237,8 @@ int gpio_direction_input(unsigned gpio)
if (!gpio_is_onchip(gpio, chip))
goto fail;
+ gpio_ensure_requested(gpio);
gpio -= chip->base;
- gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
@@ -267,8 +273,8 @@ int gpio_direction_output(unsigned gpio, int value)
if (!gpio_is_onchip(gpio, chip))
goto fail;
+ gpio_ensure_requested(gpio);
gpio -= chip->base;
- gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
@@ -304,7 +310,7 @@ int __gpio_get_value(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
if (extra_checks)
- gpio_ensure_requested(chip, gpio - chip->base);
+ gpio_ensure_requested(gpio);
spin_unlock_irqrestore(&gpio_lock, flags);
if (unlikely(chip->can_sleep)) {
@@ -323,7 +329,7 @@ void __gpio_set_value(unsigned gpio, int value)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
if (extra_checks)
- gpio_ensure_requested(chip, gpio - chip->base);
+ gpio_ensure_requested(gpio);
spin_unlock_irqrestore(&gpio_lock, flags);
if (unlikely(chip->can_sleep))
@@ -341,7 +347,7 @@ int __gpio_cansleep(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
if (extra_checks)
- gpio_ensure_requested(chip, gpio - chip->base);
+ gpio_ensure_requested(gpio);
spin_unlock_irqrestore(&gpio_lock, flags);
return chip->can_sleep;
}
@@ -363,7 +369,7 @@ int gpio_get_value_cansleep(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
if (extra_checks)
- gpio_ensure_requested(chip, gpio - chip->base);
+ gpio_ensure_requested(gpio);
spin_unlock_irqrestore(&gpio_lock, flags);
return chip->get(chip, gpio - chip->base);
@@ -380,7 +386,7 @@ void gpio_set_value_cansleep(unsigned gpio, int value)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
if (extra_checks)
- gpio_ensure_requested(chip, gpio - chip->base);
+ gpio_ensure_requested(gpio);
spin_unlock_irqrestore(&gpio_lock, flags);
chip->set(chip, gpio - chip->base, value);
@@ -401,21 +407,23 @@ static void gpiolib_dbg_show(struct seq_file *s,
struct gpio_chip *chip)
for (i = 0; i < chip->ngpio; i++) {
unsigned gpio;
int is_out;
+ struct gpio_desc *desc;
- if (!chip->requested_str[i])
+ if (!desc->requested)
continue;
gpio = chip->base + i;
- is_out = gpio_desc[gpio].is_out;
+ desc = &gpio_desc[gpio];
+ is_out = desc->is_out;
seq_printf(s, " gpio-%-3d (%-12s) %s %s",
- gpio, chip->requested_str[i],
- is_out ? "out" : "in ",
+ gpio, desc->requested_str,
+ desc->is_out ? "out" : "in ",
chip->get
? (chip->get(chip, i) ? "hi" : "lo")
: "? ");
- if (!is_out) {
+ if (!desc->is_out) {
int irq = gpio_to_irq(gpio);
struct irq_desc *desc = irq_desc + irq;
--
1.5.2.5.GIT
-
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