mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-11-02 00:19:20 +02:00
c5552ad039
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21952 3c298f89-4303-0410-b956-a3cf2f4a3e73
113 lines
3.4 KiB
Diff
113 lines
3.4 KiB
Diff
From: Anton Vorontsov <avorontsov@ru.mvista.com>
|
|
Date: Mon, 28 Apr 2008 09:14:47 +0000 (-0700)
|
|
Subject: gpiochip_reserve()
|
|
X-Git-Tag: v2.6.26-rc1~847
|
|
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=169b6a7a6e91e1ea32136681b475cbaf2074bf35
|
|
|
|
gpiochip_reserve()
|
|
|
|
Add a new function gpiochip_reserve() to reserve ranges of gpios that platform
|
|
code has pre-allocated. That is, this marks gpio numbers which will be
|
|
claimed by drivers that haven't yet been loaded, and thus are not available
|
|
for dynamic gpio number allocation.
|
|
|
|
[akpm@linux-foundation.org: remove unneeded __must_check]
|
|
[david-b@pacbell.net: don't export gpiochip_reserve (section fix)]
|
|
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
|
|
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
|
|
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
---
|
|
|
|
--- a/drivers/gpio/gpiolib.c
|
|
+++ b/drivers/gpio/gpiolib.c
|
|
@@ -43,6 +43,7 @@ struct gpio_desc {
|
|
/* flag symbols are bit numbers */
|
|
#define FLAG_REQUESTED 0
|
|
#define FLAG_IS_OUT 1
|
|
+#define FLAG_RESERVED 2
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
const char *label;
|
|
@@ -88,9 +89,10 @@ static int gpiochip_find_base(int ngpio)
|
|
int base = -ENOSPC;
|
|
|
|
for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) {
|
|
- struct gpio_chip *chip = gpio_desc[i].chip;
|
|
+ struct gpio_desc *desc = &gpio_desc[i];
|
|
+ struct gpio_chip *chip = desc->chip;
|
|
|
|
- if (!chip) {
|
|
+ if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) {
|
|
spare++;
|
|
if (spare == ngpio) {
|
|
base = i;
|
|
@@ -98,7 +100,8 @@ static int gpiochip_find_base(int ngpio)
|
|
}
|
|
} else {
|
|
spare = 0;
|
|
- i -= chip->ngpio - 1;
|
|
+ if (chip)
|
|
+ i -= chip->ngpio - 1;
|
|
}
|
|
}
|
|
|
|
@@ -108,6 +111,47 @@ static int gpiochip_find_base(int ngpio)
|
|
}
|
|
|
|
/**
|
|
+ * gpiochip_reserve() - reserve range of gpios to use with platform code only
|
|
+ * @start: starting gpio number
|
|
+ * @ngpio: number of gpios to reserve
|
|
+ * Context: platform init, potentially before irqs or kmalloc will work
|
|
+ *
|
|
+ * Returns a negative errno if any gpio within the range is already reserved
|
|
+ * or registered, else returns zero as a success code. Use this function
|
|
+ * to mark a range of gpios as unavailable for dynamic gpio number allocation,
|
|
+ * for example because its driver support is not yet loaded.
|
|
+ */
|
|
+int __init gpiochip_reserve(int start, int ngpio)
|
|
+{
|
|
+ int ret = 0;
|
|
+ unsigned long flags;
|
|
+ int i;
|
|
+
|
|
+ if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio))
|
|
+ return -EINVAL;
|
|
+
|
|
+ spin_lock_irqsave(&gpio_lock, flags);
|
|
+
|
|
+ for (i = start; i < start + ngpio; i++) {
|
|
+ struct gpio_desc *desc = &gpio_desc[i];
|
|
+
|
|
+ if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) {
|
|
+ ret = -EBUSY;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ set_bit(FLAG_RESERVED, &desc->flags);
|
|
+ }
|
|
+
|
|
+ pr_debug("%s: reserved gpios from %d to %d\n",
|
|
+ __func__, start, start + ngpio - 1);
|
|
+err:
|
|
+ spin_unlock_irqrestore(&gpio_lock, flags);
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+/**
|
|
* gpiochip_add() - register a gpio_chip
|
|
* @chip: the chip to register, with chip->base initialized
|
|
* Context: potentially before irqs or kmalloc will work
|
|
--- a/include/asm-generic/gpio.h
|
|
+++ b/include/asm-generic/gpio.h
|
|
@@ -74,6 +74,7 @@ struct gpio_chip {
|
|
|
|
extern const char *gpiochip_is_requested(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
+extern int __init __must_check gpiochip_reserve(int start, int ngpio);
|
|
|
|
/* add/remove chips */
|
|
extern int gpiochip_add(struct gpio_chip *chip);
|