From: "eric miao" <eric.y.miao@gmail.com>
To: "David Brownell" <david-b@pacbell.net>
Cc: "Linux Kernel list" <linux-kernel@vger.kernel.org>,
"Felipe Balbi" <felipebalbi@users.sourceforge.net>,
"Bill Gatliff" <bgat@billgatliff.com>,
"Haavard Skinnemoen" <hskinnemoen@atmel.com>,
"Andrew Victor" <andrew@sanpeople.com>,
"Tony Lindgren" <tony@atomide.com>,
"Jean Delvare" <khali@linux-fr.org>,
"Kevin Hilman" <khilman@mvista.com>,
"Paul Mundt" <lethal@linux-sh.org>,
"Ben Dooks" <ben@trinity.fluff.org>
Subject: Re: [patch/rfc 1/4] GPIO implementation framework
Date: Wed, 14 Nov 2007 09:00:46 +0800 [thread overview]
Message-ID: <f17812d70711131700n74236a8naa6dbfc5cb62e42d@mail.gmail.com> (raw)
In-Reply-To: <f17812d70711131657wbdcc089kadb6024a47ad4a3@mail.gmail.com>
Here comes a bunch of patches to illustrate my idea, some are not related to
the point I mentioned, and they are not mature for now :-)
Subject: [PATCH 1/5] add gpio_is_onchip() for commonly used gpio range checking
---
lib/gpiolib.c | 32 ++++++++++++++++++++++----------
1 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/lib/gpiolib.c b/lib/gpiolib.c
index f2ae689..c627efb 100644
--- a/lib/gpiolib.c
+++ b/lib/gpiolib.c
@@ -33,6 +33,14 @@ static DEFINE_SPINLOCK(gpio_lock);
static struct gpio_chip *chips[DIV_ROUND_UP(ARCH_NR_GPIOS,
ARCH_GPIOS_PER_CHIP)];
+static inline int gpio_is_onchip(unsigned gpio, struct gpio_chip *chip)
+{
+ if (chip && gpio >= chip->base && gpio < chip->base + chip->ngpio)
+ return 1;
+ else
+ return 0;
+}
+
/* Warn when drivers omit gpio_request() calls -- legal but
* ill-advised when setting direction, and otherwise illegal.
*/
@@ -139,11 +147,11 @@ int gpio_request(unsigned gpio, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
- if (!chip)
+
+ if (!gpio_is_onchip(gpio, chip))
goto done;
+
gpio -= chip->base;
- if (gpio >= chip->ngpio)
- goto done;
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled.
@@ -176,11 +184,11 @@ void gpio_free(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
- if (!chip)
+
+ if (!gpio_is_onchip(gpio, chip))
goto done;
+
gpio -= chip->base;
- if (gpio >= chip->ngpio)
- goto done;
#ifdef CONFIG_DEBUG_FS
if (chip->requested[gpio])
@@ -218,9 +226,11 @@ int gpio_direction_input(unsigned gpio)
chip = gpio_to_chip(gpio);
if (!chip || !chip->get || !chip->direction_input)
goto fail;
- gpio -= chip->base;
- if (gpio >= chip->ngpio)
+
+ if (!gpio_is_onchip(gpio, chip))
goto fail;
+
+ gpio -= chip->base;
gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
@@ -250,9 +260,11 @@ int gpio_direction_output(unsigned gpio, int value)
chip = gpio_to_chip(gpio);
if (!chip || !chip->get || !chip->direction_output)
goto fail;
- gpio -= chip->base;
- if (gpio >= chip->ngpio)
+
+ if (!gpio_is_onchip(gpio, chip))
goto fail;
+
+ gpio -= chip->base;
gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
--
1.5.2.5.GIT
next prev parent reply other threads:[~2007-11-14 1:00 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200710291809.29936.david-b@pacbell.net>
2007-10-30 1:51 ` [patch/rfc 1/4] GPIO implementation framework David Brownell
2007-11-05 21:05 ` David Brownell
2007-11-13 2:28 ` eric miao
2007-11-13 19:06 ` David Brownell
2007-11-14 0:57 ` eric miao
2007-11-14 1:00 ` eric miao [this message]
2007-11-14 1:02 ` eric miao
2007-11-14 1:03 ` eric miao
2007-11-14 1:04 ` eric miao
2007-11-14 1:04 ` eric miao
2007-11-14 4:36 ` David Brownell
2007-11-14 6:51 ` eric miao
2007-11-14 7:19 ` David Brownell
2007-11-14 7:36 ` eric miao
2007-11-17 10:38 ` Jean Delvare
2007-11-17 17:36 ` David Brownell
2007-11-20 15:20 ` Jean Delvare
2007-11-14 4:18 ` David Brownell
2007-11-14 6:46 ` eric miao
2007-11-14 3:28 ` David Brownell
2007-11-14 3:25 ` David Brownell
2007-11-14 3:53 ` David Brownell
2007-11-14 6:37 ` eric miao
2007-11-14 3:30 ` David Brownell
2007-11-14 6:40 ` eric miao
2007-11-14 7:08 ` David Brownell
2007-11-27 1:46 ` David Brownell
2007-11-27 10:58 ` eric miao
2007-11-27 17:26 ` David Brownell
2007-11-27 19:03 ` David Brownell
2007-11-27 19:29 ` David Brownell
2007-11-28 5:11 ` eric miao
2007-11-28 3:15 ` [patch/rfc 2.6.24-rc3-mm] gpiolib grows a gpio_desc David Brownell
2007-11-28 9:10 ` eric miao
2007-11-28 9:53 ` David Brownell
2007-10-30 1:51 ` [patch/rfc 2/4] pcf875x I2C GPIO expander driver David Brownell
2007-11-30 12:32 ` Jean Delvare
2007-11-30 13:04 ` Bill Gatliff
2007-11-30 13:36 ` Jean Delvare
2007-11-30 14:09 ` Bill Gatliff
2007-11-30 18:40 ` David Brownell
2007-11-30 20:13 ` Jean Delvare
2007-11-30 20:59 ` David Brownell
2008-04-04 2:06 ` Trent Piepho
2008-04-04 2:45 ` Ben Nizette
2008-04-04 3:33 ` Trent Piepho
2008-04-04 4:57 ` Ben Nizette
2008-04-05 4:05 ` userspace GPIO access (WAS: [patch/rfc 2/4] pcf875x ...) David Brownell
2008-04-07 17:56 ` Trent Piepho
2008-04-04 8:09 ` [patch/rfc 2/4] pcf875x I2C GPIO expander driver Jean Delvare
2008-04-04 19:07 ` Trent Piepho
2008-04-04 19:36 ` Jean Delvare
2008-04-04 20:18 ` Trent Piepho
2008-04-05 2:51 ` David Brownell
2008-04-05 2:53 ` David Brownell
2007-12-06 3:03 ` [patch/rfc 2/4] pcf857x " David Brownell
2007-12-06 23:17 ` Jean Delvare
2007-12-07 4:02 ` David Brownell
2007-10-30 1:53 ` [patch/rfc 3/4] DaVinci platform uses new GPIOLIB David Brownell
2007-10-30 1:54 ` [patch/rfc 4/4] DaVinci EVM uses pcf857x GPIO driver David Brownell
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