2007-02-27 12:49:53 -07:00
|
|
|
/*
|
|
|
|
* LEDs driver for GPIOs
|
|
|
|
*
|
|
|
|
* Copyright (C) 2007 8D Technologies inc.
|
|
|
|
* Raphael Assenat <raph@8d.com>
|
2009-01-10 10:26:01 -07:00
|
|
|
* Copyright (C) 2008 Freescale Semiconductor, Inc.
|
2007-02-27 12:49:53 -07:00
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
|
|
* published by the Free Software Foundation.
|
|
|
|
*
|
|
|
|
*/
|
2014-09-28 02:57:14 -06:00
|
|
|
#include <linux/err.h>
|
2012-03-23 16:02:11 -06:00
|
|
|
#include <linux/gpio.h>
|
2014-10-27 16:29:32 -06:00
|
|
|
#include <linux/gpio/consumer.h>
|
2014-09-28 02:57:14 -06:00
|
|
|
#include <linux/kernel.h>
|
2007-02-27 12:49:53 -07:00
|
|
|
#include <linux/leds.h>
|
2014-09-28 02:57:14 -06:00
|
|
|
#include <linux/module.h>
|
2013-09-28 05:38:30 -06:00
|
|
|
#include <linux/of.h>
|
2011-02-22 20:06:04 -07:00
|
|
|
#include <linux/of_gpio.h>
|
2014-09-28 02:57:14 -06:00
|
|
|
#include <linux/of_platform.h>
|
|
|
|
#include <linux/platform_device.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
|
|
|
#include <linux/slab.h>
|
2007-05-10 03:51:41 -06:00
|
|
|
#include <linux/workqueue.h>
|
|
|
|
|
2007-02-27 12:49:53 -07:00
|
|
|
struct gpio_led_data {
|
|
|
|
struct led_classdev cdev;
|
2014-10-27 16:29:32 -06:00
|
|
|
struct gpio_desc *gpiod;
|
2007-05-10 03:51:41 -06:00
|
|
|
struct work_struct work;
|
|
|
|
u8 new_level;
|
|
|
|
u8 can_sleep;
|
2010-05-22 04:54:55 -06:00
|
|
|
u8 blinking;
|
|
|
|
int (*platform_gpio_blink_set)(unsigned gpio, int state,
|
2008-03-09 17:48:25 -06:00
|
|
|
unsigned long *delay_on, unsigned long *delay_off);
|
2007-02-27 12:49:53 -07:00
|
|
|
};
|
|
|
|
|
2007-05-10 03:51:41 -06:00
|
|
|
static void gpio_led_work(struct work_struct *work)
|
|
|
|
{
|
2014-09-28 02:57:16 -06:00
|
|
|
struct gpio_led_data *led_dat =
|
2007-05-10 03:51:41 -06:00
|
|
|
container_of(work, struct gpio_led_data, work);
|
|
|
|
|
2010-05-22 04:54:55 -06:00
|
|
|
if (led_dat->blinking) {
|
2014-10-27 16:29:32 -06:00
|
|
|
int gpio = desc_to_gpio(led_dat->gpiod);
|
|
|
|
int level = led_dat->new_level;
|
|
|
|
|
|
|
|
if (gpiod_is_active_low(led_dat->gpiod))
|
|
|
|
level = !level;
|
|
|
|
|
|
|
|
led_dat->platform_gpio_blink_set(gpio, level, NULL, NULL);
|
2010-05-22 04:54:55 -06:00
|
|
|
led_dat->blinking = 0;
|
|
|
|
} else
|
2014-10-27 16:29:32 -06:00
|
|
|
gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
|
2007-05-10 03:51:41 -06:00
|
|
|
}
|
2007-02-27 12:49:53 -07:00
|
|
|
|
|
|
|
static void gpio_led_set(struct led_classdev *led_cdev,
|
|
|
|
enum led_brightness value)
|
|
|
|
{
|
|
|
|
struct gpio_led_data *led_dat =
|
|
|
|
container_of(led_cdev, struct gpio_led_data, cdev);
|
|
|
|
int level;
|
|
|
|
|
|
|
|
if (value == LED_OFF)
|
|
|
|
level = 0;
|
|
|
|
else
|
|
|
|
level = 1;
|
|
|
|
|
2008-03-26 18:59:02 -06:00
|
|
|
/* Setting GPIOs with I2C/etc requires a task context, and we don't
|
|
|
|
* seem to have a reliable way to know if we're already in one; so
|
|
|
|
* let's just assume the worst.
|
|
|
|
*/
|
2007-05-10 03:51:41 -06:00
|
|
|
if (led_dat->can_sleep) {
|
2008-03-26 18:59:02 -06:00
|
|
|
led_dat->new_level = level;
|
|
|
|
schedule_work(&led_dat->work);
|
2010-05-22 04:54:55 -06:00
|
|
|
} else {
|
|
|
|
if (led_dat->blinking) {
|
2014-10-27 16:29:32 -06:00
|
|
|
int gpio = desc_to_gpio(led_dat->gpiod);
|
|
|
|
|
|
|
|
if (gpiod_is_active_low(led_dat->gpiod))
|
|
|
|
level = !level;
|
|
|
|
|
|
|
|
led_dat->platform_gpio_blink_set(gpio, level, NULL,
|
|
|
|
NULL);
|
2010-05-22 04:54:55 -06:00
|
|
|
led_dat->blinking = 0;
|
|
|
|
} else
|
2014-10-27 16:29:32 -06:00
|
|
|
gpiod_set_value(led_dat->gpiod, level);
|
2010-05-22 04:54:55 -06:00
|
|
|
}
|
2007-02-27 12:49:53 -07:00
|
|
|
}
|
|
|
|
|
2008-03-09 17:48:25 -06:00
|
|
|
static int gpio_blink_set(struct led_classdev *led_cdev,
|
|
|
|
unsigned long *delay_on, unsigned long *delay_off)
|
|
|
|
{
|
|
|
|
struct gpio_led_data *led_dat =
|
|
|
|
container_of(led_cdev, struct gpio_led_data, cdev);
|
2014-10-27 16:29:32 -06:00
|
|
|
int gpio = desc_to_gpio(led_dat->gpiod);
|
2008-03-09 17:48:25 -06:00
|
|
|
|
2010-05-22 04:54:55 -06:00
|
|
|
led_dat->blinking = 1;
|
2014-10-27 16:29:32 -06:00
|
|
|
return led_dat->platform_gpio_blink_set(gpio, GPIO_LED_BLINK,
|
2010-05-22 04:54:55 -06:00
|
|
|
delay_on, delay_off);
|
2008-03-09 17:48:25 -06:00
|
|
|
}
|
|
|
|
|
2012-11-19 11:23:02 -07:00
|
|
|
static int create_gpio_led(const struct gpio_led *template,
|
2009-01-10 10:26:01 -07:00
|
|
|
struct gpio_led_data *led_dat, struct device *parent,
|
2010-05-22 04:54:55 -06:00
|
|
|
int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
|
2009-01-10 10:26:01 -07:00
|
|
|
{
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
int ret, state;
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2014-10-27 16:29:32 -06:00
|
|
|
if (!template->gpiod) {
|
|
|
|
unsigned long flags = 0;
|
2009-11-15 15:48:32 -07:00
|
|
|
|
2014-10-27 16:29:32 -06:00
|
|
|
/* skip leds that aren't available */
|
|
|
|
if (!gpio_is_valid(template->gpio)) {
|
|
|
|
dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
|
|
|
|
template->gpio, template->name);
|
|
|
|
return 0;
|
|
|
|
}
|
2009-03-05 17:46:44 -07:00
|
|
|
|
2014-10-27 16:29:32 -06:00
|
|
|
if (template->active_low)
|
|
|
|
flags |= GPIOF_ACTIVE_LOW;
|
|
|
|
|
|
|
|
ret = devm_gpio_request_one(parent, template->gpio, flags,
|
|
|
|
template->name);
|
|
|
|
if (ret < 0)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
led_dat->gpiod = gpio_to_desc(template->gpio);
|
|
|
|
if (IS_ERR(led_dat->gpiod))
|
|
|
|
return PTR_ERR(led_dat->gpiod);
|
|
|
|
}
|
2013-05-17 01:48:39 -06:00
|
|
|
|
2009-01-10 10:26:01 -07:00
|
|
|
led_dat->cdev.name = template->name;
|
|
|
|
led_dat->cdev.default_trigger = template->default_trigger;
|
2014-10-27 16:29:32 -06:00
|
|
|
led_dat->gpiod = template->gpiod;
|
|
|
|
led_dat->can_sleep = gpiod_cansleep(template->gpiod);
|
2010-05-22 04:54:55 -06:00
|
|
|
led_dat->blinking = 0;
|
2009-01-10 10:26:01 -07:00
|
|
|
if (blink_set) {
|
|
|
|
led_dat->platform_gpio_blink_set = blink_set;
|
|
|
|
led_dat->cdev.blink_set = gpio_blink_set;
|
|
|
|
}
|
|
|
|
led_dat->cdev.brightness_set = gpio_led_set;
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
|
2014-10-27 16:29:32 -06:00
|
|
|
state = !!gpiod_get_value_cansleep(led_dat->gpiod);
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
else
|
|
|
|
state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
|
|
|
|
led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
|
2009-02-17 08:04:07 -07:00
|
|
|
if (!template->retain_state_suspended)
|
|
|
|
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2014-10-27 16:29:32 -06:00
|
|
|
ret = gpiod_direction_output(led_dat->gpiod, state);
|
2009-01-10 10:26:01 -07:00
|
|
|
if (ret < 0)
|
2012-10-23 06:17:11 -06:00
|
|
|
return ret;
|
|
|
|
|
2009-01-10 10:26:01 -07:00
|
|
|
INIT_WORK(&led_dat->work, gpio_led_work);
|
|
|
|
|
2014-10-27 16:29:32 -06:00
|
|
|
return led_classdev_register(parent, &led_dat->cdev);
|
2009-01-10 10:26:01 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
static void delete_gpio_led(struct gpio_led_data *led)
|
|
|
|
{
|
|
|
|
led_classdev_unregister(&led->cdev);
|
|
|
|
cancel_work_sync(&led->work);
|
|
|
|
}
|
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
struct gpio_leds_priv {
|
|
|
|
int num_leds;
|
|
|
|
struct gpio_led_data leds[];
|
|
|
|
};
|
2007-02-27 12:49:53 -07:00
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
static inline int sizeof_gpio_leds_priv(int num_leds)
|
2007-02-27 12:49:53 -07:00
|
|
|
{
|
2011-02-22 20:06:04 -07:00
|
|
|
return sizeof(struct gpio_leds_priv) +
|
|
|
|
(sizeof(struct gpio_led_data) * num_leds);
|
2007-02-27 12:49:53 -07:00
|
|
|
}
|
|
|
|
|
2009-01-10 10:26:01 -07:00
|
|
|
/* Code to create from OpenFirmware platform devices */
|
2011-05-31 02:23:43 -06:00
|
|
|
#ifdef CONFIG_OF_GPIO
|
2012-11-19 11:23:02 -07:00
|
|
|
static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev)
|
2009-01-10 10:26:01 -07:00
|
|
|
{
|
2011-02-22 20:06:04 -07:00
|
|
|
struct device_node *np = pdev->dev.of_node, *child;
|
|
|
|
struct gpio_leds_priv *priv;
|
2012-08-21 03:21:53 -06:00
|
|
|
int count, ret;
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
/* count LEDs in this device, so we know how much to allocate */
|
2013-09-26 05:27:56 -06:00
|
|
|
count = of_get_available_child_count(np);
|
2009-01-10 10:26:01 -07:00
|
|
|
if (!count)
|
2012-10-28 09:34:59 -06:00
|
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
|
2013-09-26 05:27:56 -06:00
|
|
|
for_each_available_child_of_node(np, child)
|
2012-10-28 09:34:59 -06:00
|
|
|
if (of_get_gpio(child, 0) == -EPROBE_DEFER)
|
|
|
|
return ERR_PTR(-EPROBE_DEFER);
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2012-07-03 21:35:44 -06:00
|
|
|
priv = devm_kzalloc(&pdev->dev, sizeof_gpio_leds_priv(count),
|
|
|
|
GFP_KERNEL);
|
2011-02-22 20:06:04 -07:00
|
|
|
if (!priv)
|
2012-10-28 09:34:59 -06:00
|
|
|
return ERR_PTR(-ENOMEM);
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2013-09-26 05:27:56 -06:00
|
|
|
for_each_available_child_of_node(np, child) {
|
2010-03-11 14:58:47 -07:00
|
|
|
struct gpio_led led = {};
|
2009-01-10 10:26:01 -07:00
|
|
|
enum of_gpio_flags flags;
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
const char *state;
|
2009-01-10 10:26:01 -07:00
|
|
|
|
|
|
|
led.gpio = of_get_gpio_flags(child, 0, &flags);
|
|
|
|
led.active_low = flags & OF_GPIO_ACTIVE_LOW;
|
|
|
|
led.name = of_get_property(child, "label", NULL) ? : child->name;
|
|
|
|
led.default_trigger =
|
|
|
|
of_get_property(child, "linux,default-trigger", NULL);
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
state = of_get_property(child, "default-state", NULL);
|
|
|
|
if (state) {
|
|
|
|
if (!strcmp(state, "keep"))
|
|
|
|
led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
|
2011-02-22 20:06:04 -07:00
|
|
|
else if (!strcmp(state, "on"))
|
leds: Add options to have GPIO LEDs start on or keep their state
There already is a "default-on" trigger but there are problems with it.
For one, it's a inefficient way to do it and requires led trigger support
to be compiled in.
But the real reason is that is produces a glitch on the LED. The GPIO is
allocate with the LED *off*, then *later* when the trigger runs it is
turned back on. If the LED was already on via the GPIO's reset default or
action of the firmware, this produces a glitch where the LED goes from on
to off to on. While normally this is fast enough that it wouldn't be
noticeable to a human observer, there are still serious problems.
One is that there may be something else on the GPIO line, like a hardware
alarm or watchdog, that is fast enough to notice the glitch.
Another is that the kernel may panic before the LED is turned back on, thus
hanging with the LED in the wrong state. This is not just speculation, but
actually happened to me with an embedded system that has an LED which
should turn off when the kernel finishes booting, which was left in the
incorrect state due to a bug in the OF LED binding code.
We also let GPIO LEDs get their initial value from whatever the current
state of the GPIO line is. On some systems the LEDs are put into some
state by the firmware or hardware before Linux boots, and it is desired to
have them keep this state which is otherwise unknown to Linux.
This requires that the underlying GPIO driver support reading the value of
output GPIOs. Some drivers support this and some do not.
The platform device binding gains a field in the platform data
"default_state" that controls this. There are three constants defined to
select from on, off, or keeping the current state. The OpenFirmware
binding uses a property named "default-state" that can be set to "on",
"off", or "keep". The default if the property isn't present is off.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-05-12 16:33:12 -06:00
|
|
|
led.default_state = LEDS_GPIO_DEFSTATE_ON;
|
|
|
|
else
|
|
|
|
led.default_state = LEDS_GPIO_DEFSTATE_OFF;
|
|
|
|
}
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2014-01-20 04:41:26 -07:00
|
|
|
if (of_get_property(child, "retain-state-suspended", NULL))
|
|
|
|
led.retain_state_suspended = 1;
|
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
|
|
|
|
&pdev->dev, NULL);
|
2009-01-10 10:26:01 -07:00
|
|
|
if (ret < 0) {
|
|
|
|
of_node_put(child);
|
|
|
|
goto err;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
return priv;
|
2009-01-10 10:26:01 -07:00
|
|
|
|
|
|
|
err:
|
2011-02-22 20:06:04 -07:00
|
|
|
for (count = priv->num_leds - 2; count >= 0; count--)
|
|
|
|
delete_gpio_led(&priv->leds[count]);
|
2012-10-28 09:34:59 -06:00
|
|
|
return ERR_PTR(-ENODEV);
|
2011-02-22 20:06:04 -07:00
|
|
|
}
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
static const struct of_device_id of_gpio_leds_match[] = {
|
|
|
|
{ .compatible = "gpio-leds", },
|
|
|
|
{},
|
|
|
|
};
|
2014-03-06 10:18:37 -07:00
|
|
|
|
|
|
|
MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
|
2011-05-31 02:23:43 -06:00
|
|
|
#else /* CONFIG_OF_GPIO */
|
2012-11-19 11:23:02 -07:00
|
|
|
static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev)
|
2011-02-22 20:06:04 -07:00
|
|
|
{
|
2012-10-28 09:34:59 -06:00
|
|
|
return ERR_PTR(-ENODEV);
|
2011-02-22 20:06:04 -07:00
|
|
|
}
|
2011-05-31 02:23:43 -06:00
|
|
|
#endif /* CONFIG_OF_GPIO */
|
2009-01-10 10:26:01 -07:00
|
|
|
|
2012-11-19 11:23:02 -07:00
|
|
|
static int gpio_led_probe(struct platform_device *pdev)
|
2011-02-22 20:06:04 -07:00
|
|
|
{
|
2013-07-30 02:07:35 -06:00
|
|
|
struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
|
2011-02-22 20:06:04 -07:00
|
|
|
struct gpio_leds_priv *priv;
|
|
|
|
int i, ret = 0;
|
|
|
|
|
|
|
|
if (pdata && pdata->num_leds) {
|
2012-07-03 21:35:44 -06:00
|
|
|
priv = devm_kzalloc(&pdev->dev,
|
|
|
|
sizeof_gpio_leds_priv(pdata->num_leds),
|
|
|
|
GFP_KERNEL);
|
2011-02-22 20:06:04 -07:00
|
|
|
if (!priv)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
priv->num_leds = pdata->num_leds;
|
|
|
|
for (i = 0; i < priv->num_leds; i++) {
|
|
|
|
ret = create_gpio_led(&pdata->leds[i],
|
|
|
|
&priv->leds[i],
|
|
|
|
&pdev->dev, pdata->gpio_blink_set);
|
|
|
|
if (ret < 0) {
|
|
|
|
/* On failure: unwind the led creations */
|
|
|
|
for (i = i - 1; i >= 0; i--)
|
|
|
|
delete_gpio_led(&priv->leds[i]);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
priv = gpio_leds_create_of(pdev);
|
2012-10-28 09:34:59 -06:00
|
|
|
if (IS_ERR(priv))
|
|
|
|
return PTR_ERR(priv);
|
2011-02-22 20:06:04 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
platform_set_drvdata(pdev, priv);
|
|
|
|
|
|
|
|
return 0;
|
2009-01-10 10:26:01 -07:00
|
|
|
}
|
|
|
|
|
2012-11-19 11:26:00 -07:00
|
|
|
static int gpio_led_remove(struct platform_device *pdev)
|
2009-01-10 10:26:01 -07:00
|
|
|
{
|
2012-08-16 04:36:13 -06:00
|
|
|
struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
|
2009-01-10 10:26:01 -07:00
|
|
|
int i;
|
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
for (i = 0; i < priv->num_leds; i++)
|
|
|
|
delete_gpio_led(&priv->leds[i]);
|
2009-01-10 10:26:01 -07:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2011-02-22 20:06:04 -07:00
|
|
|
static struct platform_driver gpio_led_driver = {
|
|
|
|
.probe = gpio_led_probe,
|
2012-11-19 11:20:20 -07:00
|
|
|
.remove = gpio_led_remove,
|
2011-02-22 20:06:04 -07:00
|
|
|
.driver = {
|
|
|
|
.name = "leds-gpio",
|
|
|
|
.owner = THIS_MODULE,
|
2012-08-16 04:35:36 -06:00
|
|
|
.of_match_table = of_match_ptr(of_gpio_leds_match),
|
2009-01-10 10:26:01 -07:00
|
|
|
},
|
|
|
|
};
|
2011-02-22 20:06:04 -07:00
|
|
|
|
2012-01-10 16:09:24 -07:00
|
|
|
module_platform_driver(gpio_led_driver);
|
2009-01-10 10:26:01 -07:00
|
|
|
|
|
|
|
MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
|
2007-02-27 12:49:53 -07:00
|
|
|
MODULE_DESCRIPTION("GPIO LED driver");
|
|
|
|
MODULE_LICENSE("GPL");
|
2012-01-10 16:09:24 -07:00
|
|
|
MODULE_ALIAS("platform:leds-gpio");
|