* [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
@ 2015-09-02 18:00 Justin Chen
2015-09-02 20:19 ` Guenter Roeck
2015-10-27 15:47 ` Wim Van Sebroeck
0 siblings, 2 replies; 7+ messages in thread
From: Justin Chen @ 2015-09-02 18:00 UTC (permalink / raw)
To: linux-kernel
Cc: wim, linux-watchdog, linux, bcm-kernel-feedback-list, Justin Chen
Currently there is no way to easily differentiate multiple
watchdog devices. The watchdogs are named by the order they
are probed.
1st probed watchdog: /dev/watchdog0
2nd probed watchdog: /dev/watchdog1
...
This change uses the alias of the watchdog device node for
the name of the watchdog.
aliases {
watchdog0 = "/...../...."
watchdog3 = "/..../....."
watchdog2 = "/..../....."
...
}
This will translate to...
/dev/watchdog0
/dev/watchdog3
/dev/watchdog2
v2
Assign alias number to id in watchdog_core instead of watchdog_dev.
If failed to get id, fallback to original ida_simple_get call.
Signed-off-by: Justin Chen <justinpopo6@gmail.com>
---
drivers/watchdog/watchdog_core.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 1a80594..873f139 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -139,7 +139,7 @@ EXPORT_SYMBOL_GPL(watchdog_init_timeout);
static int __watchdog_register_device(struct watchdog_device *wdd)
{
- int ret, id, devno;
+ int ret, id = -1, devno;
if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -EINVAL;
@@ -157,7 +157,18 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
*/
mutex_init(&wdd->lock);
- id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
+
+ /* Use alias for watchdog id if possible */
+ if (wdd->parent) {
+ ret = of_alias_get_id(wdd->parent->of_node, "watchdog");
+ if (ret >= 0)
+ id = ida_simple_get(&watchdog_ida, ret,
+ ret + 1, GFP_KERNEL);
+ }
+
+ if (id < 0)
+ id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
+
if (id < 0)
return id;
wdd->id = id;
--
2.1.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
2015-09-02 18:00 [PATCH] watchdog_dev: Use device tree alias for naming watchdogs Justin Chen
@ 2015-09-02 20:19 ` Guenter Roeck
2015-10-27 15:47 ` Wim Van Sebroeck
1 sibling, 0 replies; 7+ messages in thread
From: Guenter Roeck @ 2015-09-02 20:19 UTC (permalink / raw)
To: Justin Chen; +Cc: linux-kernel, wim, linux-watchdog, bcm-kernel-feedback-list
Hi Justin,
On Wed, Sep 02, 2015 at 11:00:17AM -0700, Justin Chen wrote:
> Currently there is no way to easily differentiate multiple
> watchdog devices. The watchdogs are named by the order they
> are probed.
> 1st probed watchdog: /dev/watchdog0
> 2nd probed watchdog: /dev/watchdog1
> ...
>
> This change uses the alias of the watchdog device node for
> the name of the watchdog.
> aliases {
> watchdog0 = "/...../...."
> watchdog3 = "/..../....."
> watchdog2 = "/..../....."
> ...
> }
>
> This will translate to...
> /dev/watchdog0
> /dev/watchdog3
> /dev/watchdog2
>
> v2
> Assign alias number to id in watchdog_core instead of watchdog_dev.
> If failed to get id, fallback to original ida_simple_get call.
>
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Minor nitpick: the changelog should be after the '---'.
Other than that, I really like it. Well done.
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Thanks,
Guenter
> ---
> drivers/watchdog/watchdog_core.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
> index 1a80594..873f139 100644
> --- a/drivers/watchdog/watchdog_core.c
> +++ b/drivers/watchdog/watchdog_core.c
> @@ -139,7 +139,7 @@ EXPORT_SYMBOL_GPL(watchdog_init_timeout);
>
> static int __watchdog_register_device(struct watchdog_device *wdd)
> {
> - int ret, id, devno;
> + int ret, id = -1, devno;
>
> if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
> return -EINVAL;
> @@ -157,7 +157,18 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
> */
>
> mutex_init(&wdd->lock);
> - id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
> +
> + /* Use alias for watchdog id if possible */
> + if (wdd->parent) {
> + ret = of_alias_get_id(wdd->parent->of_node, "watchdog");
> + if (ret >= 0)
> + id = ida_simple_get(&watchdog_ida, ret,
> + ret + 1, GFP_KERNEL);
> + }
> +
> + if (id < 0)
> + id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
> +
> if (id < 0)
> return id;
> wdd->id = id;
> --
> 2.1.0
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
2015-09-02 18:00 [PATCH] watchdog_dev: Use device tree alias for naming watchdogs Justin Chen
2015-09-02 20:19 ` Guenter Roeck
@ 2015-10-27 15:47 ` Wim Van Sebroeck
1 sibling, 0 replies; 7+ messages in thread
From: Wim Van Sebroeck @ 2015-10-27 15:47 UTC (permalink / raw)
To: Justin Chen; +Cc: linux-kernel, linux-watchdog, linux, bcm-kernel-feedback-list
Hi Justin,
> Currently there is no way to easily differentiate multiple
> watchdog devices. The watchdogs are named by the order they
> are probed.
> 1st probed watchdog: /dev/watchdog0
> 2nd probed watchdog: /dev/watchdog1
> ...
>
> This change uses the alias of the watchdog device node for
> the name of the watchdog.
> aliases {
> watchdog0 = "/...../...."
> watchdog3 = "/..../....."
> watchdog2 = "/..../....."
> ...
> }
>
> This will translate to...
> /dev/watchdog0
> /dev/watchdog3
> /dev/watchdog2
>
> v2
> Assign alias number to id in watchdog_core instead of watchdog_dev.
> If failed to get id, fallback to original ida_simple_get call.
>
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
> ---
> drivers/watchdog/watchdog_core.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
> index 1a80594..873f139 100644
> --- a/drivers/watchdog/watchdog_core.c
> +++ b/drivers/watchdog/watchdog_core.c
> @@ -139,7 +139,7 @@ EXPORT_SYMBOL_GPL(watchdog_init_timeout);
>
> static int __watchdog_register_device(struct watchdog_device *wdd)
> {
> - int ret, id, devno;
> + int ret, id = -1, devno;
>
> if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
> return -EINVAL;
> @@ -157,7 +157,18 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
> */
>
> mutex_init(&wdd->lock);
> - id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
> +
> + /* Use alias for watchdog id if possible */
> + if (wdd->parent) {
> + ret = of_alias_get_id(wdd->parent->of_node, "watchdog");
> + if (ret >= 0)
> + id = ida_simple_get(&watchdog_ida, ret,
> + ret + 1, GFP_KERNEL);
> + }
> +
> + if (id < 0)
> + id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
> +
> if (id < 0)
> return id;
> wdd->id = id;
> --
> 2.1.0
>
Added to linux-watchdog-next.
Kind regards,
Wim.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
2015-09-01 17:20 ` Justin Chen
@ 2015-09-01 17:53 ` Guenter Roeck
0 siblings, 0 replies; 7+ messages in thread
From: Guenter Roeck @ 2015-09-01 17:53 UTC (permalink / raw)
To: Justin Chen; +Cc: linux-kernel, wim, linux-watchdog, bcm-kernel-feedback-list
On Tue, Sep 01, 2015 at 10:20:36AM -0700, Justin Chen wrote:
> On Sat, Aug 29, 2015 at 2:53 AM, Guenter Roeck <linux@roeck-us.net> wrote:
> > On 08/28/2015 02:58 PM, Justin Chen wrote:
> >>
> >> Currently there is no way to easily differentiate multiple
> >> watchdog devices. The watchdogs are named by the order they
> >> are probed.
> >> 1st probed watchdog: /dev/watchdog0
> >> 2nd probed watchdog: /dev/watchdog1
> >> ...
> >>
> >> This change uses the alias of the watchdog device node for
> >> the name of the watchdog.
> >> aliases {
> >> watchdog0 = "/...../...."
> >> watchdog3 = "/..../....."
> >> watchdog2 = "/..../....."
> >> ...
> >> }
> >>
> >> This will translate to...
> >> /dev/watchdog0
> >> /dev/watchdog3
> >> /dev/watchdog2
> >>
> >> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
> >
> >
> > Interesting idea. Checking through other subsystems, many others do the
> > same,
> > so it makes sense to use that mechanism.
> >
> > However, the id assignment should be in the calling code, in
> > __watchdog_register_device,
> > to avoid that another id, possibly conflicting, is assigned through the
> ida
> > mechanism.
> >
> > This is a bit more complicated than it looks like to ensure correct id
> > assignment.
> > Have a look into the i2c code to see how it is handled. Essentially we
> must
> > pass
> > the requested number to ida_simple_get().
> >
> > Thanks,
> > Guenter
>
> Ok that makes sense. I will put a wrapper function around ida_simple_get()
> that will request a specific number, if that fails then do a normal request.
> Something like this...
>
> ret = of_alias_get_id(....)
>
> id = ida_simple_get(&watchdog_ida, ret, ret, GFP_KERNEL);
>
ret, ret + 1
but something like
ret = of_alias_get_id(...);
if (ret >= 0)
id = ida_simple_get(&watchdog_ida, ret, ret + 1, GFP_KERNEL);
else
id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
if (id < 0)
return id;
would be better. Passing 'ret' directly would not work, because
ida_simple_get() expects an unsigned range as parameters, and
of_alias_get_id() can return a negative error code.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
2015-08-29 9:53 ` Guenter Roeck
@ 2015-09-01 17:20 ` Justin Chen
2015-09-01 17:53 ` Guenter Roeck
0 siblings, 1 reply; 7+ messages in thread
From: Justin Chen @ 2015-09-01 17:20 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-kernel, wim, linux-watchdog, bcm-kernel-feedback-list
[-- Attachment #1: Type: text/plain, Size: 2762 bytes --]
On Sat, Aug 29, 2015 at 2:53 AM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 08/28/2015 02:58 PM, Justin Chen wrote:
>>
>> Currently there is no way to easily differentiate multiple
>> watchdog devices. The watchdogs are named by the order they
>> are probed.
>> 1st probed watchdog: /dev/watchdog0
>> 2nd probed watchdog: /dev/watchdog1
>> ...
>>
>> This change uses the alias of the watchdog device node for
>> the name of the watchdog.
>> aliases {
>> watchdog0 = "/...../...."
>> watchdog3 = "/..../....."
>> watchdog2 = "/..../....."
>> ...
>> }
>>
>> This will translate to...
>> /dev/watchdog0
>> /dev/watchdog3
>> /dev/watchdog2
>>
>> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
>
>
> Interesting idea. Checking through other subsystems, many others do the
> same,
> so it makes sense to use that mechanism.
>
> However, the id assignment should be in the calling code, in
> __watchdog_register_device,
> to avoid that another id, possibly conflicting, is assigned through the
ida
> mechanism.
>
> This is a bit more complicated than it looks like to ensure correct id
> assignment.
> Have a look into the i2c code to see how it is handled. Essentially we
must
> pass
> the requested number to ida_simple_get().
>
> Thanks,
> Guenter
Ok that makes sense. I will put a wrapper function around ida_simple_get()
that will request a specific number, if that fails then do a normal request.
Something like this...
ret = of_alias_get_id(....)
id = ida_simple_get(&watchdog_ida, ret, ret, GFP_KERNEL);
if (id != ret)
id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KENREL);
thanks,
Justin
>
>
>> ---
>> drivers/watchdog/watchdog_dev.c | 9 ++++++++-
>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/watchdog/watchdog_dev.c
>> b/drivers/watchdog/watchdog_dev.c
>> index 6aaefba..52b1f0b 100644
>> --- a/drivers/watchdog/watchdog_dev.c
>> +++ b/drivers/watchdog/watchdog_dev.c
>> @@ -41,6 +41,7 @@
>> #include <linux/miscdevice.h> /* For handling misc devices */
>> #include <linux/init.h> /* For __init/__exit/... */
>> #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
>> +#include <linux/of.h>
>>
>> #include "watchdog_core.h"
>>
>> @@ -522,7 +523,13 @@ static struct miscdevice watchdog_miscdev = {
>>
>> int watchdog_dev_register(struct watchdog_device *watchdog)
>> {
>> - int err, devno;
>> + int err, devno, ret;
>> +
>> + if (watchdog->parent) {
>> + ret = of_alias_get_id(watchdog->parent->of_node,
>> "watchdog");
>> + if (ret >= 0)
>> + watchdog->id = ret;
>> + }
>>
>> if (watchdog->id == 0) {
>> old_wdd = watchdog;
>>
>
[-- Attachment #2: Type: text/html, Size: 3776 bytes --]
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
2015-08-28 21:58 Justin Chen
@ 2015-08-29 9:53 ` Guenter Roeck
2015-09-01 17:20 ` Justin Chen
0 siblings, 1 reply; 7+ messages in thread
From: Guenter Roeck @ 2015-08-29 9:53 UTC (permalink / raw)
To: Justin Chen, linux-kernel; +Cc: wim, linux-watchdog, bcm-kernel-feedback-list
On 08/28/2015 02:58 PM, Justin Chen wrote:
> Currently there is no way to easily differentiate multiple
> watchdog devices. The watchdogs are named by the order they
> are probed.
> 1st probed watchdog: /dev/watchdog0
> 2nd probed watchdog: /dev/watchdog1
> ...
>
> This change uses the alias of the watchdog device node for
> the name of the watchdog.
> aliases {
> watchdog0 = "/...../...."
> watchdog3 = "/..../....."
> watchdog2 = "/..../....."
> ...
> }
>
> This will translate to...
> /dev/watchdog0
> /dev/watchdog3
> /dev/watchdog2
>
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Interesting idea. Checking through other subsystems, many others do the same,
so it makes sense to use that mechanism.
However, the id assignment should be in the calling code, in __watchdog_register_device,
to avoid that another id, possibly conflicting, is assigned through the ida mechanism.
This is a bit more complicated than it looks like to ensure correct id assignment.
Have a look into the i2c code to see how it is handled. Essentially we must pass
the requested number to ida_simple_get().
Thanks,
Guenter
> ---
> drivers/watchdog/watchdog_dev.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> index 6aaefba..52b1f0b 100644
> --- a/drivers/watchdog/watchdog_dev.c
> +++ b/drivers/watchdog/watchdog_dev.c
> @@ -41,6 +41,7 @@
> #include <linux/miscdevice.h> /* For handling misc devices */
> #include <linux/init.h> /* For __init/__exit/... */
> #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
> +#include <linux/of.h>
>
> #include "watchdog_core.h"
>
> @@ -522,7 +523,13 @@ static struct miscdevice watchdog_miscdev = {
>
> int watchdog_dev_register(struct watchdog_device *watchdog)
> {
> - int err, devno;
> + int err, devno, ret;
> +
> + if (watchdog->parent) {
> + ret = of_alias_get_id(watchdog->parent->of_node, "watchdog");
> + if (ret >= 0)
> + watchdog->id = ret;
> + }
>
> if (watchdog->id == 0) {
> old_wdd = watchdog;
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] watchdog_dev: Use device tree alias for naming watchdogs
@ 2015-08-28 21:58 Justin Chen
2015-08-29 9:53 ` Guenter Roeck
0 siblings, 1 reply; 7+ messages in thread
From: Justin Chen @ 2015-08-28 21:58 UTC (permalink / raw)
To: linux-kernel; +Cc: wim, linux-watchdog, bcm-kernel-feedback-list, Justin Chen
Currently there is no way to easily differentiate multiple
watchdog devices. The watchdogs are named by the order they
are probed.
1st probed watchdog: /dev/watchdog0
2nd probed watchdog: /dev/watchdog1
...
This change uses the alias of the watchdog device node for
the name of the watchdog.
aliases {
watchdog0 = "/...../...."
watchdog3 = "/..../....."
watchdog2 = "/..../....."
...
}
This will translate to...
/dev/watchdog0
/dev/watchdog3
/dev/watchdog2
Signed-off-by: Justin Chen <justinpopo6@gmail.com>
---
drivers/watchdog/watchdog_dev.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..52b1f0b 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -41,6 +41,7 @@
#include <linux/miscdevice.h> /* For handling misc devices */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
+#include <linux/of.h>
#include "watchdog_core.h"
@@ -522,7 +523,13 @@ static struct miscdevice watchdog_miscdev = {
int watchdog_dev_register(struct watchdog_device *watchdog)
{
- int err, devno;
+ int err, devno, ret;
+
+ if (watchdog->parent) {
+ ret = of_alias_get_id(watchdog->parent->of_node, "watchdog");
+ if (ret >= 0)
+ watchdog->id = ret;
+ }
if (watchdog->id == 0) {
old_wdd = watchdog;
--
2.1.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-10-27 15:47 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2015-09-02 18:00 [PATCH] watchdog_dev: Use device tree alias for naming watchdogs Justin Chen
2015-09-02 20:19 ` Guenter Roeck
2015-10-27 15:47 ` Wim Van Sebroeck
-- strict thread matches above, loose matches on Subject: below --
2015-08-28 21:58 Justin Chen
2015-08-29 9:53 ` Guenter Roeck
2015-09-01 17:20 ` Justin Chen
2015-09-01 17:53 ` Guenter Roeck
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