[PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Pramod Gurav]

This change replaces use of arm_pm_restart with recently introduced
reset mechanism in Linux kernel called restart_notifier.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-pm@vger.kernel.org

Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
---
Tested on Dragonboard APQ8074

Changes since v2:
- Removed unwanted header file and added linux/pm.h

Changes since v1:
- Initialized restart_nb with its declaration
- Removed return check for register_restart_handler as it always
  returns 0 as per Guenter's suggestion to Josh's similar patch.
  This takes care of Guenter's comments on error logs and NULL
  initialization of restart_nb.notifier_call.
---
 drivers/power/reset/msm-poweroff.c |   20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/power/reset/msm-poweroff.c b/drivers/power/reset/msm-poweroff.c
index 774f9a3..4702efd 100644
--- a/drivers/power/reset/msm-poweroff.c
+++ b/drivers/power/reset/msm-poweroff.c
@@ -20,21 +20,27 @@
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <linux/reboot.h>
-
-#include <asm/system_misc.h>
+#include <linux/pm.h>
 
 static void __iomem *msm_ps_hold;
-
-static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd)
+static int do_msm_restart(struct notifier_block *nb, unsigned long action,
+			   void *data)
 {
 	writel(0, msm_ps_hold);
 	mdelay(10000);
+
+	return NOTIFY_DONE;
 }
 
+static struct notifier_block restart_nb = {
+	.notifier_call = do_msm_restart,
+	.priority = 128,
+};
+
 static void do_msm_poweroff(void)
 {
 	/* TODO: Add poweroff capability */
-	do_msm_restart(REBOOT_HARD, NULL);
+	do_msm_restart(&restart_nb, 0, NULL);
 }
 
 static int msm_restart_probe(struct platform_device *pdev)
@@ -47,8 +53,10 @@ static int msm_restart_probe(struct platform_device *pdev)
 	if (IS_ERR(msm_ps_hold))
 		return PTR_ERR(msm_ps_hold);
 
+	register_restart_handler(&restart_nb);
+
 	pm_power_off = do_msm_poweroff;
-	arm_pm_restart = do_msm_restart;
+
 	return 0;
 }
 
-- 
1.7.9.5

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Pramod Gurav]

+linux-arm-msm
On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
> This change replaces use of arm_pm_restart with recently introduced
> reset mechanism in Linux kernel called restart_notifier.
> 
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Josh Cartwright <joshc@codeaurora.org>
> Cc: Sebastian Reichel <sre@kernel.org>
> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: linux-pm@vger.kernel.org
> 
> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
> ---
> Tested on Dragonboard APQ8074
> 
> Changes since v2:
> - Removed unwanted header file and added linux/pm.h
> 
> Changes since v1:
> - Initialized restart_nb with its declaration
> - Removed return check for register_restart_handler as it always
>   returns 0 as per Guenter's suggestion to Josh's similar patch.
>   This takes care of Guenter's comments on error logs and NULL
>   initialization of restart_nb.notifier_call.
> ---
>  drivers/power/reset/msm-poweroff.c |   20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/power/reset/msm-poweroff.c b/drivers/power/reset/msm-poweroff.c
> index 774f9a3..4702efd 100644
> --- a/drivers/power/reset/msm-poweroff.c
> +++ b/drivers/power/reset/msm-poweroff.c
> @@ -20,21 +20,27 @@
>  #include <linux/platform_device.h>
>  #include <linux/module.h>
>  #include <linux/reboot.h>
> -
> -#include <asm/system_misc.h>
> +#include <linux/pm.h>
>  
>  static void __iomem *msm_ps_hold;
> -
> -static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd)
> +static int do_msm_restart(struct notifier_block *nb, unsigned long action,
> +			   void *data)
>  {
>  	writel(0, msm_ps_hold);
>  	mdelay(10000);
> +
> +	return NOTIFY_DONE;
>  }
>  
> +static struct notifier_block restart_nb = {
> +	.notifier_call = do_msm_restart,
> +	.priority = 128,
> +};
> +
>  static void do_msm_poweroff(void)
>  {
>  	/* TODO: Add poweroff capability */
> -	do_msm_restart(REBOOT_HARD, NULL);
> +	do_msm_restart(&restart_nb, 0, NULL);
>  }
>  
>  static int msm_restart_probe(struct platform_device *pdev)
> @@ -47,8 +53,10 @@ static int msm_restart_probe(struct platform_device *pdev)
>  	if (IS_ERR(msm_ps_hold))
>  		return PTR_ERR(msm_ps_hold);
>  
> +	register_restart_handler(&restart_nb);
> +
>  	pm_power_off = do_msm_poweroff;
> -	arm_pm_restart = do_msm_restart;
> +
>  	return 0;
>  }
>  
> 

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Stephen Boyd]

On 09/22/14 23:28, Pramod Gurav wrote:
> +linux-arm-msm
> On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
>> This change replaces use of arm_pm_restart with recently introduced
>> reset mechanism in Linux kernel called restart_notifier.
>>
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Josh Cartwright <joshc@codeaurora.org>
>> Cc: Sebastian Reichel <sre@kernel.org>
>> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>> Cc: David Woodhouse <dwmw2@infradead.org>
>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>> Cc: linux-pm@vger.kernel.org
>>
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Kumar Gala]

On Sep 23, 2014, at 1:28 AM, Pramod Gurav <pramod.gurav@smartplayin.com> wrote:

> +linux-arm-msm
> On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
>> This change replaces use of arm_pm_restart with recently introduced
>> reset mechanism in Linux kernel called restart_notifier.

Can you update the commit message to include details about the priority level we are setting it to.

Probably something like Josh had:

Choose priority 128, as according to documentation, this mechanism "is
sufficient to restart the entire system”.

Hmm, what happens if we have ps_hold restart and msm-poweroff enabled.  Which one should have priority?

>> 
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Josh Cartwright <joshc@codeaurora.org>
>> Cc: Sebastian Reichel <sre@kernel.org>
>> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>> Cc: David Woodhouse <dwmw2@infradead.org>
>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>> Cc: linux-pm@vger.kernel.org
>> 
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---
>> Tested on Dragonboard APQ8074
>> 
>> Changes since v2:
>> - Removed unwanted header file and added linux/pm.h
>> 
>> Changes since v1:
>> - Initialized restart_nb with its declaration
>> - Removed return check for register_restart_handler as it always
>>  returns 0 as per Guenter's suggestion to Josh's similar patch.
>>  This takes care of Guenter's comments on error logs and NULL
>>  initialization of restart_nb.notifier_call.
>> ---
>> drivers/power/reset/msm-poweroff.c |   20 ++++++++++++++------
>> 1 file changed, 14 insertions(+), 6 deletions(-)
>> 
>> diff --git a/drivers/power/reset/msm-poweroff.c b/drivers/power/reset/msm-poweroff.c
>> index 774f9a3..4702efd 100644
>> --- a/drivers/power/reset/msm-poweroff.c
>> +++ b/drivers/power/reset/msm-poweroff.c
>> @@ -20,21 +20,27 @@
>> #include <linux/platform_device.h>
>> #include <linux/module.h>
>> #include <linux/reboot.h>
>> -
>> -#include <asm/system_misc.h>
>> +#include <linux/pm.h>
>> 
>> static void __iomem *msm_ps_hold;
>> -
>> -static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd)
>> +static int do_msm_restart(struct notifier_block *nb, unsigned long action,
>> +			   void *data)
>> {
>> 	writel(0, msm_ps_hold);
>> 	mdelay(10000);
>> +
>> +	return NOTIFY_DONE;
>> }
>> 
>> +static struct notifier_block restart_nb = {
>> +	.notifier_call = do_msm_restart,
>> +	.priority = 128,
>> +};
>> +
>> static void do_msm_poweroff(void)
>> {
>> 	/* TODO: Add poweroff capability */
>> -	do_msm_restart(REBOOT_HARD, NULL);
>> +	do_msm_restart(&restart_nb, 0, NULL);
>> }
>> 
>> static int msm_restart_probe(struct platform_device *pdev)
>> @@ -47,8 +53,10 @@ static int msm_restart_probe(struct platform_device *pdev)
>> 	if (IS_ERR(msm_ps_hold))
>> 		return PTR_ERR(msm_ps_hold);
>> 
>> +	register_restart_handler(&restart_nb);
>> +
>> 	pm_power_off = do_msm_poweroff;
>> -	arm_pm_restart = do_msm_restart;
>> +
>> 	return 0;
>> }
>> 
>> 
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-- 
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Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Josh Cartwright]

On Tue, Sep 23, 2014 at 12:48:42PM -0500, Kumar Gala wrote:
> 
> On Sep 23, 2014, at 1:28 AM, Pramod Gurav <pramod.gurav@smartplayin.com> wrote:
> 
> > +linux-arm-msm
> > On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
> >> This change replaces use of arm_pm_restart with recently introduced
> >> reset mechanism in Linux kernel called restart_notifier.
> 
> Can you update the commit message to include details about the priority level we are setting it to.
> 
> Probably something like Josh had:
> 
> Choose priority 128, as according to documentation, this mechanism "is
> sufficient to restart the entire system?.
> 
> Hmm, what happens if we have ps_hold restart and msm-poweroff enabled.
> Which one should have priority?

I would hope we would avoid a situation where both this driver is
probed, and the pinctrl-msm driver has registered a restart handler?

That is, we wouldn't ever mix the pinctrl-msm ps_hold mechanism (for
MSM8660/MSM8960/APQ8064, etc) and msm-poweroff (APQ8074 and later).  Is
this a case you're worried about?

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Kumar Gala]

On Sep 23, 2014, at 12:55 PM, Josh Cartwright <joshc@codeaurora.org> wrote:

> On Tue, Sep 23, 2014 at 12:48:42PM -0500, Kumar Gala wrote:
>> 
>> On Sep 23, 2014, at 1:28 AM, Pramod Gurav <pramod.gurav@smartplayin.com> wrote:
>> 
>>> +linux-arm-msm
>>> On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
>>>> This change replaces use of arm_pm_restart with recently introduced
>>>> reset mechanism in Linux kernel called restart_notifier.
>> 
>> Can you update the commit message to include details about the priority level we are setting it to.
>> 
>> Probably something like Josh had:
>> 
>> Choose priority 128, as according to documentation, this mechanism "is
>> sufficient to restart the entire system?.
>> 
>> Hmm, what happens if we have ps_hold restart and msm-poweroff enabled.
>> Which one should have priority?
> 
> I would hope we would avoid a situation where both this driver is
> probed, and the pinctrl-msm driver has registered a restart handler?
> 
> That is, we wouldn't ever mix the pinctrl-msm ps_hold mechanism (for
> MSM8660/MSM8960/APQ8064, etc) and msm-poweroff (APQ8074 and later).  Is
> this a case you're worried about?

Yes, I’m worried about possibly case of having both solutions on a device.

- k

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH v3] power: reset: use restart_notifier mechanism for msm-poweroff

[Pramod Gurav]

Hi Kumar,

On 23-09-2014 11:18 PM, Kumar Gala wrote:
> 
> On Sep 23, 2014, at 1:28 AM, Pramod Gurav <pramod.gurav@smartplayin.com> wrote:
> 
>> +linux-arm-msm
>> On Tuesday 23 September 2014 11:38 AM, Pramod Gurav wrote:
>>> This change replaces use of arm_pm_restart with recently introduced
>>> reset mechanism in Linux kernel called restart_notifier.
> 
> Can you update the commit message to include details about the priority level we are setting it to.
> 
> Probably something like Josh had:
> 
> Choose priority 128, as according to documentation, this mechanism "is
> sufficient to restart the entire system”.
Will update the commit message.
> 
> Hmm, what happens if we have ps_hold restart and msm-poweroff enabled.  Which one should have priority?
In case of A-family/apq8064, the ps_hold register region is owned by
pinctrl hence the reset is implemented in pinctrl driver as the region
is already mapped there.
I have had a discussion with Stephen Boyd and was informed that ps_hold
register region in apq8074/B-family are moved to its own region and we
need to reset it through pinctrl.

So, for b family there is no need for ps_hold to be configured/muxed in
pinctrl and Josh's changes wont execute. Hence msm-poweroff wil be the
default reset as 128 in the default priority.

Hope I was able to put it well to answer your comment.
> 
>>>
>>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>> Cc: Josh Cartwright <joshc@codeaurora.org>
>>> Cc: Sebastian Reichel <sre@kernel.org>
>>> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>>> Cc: David Woodhouse <dwmw2@infradead.org>
>>> Cc: Stephen Boyd <sboyd@codeaurora.org>
>>> Cc: linux-pm@vger.kernel.org
>>>
>>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>>> ---
>>> Tested on Dragonboard APQ8074
>>>
>>> Changes since v2:
>>> - Removed unwanted header file and added linux/pm.h
>>>
>>> Changes since v1:
>>> - Initialized restart_nb with its declaration
>>> - Removed return check for register_restart_handler as it always
>>>  returns 0 as per Guenter's suggestion to Josh's similar patch.
>>>  This takes care of Guenter's comments on error logs and NULL
>>>  initialization of restart_nb.notifier_call.
>>> ---
>>> drivers/power/reset/msm-poweroff.c |   20 ++++++++++++++------
>>> 1 file changed, 14 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/power/reset/msm-poweroff.c b/drivers/power/reset/msm-poweroff.c
>>> index 774f9a3..4702efd 100644
>>> --- a/drivers/power/reset/msm-poweroff.c
>>> +++ b/drivers/power/reset/msm-poweroff.c
>>> @@ -20,21 +20,27 @@
>>> #include <linux/platform_device.h>
>>> #include <linux/module.h>
>>> #include <linux/reboot.h>
>>> -
>>> -#include <asm/system_misc.h>
>>> +#include <linux/pm.h>
>>>
>>> static void __iomem *msm_ps_hold;
>>> -
>>> -static void do_msm_restart(enum reboot_mode reboot_mode, const char *cmd)
>>> +static int do_msm_restart(struct notifier_block *nb, unsigned long action,
>>> +			   void *data)
>>> {
>>> 	writel(0, msm_ps_hold);
>>> 	mdelay(10000);
>>> +
>>> +	return NOTIFY_DONE;
>>> }
>>>
>>> +static struct notifier_block restart_nb = {
>>> +	.notifier_call = do_msm_restart,
>>> +	.priority = 128,
>>> +};
>>> +
>>> static void do_msm_poweroff(void)
>>> {
>>> 	/* TODO: Add poweroff capability */
>>> -	do_msm_restart(REBOOT_HARD, NULL);
>>> +	do_msm_restart(&restart_nb, 0, NULL);
>>> }
>>>
>>> static int msm_restart_probe(struct platform_device *pdev)
>>> @@ -47,8 +53,10 @@ static int msm_restart_probe(struct platform_device *pdev)
>>> 	if (IS_ERR(msm_ps_hold))
>>> 		return PTR_ERR(msm_ps_hold);
>>>
>>> +	register_restart_handler(&restart_nb);
>>> +
>>> 	pm_power_off = do_msm_poweroff;
>>> -	arm_pm_restart = do_msm_restart;
>>> +
>>> 	return 0;
>>> }
>>>
>>>
>> --
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>