* [RFC PATCH v2] watchdog: sp805: Add clock-frequency property
@ 2018-07-09 10:19 Srinath Mannam
2018-07-09 13:45 ` Guenter Roeck
0 siblings, 1 reply; 4+ messages in thread
From: Srinath Mannam @ 2018-07-09 10:19 UTC (permalink / raw)
To: wim, linux
Cc: ray.jui, vladimir.olovyannikov, vikram.prakash, scott.branden,
sudeep.holla, linux-watchdog, linux-kernel, Srinath Mannam
When using ACPI node, binding clock devices are
not available as device tree, So clock-frequency
property given in _DSD object of ACPI device is
used to calculate Watchdog rate.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
---
drivers/watchdog/sp805_wdt.c | 34 ++++++++++++++++++++++++++--------
1 file changed, 26 insertions(+), 8 deletions(-)
diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index 9849db0..ad5ed64 100644
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -11,6 +11,7 @@
* warranty of any kind, whether express or implied.
*/
+#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/resource.h>
#include <linux/amba/bus.h>
@@ -22,6 +23,7 @@
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/of.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
@@ -65,6 +67,7 @@ struct sp805_wdt {
spinlock_t lock;
void __iomem *base;
struct clk *clk;
+ u64 rate;
struct amba_device *adev;
unsigned int load_val;
};
@@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
u64 load, rate;
- rate = clk_get_rate(wdt->clk);
+ rate = wdt->rate;
/*
* sp805 runs counter with given value twice, after the end of first
@@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
static unsigned int wdt_timeleft(struct watchdog_device *wdd)
{
struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
- u64 load, rate;
-
- rate = clk_get_rate(wdt->clk);
+ u64 load;
spin_lock(&wdt->lock);
load = readl_relaxed(wdt->base + WDTVALUE);
@@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct watchdog_device *wdd)
load += wdt->load_val + 1;
spin_unlock(&wdt->lock);
- return div_u64(load, rate);
+ return div_u64(load, wdt->rate);
}
static int
@@ -228,10 +229,27 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);
- wdt->clk = devm_clk_get(&adev->dev, NULL);
- if (IS_ERR(wdt->clk)) {
+ if (adev->dev.of_node) {
+ wdt->clk = devm_clk_get(&adev->dev, NULL);
+ if (IS_ERR(wdt->clk)) {
+ ret = PTR_ERR(wdt->clk);
+ wdt->clk = NULL;
+ } else
+ wdt->rate = clk_get_rate(wdt->clk);
+ } else if (has_acpi_companion(&adev->dev)) {
+ /*
+ * When Driver probe with ACPI device, clock devices
+ * are not available, so watchdog rate get from
+ * clock-frequency property given in _DSD object.
+ */
+ device_property_read_u64(&adev->dev, "clock-frequency",
+ &wdt->rate);
+ if (!wdt->rate)
+ ret = -ENODEV;
+ }
+
+ if (ret) {
dev_warn(&adev->dev, "Clock not found\n");
- ret = PTR_ERR(wdt->clk);
goto err;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RFC PATCH v2] watchdog: sp805: Add clock-frequency property
2018-07-09 10:19 [RFC PATCH v2] watchdog: sp805: Add clock-frequency property Srinath Mannam
@ 2018-07-09 13:45 ` Guenter Roeck
2018-07-10 7:57 ` Srinath Mannam
0 siblings, 1 reply; 4+ messages in thread
From: Guenter Roeck @ 2018-07-09 13:45 UTC (permalink / raw)
To: Srinath Mannam, wim
Cc: ray.jui, vladimir.olovyannikov, vikram.prakash, scott.branden,
sudeep.holla, linux-watchdog, linux-kernel
On 07/09/2018 03:19 AM, Srinath Mannam wrote:
> When using ACPI node, binding clock devices are
> not available as device tree, So clock-frequency
> property given in _DSD object of ACPI device is
> used to calculate Watchdog rate.
>
> Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
> ---
> drivers/watchdog/sp805_wdt.c | 34 ++++++++++++++++++++++++++--------
> 1 file changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
> index 9849db0..ad5ed64 100644
> --- a/drivers/watchdog/sp805_wdt.c
> +++ b/drivers/watchdog/sp805_wdt.c
> @@ -11,6 +11,7 @@
> * warranty of any kind, whether express or implied.
> */
>
> +#include <linux/acpi.h>
> #include <linux/device.h>
> #include <linux/resource.h>
> #include <linux/amba/bus.h>
> @@ -22,6 +23,7 @@
> #include <linux/math64.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> +#include <linux/of.h>
> #include <linux/pm.h>
> #include <linux/slab.h>
> #include <linux/spinlock.h>
> @@ -65,6 +67,7 @@ struct sp805_wdt {
> spinlock_t lock;
> void __iomem *base;
> struct clk *clk;
> + u64 rate;
> struct amba_device *adev;
> unsigned int load_val;
> };
> @@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
> u64 load, rate;
>
> - rate = clk_get_rate(wdt->clk);
> + rate = wdt->rate;
>
> /*
> * sp805 runs counter with given value twice, after the end of first
> @@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
> static unsigned int wdt_timeleft(struct watchdog_device *wdd)
> {
> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
> - u64 load, rate;
> -
> - rate = clk_get_rate(wdt->clk);
> + u64 load;
>
> spin_lock(&wdt->lock);
> load = readl_relaxed(wdt->base + WDTVALUE);
> @@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct watchdog_device *wdd)
> load += wdt->load_val + 1;
> spin_unlock(&wdt->lock);
>
> - return div_u64(load, rate);
> + return div_u64(load, wdt->rate);
> }
>
> static int
> @@ -228,10 +229,27 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)
> if (IS_ERR(wdt->base))
> return PTR_ERR(wdt->base);
>
> - wdt->clk = devm_clk_get(&adev->dev, NULL);
> - if (IS_ERR(wdt->clk)) {
> + if (adev->dev.of_node) {
> + wdt->clk = devm_clk_get(&adev->dev, NULL);
> + if (IS_ERR(wdt->clk)) {
> + ret = PTR_ERR(wdt->clk);
> + wdt->clk = NULL;
Clearing wdt->clk is useless.
> + } else
> + wdt->rate = clk_get_rate(wdt->clk);
The else branch should be in { } as well per coding style.
> + } else if (has_acpi_companion(&adev->dev)) {
> + /*
> + * When Driver probe with ACPI device, clock devices
> + * are not available, so watchdog rate get from
> + * clock-frequency property given in _DSD object.
> + */
> + device_property_read_u64(&adev->dev, "clock-frequency",
> + &wdt->rate);
Continuation line alignment is off.
Still not documented. Maybe that is common for ACPI devices nowadays.
If so, I'll need at least a pointer to a document or something declaring
that ACPI devices do not use well documented properties, and a confirmation
that using such properties is acceptable in the Linux kernel.
> + if (!wdt->rate)
> + ret = -ENODEV;
> + }
> +
> + if (ret) {
> dev_warn(&adev->dev, "Clock not found\n");
> - ret = PTR_ERR(wdt->clk);
> goto err;
> }
Please move the error handling to where the error occurs. While doing that,
please change the message to dev_err() - this is an error, not a warning -
and change the second error message to match the error (it did not find
the property).
Also, return directly - the goto just generates another error message
which is ridiculous.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC PATCH v2] watchdog: sp805: Add clock-frequency property
2018-07-09 13:45 ` Guenter Roeck
@ 2018-07-10 7:57 ` Srinath Mannam
2018-07-10 8:01 ` Srinath Mannam
0 siblings, 1 reply; 4+ messages in thread
From: Srinath Mannam @ 2018-07-10 7:57 UTC (permalink / raw)
To: Guenter Roeck
Cc: wim, Ray Jui, Vladimir Olovyannikov, Vikram Prakash,
Scott Branden, Sudeep Holla, linux-watchdog,
Linux Kernel Mailing List
Hi Guenter,
Thank you for your feedback. Please find my answers in lined.
On Mon, Jul 9, 2018 at 7:15 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 07/09/2018 03:19 AM, Srinath Mannam wrote:
>>
>> When using ACPI node, binding clock devices are
>> not available as device tree, So clock-frequency
>> property given in _DSD object of ACPI device is
>> used to calculate Watchdog rate.
>>
>> Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
>> ---
>> drivers/watchdog/sp805_wdt.c | 34 ++++++++++++++++++++++++++--------
>> 1 file changed, 26 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
>> index 9849db0..ad5ed64 100644
>> --- a/drivers/watchdog/sp805_wdt.c
>> +++ b/drivers/watchdog/sp805_wdt.c
>> @@ -11,6 +11,7 @@
>> * warranty of any kind, whether express or implied.
>> */
>> +#include <linux/acpi.h>
>> #include <linux/device.h>
>> #include <linux/resource.h>
>> #include <linux/amba/bus.h>
>> @@ -22,6 +23,7 @@
>> #include <linux/math64.h>
>> #include <linux/module.h>
>> #include <linux/moduleparam.h>
>> +#include <linux/of.h>
>> #include <linux/pm.h>
>> #include <linux/slab.h>
>> #include <linux/spinlock.h>
>> @@ -65,6 +67,7 @@ struct sp805_wdt {
>> spinlock_t lock;
>> void __iomem *base;
>> struct clk *clk;
>> + u64 rate;
>> struct amba_device *adev;
>> unsigned int load_val;
>> };
>> @@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd,
>> unsigned int timeout)
>> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
>> u64 load, rate;
>> - rate = clk_get_rate(wdt->clk);
>> + rate = wdt->rate;
>> /*
>> * sp805 runs counter with given value twice, after the end of
>> first
>> @@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd,
>> unsigned int timeout)
>> static unsigned int wdt_timeleft(struct watchdog_device *wdd)
>> {
>> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
>> - u64 load, rate;
>> -
>> - rate = clk_get_rate(wdt->clk);
>> + u64 load;
>> spin_lock(&wdt->lock);
>> load = readl_relaxed(wdt->base + WDTVALUE);
>> @@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct
>> watchdog_device *wdd)
>> load += wdt->load_val + 1;
>> spin_unlock(&wdt->lock);
>> - return div_u64(load, rate);
>> + return div_u64(load, wdt->rate);
>> }
>> static int
>> @@ -228,10 +229,27 @@ sp805_wdt_probe(struct amba_device *adev, const
>> struct amba_id *id)
>> if (IS_ERR(wdt->base))
>> return PTR_ERR(wdt->base);
>> - wdt->clk = devm_clk_get(&adev->dev, NULL);
>> - if (IS_ERR(wdt->clk)) {
>> + if (adev->dev.of_node) {
>> + wdt->clk = devm_clk_get(&adev->dev, NULL);
>> + if (IS_ERR(wdt->clk)) {
>> + ret = PTR_ERR(wdt->clk);
>> + wdt->clk = NULL;
>
>
> Clearing wdt->clk is useless.
If not, clk_prepare_enable and clk_disable_unprepare functions calls
made in this driver will crash.
>
>> + } else
>> + wdt->rate = clk_get_rate(wdt->clk);
>
>
> The else branch should be in { } as well per coding style.
I will add the change.
>
>> + } else if (has_acpi_companion(&adev->dev)) {
>> + /*
>> + * When Driver probe with ACPI device, clock devices
>> + * are not available, so watchdog rate get from
>> + * clock-frequency property given in _DSD object.
>> + */
>> + device_property_read_u64(&adev->dev, "clock-frequency",
>> + &wdt->rate);
>
>
> Continuation line alignment is off.
I missed it, Thank you, I will make the change.
>
> Still not documented. Maybe that is common for ACPI devices nowadays.
> If so, I'll need at least a pointer to a document or something declaring
> that ACPI devices do not use well documented properties, and a confirmation
> that using such properties is acceptable in the Linux kernel.
>
patches listed below has same approach to add ACPI support.
ex:
1. commit 515da746983bc6382e380ba8b1ce9345a9550ffe
Author: Naveen Kaje <nkaje@codeaurora.org>
Date: Tue Oct 11 10:27:56 2016 -0600
i2c: qup: add ACPI support
2. commit 82a19035d000c8b4fd7d6f61b614f63dec75d389
Author: Lendacky, Thomas <Thomas.Lendacky@amd.com>
Date: Fri Jan 16 12:47:16 2015 -0600
amd-xgbe: Add ACPI support
>> + if (!wdt->rate)
>> + ret = -ENODEV;
>> + }
>> +
>> + if (ret) {
>> dev_warn(&adev->dev, "Clock not found\n");
>> - ret = PTR_ERR(wdt->clk);
>> goto err;
>> }
>
>
> Please move the error handling to where the error occurs. While doing that,
> please change the message to dev_err() - this is an error, not a warning -
> and change the second error message to match the error (it did not find
> the property).
>
> Also, return directly - the goto just generates another error message
> which is ridiculous.
Thank you, I will add the changes.
>
> Thanks,
> Guenter
Regards,
Srinath.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC PATCH v2] watchdog: sp805: Add clock-frequency property
2018-07-10 7:57 ` Srinath Mannam
@ 2018-07-10 8:01 ` Srinath Mannam
0 siblings, 0 replies; 4+ messages in thread
From: Srinath Mannam @ 2018-07-10 8:01 UTC (permalink / raw)
To: Guenter Roeck
Cc: wim, Ray Jui, Vladimir Olovyannikov, Vikram Prakash,
Scott Branden, Sudeep Holla, linux-watchdog,
Linux Kernel Mailing List
Hi Guenter,
I missed your comment about "Clearing wdt->clk is useless." I will
remove that line.
Regards,
Srinath.
On Tue, Jul 10, 2018 at 1:27 PM, Srinath Mannam
<srinath.mannam@broadcom.com> wrote:
> Hi Guenter,
>
> Thank you for your feedback. Please find my answers in lined.
>
> On Mon, Jul 9, 2018 at 7:15 PM, Guenter Roeck <linux@roeck-us.net> wrote:
>> On 07/09/2018 03:19 AM, Srinath Mannam wrote:
>>>
>>> When using ACPI node, binding clock devices are
>>> not available as device tree, So clock-frequency
>>> property given in _DSD object of ACPI device is
>>> used to calculate Watchdog rate.
>>>
>>> Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
>>> ---
>>> drivers/watchdog/sp805_wdt.c | 34 ++++++++++++++++++++++++++--------
>>> 1 file changed, 26 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
>>> index 9849db0..ad5ed64 100644
>>> --- a/drivers/watchdog/sp805_wdt.c
>>> +++ b/drivers/watchdog/sp805_wdt.c
>>> @@ -11,6 +11,7 @@
>>> * warranty of any kind, whether express or implied.
>>> */
>>> +#include <linux/acpi.h>
>>> #include <linux/device.h>
>>> #include <linux/resource.h>
>>> #include <linux/amba/bus.h>
>>> @@ -22,6 +23,7 @@
>>> #include <linux/math64.h>
>>> #include <linux/module.h>
>>> #include <linux/moduleparam.h>
>>> +#include <linux/of.h>
>>> #include <linux/pm.h>
>>> #include <linux/slab.h>
>>> #include <linux/spinlock.h>
>>> @@ -65,6 +67,7 @@ struct sp805_wdt {
>>> spinlock_t lock;
>>> void __iomem *base;
>>> struct clk *clk;
>>> + u64 rate;
>>> struct amba_device *adev;
>>> unsigned int load_val;
>>> };
>>> @@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd,
>>> unsigned int timeout)
>>> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
>>> u64 load, rate;
>>> - rate = clk_get_rate(wdt->clk);
>>> + rate = wdt->rate;
>>> /*
>>> * sp805 runs counter with given value twice, after the end of
>>> first
>>> @@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd,
>>> unsigned int timeout)
>>> static unsigned int wdt_timeleft(struct watchdog_device *wdd)
>>> {
>>> struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
>>> - u64 load, rate;
>>> -
>>> - rate = clk_get_rate(wdt->clk);
>>> + u64 load;
>>> spin_lock(&wdt->lock);
>>> load = readl_relaxed(wdt->base + WDTVALUE);
>>> @@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct
>>> watchdog_device *wdd)
>>> load += wdt->load_val + 1;
>>> spin_unlock(&wdt->lock);
>>> - return div_u64(load, rate);
>>> + return div_u64(load, wdt->rate);
>>> }
>>> static int
>>> @@ -228,10 +229,27 @@ sp805_wdt_probe(struct amba_device *adev, const
>>> struct amba_id *id)
>>> if (IS_ERR(wdt->base))
>>> return PTR_ERR(wdt->base);
>>> - wdt->clk = devm_clk_get(&adev->dev, NULL);
>>> - if (IS_ERR(wdt->clk)) {
>>> + if (adev->dev.of_node) {
>>> + wdt->clk = devm_clk_get(&adev->dev, NULL);
>>> + if (IS_ERR(wdt->clk)) {
>>> + ret = PTR_ERR(wdt->clk);
>>> + wdt->clk = NULL;
>>
>>
>> Clearing wdt->clk is useless.
>
> If not, clk_prepare_enable and clk_disable_unprepare functions calls
> made in this driver will crash.
Sorry I missed your point. I will remove that.
>
>>
>>> + } else
>>> + wdt->rate = clk_get_rate(wdt->clk);
>>
>>
>> The else branch should be in { } as well per coding style.
> I will add the change.
>>
>>> + } else if (has_acpi_companion(&adev->dev)) {
>>> + /*
>>> + * When Driver probe with ACPI device, clock devices
>>> + * are not available, so watchdog rate get from
>>> + * clock-frequency property given in _DSD object.
>>> + */
>>> + device_property_read_u64(&adev->dev, "clock-frequency",
>>> + &wdt->rate);
>>
>>
>> Continuation line alignment is off.
> I missed it, Thank you, I will make the change.
>>
>> Still not documented. Maybe that is common for ACPI devices nowadays.
>> If so, I'll need at least a pointer to a document or something declaring
>> that ACPI devices do not use well documented properties, and a confirmation
>> that using such properties is acceptable in the Linux kernel.
>>
> patches listed below has same approach to add ACPI support.
> ex:
> 1. commit 515da746983bc6382e380ba8b1ce9345a9550ffe
> Author: Naveen Kaje <nkaje@codeaurora.org>
> Date: Tue Oct 11 10:27:56 2016 -0600
>
> i2c: qup: add ACPI support
>
> 2. commit 82a19035d000c8b4fd7d6f61b614f63dec75d389
> Author: Lendacky, Thomas <Thomas.Lendacky@amd.com>
> Date: Fri Jan 16 12:47:16 2015 -0600
>
> amd-xgbe: Add ACPI support
>
>>> + if (!wdt->rate)
>>> + ret = -ENODEV;
>>> + }
>>> +
>>> + if (ret) {
>>> dev_warn(&adev->dev, "Clock not found\n");
>>> - ret = PTR_ERR(wdt->clk);
>>> goto err;
>>> }
>>
>>
>> Please move the error handling to where the error occurs. While doing that,
>> please change the message to dev_err() - this is an error, not a warning -
>> and change the second error message to match the error (it did not find
>> the property).
>>
>> Also, return directly - the goto just generates another error message
>> which is ridiculous.
> Thank you, I will add the changes.
>>
>> Thanks,
>> Guenter
>
> Regards,
> Srinath.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-07-09 10:19 [RFC PATCH v2] watchdog: sp805: Add clock-frequency property Srinath Mannam
2018-07-09 13:45 ` Guenter Roeck
2018-07-10 7:57 ` Srinath Mannam
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