Re: [PATCH] of/irq: introduce of_has_named_irqs helper

["R, Vignesh" <vigneshr-l0cyMroinI0@public.gmane.org>]

Hi,

On 7/28/2015 10:53 PM, Dmitry Torokhov wrote:
> On Tue, Jul 28, 2015 at 06:53:52PM +0530, Vignesh R wrote:
>> Hi Dmitry,
>>
>> On 07/25/2015 01:46 AM, Dmitry Torokhov wrote:
>>> On Fri, Jul 24, 2015 at 12:26:19PM -0700, Dmitry Torokhov wrote:
>>>> On Fri, Jul 24, 2015 at 02:14:57PM -0500, Rob Herring wrote:
>>>>> On Fri, Jul 24, 2015 at 1:26 PM, Dmitry Torokhov
>>>>> <dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>>>>> Sometimes drivers might wish to transition from index-based to named
>>>>>> interrupt descriptions. To aid in decision-making when parsing device
>>>>>> tree data let's provide a helper that will indicate the scheme that is
>>>>>> being used.
>>>>>
>>>>> Generally, IRQs are retrieved by platform_get_irq or
>>>>> platform_get_irq_byname. Drivers should not call the of_irq_*
>>>>> functions directly in most cases.
>>>>
>>>> That would be true for platform drivers, but not all devices are
>>>> platform devices.
>>>>
>>>>>
>>>>>>
>>>>>> Signed-off-by: Dmitry Torokhov <dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>>>>>> ---
>>>>>>
>>>>>> The intent is to it like this:
>>>>>>
>>>>>>         if (of_has_named_irqs(np) {
>>>>>>                 /* Wake IRQ is optional */
>>>>>>                 dev->wakeirq = of_irq_get_byname(np, "wakeup");
>>>>>>                 if (dev->wakeirq < 0 && dev->wakeirq != -ENODATA)
>>>>>>                         return dev->wakeirq;
>>>>>>         }
>>>>>
>>>>> of_irq_get_byname will already return an error if the property is not
>>>>> present. Use that.
>>>>
>>>> I do not like that it returns -EINVAL when property is missing, can we
>>>> change it to return -ENODATA (so it is the same as when the property is
>>>> defined but such name is missing)?
>>>
>>> So here is what I had in mind.. It is based on recent patch by Vignesh
>>> for pixcir touchscreen, but I think it should be made available to all
>>> I2C devices. Completely untested at the moment.
>>>
>>
>> Thanks for the patch! I tested this on am437x-gp-evm and the
>> suspend/resume worked fine (below patch + $subject patch). I was able to
>> wake the system from low power state using touchscreen. Also verified
>> module insertion and removal. One comment though, please see below.
>>
>>> ---
>>>  drivers/i2c/i2c-core.c |   43 +++++++++++++++++++++++++++++++++++++------
>>>  1 file changed, 37 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
>>> index e6d4935..3971461 100644
>>> --- a/drivers/i2c/i2c-core.c
>>> +++ b/drivers/i2c/i2c-core.c
>>> @@ -47,6 +47,7 @@
>>>  #include <linux/rwsem.h>
>>>  #include <linux/pm_runtime.h>
>>>  #include <linux/pm_domain.h>
>>> +#include <linux/pm_wakeirq.h>
>>>  #include <linux/acpi.h>
>>>  #include <linux/jump_label.h>
>>>  #include <asm/uaccess.h>
>>> @@ -631,6 +632,7 @@ static int i2c_device_probe(struct device *dev)
>>>  {
>>>  	struct i2c_client	*client = i2c_verify_client(dev);
>>>  	struct i2c_driver	*driver;
>>> +	int wakeirq = 0;
>>>  	int status;
>>>  
>>>  	if (!client)
>>> @@ -639,11 +641,13 @@ static int i2c_device_probe(struct device *dev)
>>>  	if (!client->irq) {
>>>  		int irq = -ENOENT;
>>>  
>>> -		if (dev->of_node)
>>> -			irq = of_irq_get(dev->of_node, 0);
>>> -		else if (ACPI_COMPANION(dev))
>>> +		if (dev->of_node) {
>>> +			irq = of_has_named_irqs(dev->of_node) ?
>>> +				of_irq_get_byname(dev->of_node, "irq") :
>>> +				of_irq_get(dev->of_node, 0);
>>> +		} else if (ACPI_COMPANION(dev)) {
>>>  			irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
>>> -
>>> +		}
>>>  		if (irq == -EPROBE_DEFER)
>>>  			return irq;
>>>  		if (irq < 0)
>>> @@ -652,6 +656,15 @@ static int i2c_device_probe(struct device *dev)
>>>  		client->irq = irq;
>>>  	}
>>>  
>>> +	if (dev->of_node && of_has_named_irqs(dev->of_node)) {
>>> +		wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
>>> +		if (wakeirq < 0) {
>>> +			if (wakeirq != -ENODATA)
>>> +				return wakeirq;
>>> +			wakeirq = 0;
>>> +		}
>>> +	}
>>> +
>>>  	driver = to_i2c_driver(dev->driver);
>>>  	if (!driver->probe || !driver->id_table)
>>>  		return -ENODEV;diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
index 8f3e243a62bf..6bd1d1ca9883 100644
--- a/drivers/input/touchscreen/pixcir_i2c_ts.c
+++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
@@ -365,7 +365,6 @@ static int __maybe_unused
pixcir_i2c_ts_suspend(struct device *dev)
                        }
                }

-               enable_irq_wake(client->irq);
        } else if (input->users) {
                ret = pixcir_stop(ts);
        }
@@ -386,7 +385,6 @@ static int __maybe_unused
pixcir_i2c_ts_resume(struct device *dev)
        mutex_lock(&input->mutex);

        if (device_may_wakeup(&client->dev)) {
-               disable_irq_wake(client->irq);

                if (!input->users) {
                        ret = pixcir_stop(ts);
@@ -464,7 +462,7 @@ static int pixcir_i2c_ts_probe(struct i2c_client
*client,
        struct pixcir_i2c_ts_data *tsdata;
        struct input_dev *input;
        int error;
-
+printk("PROBING PIXCIR\n");
        if (np && !pdata) {
                pdata = pixcir_parse_dt(dev);
                if (IS_ERR(pdata))
@@ -562,14 +560,6 @@ static int pixcir_i2c_ts_probe(struct i2c_client
*client,
                return error;

        i2c_set_clientdata(client, tsdata);
-       device_init_wakeup(&client->dev, 1);
-
-       return 0;
-}
-
-static int pixcir_i2c_ts_remove(struct i2c_client *client)
-{
-       device_init_wakeup(&client->dev, 0);

        return 0;
 }
@@ -608,7 +598,6 @@ static struct i2c_driver pixcir_i2c_ts_driver = {
                .of_match_table = of_match_ptr(pixcir_of_match),
        },
        .probe          = pixcir_i2c_ts_probe,
-       .remove         = pixcir_i2c_ts_remove,
        .id_table       = pixcir_i2c_ts_id,
 };
>>> @@ -659,20 +672,34 @@ static int i2c_device_probe(struct device *dev)
>>>  	if y i2c(!device_can_wakeup(&client->dev))
>>>  		device_init_wakeup(&client->dev,
>>>  					client->flags & I2C_CLIENT_WAKE);
>>> +
>>> +	status = wakeirq > 0 ?
>>> +			dev_pm_set_dedicated_wake_irq(dev, wakeirq) :
>>> +			(client->irq > 0 ?
>>> +				dev_pm_set_wake_irq(dev, client->irq) : 0);
>>
>> Above code tries to register wakeirq irrespective of whether the device
>> is specified as wakeup-source in the dt or not. Hence, I see warn
>> messages from every i2c device that has irq line but hasn't declared
>> itself as wakeup-source:
>> For example tps is on i2c:
>> [    1.961613] tps65218 0-0024: forgot to call call device_init_wakeup?
>> [    1.968340] tps65218 0-0024: failed to set up wakeup irq
>>
>> May be you can register wakeup-source only if I2C_CLIENT_WAKE flag is
>> set in client->flags?
> 
> Makes sense, I'll prepare a new version.
> 
> Just to confirm: do you see any issues with these 2 patches if you do
> not modify the drivers to drop calls enable_irq_wake() from them?

No, I didn't test w/o dropping enable_irq_wake() calls. I will do that
tomo. Is this to verify that these 2 patches can be added w/o dropping
enable_irq_wake() from other i2c drivers currently using them?

Regards
Vignesh