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

From: R, Vignesh
Date: Tue Jul 28 2015 - 13:47:34 EST

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@xxxxxxxxx> 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@xxxxxxxxx>
>>>>>> ---
>>>>>>
>>>>>> 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
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