On 1/26/2016 7:38 AM, Andy Shevchenko wrote:
> On Mon, Jan 25, 2016 at 11:29 PM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
>
> Few comments below.
>
>> Generic Event Device described in ACPI 6.1 allows platforms to handle
>> platform interrupts in ACPI ASL statements. It borrows constructs like
>> _EVT from GPIO events.
>
> Can it share code with gpiolib-acpi.c ? I see some duplication.
The interrupt registration mechanism could be made common but they have their own
data structure types.
Can Rafael think of any higher level API like acpi_dev_resource_interrupt below?
>
>> All interrupts are listed in _CRS and the handler
>> is written in _EVT method. Here is an example.
>
>
>>
>> Device (GED0)
>> {
>>
>> Name (_HID, "ACPI0013")
>> Name (_UID, 0)
>> Name(_CRS, ResourceTemplate ()
>> {
>> Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )
>> {123}
>> })
>>
>> Method (_EVT, 1) {
>> if (Lequal(123, Arg0))
>> {
>> }
>> }
>> }
>>
>> Wake capability has not been implemented yet.
>>
>> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
>> ---
>> drivers/acpi/Makefile | 1 +
>> drivers/acpi/evged.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 163 insertions(+)
>> create mode 100644 drivers/acpi/evged.c
>>
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index b5e7cd8..4dbb732 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -46,6 +46,7 @@ acpi-y += acpi_pnp.o
>> acpi-y += int340x_thermal.o
>> acpi-y += power.o
>> acpi-y += event.o
>> +acpi-$(CONFIG_ACPI_REDUCED_HARDWARE_ONLY) += evged.o
>> acpi-y += sysfs.o
>> acpi-y += property.o
>> acpi-$(CONFIG_X86) += acpi_cmos_rtc.o
>> diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
>> new file mode 100644
>> index 0000000..a904676
>> --- /dev/null
>> +++ b/drivers/acpi/evged.c
>> @@ -0,0 +1,162 @@
>> +/*
>> + * Generic Event Device for ACPI.
>> + *
>> + * Copyright (c) 2016, The Linux Foundation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only version 2 as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + * Generic Event Device allows platforms to handle
>> + * interrupts in ACPI ASL statements. It follows very similar
>> + * _EVT method approach from GPIO events.
>> + * All interrupts are listed in _CRS and the handler
>> + * is written in _EVT method. Here is an example.
>
> Can it be wider on screen?
>
sure
>
>> +
>> + event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
>> + if (!event)
>> + return AE_ERROR;
>> +
>> + event->gsi = gsi;
>> + event->dev = dev;
>> + event->irq = irq;
>> + event->handle = evt_handle;
>> +
>> + if (r.flags & IORESOURCE_IRQ_SHAREABLE)
>> + irqflags |= IRQF_SHARED;
>> +
>> + if (devm_request_threaded_irq(dev, irq, NULL, acpi_ged_irq_handler,
>> + irqflags, "ACPI:Ged", event)) {
>> + dev_err(dev, "failed to setup event handler for irq %u\n", irq);
>> + return AE_ERROR;
>> + }
>
> The above part is clearly belongs to ged_probe().
>
It depends. The implementation needs to find all the interrupt entries in _CRS. That's why,
the interrupt registration is done inside the ACPI callback.
I originally tried using the platform_get_irq() method rather than walking the ACPI resources.
Any resource listed in _CRS is accessible via standard platform API. However, I couldn't obtain
the shareability and other edge/level attributes through the standard APIs. Most drivers I have
seen hardcode this information when calling devm_request_threaded_irq function.
Here, the type of interrupt is declared in the ACPI and the registration is done based on passed
attributes.
>> +
>> + return AE_OK;
>> +}
>> +
>> +static int ged_probe(struct platform_device *pdev)
>> +{
>> + acpi_status acpi_ret;
>> +
>> + acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
>> + acpi_ged_request_interrupt, &pdev->dev);
>> + if (ACPI_FAILURE(acpi_ret)) {
>> + dev_err(&pdev->dev, "unable to parse the _CRS record\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static const struct acpi_device_id ged_acpi_ids[] = {
>> + {"ACPI0013"},
>> + {},
>> +};
>> +
>> +static struct platform_driver ged_driver = {
>> + .probe = ged_probe,
>> + .driver = {
>> + .name = MODULE_NAME,
>
>> + .owner = THIS_MODULE,
>
> Do you need this one?
I'll get rid of it.
>
>
>> + .acpi_match_table = ACPI_PTR(ged_acpi_ids),
>> + },
>> +};
>> +
>> +static int __init ged_init(void)
>> +{
>> + return platform_driver_register(&ged_driver);
>> +}
>> +
>
>> +subsys_initcall(ged_init);
>
> Any specific reason to have on that level?
>
changed to module_platform_driver(ged_driver);
--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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