On Mon, Oct 01, 2012 at 02:19:49PM +0000, Zhang, Rui wrote:
>
>
> > -----Original Message-----
> > From: linux-i2c-ow...@vger.kernel.org [mailto:linux-i2c-
> > ow...@vger.kernel.org] On Behalf Of Mika Westerberg
> > Sent: Monday, October 01, 2012 2:55 PM
> > To: Zhang, Rui
> > Cc: LKML; linux-pm; linux-i2c; linux-a...@vger.kernel.org; Len, Brown;
> > Rafael J. Wysocki; Grant Likely; Dirk Brandewie
> > Subject: Re: [RFC PATCH 5/6] ACPI: Introduce ACPI I2C controller
> > enumeration driver
> > Importance: High
> >
> > On Fri, Sep 28, 2012 at 03:40:32PM +0800, Zhang Rui wrote:
> > > +acpi_status __init i2c_enumerate_slave(acpi_handle handle, u32 level,
> > > + void *data, void **return_value) {
> > > + int result;
> > > + acpi_status status;
> > > + struct acpi_buffer buffer;
> > > + struct acpi_resource *resource;
> > > + struct acpi_resource_gpio *gpio;
> > > + struct acpi_resource_i2c_serialbus *i2c;
> > > + int i;
> > > + struct acpi_i2c_root *root = data;
> > > + struct i2c_board_info info;
> > > + struct acpi_device *device;
> > > +
> > > + if (acpi_bus_get_device(handle, &device))
> > > + return AE_OK;
> > > +
> > > + status = acpi_get_current_resources(handle, &buffer);
> > > + if (ACPI_FAILURE(status)) {
> > > + dev_err(&device->dev, "Failed to get ACPI resources\n");
> > > + return AE_OK;
> > > + }
> > > +
> > > + for (i = 0; i < buffer.length; i += sizeof(struct acpi_resource))
> > {
> > > + resource = (struct acpi_resource *)(buffer.pointer + i);
> > > +
> > > + switch (resource->type) {
> > > + case ACPI_RESOURCE_TYPE_GPIO:
> > > + gpio = &resource->data.gpio;
> > > +
> > > + if (gpio->connection_type ==
> > ACPI_RESOURCE_GPIO_TYPE_INT) {
> > > + result =
> > > + acpi_device_get_gpio_irq
> > > + (gpio->resource_source.string_ptr,
> > > + gpio->pin_table[0], &info.irq);
> >
> > acpi_device_get_gpio_irq() is not defined in this patch series?
> >
> ACPI GPIO controller patch has already been sent out, but in ACPI mailing
> list only.
It would have been good idea to mention this in the cover letter at least.
>
> > Also you need to do the gpio_request()/gpio_to_irq() things somewhere.
> > Are they handled in acpi_device_get_gpio_irq()?
> >
> Yep.
>
> > How about GpioIo resources?
> >
> This is not covered in this patch set, but will be in the next patch set.
>
> > > + if (result)
> > > + dev_err(&device->dev,
> > > + "Failed to get IRQ\n");
> > > + }
> > > + break;
> > > + case ACPI_RESOURCE_TYPE_SERIAL_BUS:
> > > + i2c = &resource->data.i2c_serial_bus;
> > > +
> > > + info.addr = i2c->slave_address;
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > + }
> > > +
> > > + add_slave(root, &info);
> > > +
> > > + kfree(buffer.pointer);
> > > + return AE_OK;
> > > +}
> > > +
> > > +static int __devinit acpi_i2c_root_add(struct acpi_device *device) {
> > > + acpi_status status;
> > > + struct acpi_i2c_root *root;
> > > + struct resource *resources;
> > > + int result;
> > > +
> > > + if (!device->pnp.unique_id) {
> > > + dev_err(&device->dev,
> > > + "Unsupported ACPI I2C controller. No UID\n");
> >
> > Where does this restriction come from? As far as I understand UID is
> > optional.
> >
>
> _UID is optional.
> But it seems to be required for SPB buses that need ACPI device enumeration.
> At least this is true for the ACPI 5 compatible ACPI tables I have.
Yes but if some vendor is not setting it (as it is optional) you still want
your code to work, right?
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