[V2 PATCH 2/2] ata: ahci_platform: Add ACPI _CLS matching

[Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>]

This patch adds ACPI supports for AHCI platform driver, which uses _CLS
method to match the device.

The following is an example of ASL structure in DSDT for a SATA controller,
which contains _CLS package to be matched by the ahci_platform driver:

  Device (AHC0) // AHCI Controller
  {
    Name(_HID, "AMDI0600")
    Name (_CCA, 1)
    Name (_CLS, Package (3)
    {
      0x01, // Base Class: Mass Storage
      0x06, // Sub-Class: serial ATA
      0x01, // Interface: AHCI
    })
    Name (_CRS, ResourceTemplate ()
    {
      Memory32Fixed (ReadWrite, 0xE0300000, 0x00010000)
      Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive,,,) { 387 }
    })
  }

Also, since ATA driver should not require PCI support for ATA_ACPI,
this patch removes dependency in the driver/ata/Kconfig.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/ata/Kconfig         | 2 +-
 drivers/ata/ahci_platform.c | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index a3a1360..edca892 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -48,7 +48,7 @@ config ATA_VERBOSE_ERROR
 
 config ATA_ACPI
 	bool "ATA ACPI Support"
-	depends on ACPI && PCI
+	depends on ACPI
 	default y
 	help
 	  This option adds support for ATA-related ACPI objects.
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 18d5398..ae66974 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -71,12 +71,15 @@ static const struct of_device_id ahci_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, ahci_of_match);
 
+static const struct acpi_device_cls ahci_cls = {0x01, 0x06, 0x01};
+
 static struct platform_driver ahci_driver = {
 	.probe = ahci_probe,
 	.remove = ata_platform_remove_one,
 	.driver = {
 		.name = "ahci",
 		.of_match_table = ahci_of_match,
+		.acpi_match_cls = &ahci_cls,
 		.pm = &ahci_pm_ops,
 	},
 };
-- 
1.9.3