[V9 PATCH 0/3] Introduce ACPI support for ahci_platform driver

[V9 PATCH 0/3] Introduce ACPI support for ahci_platform driver

[Suravee Suthikulpanit]

This patch series introduce ACPI support for AHCI platform driver.
Existing ACPI support for AHCI assumes the device controller is a PCI device.
Since there is no ACPI _CID for generic AHCI controller, the driver
could not use it for matching devices. Therefore, this patch introduces
a mechanism for drivers to match devices using ACPI _CLS method.
_CLS contains PCI-defined class-code.

This patch series also modifies ACPI modalias to add class-code to the
exisiting format, which currently only uses _HID and _CIDs. This is required
to support loadable modules w/ _CLS.

This is rebased from and tested with linux-4.1-rc1

This topic was discussed earlier here (as part of introducing support for
AMD Seattle SATA controller):

    http://marc.info/?l=linux-arm-kernel&m=141083492521584&w=2

Changes from V8 (https://lkml.org/lkml/2015/3/30/729)
	* Rebased to 4.1-rc1
	* [1/3] Misc changes for ACPICA:
		- Re-organized certain parts from patch 2 since it should
		  have been part of the ACPICA.
		- Modified logic for copying class code string (Lv)
		- Add changes and signed-off-by Lv Zheng
	* [2/3] Rebased due to added PRP001 matching code

Changes from V7 (https://lkml.org/lkml/2015/3/26/592)
	* [1/3] Return AE_AML_OPERAND_TYPE when _CLS package containing
	  invalid type (per Robert Moore suggestion). 
	* [2/3] Fixed build error due missing ACPI_DEVICE_CLASS definition
	  when disabling ACPI.

Changes from V6 (https://lkml.org/lkml/2015/3/25/797)
	* Adding Acked-by Mika, and Reviewed-by Hanjun
	* Minor clen up to use lower case 0xffffff for cls_msk
	  (per Mika suggestions).
	* Modify the ACPI_DEVICE_CLASS macro to use designated initializer
	  (per Mika suggestions).

Changes from V5 (https://lkml.org/lkml/2015/3/6/24)
	* Rebased and tested with acpi-5.1-v11
	* Splitting up the ACPICA changes into a separate patch [1/3].
	  (per Mika suggestion)
	* Adding class-code mask support (per Mika suggestion)
	* Use macro to define struct acpi_device_id entry (per Mika suggestion)
	* Note: Mika also recommend reordering the member of struct acpi_device_id
	  and define a macro to be used for declaring each table entry. This is a
	  large amount of changes, and will be done separtely from this patch series.

Changes from V4 (https://lkml.org/lkml/2015/3/2/56)
	* [1/2] Bug fixed: Reorder the declaration of
	  struct acpi_pnp_device_id cls in the struct acpi_device_info
	  (include/acpi/actypes.h) since compatible_id_list must be last one.
	* [2/2] Added Acked-by: Tejun Heo <tj@kernel.org>

Changes from V3 (https://lkml.org/lkml/2015/2/8/106)
	* Instead of introducing new structure acpi_device_cls, add cls into
	  the acpi_device_id, and modify the __acpi_match_device
	  to also match for cls. (per Mika suggestion.)
	* Add loadable module support, which requires changes in ACPI
	  modalias. (per Mika suggestion.)
	* Rebased and tested with acpi-5.1-v9

Changes from V2 (https://lkml.org/lkml/2015/1/5/662)
	* Update with review comment from Rafael in patch 1/2
	* Rebased and tested with acpi-5.1-v8

Changes from V1 (https://lkml.org/lkml/2014/12/19/345)
	* Rebased to 3.19.0-rc2
	* Change from acpi_cls in device_driver to acpi_match_cls (Hanjun comment)
	* Change the matching logic in acpi_driver_match_device() due to the new
	  special PRP0001 _HID.
	* Simplify the return type of acpi_match_device_cls() to boolean.

Changes from RFC (https://lkml.org/lkml/2014/12/17/446)
	* Remove #ifdef and make non-ACPI version of the acpi_match_device_cls
	  as inline. (per Arnd)
	* Simplify logic to retrieve and evaluate _CLS handle. (per Hanjun)

Suravee Suthikulpanit (3):
  ACPICA: Utilities: Add _CLS processing
  ACPI / scan: Add support for ACPI _CLS device matching
  ata: ahci_platform: Add ACPI _CLS matching

 drivers/acpi/acpica/acinterp.h    |  2 +
 drivers/acpi/acpica/acutils.h     |  4 ++
 drivers/acpi/acpica/exutils.c     | 32 ++++++++++++++
 drivers/acpi/acpica/nsxfname.c    | 23 ++++++++--
 drivers/acpi/acpica/utids.c       | 91 ++++++++++++++++++++++++++++++++++++++-
 drivers/acpi/scan.c               | 32 +++++++++++++-
 drivers/ata/Kconfig               |  2 +-
 drivers/ata/ahci_platform.c       |  9 ++++
 include/acpi/acnames.h            |  1 +
 include/acpi/actypes.h            | 24 +++++++----
 include/linux/acpi.h              | 14 ++++++
 include/linux/mod_devicetable.h   |  2 +
 scripts/mod/devicetable-offsets.c |  2 +
 scripts/mod/file2alias.c          | 32 +++++++++++++-
 14 files changed, 252 insertions(+), 18 deletions(-)

-- 
2.1.0

[V9 PATCH 1/3] ACPICA: Utilities: Add _CLS processing

[Suravee Suthikulpanit]

ACPI Device object often contains a _CLS object to suppy PCI-defined class
code for the device. This patch introduces logic to process the _CLS
object.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
---
 drivers/acpi/acpica/acinterp.h |  2 +
 drivers/acpi/acpica/acutils.h  |  4 ++
 drivers/acpi/acpica/exutils.c  | 32 +++++++++++++++
 drivers/acpi/acpica/nsxfname.c | 23 +++++++++--
 drivers/acpi/acpica/utids.c    | 91 +++++++++++++++++++++++++++++++++++++++++-
 include/acpi/acnames.h         |  1 +
 include/acpi/actypes.h         | 24 ++++++-----
 7 files changed, 164 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/acpica/acinterp.h b/drivers/acpi/acpica/acinterp.h
index 1886bde..7ac9800 100644
--- a/drivers/acpi/acpica/acinterp.h
+++ b/drivers/acpi/acpica/acinterp.h
@@ -468,6 +468,8 @@ void acpi_ex_eisa_id_to_string(char *dest, u64 compressed_id);
 
 void acpi_ex_integer_to_string(char *dest, u64 value);
 
+void acpi_ex_pci_cls_to_string(char *dest, u8 class_code[3]);
+
 u8 acpi_is_valid_space_id(u8 space_id);
 
 /*
diff --git a/drivers/acpi/acpica/acutils.h b/drivers/acpi/acpica/acutils.h
index 2b3c5bd..f1f4c83 100644
--- a/drivers/acpi/acpica/acutils.h
+++ b/drivers/acpi/acpica/acutils.h
@@ -430,6 +430,10 @@ acpi_status
 acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
 		    struct acpi_pnp_device_id_list ** return_cid_list);
 
+acpi_status
+acpi_ut_execute_CLS(struct acpi_namespace_node *device_node,
+		    struct acpi_pnp_device_id **return_id);
+
 /*
  * utlock - reader/writer locks
  */
diff --git a/drivers/acpi/acpica/exutils.c b/drivers/acpi/acpica/exutils.c
index 3f4225e..30c3f46 100644
--- a/drivers/acpi/acpica/exutils.c
+++ b/drivers/acpi/acpica/exutils.c
@@ -380,6 +380,38 @@ void acpi_ex_integer_to_string(char *out_string, u64 value)
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ex_pci_cls_to_string
+ *
+ * PARAMETERS:  out_string      - Where to put the converted string (7 bytes)
+ * PARAMETERS:  class_code      - PCI class code to be converted (3 bytes)
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Convert 3-bytes PCI class code to string representation.
+ *              Return buffer must be large enough to hold the string. The
+ *              string returned is always exactly of length
+ *              ACPI_PCICLS_STRING_SIZE (includes null terminator).
+ *
+ ******************************************************************************/
+
+void acpi_ex_pci_cls_to_string(char *out_string, u8 class_code[3])
+{
+
+	ACPI_FUNCTION_ENTRY();
+
+	/* All 3 bytes are hexadecimal */
+
+	out_string[0] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 4);
+	out_string[1] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 0);
+	out_string[2] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 4);
+	out_string[3] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 0);
+	out_string[4] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 4);
+	out_string[5] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 0);
+	out_string[6] = 0;
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_is_valid_space_id
  *
  * PARAMETERS:  space_id            - ID to be validated
diff --git a/drivers/acpi/acpica/nsxfname.c b/drivers/acpi/acpica/nsxfname.c
index d66c326..49266b4 100644
--- a/drivers/acpi/acpica/nsxfname.c
+++ b/drivers/acpi/acpica/nsxfname.c
@@ -260,7 +260,7 @@ static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  *              control methods (Such as in the case of a device.)
  *
  * For Device and Processor objects, run the Device _HID, _UID, _CID, _SUB,
- * _STA, _ADR, _sx_w, and _sx_d methods.
+ * _CLS, _STA, _ADR, _sx_w, and _sx_d methods.
  *
  * Note: Allocates the return buffer, must be freed by the caller.
  *
@@ -276,11 +276,12 @@ acpi_get_object_info(acpi_handle handle,
 	struct acpi_pnp_device_id *hid = NULL;
 	struct acpi_pnp_device_id *uid = NULL;
 	struct acpi_pnp_device_id *sub = NULL;
+	struct acpi_pnp_device_id *cls = NULL;
 	char *next_id_string;
 	acpi_object_type type;
 	acpi_name name;
 	u8 param_count = 0;
-	u8 valid = 0;
+	u16 valid = 0;
 	u32 info_size;
 	u32 i;
 	acpi_status status;
@@ -320,7 +321,7 @@ acpi_get_object_info(acpi_handle handle,
 	if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
 		/*
 		 * Get extra info for ACPI Device/Processor objects only:
-		 * Run the Device _HID, _UID, _SUB, and _CID methods.
+		 * Run the Device _HID, _UID, _SUB, _CID, and _CLS methods.
 		 *
 		 * Note: none of these methods are required, so they may or may
 		 * not be present for this device. The Info->Valid bitfield is used
@@ -363,6 +364,14 @@ acpi_get_object_info(acpi_handle handle,
 			     sizeof(struct acpi_pnp_device_id_list));
 			valid |= ACPI_VALID_CID;
 		}
+
+		/* Execute the Device._CLS method */
+
+		status = acpi_ut_execute_CLS(node, &cls);
+		if (ACPI_SUCCESS(status)) {
+			info_size += cls->length;
+			valid |= ACPI_VALID_CLS;
+		}
 	}
 
 	/*
@@ -486,6 +495,11 @@ acpi_get_object_info(acpi_handle handle,
 		}
 	}
 
+	if (cls) {
+		next_id_string = acpi_ns_copy_device_id(&info->cls,
+							cls, next_id_string);
+	}
+
 	/* Copy the fixed-length data */
 
 	info->info_size = info_size;
@@ -510,6 +524,9 @@ cleanup:
 	if (cid_list) {
 		ACPI_FREE(cid_list);
 	}
+	if (cls) {
+		ACPI_FREE(cls);
+	}
 	return (status);
 }
 
diff --git a/drivers/acpi/acpica/utids.c b/drivers/acpi/acpica/utids.c
index 27431cf..3afe07f 100644
--- a/drivers/acpi/acpica/utids.c
+++ b/drivers/acpi/acpica/utids.c
@@ -1,6 +1,6 @@
 /******************************************************************************
  *
- * Module Name: utids - support for device Ids - HID, UID, CID
+ * Module Name: utids - support for device Ids - HID, UID, CID, SUB, CLS
  *
  *****************************************************************************/
 
@@ -416,3 +416,92 @@ cleanup:
 	acpi_ut_remove_reference(obj_desc);
 	return_ACPI_STATUS(status);
 }
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ut_execute_CLS
+ *
+ * PARAMETERS:  device_node         - Node for the device
+ *              return_id           - Where the _CLS is returned
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Executes the _CLS control method that returns PCI-defined
+ *              class code of the device. The _CLS value is always a package
+ *              containing PCI class information as a list of integers.
+ *              The returned string has format "BBSSPP", where:
+ *                BB = Base-class code
+ *                SS = Sub-class code
+ *                PP = Programming Interface code
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ut_execute_CLS(struct acpi_namespace_node *device_node,
+		    struct acpi_pnp_device_id **return_id)
+{
+	union acpi_operand_object *obj_desc;
+	union acpi_operand_object **cls_objects;
+	u32 count;
+	struct acpi_pnp_device_id *cls;
+	u32 length;
+	acpi_status status;
+	u8 class_code[3] = { 0, 0, 0 };
+
+	ACPI_FUNCTION_TRACE(ut_execute_CLS);
+
+	status = acpi_ut_evaluate_object(device_node, METHOD_NAME__CLS,
+					 ACPI_BTYPE_PACKAGE, &obj_desc);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Get the size of the String to be returned, includes null terminator */
+
+	length = ACPI_PCICLS_STRING_SIZE;
+	cls_objects = obj_desc->package.elements;
+	count = obj_desc->package.count;
+
+	if (obj_desc->common.type == ACPI_TYPE_PACKAGE) {
+		if (count > 0
+		    && cls_objects[0]->common.type == ACPI_TYPE_INTEGER) {
+			class_code[0] = (u8)cls_objects[0]->integer.value;
+		}
+		if (count > 1
+		    && cls_objects[1]->common.type == ACPI_TYPE_INTEGER) {
+			class_code[1] = (u8)cls_objects[1]->integer.value;
+		}
+		if (count > 2
+		    && cls_objects[2]->common.type == ACPI_TYPE_INTEGER) {
+			class_code[2] = (u8)cls_objects[2]->integer.value;
+		}
+	}
+
+	/* Allocate a buffer for the CLS */
+
+	cls =
+	    ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
+				 (acpi_size) length);
+	if (!cls) {
+		status = AE_NO_MEMORY;
+		goto cleanup;
+	}
+
+	/* Area for the string starts after PNP_DEVICE_ID struct */
+
+	cls->string =
+	    ACPI_ADD_PTR(char, cls, sizeof(struct acpi_pnp_device_id));
+
+	/* Simply copy existing string */
+
+	acpi_ex_pci_cls_to_string(cls->string, class_code);
+	cls->length = length;
+	*return_id = cls;
+
+cleanup:
+
+	/* On exit, we must delete the return object */
+
+	acpi_ut_remove_reference(obj_desc);
+	return_ACPI_STATUS(status);
+}
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 273de70..b52c0dc 100644
--- a/include/acpi/acnames.h
+++ b/include/acpi/acnames.h
@@ -51,6 +51,7 @@
 #define METHOD_NAME__BBN        "_BBN"
 #define METHOD_NAME__CBA        "_CBA"
 #define METHOD_NAME__CID        "_CID"
+#define METHOD_NAME__CLS        "_CLS"
 #define METHOD_NAME__CRS        "_CRS"
 #define METHOD_NAME__DDN        "_DDN"
 #define METHOD_NAME__HID        "_HID"
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index f5ca0e9..3da3ea2 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -1145,6 +1145,10 @@ u32 (*acpi_interface_handler) (acpi_string interface_name, u32 supported);
 
 #define ACPI_UUID_LENGTH                16
 
+/* Length of 3-byte PCI class code values when converted back to a string */
+
+#define ACPI_PCICLS_STRING_SIZE         7	/* Includes null terminator */
+
 /* Structures used for device/processor HID, UID, CID, and SUB */
 
 struct acpi_pnp_device_id {
@@ -1167,7 +1171,7 @@ struct acpi_device_info {
 	u32 name;		/* ACPI object Name */
 	acpi_object_type type;	/* ACPI object Type */
 	u8 param_count;		/* If a method, required parameter count */
-	u8 valid;		/* Indicates which optional fields are valid */
+	u16 valid;		/* Indicates which optional fields are valid */
 	u8 flags;		/* Miscellaneous info */
 	u8 highest_dstates[4];	/* _sx_d values: 0xFF indicates not valid */
 	u8 lowest_dstates[5];	/* _sx_w values: 0xFF indicates not valid */
@@ -1176,6 +1180,7 @@ struct acpi_device_info {
 	struct acpi_pnp_device_id hardware_id;	/* _HID value */
 	struct acpi_pnp_device_id unique_id;	/* _UID value */
 	struct acpi_pnp_device_id subsystem_id;	/* _SUB value */
+	struct acpi_pnp_device_id cls;		/* _CLS value */
 	struct acpi_pnp_device_id_list compatible_id_list;	/* _CID list <must be last> */
 };
 
@@ -1185,14 +1190,15 @@ struct acpi_device_info {
 
 /* Flags for Valid field above (acpi_get_object_info) */
 
-#define ACPI_VALID_STA                  0x01
-#define ACPI_VALID_ADR                  0x02
-#define ACPI_VALID_HID                  0x04
-#define ACPI_VALID_UID                  0x08
-#define ACPI_VALID_SUB                  0x10
-#define ACPI_VALID_CID                  0x20
-#define ACPI_VALID_SXDS                 0x40
-#define ACPI_VALID_SXWS                 0x80
+#define ACPI_VALID_STA                  0x0001
+#define ACPI_VALID_ADR                  0x0002
+#define ACPI_VALID_HID                  0x0004
+#define ACPI_VALID_UID                  0x0008
+#define ACPI_VALID_SUB                  0x0010
+#define ACPI_VALID_CID                  0x0020
+#define ACPI_VALID_CLS                  0x0040
+#define ACPI_VALID_SXDS                 0x0100
+#define ACPI_VALID_SXWS                 0x0200
 
 /* Flags for _STA return value (current_status above) */
 
-- 
2.1.0

[V9 PATCH 2/3] ACPI / scan: Add support for ACPI _CLS device matching

[Suravee Suthikulpanit]

Device drivers typically use ACPI _HIDs/_CIDs listed in struct device_driver
acpi_match_table to match devices. However, for generic drivers, we do not
want to list _HID for all supported devices. Also, certain classes of devices
do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS,
which specifies PCI-defined class code (i.e. base-class, subclass and
programming interface). This patch adds support for matching ACPI devices using
the _CLS method.

To support loadable module, current design uses _HID or _CID to match device's
modalias. With the new way of matching with _CLS this would requires modification
to the current ACPI modalias key to include _CLS. This patch appends PCI-defined
class-code to the existing ACPI modalias as following.

    acpi:<HID>:<CID1>:<CID2>:..:<CIDn>:<bbsspp>:
E.g:
    # cat /sys/devices/platform/AMDI0600:00/modalias
    acpi:AMDI0600:010601:

where bb is th base-class code, ss is te sub-class code, and pp is the
programming interface code

Since there would not be _HID/_CID in the ACPI matching table of the driver,
this patch adds a field to acpi_device_id to specify the matching _CLS.

    static const struct acpi_device_id ahci_acpi_match[] = {
        { ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
        {},
    };

In this case, the corresponded entry in modules.alias file would be:

    alias acpi*:010601:* ahci_platform

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/acpi/scan.c               | 32 ++++++++++++++++++++++++++++++--
 include/linux/acpi.h              | 14 ++++++++++++++
 include/linux/mod_devicetable.h   |  2 ++
 scripts/mod/devicetable-offsets.c |  2 ++
 scripts/mod/file2alias.c          | 32 ++++++++++++++++++++++++++++++--
 5 files changed, 78 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 79a48bb..f0662aa 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1017,6 +1017,29 @@ static bool acpi_of_match_device(struct acpi_device *adev,
 	return false;
 }
 
+static bool __acpi_match_device_cls(const struct acpi_device_id *id,
+				    struct acpi_hardware_id *hwid)
+{
+	int i, msk, byte_shift;
+	char buf[3];
+
+	if (!id->cls)
+		return false;
+
+	/* Apply class-code bitmask, before checking each class-code byte */
+	for (i = 1; i <= 3; i++) {
+		byte_shift = 8 * (3 - i);
+		msk = (id->cls_msk >> byte_shift) & 0xFF;
+		if (!msk)
+			continue;
+
+		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
+		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
+			return false;
+	}
+	return true;
+}
+
 static const struct acpi_device_id *__acpi_match_device(
 	struct acpi_device *device,
 	const struct acpi_device_id *ids,
@@ -1034,9 +1057,12 @@ static const struct acpi_device_id *__acpi_match_device(
 
 	list_for_each_entry(hwid, &device->pnp.ids, list) {
 		/* First, check the ACPI/PNP IDs provided by the caller. */
-		for (id = ids; id->id[0]; id++)
-			if (!strcmp((char *) id->id, hwid->id))
+		for (id = ids; id->id[0] || id->cls; id++) {
+			if (id->id[0] && !strcmp((char *) id->id, hwid->id))
 				return id;
+			else if (id->cls && __acpi_match_device_cls(id, hwid))
+				return id;
+		}
 
 		/*
 		 * Next, check the special "PRP0001" ID and try to match the
@@ -2057,6 +2083,8 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
 		if (info->valid & ACPI_VALID_UID)
 			pnp->unique_id = kstrdup(info->unique_id.string,
 							GFP_KERNEL);
+		if (info->valid & ACPI_VALID_CLS)
+			acpi_add_id(pnp, info->cls.string);
 
 		kfree(info);
 
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index e4da5e3..b10c4a6 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -58,6 +58,19 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev)
 	acpi_fwnode_handle(adev) : NULL)
 #define ACPI_HANDLE(dev)		acpi_device_handle(ACPI_COMPANION(dev))
 
+/**
+ * ACPI_DEVICE_CLASS - macro used to describe an ACPI device with
+ * the PCI-defined class-code information
+ *
+ * @_cls : the class, subclass, prog-if triple for this device
+ * @_msk : the class mask for this device
+ *
+ * This macro is used to create a struct acpi_device_id that matches a
+ * specific PCI class. The .id and .driver_data fields will be left
+ * initialized with the default value.
+ */
+#define ACPI_DEVICE_CLASS(_cls, _msk)	.cls = (_cls), .cls_msk = (_msk),
+
 static inline bool has_acpi_companion(struct device *dev)
 {
 	return is_acpi_node(dev->fwnode);
@@ -465,6 +478,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *);
 #define ACPI_COMPANION(dev)		(NULL)
 #define ACPI_COMPANION_SET(dev, adev)	do { } while (0)
 #define ACPI_HANDLE(dev)		(NULL)
+#define ACPI_DEVICE_CLASS(_cls, _msk)	.cls = (0), .cls_msk = (0),
 
 struct fwnode_handle;
 
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 3bfd567..242037b 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -189,6 +189,8 @@ struct css_device_id {
 struct acpi_device_id {
 	__u8 id[ACPI_ID_LEN];
 	kernel_ulong_t driver_data;
+	__u32 cls;
+	__u32 cls_msk;
 };
 
 #define PNP_ID_LEN	8
diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index fce36d0..0ced0ca 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -63,6 +63,8 @@ int main(void)
 
 	DEVID(acpi_device_id);
 	DEVID_FIELD(acpi_device_id, id);
+	DEVID_FIELD(acpi_device_id, cls);
+	DEVID_FIELD(acpi_device_id, cls_msk);
 
 	DEVID(pnp_device_id);
 	DEVID_FIELD(pnp_device_id, id);
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 78691d5..ea238e2f 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -511,12 +511,40 @@ static int do_serio_entry(const char *filename,
 }
 ADD_TO_DEVTABLE("serio", serio_device_id, do_serio_entry);
 
-/* looks like: "acpi:ACPI0003 or acpi:PNP0C0B" or "acpi:LNXVIDEO" */
+/* looks like: "acpi:ACPI0003" or "acpi:PNP0C0B" or "acpi:LNXVIDEO" or
+ *             "acpi:bbsspp" (bb=base-class, ss=sub-class, pp=prog-if)
+ *
+ * NOTE: Each driver should use one of the following : _HID, _CIDs
+ *       or _CLS. Also, bb, ss, and pp can be substituted with ??
+ *       as don't care byte.
+ */
 static int do_acpi_entry(const char *filename,
 			void *symval, char *alias)
 {
 	DEF_FIELD_ADDR(symval, acpi_device_id, id);
-	sprintf(alias, "acpi*:%s:*", *id);
+	DEF_FIELD_ADDR(symval, acpi_device_id, cls);
+	DEF_FIELD_ADDR(symval, acpi_device_id, cls_msk);
+
+	if (id && strlen((const char *)*id))
+		sprintf(alias, "acpi*:%s:*", *id);
+	else if (cls) {
+		int i, byte_shift, cnt = 0;
+		unsigned int msk;
+
+		sprintf(&alias[cnt], "acpi*:");
+		cnt = 6;
+		for (i = 1; i <= 3; i++) {
+			byte_shift = 8 * (3-i);
+			msk = (*cls_msk >> byte_shift) & 0xFF;
+			if (msk)
+				sprintf(&alias[cnt], "%02x",
+					(*cls >> byte_shift) & 0xFF);
+			else
+				sprintf(&alias[cnt], "??");
+			cnt += 2;
+		}
+		sprintf(&alias[cnt], ":*");
+	}
 	return 1;
 }
 ADD_TO_DEVTABLE("acpi", acpi_device_id, do_acpi_entry);
-- 
2.1.0

[V9 PATCH 3/3] ata: ahci_platform: Add ACPI _CLS matching

[Suravee Suthikulpanit]

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>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/ata/Kconfig         | 2 +-
 drivers/ata/ahci_platform.c | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 5f60155..50305e3 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 78d6ae0..04975b8 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -20,6 +20,8 @@
 #include <linux/platform_device.h>
 #include <linux/libata.h>
 #include <linux/ahci_platform.h>
+#include <linux/acpi.h>
+#include <linux/pci_ids.h>
 #include "ahci.h"
 
 #define DRV_NAME "ahci"
@@ -78,12 +80,19 @@ static const struct of_device_id ahci_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, ahci_of_match);
 
+static const struct acpi_device_id ahci_acpi_match[] = {
+	{ ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, ahci_acpi_match);
+
 static struct platform_driver ahci_driver = {
 	.probe = ahci_probe,
 	.remove = ata_platform_remove_one,
 	.driver = {
 		.name = DRV_NAME,
 		.of_match_table = ahci_of_match,
+		.acpi_match_table = ahci_acpi_match,
 		.pm = &ahci_pm_ops,
 	},
 };
-- 
2.1.0