[V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[Suravee Suthikulpanit]

This patch series introduce ACPI support for non-PCI AHCI platform driver.
Existing ACPI support for AHCI assumes the device controller is a PCI device.

Also, since there is no ACPI _HID/_CID for generic AHCI controller, the driver
could not use them for matching devices. Therefore, this patch introduces
a mechanism for drivers to match devices using ACPI _CLS method.

This patch series is rebased from and tested with:

    http://git.linaro.org/leg/acpi/acpi.git acpi-5.1-v7

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

NOTE:
	* PATCH 2/2 has already been Acked-by Tejun Heo in V1. I only made
	  a minor renaming of the acpi_cls to acpi_match_cls for clarity
	  in V2. It probably should be routed together with the PATCH 1/2
	  (once acked) since it defines the new member in the struct.

Changes 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 (2):
  ACPI / scan: Add support for ACPI _CLS device matching
  ata: ahci_platform: Add ACPI _CLS matching

 drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
 drivers/ata/Kconfig             |  2 +-
 drivers/ata/ahci_platform.c     |  3 ++
 include/acpi/acnames.h          |  1 +
 include/linux/acpi.h            | 10 ++++++
 include/linux/device.h          |  1 +
 include/linux/mod_devicetable.h |  6 ++++
 7 files changed, 98 insertions(+), 4 deletions(-)

-- 
1.9.3

[V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[Suravee Suthikulpanit]

This patch series introduce ACPI support for non-PCI AHCI platform driver.
Existing ACPI support for AHCI assumes the device controller is a PCI device.

Also, since there is no ACPI _HID/_CID for generic AHCI controller, the driver
could not use them for matching devices. Therefore, this patch introduces
a mechanism for drivers to match devices using ACPI _CLS method.

This patch series is rebased from and tested with:

    http://git.linaro.org/leg/acpi/acpi.git acpi-5.1-v7

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

NOTE:
	* PATCH 2/2 has already been Acked-by Tejun Heo in V1. I only made
	  a minor renaming of the acpi_cls to acpi_match_cls for clarity
	  in V2. It probably should be routed together with the PATCH 1/2
	  (once acked) since it defines the new member in the struct.

Changes 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 (2):
  ACPI / scan: Add support for ACPI _CLS device matching
  ata: ahci_platform: Add ACPI _CLS matching

 drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
 drivers/ata/Kconfig             |  2 +-
 drivers/ata/ahci_platform.c     |  3 ++
 include/acpi/acnames.h          |  1 +
 include/linux/acpi.h            | 10 ++++++
 include/linux/device.h          |  1 +
 include/linux/mod_devicetable.h |  6 ++++
 7 files changed, 98 insertions(+), 4 deletions(-)

-- 
1.9.3

[V2 PATCH 1/2] 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, and some device classes
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.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
 include/acpi/acnames.h          |  1 +
 include/linux/acpi.h            | 10 ++++++
 include/linux/device.h          |  1 +
 include/linux/mod_devicetable.h |  6 ++++
 5 files changed, 94 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 16914cc..7b25221 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev,
 bool acpi_driver_match_device(struct device *dev,
 			      const struct device_driver *drv)
 {
-	if (!drv->acpi_match_table)
-		return acpi_of_driver_match_device(dev, drv);
+	bool ret = false;
 
-	return !!acpi_match_device(drv->acpi_match_table, dev);
+	if (drv->acpi_match_table)
+		ret = !!acpi_match_device(drv->acpi_match_table, dev);
+
+	/* Next, try to match with special "PRP0001" _HID */
+	if (!ret && drv->of_match_table)
+		ret = acpi_of_driver_match_device(dev, drv);
+
+	/* Next, try to match with PCI-defined class-code */
+	if (!ret && drv->acpi_match_cls)
+		ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
 
+/**
+ * acpi_match_device_cls - Match a struct device against a ACPI _CLS method
+ * @dev_cls: A pointer to struct acpi_device_cls object to match against.
+ * @dev: The ACPI device structure to match.
+ *
+ * Check if @dev has a valid ACPI and _CLS handle. If there is a
+ * struct acpi_device_cls object for that handle, use that object to match
+ * against the given struct acpi_device_cls object.
+ *
+ * Return true on success or false on failure.
+ */
+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+			  const struct device *dev)
+{
+	bool ret = false;
+	acpi_status status;
+	union acpi_object *pkg;
+	struct acpi_device_cls cls;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_buffer format = { sizeof("NNN"), "NNN" };
+	struct acpi_buffer state = { 0, NULL };
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	acpi_handle handle = ACPI_HANDLE(dev);
+
+	if (!handle || !adev || !adev->status.present || !dev_cls)
+		return ret;
+
+	status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return ret;
+
+	/**
+	 * Note:
+	 * ACPIv5.1 defines the package to contain 3 integers for
+	 * Base-Class code, Sub-Class code, and Programming Interface code.
+	 */
+	pkg = buffer.pointer;
+	if (!pkg ||
+	    (pkg->type != ACPI_TYPE_PACKAGE) ||
+	    (pkg->package.count != 3)) {
+		dev_err(&adev->dev, "Invalid _CLS data\n");
+		goto out;
+	}
+
+	state.length = sizeof(struct acpi_device_cls);
+	state.pointer = &cls;
+
+	status = acpi_extract_package(pkg, &format, &state);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
+		goto out;
+	}
+
+	if ((dev_cls->base_class == cls.base_class) &&
+	    (dev_cls->sub_class == cls.sub_class) &&
+	    (dev_cls->prog_interface == cls.prog_interface))
+		ret = true;
+out:
+	kfree(buffer.pointer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_match_device_cls);
+
 static void acpi_free_power_resources_lists(struct acpi_device *device)
 {
 	int i;
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 7461327..22332a6 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/linux/acpi.h b/include/linux/acpi.h
index 87f365e..2f2b8ce 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 
 extern bool acpi_driver_match_device(struct device *dev,
 				     const struct device_driver *drv);
+
+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+			   const struct device *dev);
+
 int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
 int acpi_device_modalias(struct device *, char *, int);
 void acpi_walk_dep_device_list(acpi_handle handle);
@@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device(
 	return NULL;
 }
 
+static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+					 const struct device *dev)
+{
+	return false;
+}
+
 static inline bool acpi_driver_match_device(struct device *dev,
 					    const struct device_driver *drv)
 {
diff --git a/include/linux/device.h b/include/linux/device.h
index fb50673..8e259c5c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -237,6 +237,7 @@ struct device_driver {
 
 	const struct of_device_id	*of_match_table;
 	const struct acpi_device_id	*acpi_match_table;
+	const struct acpi_device_cls	*acpi_match_cls;
 
 	int (*probe) (struct device *dev);
 	int (*remove) (struct device *dev);
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 745def8..00e94ec 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -186,6 +186,12 @@ struct css_device_id {
 
 #define ACPI_ID_LEN	9
 
+struct acpi_device_cls {
+	kernel_ulong_t base_class;
+	kernel_ulong_t sub_class;
+	kernel_ulong_t prog_interface;
+};
+
 struct acpi_device_id {
 	__u8 id[ACPI_ID_LEN];
 	kernel_ulong_t driver_data;
-- 
1.9.3

[V2 PATCH 1/2] 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, and some device classes
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.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
 include/acpi/acnames.h          |  1 +
 include/linux/acpi.h            | 10 ++++++
 include/linux/device.h          |  1 +
 include/linux/mod_devicetable.h |  6 ++++
 5 files changed, 94 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 16914cc..7b25221 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev,
 bool acpi_driver_match_device(struct device *dev,
 			      const struct device_driver *drv)
 {
-	if (!drv->acpi_match_table)
-		return acpi_of_driver_match_device(dev, drv);
+	bool ret = false;
 
-	return !!acpi_match_device(drv->acpi_match_table, dev);
+	if (drv->acpi_match_table)
+		ret = !!acpi_match_device(drv->acpi_match_table, dev);
+
+	/* Next, try to match with special "PRP0001" _HID */
+	if (!ret && drv->of_match_table)
+		ret = acpi_of_driver_match_device(dev, drv);
+
+	/* Next, try to match with PCI-defined class-code */
+	if (!ret && drv->acpi_match_cls)
+		ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
 
+/**
+ * acpi_match_device_cls - Match a struct device against a ACPI _CLS method
+ * @dev_cls: A pointer to struct acpi_device_cls object to match against.
+ * @dev: The ACPI device structure to match.
+ *
+ * Check if @dev has a valid ACPI and _CLS handle. If there is a
+ * struct acpi_device_cls object for that handle, use that object to match
+ * against the given struct acpi_device_cls object.
+ *
+ * Return true on success or false on failure.
+ */
+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+			  const struct device *dev)
+{
+	bool ret = false;
+	acpi_status status;
+	union acpi_object *pkg;
+	struct acpi_device_cls cls;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_buffer format = { sizeof("NNN"), "NNN" };
+	struct acpi_buffer state = { 0, NULL };
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	acpi_handle handle = ACPI_HANDLE(dev);
+
+	if (!handle || !adev || !adev->status.present || !dev_cls)
+		return ret;
+
+	status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return ret;
+
+	/**
+	 * Note:
+	 * ACPIv5.1 defines the package to contain 3 integers for
+	 * Base-Class code, Sub-Class code, and Programming Interface code.
+	 */
+	pkg = buffer.pointer;
+	if (!pkg ||
+	    (pkg->type != ACPI_TYPE_PACKAGE) ||
+	    (pkg->package.count != 3)) {
+		dev_err(&adev->dev, "Invalid _CLS data\n");
+		goto out;
+	}
+
+	state.length = sizeof(struct acpi_device_cls);
+	state.pointer = &cls;
+
+	status = acpi_extract_package(pkg, &format, &state);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
+		goto out;
+	}
+
+	if ((dev_cls->base_class == cls.base_class) &&
+	    (dev_cls->sub_class == cls.sub_class) &&
+	    (dev_cls->prog_interface == cls.prog_interface))
+		ret = true;
+out:
+	kfree(buffer.pointer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_match_device_cls);
+
 static void acpi_free_power_resources_lists(struct acpi_device *device)
 {
 	int i;
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 7461327..22332a6 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/linux/acpi.h b/include/linux/acpi.h
index 87f365e..2f2b8ce 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 
 extern bool acpi_driver_match_device(struct device *dev,
 				     const struct device_driver *drv);
+
+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+			   const struct device *dev);
+
 int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
 int acpi_device_modalias(struct device *, char *, int);
 void acpi_walk_dep_device_list(acpi_handle handle);
@@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device(
 	return NULL;
 }
 
+static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+					 const struct device *dev)
+{
+	return false;
+}
+
 static inline bool acpi_driver_match_device(struct device *dev,
 					    const struct device_driver *drv)
 {
diff --git a/include/linux/device.h b/include/linux/device.h
index fb50673..8e259c5c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -237,6 +237,7 @@ struct device_driver {
 
 	const struct of_device_id	*of_match_table;
 	const struct acpi_device_id	*acpi_match_table;
+	const struct acpi_device_cls	*acpi_match_cls;
 
 	int (*probe) (struct device *dev);
 	int (*remove) (struct device *dev);
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 745def8..00e94ec 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -186,6 +186,12 @@ struct css_device_id {
 
 #define ACPI_ID_LEN	9
 
+struct acpi_device_cls {
+	kernel_ulong_t base_class;
+	kernel_ulong_t sub_class;
+	kernel_ulong_t prog_interface;
+};
+
 struct acpi_device_id {
 	__u8 id[ACPI_ID_LEN];
 	kernel_ulong_t driver_data;
-- 
1.9.3

[V2 PATCH 2/2] 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>
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

[V2 PATCH 2/2] 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>
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

Re: [V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[Rafael J. Wysocki]

On Monday, January 05, 2015 03:11:13 PM Suravee Suthikulpanit wrote:
> This patch series introduce ACPI support for non-PCI AHCI platform driver.
> Existing ACPI support for AHCI assumes the device controller is a PCI device.
> 
> Also, since there is no ACPI _HID/_CID for generic AHCI controller, the driver
> could not use them for matching devices. Therefore, this patch introduces
> a mechanism for drivers to match devices using ACPI _CLS method.
> 
> This patch series is rebased from and tested with:
> 
>     http://git.linaro.org/leg/acpi/acpi.git acpi-5.1-v7
> 
> 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
> 
> NOTE:
> 	* PATCH 2/2 has already been Acked-by Tejun Heo in V1. I only made
> 	  a minor renaming of the acpi_cls to acpi_match_cls for clarity
> 	  in V2. It probably should be routed together with the PATCH 1/2
> 	  (once acked) since it defines the new member in the struct.
> 
> Changes 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 (2):
>   ACPI / scan: Add support for ACPI _CLS device matching
>   ata: ahci_platform: Add ACPI _CLS matching
> 
>  drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>  drivers/ata/Kconfig             |  2 +-
>  drivers/ata/ahci_platform.c     |  3 ++
>  include/acpi/acnames.h          |  1 +
>  include/linux/acpi.h            | 10 ++++++
>  include/linux/device.h          |  1 +
>  include/linux/mod_devicetable.h |  6 ++++
>  7 files changed, 98 insertions(+), 4 deletions(-)

I'll take care of this when I'm back from travels later this month.  Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[Suravee Suthikulanit]

On 1/5/2015 5:24 PM, Rafael J. Wysocki wrote:
> On Monday, January 05, 2015 03:11:13 PM Suravee Suthikulpanit wrote:
>> This patch series introduce ACPI support for non-PCI AHCI platform driver.
>> Existing ACPI support for AHCI assumes the device controller is a PCI device.
>>
>> Also, since there is no ACPI _HID/_CID for generic AHCI controller, the driver
>> could not use them for matching devices. Therefore, this patch introduces
>> a mechanism for drivers to match devices using ACPI _CLS method.
>>
>> This patch series is rebased from and tested with:
>>
>>      http://git.linaro.org/leg/acpi/acpi.git acpi-5.1-v7
>>
>> 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
>>
>> NOTE:
>> 	* PATCH 2/2 has already been Acked-by Tejun Heo in V1. I only made
>> 	  a minor renaming of the acpi_cls to acpi_match_cls for clarity
>> 	  in V2. It probably should be routed together with the PATCH 1/2
>> 	  (once acked) since it defines the new member in the struct.
>>
>> Changes 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 (2):
>>    ACPI / scan: Add support for ACPI _CLS device matching
>>    ata: ahci_platform: Add ACPI _CLS matching
>>
>>   drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>>   drivers/ata/Kconfig             |  2 +-
>>   drivers/ata/ahci_platform.c     |  3 ++
>>   include/acpi/acnames.h          |  1 +
>>   include/linux/acpi.h            | 10 ++++++
>>   include/linux/device.h          |  1 +
>>   include/linux/mod_devicetable.h |  6 ++++
>>   7 files changed, 98 insertions(+), 4 deletions(-)
>
> I'll take care of this when I'm back from travels later this month.  Thanks!
>

Thanks Rafael.

Suravee

Re: [V2 PATCH 0/2] Introduce ACPI support for ahci_platform driver

[Suravee Suthikulanit]

On 1/5/2015 5:24 PM, Rafael J. Wysocki wrote:
> On Monday, January 05, 2015 03:11:13 PM Suravee Suthikulpanit wrote:
>> This patch series introduce ACPI support for non-PCI AHCI platform driver.
>> Existing ACPI support for AHCI assumes the device controller is a PCI device.
>>
>> Also, since there is no ACPI _HID/_CID for generic AHCI controller, the driver
>> could not use them for matching devices. Therefore, this patch introduces
>> a mechanism for drivers to match devices using ACPI _CLS method.
>>
>> This patch series is rebased from and tested with:
>>
>>      http://git.linaro.org/leg/acpi/acpi.git acpi-5.1-v7
>>
>> 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
>>
>> NOTE:
>> 	* PATCH 2/2 has already been Acked-by Tejun Heo in V1. I only made
>> 	  a minor renaming of the acpi_cls to acpi_match_cls for clarity
>> 	  in V2. It probably should be routed together with the PATCH 1/2
>> 	  (once acked) since it defines the new member in the struct.
>>
>> Changes 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 (2):
>>    ACPI / scan: Add support for ACPI _CLS device matching
>>    ata: ahci_platform: Add ACPI _CLS matching
>>
>>   drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>>   drivers/ata/Kconfig             |  2 +-
>>   drivers/ata/ahci_platform.c     |  3 ++
>>   include/acpi/acnames.h          |  1 +
>>   include/linux/acpi.h            | 10 ++++++
>>   include/linux/device.h          |  1 +
>>   include/linux/mod_devicetable.h |  6 ++++
>>   7 files changed, 98 insertions(+), 4 deletions(-)
>
> I'll take care of this when I'm back from travels later this month.  Thanks!
>

Thanks Rafael.

Suravee

Re: [V2 PATCH 1/2] ACPI / scan: Add support for ACPI _CLS device matching

[Rafael J. Wysocki]

On Monday, January 05, 2015 03:11:14 PM Suravee Suthikulpanit wrote:
> 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, and some device classes
> 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.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> ---
>  drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>  include/acpi/acnames.h          |  1 +
>  include/linux/acpi.h            | 10 ++++++
>  include/linux/device.h          |  1 +
>  include/linux/mod_devicetable.h |  6 ++++
>  5 files changed, 94 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 16914cc..7b25221 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev,
>  bool acpi_driver_match_device(struct device *dev,
>  			      const struct device_driver *drv)
>  {
> -	if (!drv->acpi_match_table)
> -		return acpi_of_driver_match_device(dev, drv);
> +	bool ret = false;
>  
> -	return !!acpi_match_device(drv->acpi_match_table, dev);
> +	if (drv->acpi_match_table)
> +		ret = !!acpi_match_device(drv->acpi_match_table, dev);
> +
> +	/* Next, try to match with special "PRP0001" _HID */
> +	if (!ret && drv->of_match_table)
> +		ret = acpi_of_driver_match_device(dev, drv);
> +
> +	/* Next, try to match with PCI-defined class-code */
> +	if (!ret && drv->acpi_match_cls)
> +		ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(acpi_driver_match_device);
>  
> +/**
> + * acpi_match_device_cls - Match a struct device against a ACPI _CLS method
> + * @dev_cls: A pointer to struct acpi_device_cls object to match against.
> + * @dev: The ACPI device structure to match.
> + *
> + * Check if @dev has a valid ACPI and _CLS handle. If there is a
> + * struct acpi_device_cls object for that handle, use that object to match
> + * against the given struct acpi_device_cls object.
> + *
> + * Return true on success or false on failure.
> + */
> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
> +			  const struct device *dev)
> +{
> +	bool ret = false;
> +	acpi_status status;
> +	union acpi_object *pkg;
> +	struct acpi_device_cls cls;
> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +	struct acpi_buffer format = { sizeof("NNN"), "NNN" };
> +	struct acpi_buffer state = { 0, NULL };
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
> +	acpi_handle handle = ACPI_HANDLE(dev);

That must be equal to adev->handle, so it is not necessary to use ACPI_HANDLE() here.

> +
> +	if (!handle || !adev || !adev->status.present || !dev_cls)
> +		return ret;

		return false;

and set 'ret' later.  And if you check 'adev', you don't need to check 'handle'.
And you can use adev->handle directly below, so the 'handle' variable is not
necessary.

> +
> +	status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
> +	if (ACPI_FAILURE(status))
> +		return ret;

		return false;

> +
> +	/**
> +	 * Note:
> +	 * ACPIv5.1 defines the package to contain 3 integers for
> +	 * Base-Class code, Sub-Class code, and Programming Interface code.
> +	 */
> +	pkg = buffer.pointer;
> +	if (!pkg ||
> +	    (pkg->type != ACPI_TYPE_PACKAGE) ||
> +	    (pkg->package.count != 3)) {
> +		dev_err(&adev->dev, "Invalid _CLS data\n");

dev_dbg() here, please.

> +		goto out;
> +	}
> +
> +	state.length = sizeof(struct acpi_device_cls);
> +	state.pointer = &cls;
> +
> +	status = acpi_extract_package(pkg, &format, &state);
> +	if (ACPI_FAILURE(status)) {
> +		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));

I'm not sure how useful that message is going to be to be honest.

> +		goto out;
> +	}
> +
> +	if ((dev_cls->base_class == cls.base_class) &&
> +	    (dev_cls->sub_class == cls.sub_class) &&
> +	    (dev_cls->prog_interface == cls.prog_interface))
> +		ret = true;

	ret = dev_cls->base_class == cls.base_class &&
		dev_cls->sub_class == cls.sub_class &&
		dev_cls->prog_interface == cls.prog_interface;

> +out:
> +	kfree(buffer.pointer);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(acpi_match_device_cls);
> +
>  static void acpi_free_power_resources_lists(struct acpi_device *device)
>  {
>  	int i;
> diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
> index 7461327..22332a6 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/linux/acpi.h b/include/linux/acpi.h
> index 87f365e..2f2b8ce 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
>  
>  extern bool acpi_driver_match_device(struct device *dev,
>  				     const struct device_driver *drv);
> +
> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
> +			   const struct device *dev);
> +
>  int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
>  int acpi_device_modalias(struct device *, char *, int);
>  void acpi_walk_dep_device_list(acpi_handle handle);
> @@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device(
>  	return NULL;
>  }
>  
> +static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
> +					 const struct device *dev)
> +{
> +	return false;
> +}
> +
>  static inline bool acpi_driver_match_device(struct device *dev,
>  					    const struct device_driver *drv)
>  {
> diff --git a/include/linux/device.h b/include/linux/device.h
> index fb50673..8e259c5c 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -237,6 +237,7 @@ struct device_driver {
>  
>  	const struct of_device_id	*of_match_table;
>  	const struct acpi_device_id	*acpi_match_table;
> +	const struct acpi_device_cls	*acpi_match_cls;
>  
>  	int (*probe) (struct device *dev);
>  	int (*remove) (struct device *dev);
> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 745def8..00e94ec 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -186,6 +186,12 @@ struct css_device_id {
>  
>  #define ACPI_ID_LEN	9
>  
> +struct acpi_device_cls {
> +	kernel_ulong_t base_class;
> +	kernel_ulong_t sub_class;
> +	kernel_ulong_t prog_interface;
> +};
> +

Move that below the struct acpi_device_id definition.

>  struct acpi_device_id {
>  	__u8 id[ACPI_ID_LEN];
>  	kernel_ulong_t driver_data;
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [V2 PATCH 1/2] ACPI / scan: Add support for ACPI _CLS device matching

[Suravee Suthikulpanit]

Thank you for review comment.  I am sending out V3 with your suggestions.

Suravee

On 01/22/2015 06:40 AM, Rafael J. Wysocki wrote:
> On Monday, January 05, 2015 03:11:14 PM Suravee Suthikulpanit wrote:
>> 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, and some device classes
>> 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.
>>
>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> ---
>>   drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>>   include/acpi/acnames.h          |  1 +
>>   include/linux/acpi.h            | 10 ++++++
>>   include/linux/device.h          |  1 +
>>   include/linux/mod_devicetable.h |  6 ++++
>>   5 files changed, 94 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
>> index 16914cc..7b25221 100644
>> --- a/drivers/acpi/scan.c
>> +++ b/drivers/acpi/scan.c
>> @@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev,
>>   bool acpi_driver_match_device(struct device *dev,
>>   			      const struct device_driver *drv)
>>   {
>> -	if (!drv->acpi_match_table)
>> -		return acpi_of_driver_match_device(dev, drv);
>> +	bool ret = false;
>>
>> -	return !!acpi_match_device(drv->acpi_match_table, dev);
>> +	if (drv->acpi_match_table)
>> +		ret = !!acpi_match_device(drv->acpi_match_table, dev);
>> +
>> +	/* Next, try to match with special "PRP0001" _HID */
>> +	if (!ret && drv->of_match_table)
>> +		ret = acpi_of_driver_match_device(dev, drv);
>> +
>> +	/* Next, try to match with PCI-defined class-code */
>> +	if (!ret && drv->acpi_match_cls)
>> +		ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
>> +
>> +	return ret;
>>   }
>>   EXPORT_SYMBOL_GPL(acpi_driver_match_device);
>>
>> +/**
>> + * acpi_match_device_cls - Match a struct device against a ACPI _CLS method
>> + * @dev_cls: A pointer to struct acpi_device_cls object to match against.
>> + * @dev: The ACPI device structure to match.
>> + *
>> + * Check if @dev has a valid ACPI and _CLS handle. If there is a
>> + * struct acpi_device_cls object for that handle, use that object to match
>> + * against the given struct acpi_device_cls object.
>> + *
>> + * Return true on success or false on failure.
>> + */
>> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +			  const struct device *dev)
>> +{
>> +	bool ret = false;
>> +	acpi_status status;
>> +	union acpi_object *pkg;
>> +	struct acpi_device_cls cls;
>> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
>> +	struct acpi_buffer format = { sizeof("NNN"), "NNN" };
>> +	struct acpi_buffer state = { 0, NULL };
>> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>> +	acpi_handle handle = ACPI_HANDLE(dev);
>
> That must be equal to adev->handle, so it is not necessary to use ACPI_HANDLE() here.
>
>> +
>> +	if (!handle || !adev || !adev->status.present || !dev_cls)
>> +		return ret;
>
> 		return false;
>
> and set 'ret' later.  And if you check 'adev', you don't need to check 'handle'.
> And you can use adev->handle directly below, so the 'handle' variable is not
> necessary.
>
>> +
>> +	status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
>> +	if (ACPI_FAILURE(status))
>> +		return ret;
>
> 		return false;
>
>> +
>> +	/**
>> +	 * Note:
>> +	 * ACPIv5.1 defines the package to contain 3 integers for
>> +	 * Base-Class code, Sub-Class code, and Programming Interface code.
>> +	 */
>> +	pkg = buffer.pointer;
>> +	if (!pkg ||
>> +	    (pkg->type != ACPI_TYPE_PACKAGE) ||
>> +	    (pkg->package.count != 3)) {
>> +		dev_err(&adev->dev, "Invalid _CLS data\n");
>
> dev_dbg() here, please.
>
>> +		goto out;
>> +	}
>> +
>> +	state.length = sizeof(struct acpi_device_cls);
>> +	state.pointer = &cls;
>> +
>> +	status = acpi_extract_package(pkg, &format, &state);
>> +	if (ACPI_FAILURE(status)) {
>> +		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
>
> I'm not sure how useful that message is going to be to be honest.
>
>> +		goto out;
>> +	}
>> +
>> +	if ((dev_cls->base_class == cls.base_class) &&
>> +	    (dev_cls->sub_class == cls.sub_class) &&
>> +	    (dev_cls->prog_interface == cls.prog_interface))
>> +		ret = true;
>
> 	ret = dev_cls->base_class == cls.base_class &&
> 		dev_cls->sub_class == cls.sub_class &&
> 		dev_cls->prog_interface == cls.prog_interface;
>
>> +out:
>> +	kfree(buffer.pointer);
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(acpi_match_device_cls);
>> +
>>   static void acpi_free_power_resources_lists(struct acpi_device *device)
>>   {
>>   	int i;
>> diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
>> index 7461327..22332a6 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/linux/acpi.h b/include/linux/acpi.h
>> index 87f365e..2f2b8ce 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
>>
>>   extern bool acpi_driver_match_device(struct device *dev,
>>   				     const struct device_driver *drv);
>> +
>> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +			   const struct device *dev);
>> +
>>   int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
>>   int acpi_device_modalias(struct device *, char *, int);
>>   void acpi_walk_dep_device_list(acpi_handle handle);
>> @@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device(
>>   	return NULL;
>>   }
>>
>> +static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +					 const struct device *dev)
>> +{
>> +	return false;
>> +}
>> +
>>   static inline bool acpi_driver_match_device(struct device *dev,
>>   					    const struct device_driver *drv)
>>   {
>> diff --git a/include/linux/device.h b/include/linux/device.h
>> index fb50673..8e259c5c 100644
>> --- a/include/linux/device.h
>> +++ b/include/linux/device.h
>> @@ -237,6 +237,7 @@ struct device_driver {
>>
>>   	const struct of_device_id	*of_match_table;
>>   	const struct acpi_device_id	*acpi_match_table;
>> +	const struct acpi_device_cls	*acpi_match_cls;
>>
>>   	int (*probe) (struct device *dev);
>>   	int (*remove) (struct device *dev);
>> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
>> index 745def8..00e94ec 100644
>> --- a/include/linux/mod_devicetable.h
>> +++ b/include/linux/mod_devicetable.h
>> @@ -186,6 +186,12 @@ struct css_device_id {
>>
>>   #define ACPI_ID_LEN	9
>>
>> +struct acpi_device_cls {
>> +	kernel_ulong_t base_class;
>> +	kernel_ulong_t sub_class;
>> +	kernel_ulong_t prog_interface;
>> +};
>> +
>
> Move that below the struct acpi_device_id definition.
>
>>   struct acpi_device_id {
>>   	__u8 id[ACPI_ID_LEN];
>>   	kernel_ulong_t driver_data;
>>
>

Re: [V2 PATCH 1/2] ACPI / scan: Add support for ACPI _CLS device matching

[Suravee Suthikulpanit]

Thank you for review comment.  I am sending out V3 with your suggestions.

Suravee

On 01/22/2015 06:40 AM, Rafael J. Wysocki wrote:
> On Monday, January 05, 2015 03:11:14 PM Suravee Suthikulpanit wrote:
>> 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, and some device classes
>> 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.
>>
>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> ---
>>   drivers/acpi/scan.c             | 79 +++++++++++++++++++++++++++++++++++++++--
>>   include/acpi/acnames.h          |  1 +
>>   include/linux/acpi.h            | 10 ++++++
>>   include/linux/device.h          |  1 +
>>   include/linux/mod_devicetable.h |  6 ++++
>>   5 files changed, 94 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
>> index 16914cc..7b25221 100644
>> --- a/drivers/acpi/scan.c
>> +++ b/drivers/acpi/scan.c
>> @@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev,
>>   bool acpi_driver_match_device(struct device *dev,
>>   			      const struct device_driver *drv)
>>   {
>> -	if (!drv->acpi_match_table)
>> -		return acpi_of_driver_match_device(dev, drv);
>> +	bool ret = false;
>>
>> -	return !!acpi_match_device(drv->acpi_match_table, dev);
>> +	if (drv->acpi_match_table)
>> +		ret = !!acpi_match_device(drv->acpi_match_table, dev);
>> +
>> +	/* Next, try to match with special "PRP0001" _HID */
>> +	if (!ret && drv->of_match_table)
>> +		ret = acpi_of_driver_match_device(dev, drv);
>> +
>> +	/* Next, try to match with PCI-defined class-code */
>> +	if (!ret && drv->acpi_match_cls)
>> +		ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
>> +
>> +	return ret;
>>   }
>>   EXPORT_SYMBOL_GPL(acpi_driver_match_device);
>>
>> +/**
>> + * acpi_match_device_cls - Match a struct device against a ACPI _CLS method
>> + * @dev_cls: A pointer to struct acpi_device_cls object to match against.
>> + * @dev: The ACPI device structure to match.
>> + *
>> + * Check if @dev has a valid ACPI and _CLS handle. If there is a
>> + * struct acpi_device_cls object for that handle, use that object to match
>> + * against the given struct acpi_device_cls object.
>> + *
>> + * Return true on success or false on failure.
>> + */
>> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +			  const struct device *dev)
>> +{
>> +	bool ret = false;
>> +	acpi_status status;
>> +	union acpi_object *pkg;
>> +	struct acpi_device_cls cls;
>> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
>> +	struct acpi_buffer format = { sizeof("NNN"), "NNN" };
>> +	struct acpi_buffer state = { 0, NULL };
>> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>> +	acpi_handle handle = ACPI_HANDLE(dev);
>
> That must be equal to adev->handle, so it is not necessary to use ACPI_HANDLE() here.
>
>> +
>> +	if (!handle || !adev || !adev->status.present || !dev_cls)
>> +		return ret;
>
> 		return false;
>
> and set 'ret' later.  And if you check 'adev', you don't need to check 'handle'.
> And you can use adev->handle directly below, so the 'handle' variable is not
> necessary.
>
>> +
>> +	status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
>> +	if (ACPI_FAILURE(status))
>> +		return ret;
>
> 		return false;
>
>> +
>> +	/**
>> +	 * Note:
>> +	 * ACPIv5.1 defines the package to contain 3 integers for
>> +	 * Base-Class code, Sub-Class code, and Programming Interface code.
>> +	 */
>> +	pkg = buffer.pointer;
>> +	if (!pkg ||
>> +	    (pkg->type != ACPI_TYPE_PACKAGE) ||
>> +	    (pkg->package.count != 3)) {
>> +		dev_err(&adev->dev, "Invalid _CLS data\n");
>
> dev_dbg() here, please.
>
>> +		goto out;
>> +	}
>> +
>> +	state.length = sizeof(struct acpi_device_cls);
>> +	state.pointer = &cls;
>> +
>> +	status = acpi_extract_package(pkg, &format, &state);
>> +	if (ACPI_FAILURE(status)) {
>> +		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
>
> I'm not sure how useful that message is going to be to be honest.
>
>> +		goto out;
>> +	}
>> +
>> +	if ((dev_cls->base_class == cls.base_class) &&
>> +	    (dev_cls->sub_class == cls.sub_class) &&
>> +	    (dev_cls->prog_interface == cls.prog_interface))
>> +		ret = true;
>
> 	ret = dev_cls->base_class == cls.base_class &&
> 		dev_cls->sub_class == cls.sub_class &&
> 		dev_cls->prog_interface == cls.prog_interface;
>
>> +out:
>> +	kfree(buffer.pointer);
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(acpi_match_device_cls);
>> +
>>   static void acpi_free_power_resources_lists(struct acpi_device *device)
>>   {
>>   	int i;
>> diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
>> index 7461327..22332a6 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/linux/acpi.h b/include/linux/acpi.h
>> index 87f365e..2f2b8ce 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
>>
>>   extern bool acpi_driver_match_device(struct device *dev,
>>   				     const struct device_driver *drv);
>> +
>> +bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +			   const struct device *dev);
>> +
>>   int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
>>   int acpi_device_modalias(struct device *, char *, int);
>>   void acpi_walk_dep_device_list(acpi_handle handle);
>> @@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device(
>>   	return NULL;
>>   }
>>
>> +static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
>> +					 const struct device *dev)
>> +{
>> +	return false;
>> +}
>> +
>>   static inline bool acpi_driver_match_device(struct device *dev,
>>   					    const struct device_driver *drv)
>>   {
>> diff --git a/include/linux/device.h b/include/linux/device.h
>> index fb50673..8e259c5c 100644
>> --- a/include/linux/device.h
>> +++ b/include/linux/device.h
>> @@ -237,6 +237,7 @@ struct device_driver {
>>
>>   	const struct of_device_id	*of_match_table;
>>   	const struct acpi_device_id	*acpi_match_table;
>> +	const struct acpi_device_cls	*acpi_match_cls;
>>
>>   	int (*probe) (struct device *dev);
>>   	int (*remove) (struct device *dev);
>> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
>> index 745def8..00e94ec 100644
>> --- a/include/linux/mod_devicetable.h
>> +++ b/include/linux/mod_devicetable.h
>> @@ -186,6 +186,12 @@ struct css_device_id {
>>
>>   #define ACPI_ID_LEN	9
>>
>> +struct acpi_device_cls {
>> +	kernel_ulong_t base_class;
>> +	kernel_ulong_t sub_class;
>> +	kernel_ulong_t prog_interface;
>> +};
>> +
>
> Move that below the struct acpi_device_id definition.
>
>>   struct acpi_device_id {
>>   	__u8 id[ACPI_ID_LEN];
>>   	kernel_ulong_t driver_data;
>>
>