Update AMBA driver for enhanced component ID spec

The CoreSight specification (ARM IHI 0029E), updates the ID register requirements for components on an AMBA bus, to cover both traditional ARM Primecell type devices, and newer CoreSight and other components.

The Peripheral ID (PID) / Component ID (CID) pair is extended in certain cases to uniquely identify components. CoreSight components related to a single function can share Peripheral ID values, and must be further identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI, PMU and Debug hardware of the A35 all share the same PID.

Bits 11:8 of the CID are defined to be the device class.
Class 0xF remains for PrimeCell and legacy components.
Class 0x9 defines the component as CoreSight (CORESIGHT_CID above) Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support at present.
Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

The specification futher defines which classes of device use the standard CID/PID pair, and when additional ID registers are required.

The patches provide an update of amba_device and matching code to handle the additional registers required for the Class 0x9 (CoreSight) UCI. The *data pointer in the amba_id is used by the driver to provide extended ID register values for matching.

CoreSight components where PID/CID pair is currently sufficient for unique identification need not provide this additional information.

Signed-off-by Mike Leach <[email protected]>

---
  drivers/amba/bus.c       | 48 ++++++++++++++++++++++++++++++++++++----
  include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++
  2 files changed, 77 insertions(+), 4 deletions(-)

drivers/amba/bus.c +0 -0

index 41b706403ef7..6eab977f4314 100644

drivers/amba/bus.c +20 -2

+{
+	int ret = 0;
+	struct amba_cs_uci_id *uci;
+
+	uci = table->data;
+
+	/* no table data - return match on periphid */
+	if (!uci)
+		return 1;
+
+	if (uci->devarch) {
+		ret = (dev->uci.devtype == uci->devtype) &&
+		       ((dev->uci.devarch & uci->mask) == uci->devarch);
+	} else {
+		/* devtype only if devarch set to 0 */
+		ret = dev->uci.devtype == uci->devtype;
+	}
+	return ret;
+}
+
  static const struct amba_id *
  amba_lookup(const struct amba_id *table, struct amba_device *dev)
  {

@@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev)
 
  	while (table->mask) {
  		ret = (dev->periphid & table->mask) == table->id;
-		if (ret)
-			break;

drivers/amba/bus.c +0 -1

  	}
-
  	return ret ? table : NULL;
 
 

  }

drivers/amba/bus.c +13 -1

@@ -399,10 +427,22 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
  			cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
  				(i * 8);
 
+		if (cid == CORESIGHT_CID) {
+			/* set the base to the start of the last 4k block */
+			void __iomem *csbase = tmp + size - 4096;
+
+			dev->uci.devarch =
+				readl(csbase + UCI_REG_DEVARCH_OFFSET);
+			dev->uci.devtype =
+				readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+		}
+
  		amba_put_disable_pclk(dev);
 
-		if (cid == AMBA_CID || cid == CORESIGHT_CID)
+		if (cid == AMBA_CID || cid == CORESIGHT_CID) {
  			dev->periphid = pid;
+			dev->cid = cid;
+		}
 
  		if (!dev->periphid)
  			ret = -ENODEV;

include/linux/amba/bus.h +14 -0

index d143c13bed26..a83a0a3dece8 100644
@@ -25,6 +25,36 @@
  #define AMBA_CID	0xb105f00d
  #define CORESIGHT_CID	0xb105900d
 
+/*
+ * CoreSight Architecture specification updates the ID specification
+ * for components on the AMBA bus. (ARM IHI 0029E)
+ *
+ * Bits 11:8 of the CID are the device class.
+ *
+ * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
+ * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
+ * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
+ * at present.
+ * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
+ *
+ * Remaining CID bits stay as 0xb105-00d
+ */

include/linux/amba/bus.h +8 -0

+	unsigned int devtype;
+};
+
+#define UCI_REG_DEVTYPE_OFFSET	0xFCC
+#define UCI_REG_DEVARCH_OFFSET	0xFBC
+
  struct clk;
 
  struct amba_device {

@@ -32,6 +62,8 @@ struct amba_device {
  	struct resource		res;
  	struct clk		*pclk;
  	unsigned int		periphid;
+	unsigned int		cid;
+	struct amba_cs_uci_id	uci;
  	unsigned int		irq[AMBA_NR_IRQS];
  	char			*driver_override;
  };

Hi Mike,

Quoted 25 lines · Mike Leach

The CoreSight specification (ARM IHI 0029E), updates the ID register requirements for components on an AMBA bus, to cover both traditional ARM Primecell type devices, and newer CoreSight and other components.

The Peripheral ID (PID) / Component ID (CID) pair is extended in certain cases to uniquely identify components. CoreSight components related to a single function can share Peripheral ID values, and must be further identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI, PMU and Debug hardware of the A35 all share the same PID.

Bits 11:8 of the CID are defined to be the device class.
Class 0xF remains for PrimeCell and legacy components.
Class 0x9 defines the component as CoreSight (CORESIGHT_CID above) Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support at present.
Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

The specification futher defines which classes of device use the standard CID/PID pair, and when additional ID registers are required.

The patches provide an update of amba_device and matching code to handle the additional registers required for the Class 0x9 (CoreSight) UCI. The *data pointer in the amba_id is used by the driver to provide extended ID register values for matching.

Quoted 4 lines

CoreSight components where PID/CID pair is currently sufficient for unique identification need not provide this additional information.

Signed-off-by Mike Leach <[email protected]>

The patch looks good to me. A couple of minor comments below.

Quoted 10 lines

---
  drivers/amba/bus.c       | 48 ++++++++++++++++++++++++++++++++++++----
  include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++
  2 files changed, 77 insertions(+), 4 deletions(-)

drivers/amba/bus.c +0 -0

index 41b706403ef7..6eab977f4314 100644

drivers/amba/bus.c line 30

Quoted 5 lines

drivers/amba/bus.c +2 -0

@@ -26,6 +26,28 @@
 
  #define to_amba_driver(d)   container_of(d, struct amba_driver, drv)
 
+/* called on periphid match and class 0x9 coresight device. */
+static int amba_uci_match(const struct amba_id *table, struct amba_device *dev)

nit : Could we rename this function to make it explicit about the "coresight" class ? say, amba_cs_ucid_id_match() ?

Quoted 29 lines

drivers/amba/bus.c +20 -2

+{
+     int ret = 0;
+     struct amba_cs_uci_id *uci;
+
+     uci = table->data;
+
+     /* no table data - return match on periphid */
+     if (!uci)
+             return 1;
+
+     if (uci->devarch) {
+             ret = (dev->uci.devtype == uci->devtype) &&
+                    ((dev->uci.devarch & uci->mask) == uci->devarch);
+     } else {
+             /* devtype only if devarch set to 0 */
+             ret = dev->uci.devtype == uci->devtype;
+     }
+     return ret;
+}
+
  static const struct amba_id *
  amba_lookup(const struct amba_id *table, struct amba_device *dev)
  {

@@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev)
 
      while (table->mask) {
              ret = (dev->periphid & table->mask) == table->id;
-             if (ret)
-                     break;

drivers/amba/bus.c amba_lookup(const struct amba_id *table, struct amba_device *dev) · line 67

Quoted 10 lines

drivers/amba/bus.c +9 -0

+             /* matched on periphid - check UCI if CoreSight */
+             if (ret) {
+                     if (dev->cid == CORESIGHT_CID)  {
+                             ret = amba_uci_match(table, dev);
+                             if (ret)
+                                     break;
+                     } else
+                             break;
+             }
              table++;

This code looks a bit too complex with the ifs and breaks. Could we change it a bit to :

        /* For CoreSight class devices, match the UCI id */
        if ((dev->periphid & table->mask) == table->id) &&
            ((dev->cid != CORESIGHT_CID) || amba_uci_match(table, dev)))
                return table;
        table++;

Quoted 53 lines

drivers/amba/bus.c +0 -1

      }
-
      return ret ? table : NULL;
 
 

  }

drivers/amba/bus.c +13 -1

@@ -399,10 +427,22 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
                      cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
                              (i * 8);
 
+             if (cid == CORESIGHT_CID) {
+                     /* set the base to the start of the last 4k block */
+                     void __iomem *csbase = tmp + size - 4096;
+
+                     dev->uci.devarch =
+                             readl(csbase + UCI_REG_DEVARCH_OFFSET);
+                     dev->uci.devtype =
+                             readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+             }
+
              amba_put_disable_pclk(dev);
 
-             if (cid == AMBA_CID || cid == CORESIGHT_CID)
+             if (cid == AMBA_CID || cid == CORESIGHT_CID) {
                      dev->periphid = pid;
+                     dev->cid = cid;
+             }
 
              if (!dev->periphid)
                      ret = -ENODEV;

include/linux/amba/bus.h +14 -0

index d143c13bed26..a83a0a3dece8 100644
@@ -25,6 +25,36 @@
  #define AMBA_CID    0xb105f00d
  #define CORESIGHT_CID       0xb105900d
 
+/*
+ * CoreSight Architecture specification updates the ID specification
+ * for components on the AMBA bus. (ARM IHI 0029E)
+ *
+ * Bits 11:8 of the CID are the device class.
+ *
+ * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
+ * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
+ * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
+ * at present.
+ * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
+ *
+ * Remaining CID bits stay as 0xb105-00d
+ */

include/linux/amba/bus.h line 51

Quoted 10 lines

include/linux/amba/bus.h +10 -0

+
+/*
+ * Class 0x9 components use additional values to form a Unique Component
+ * Identifier (UCI), where peripheral ID values are identical for different
+ * components. Passed to the amba bus code from the component driver via
+ * the amba_id->data pointer.
+ */
+struct amba_cs_uci_id {
+     unsigned int devarch;
+     unsigned int mask;

It is worth changing the mask to reflect that it applies to the "devarch" field, than being a generic mask which is unexplained.

Quoted 19 lines

include/linux/amba/bus.h +8 -0

+     unsigned int devtype;
+};
+
+#define UCI_REG_DEVTYPE_OFFSET       0xFCC
+#define UCI_REG_DEVARCH_OFFSET       0xFBC
+
  struct clk;
 
  struct amba_device {

@@ -32,6 +62,8 @@ struct amba_device {
      struct resource         res;
      struct clk              *pclk;
      unsigned int            periphid;
+     unsigned int            cid;
+     struct amba_cs_uci_id   uci;
      unsigned int            irq[AMBA_NR_IRQS];
      char                    *driver_override;
  };

include/linux/amba/bus.h enum amba_vendor { · line 96

Quoted 4 lines

include/linux/amba/bus.h +1 -0

@@ -61,6 +93,7 @@ enum amba_vendor {
      (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \
      AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff))
 
+

spurious change ?

include/linux/amba/bus.h enum amba_vendor { · line 99

Quoted 3 lines

include/linux/amba/bus.h +0 -0

  extern struct bus_type amba_bustype;
 
  #define to_amba_device(d)   container_of(d, struct amba_device, dev)

Otherwise looks good to me.

Suzuki

The CoreSight specification (ARM IHI 0029E), updates the ID register requirements for components on an AMBA bus, to cover both traditional ARM Primecell type devices, and newer CoreSight and other components.

The Peripheral ID (PID) / Component ID (CID) pair is extended in certain cases to uniquely identify components. CoreSight components related to a single function can share Peripheral ID values, and must be further identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI, PMU and Debug hardware of the A35 all share the same PID.

Bits 11:8 of the CID are defined to be the device class.
Class 0xF remains for PrimeCell and legacy components.
Class 0x9 defines the component as CoreSight (CORESIGHT_CID above) Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support at present.
Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

The specification futher defines which classes of device use the standard CID/PID pair, and when additional ID registers are required.

The patches provide an update of amba_device and matching code to handle the additional registers required for the Class 0x9 (CoreSight) UCI. The *data pointer in the amba_id is used by the driver to provide extended ID register values for matching.

CoreSight components where PID/CID pair is currently sufficient for unique identification need not provide this additional information.

Signed-off-by Mike Leach <[email protected]>

---
 drivers/amba/bus.c       | 48 ++++++++++++++++++++++++++++++++++++----
 include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 4 deletions(-)

drivers/amba/bus.c +24 -2

index 41b706403ef7..6eab977f4314 100644
@@ -26,6 +26,28 @@
 
 #define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
 
+/* called on periphid match and class 0x9 coresight device. */
+static int amba_uci_match(const struct amba_id *table, struct amba_device *dev)
+{
+	int ret = 0;
+	struct amba_cs_uci_id *uci;
+
+	uci = table->data;
+
+	/* no table data - return match on periphid */
+	if (!uci)
+		return 1;
+
+	if (uci->devarch) {
+		ret = (dev->uci.devtype == uci->devtype) &&
+		       ((dev->uci.devarch & uci->mask) == uci->devarch);
+	} else {
+		/* devtype only if devarch set to 0 */
+		ret = dev->uci.devtype == uci->devtype;
+	}
+	return ret;
+}
+
 static const struct amba_id *
 amba_lookup(const struct amba_id *table, struct amba_device *dev)
 {

@@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev)
 
 	while (table->mask) {
 		ret = (dev->periphid & table->mask) == table->id;
-		if (ret)
-			break;
+		/* matched on periphid - check UCI if CoreSight */
+		if (ret) {

drivers/amba/bus.c +0 -0

 	return ret ? table : NULL;
 }
 

@@ -399,10 +427,22 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
 			cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<

drivers/amba/bus.c +5 -1

+		}
+
 		amba_put_disable_pclk(dev);
 
-		if (cid == AMBA_CID || cid == CORESIGHT_CID)
+		if (cid == AMBA_CID || cid == CORESIGHT_CID) {
 			dev->periphid = pid;
+			dev->cid = cid;
+		}
 
 		if (!dev->periphid)
 			ret = -ENODEV;

include/linux/amba/bus.h +33 -0

index d143c13bed26..a83a0a3dece8 100644
@@ -25,6 +25,36 @@
 #define AMBA_CID	0xb105f00d
 #define CORESIGHT_CID	0xb105900d
 
+/*
+ * CoreSight Architecture specification updates the ID specification
+ * for components on the AMBA bus. (ARM IHI 0029E)
+ *
+ * Bits 11:8 of the CID are the device class.
+ *
+ * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
+ * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
+ * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
+ * at present.
+ * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
+ *
+ * Remaining CID bits stay as 0xb105-00d
+ */
+
+/*
+ * Class 0x9 components use additional values to form a Unique Component
+ * Identifier (UCI), where peripheral ID values are identical for different
+ * components. Passed to the amba bus code from the component driver via
+ * the amba_id->data pointer.
+ */
+struct amba_cs_uci_id {
+	unsigned int devarch;
+	unsigned int mask;
+	unsigned int devtype;
+};
+
+#define UCI_REG_DEVTYPE_OFFSET	0xFCC
+#define UCI_REG_DEVARCH_OFFSET	0xFBC
+
 struct clk;
 
 struct amba_device {

@@ -32,6 +62,8 @@ struct amba_device {
 	struct resource		res;
 	struct clk		*pclk;
 	unsigned int		periphid;
+	unsigned int		cid;
+	struct amba_cs_uci_id	uci;
 	unsigned int		irq[AMBA_NR_IRQS];
 	char			*driver_override;
 };

@@ -61,6 +93,7 @@ enum amba_vendor {
 	(((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \
 	AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff))
 
+
 extern struct bus_type amba_bustype;
 
 #define to_amba_device(d)	container_of(d, struct amba_device, dev)

Signature · 1 line

2.19.1

Hi Mike,

Quoted 79 lines · Mike Leach

The CoreSight specification (ARM IHI 0029E), updates the ID register requirements for components on an AMBA bus, to cover both traditional ARM Primecell type devices, and newer CoreSight and other components.

The Peripheral ID (PID) / Component ID (CID) pair is extended in certain cases to uniquely identify components. CoreSight components related to a single function can share Peripheral ID values, and must be further identified using a Unique Component Identifier (UCI). e.g. the ETM, CTI, PMU and Debug hardware of the A35 all share the same PID.

Bits 11:8 of the CID are defined to be the device class.
Class 0xF remains for PrimeCell and legacy components.
Class 0x9 defines the component as CoreSight (CORESIGHT_CID above) Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support at present.
Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.

The specification futher defines which classes of device use the standard CID/PID pair, and when additional ID registers are required.

The patches provide an update of amba_device and matching code to handle the additional registers required for the Class 0x9 (CoreSight) UCI. The *data pointer in the amba_id is used by the driver to provide extended ID register values for matching.

CoreSight components where PID/CID pair is currently sufficient for unique identification need not provide this additional information.

Signed-off-by Mike Leach <[email protected]>

---
 drivers/amba/bus.c       | 48 ++++++++++++++++++++++++++++++++++++----
 include/linux/amba/bus.h | 33 +++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 4 deletions(-)

drivers/amba/bus.c +28 -2

index 41b706403ef7..6eab977f4314 100644
@@ -26,6 +26,28 @@
 
 #define to_amba_driver(d)    container_of(d, struct amba_driver, drv)
 
+/* called on periphid match and class 0x9 coresight device. */
+static int amba_uci_match(const struct amba_id *table, struct amba_device *dev)
+{
+     int ret = 0;
+     struct amba_cs_uci_id *uci;
+
+     uci = table->data;
+
+     /* no table data - return match on periphid */
+     if (!uci)
+             return 1;
+
+     if (uci->devarch) {
+             ret = (dev->uci.devtype == uci->devtype) &&
+                    ((dev->uci.devarch & uci->mask) == uci->devarch);
+     } else {
+             /* devtype only if devarch set to 0 */
+             ret = dev->uci.devtype == uci->devtype;
+     }
+     return ret;
+}
+
 static const struct amba_id *
 amba_lookup(const struct amba_id *table, struct amba_device *dev)
 {

@@ -33,11 +55,17 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev)
 
      while (table->mask) {
              ret = (dev->periphid & table->mask) == table->id;
-             if (ret)
-                     break;
+             /* matched on periphid - check UCI if CoreSight */
+             if (ret) {
+                     if (dev->cid == CORESIGHT_CID)  {
+                             ret = amba_uci_match(table, dev);
+                             if (ret)
+                                     break;

drivers/amba/bus.c amba_lookup(const struct amba_id *table, struct amba_device *dev) · line 40

Quoted 6 lines

drivers/amba/bus.c +3 -1

+                     } else
+                             break;
+             }
              table++;
      }
-

Carefull with the line removal.

Quoted 7 lines

drivers/amba/bus.c +0 -0

      return ret ? table : NULL;
 }
 

@@ -399,10 +427,22 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
                      cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
                              (i * 8);
 

drivers/amba/bus.c static int amba_device_try_add(struct amba_device *dev, struct resource *parent) · line 437

Quoted 8 lines

drivers/amba/bus.c +8 -0

+             if (cid == CORESIGHT_CID) {
+                     /* set the base to the start of the last 4k block */
+                     void __iomem *csbase = tmp + size - 4096;
+
+                     dev->uci.devarch =
+                             readl(csbase + UCI_REG_DEVARCH_OFFSET);
+                     dev->uci.devtype =
+                             readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;

Any reason for not masking @devarch the same way you're doing for @devtype? If we were to mask here we wouldn't have to carry the mask in struct amba_cs_uci_id and deal with it in amba_uci_match().

Russell King maintains AMBA. Please address your next revision to him and CC the rest of us, as specified by get_maintainer.pl.

Thanks,
Mathieu

Quoted 66 lines

drivers/amba/bus.c +5 -1

+             }
+
              amba_put_disable_pclk(dev);
 
-             if (cid == AMBA_CID || cid == CORESIGHT_CID)
+             if (cid == AMBA_CID || cid == CORESIGHT_CID) {
                      dev->periphid = pid;
+                     dev->cid = cid;
+             }
 
              if (!dev->periphid)
                      ret = -ENODEV;

include/linux/amba/bus.h +32 -0

index d143c13bed26..a83a0a3dece8 100644
@@ -25,6 +25,36 @@
 #define AMBA_CID     0xb105f00d
 #define CORESIGHT_CID        0xb105900d
 
+/*
+ * CoreSight Architecture specification updates the ID specification
+ * for components on the AMBA bus. (ARM IHI 0029E)
+ *
+ * Bits 11:8 of the CID are the device class.
+ *
+ * Class 0xF remains for PrimeCell and legacy components. (AMBA_CID above)
+ * Class 0x9 defines the component as CoreSight (CORESIGHT_CID above)
+ * Class 0x0, 0x1, 0xB, 0xE define components that do not have driver support
+ * at present.
+ * Class 0x2-0x8,0xA and 0xD-0xD are presently reserved.
+ *
+ * Remaining CID bits stay as 0xb105-00d
+ */
+
+/*
+ * Class 0x9 components use additional values to form a Unique Component
+ * Identifier (UCI), where peripheral ID values are identical for different
+ * components. Passed to the amba bus code from the component driver via
+ * the amba_id->data pointer.
+ */
+struct amba_cs_uci_id {
+     unsigned int devarch;
+     unsigned int mask;
+     unsigned int devtype;
+};
+
+#define UCI_REG_DEVTYPE_OFFSET       0xFCC
+#define UCI_REG_DEVARCH_OFFSET       0xFBC
+
 struct clk;
 
 struct amba_device {

@@ -32,6 +62,8 @@ struct amba_device {
      struct resource         res;
      struct clk              *pclk;
      unsigned int            periphid;
+     unsigned int            cid;
+     struct amba_cs_uci_id   uci;
      unsigned int            irq[AMBA_NR_IRQS];
      char                    *driver_override;
 };

@@ -61,6 +93,7 @@ enum amba_vendor {
      (((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \
      AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff))
 

Quoted 7 lines

include/linux/amba/bus.h +1 -1

+
 extern struct bus_type amba_bustype;
 
 #define to_amba_device(d)    container_of(d, struct amba_device, dev)
--

2.19.1

@devarch is defined as a 32 bit value. This is masked to widen / narrow matching. By default the mask will be the ARCHID field - bits 15:0, selected in the driver in the same way as the drivers currently have a mask for peripheral ID. This ignores the architect and version fields as most CS component drivers should handle differences.

Quoted 6 lines

@devarch is defined as a 32 bit value. This is masked to widen / narrow matching. By default the mask will be the ARCHID field - bits 15:0, selected in the driver in the same way as the drivers currently have a mask for peripheral ID. This ignores the architect and version fields as most CS component drivers should handle differences.

The architect field defines what the ARCHID field means (the ARCHID values are specific to each architect), it's not the same as the implementer field. You need to check both if you want to know what component driver to use. The correct mask for that is 0xfff0ffff.

Selecting on ARCHID alone, would only be valid if you are requiring the architect always to be ARM (0x23b) and have already checked that.

Al
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

Quoted 4 lines

The architect field defines what the ARCHID field means (the ARCHID values are specific to each architect), it's not the same as the implementer field. You need to check both if you want to know what component driver to use. The correct mask for that is 0xfff0ffff.

This is a fair point - thought at present the peripheral ID matching takes in the JDEC ID code of the component designer - in the ETM case ARM (though without a JDEC continuation code check).
Given this field too is specified as "designer not implementer", it seems logically unlikely that designer != architect.

If we did feel the need to alter the match value / mask values - this happens in the CS driver code, not in this patch - so will need to be addressed there.

Thanks

Mike

Quoted 2 lines

Al
IMPORTANT NOTICE: The contents of this email and any attachments are

confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK

Updates the ID register tables to contain a UCI entry for the A35 ETM device to allow correct matching of driver in the amba bus code.

Signed-off-by Mike Leach <[email protected]>

---
 drivers/hwtracing/coresight/coresight-etm4x.c | 26 +++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

drivers/hwtracing/coresight/coresight-etm4x.c +16 -0

index 53e2fb6e86f6..1dcb7e14ea6b 100644
@@ -1073,12 +1073,28 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 		.mask	= 0x000fffff,		\
 	}
 
+static struct amba_cs_uci_id uci_id_etm4[] = {
+	{
+		/*  ETMv4 UCI data */
+		.devarch	= 0x00004a13,
+		.mask		= 0x0000ffff,
+		.devtype	= 0x00000013,
+	}
+};
+
+#define ETM4x_AMBA_UCI_ID(pid)			\
+	{					\
+		.id	= pid,			\
+		.mask	= 0x000fffff,		\
+		.data	= uci_id_etm4,		\
+	}
+

drivers/hwtracing/coresight/coresight-etm4x.c +1 -0

+	ETM4x_AMBA_UCI_ID(0x000bb9da),			/* Cortex-A35 */
 	{},
 };
 

Signature · 1 line

2.19.1

Quoted 36 lines · Mike Leach

Updates the ID register tables to contain a UCI entry for the A35 ETM device to allow correct matching of driver in the amba bus code.

Signed-off-by Mike Leach <[email protected]>

---
 drivers/hwtracing/coresight/coresight-etm4x.c | 26 +++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

drivers/hwtracing/coresight/coresight-etm4x.c +16 -3

index 53e2fb6e86f6..1dcb7e14ea6b 100644
@@ -1073,12 +1073,28 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
              .mask   = 0x000fffff,           \
      }
 
+static struct amba_cs_uci_id uci_id_etm4[] = {
+     {
+             /*  ETMv4 UCI data */
+             .devarch        = 0x00004a13,
+             .mask           = 0x0000ffff,
+             .devtype        = 0x00000013,
+     }
+};
+
+#define ETM4x_AMBA_UCI_ID(pid)                       \
+     {                                       \
+             .id     = pid,                  \
+             .mask   = 0x000fffff,           \
+             .data   = uci_id_etm4,          \
+     }
+
 static const struct amba_id etm4_ids[] = {
-     ETM4x_AMBA_ID(0x000bb95d),              /* Cortex-A53 */
-     ETM4x_AMBA_ID(0x000bb95e),              /* Cortex-A57 */
-     ETM4x_AMBA_ID(0x000bb95a),              /* Cortex-A72 */

drivers/hwtracing/coresight/coresight-etm4x.c static int etm4_probe(struct amba_device *adev, const struct amba_id *id) · line 1096

Quoted 6 lines

drivers/hwtracing/coresight/coresight-etm4x.c +4 -2

-     ETM4x_AMBA_ID(0x000bb959),              /* Cortex-A73 */
-     ETM4x_AMBA_ID(0x000bb9da),              /* Cortex-A35 */
+     ETM4x_AMBA_ID(0x000bb95d),                      /* Cortex-A53 */
+     ETM4x_AMBA_ID(0x000bb95e),                      /* Cortex-A57 */
+     ETM4x_AMBA_ID(0x000bb95a),                      /* Cortex-A72 */
+     ETM4x_AMBA_ID(0x000bb959),                      /* Cortex-A73 */

There is no need to add the extra tabulation for the above.

Quoted 7 lines

drivers/hwtracing/coresight/coresight-etm4x.c +1 -1

+     ETM4x_AMBA_UCI_ID(0x000bb9da),                  /* Cortex-A35 */
      {},
 };
 
--

2.19.1