ARM: 8838/1: drivers: amba: Updates to component identification for driver matching.

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 15:12 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.

This patch introduces the amba_cs_uci_id structure which will be used in
all coresight drivers for indentification via the private data pointer in
the amba_id structure.

Existing drivers that currently use the amba_id->data pointer for private
data are updated to use the amba_cs_uci_id->data pointer. Macros and
inline functions are added to simplify this code.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index d143c13bed26..e3c36223e40b 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -25,6 +25,39 @@
 #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 15:12 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.
+ * @devarch	: coresight devarch register value
+ * @devarch_mask: mask bits used for matching. 0 indicates UCI not used.
+ * @devtype	: coresight device type value
+ * @data	: additional driver data. As we have usurped the original
+ *		pointer some devices may still need additional data
+ */
+struct amba_cs_uci_id {
+	unsigned int devarch;
+	unsigned int devarch_mask;
+	unsigned int devtype;
+	void *data;
+};
+
 struct clk;
 
 struct amba_device {