Merge tag 'soc-attr-updates-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/drivers

SoC attributes update for v5.9

1. Addition of ARM SMCCC ARCH_SOC_ID support
2. Usage of the custom soc attribute groups already supported in the
   infrastucture instead of device_create_file which eliminates the need
   for any cleanup when soc is unregistered
3. Minor clean up switching to use standard DEVICE_ATTR_RO() instead of
   direct __ATTR

* tag 'soc-attr-updates-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: smccc: Add ARCH_SOC_ID support
  ARM: OMAP2: Use custom soc attribute group instead of device_create_file
  ARM: OMAP2: Switch to use DEVICE_ATTR_RO()
  soc: ux500: Use custom soc attribute group instead of device_create_file
  soc: ux500: Switch to use DEVICE_ATTR_RO()
  soc: integrator: Use custom soc attribute group instead of device_create_file
  soc: integrator: Switch to use DEVICE_ATTR_RO()
  soc: realview: Use custom soc attribute group instead of device_create_file
  soc: realview: Switch to use DEVICE_ATTR_RO()

Link: https://lore.kernel.org/r/20200706165312.40697-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 30 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-soc b/Documentation/ABI/testing/sysfs-devices-soc
index ba3a3fac0ee1..ea999e292f11 100644
--- a/Documentation/ABI/testing/sysfs-devices-soc
+++ b/Documentation/ABI/testing/sysfs-devices-soc
@@ -26,6 +26,30 @@ Description:
 		Read-only attribute common to all SoCs. Contains SoC family name
 		(e.g. DB8500).
 
+		On many of ARM based silicon with SMCCC v1.2+ compliant firmware
+		this will contain the JEDEC JEP106 manufacturer’s identification
+		code. The format is "jep106:XXYY" where XX is identity code and
+		YY is continuation code.
+
+		This manufacturer’s identification code is defined by one
+		or more eight (8) bit fields, each consisting of seven (7)
+		data bits plus one (1) odd parity bit. It is a single field,
+		limiting the possible number of vendors to 126. To expand
+		the maximum number of identification codes, a continuation
+		scheme has been defined.
+
+		The specified mechanism is that an identity code of 0x7F
+		represents the "continuation code" and implies the presence
+		of an additional identity code field, and this mechanism
+		may be extended to multiple continuation codes followed
+		by the manufacturer's identity code.
+
+		For example, ARM has identity code 0x7F 0x7F 0x7F 0x7F 0x3B,
+		which is code 0x3B on the fifth 'page'. This is shortened
+		as JEP106 identity code of 0x3B and a continuation code of
+		0x4 to represent the four continuation codes preceding the
+		identity code.
+
 What:		/sys/devices/socX/serial_number
 Date:		January 2019
 contact:	Bjorn Andersson <bjorn.andersson@linaro.org>
@@ -40,6 +64,12 @@ Description:
 		Read-only attribute supported by most SoCs. In the case of
 		ST-Ericsson's chips this contains the SoC serial number.
 
+		On many of ARM based silicon with SMCCC v1.2+ compliant firmware
+		this will contain the SOC ID appended to the family attribute
+		to ensure there is no conflict in this namespace across various
+		vendors. The format is "jep106:XXYY:ZZZZ" where XX is identity
+		code, YY is continuation code and ZZZZ is the SOC ID.
+
 What:		/sys/devices/socX/revision
 Date:		January 2012
 contact:	Lee Jones <lee.jones@linaro.org>