Commit Graph

26 Commits

Author SHA1 Message Date
Akshay Gupta
eef2a8ddfa misc: amd-sbi: Add device tree mapping for AMD SBRMI devices
Add device tree mapping to enable SBRMI device support across
different models and steppings on the AMD Venice platform.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com>
Link: https://patch.msgid.link/20260318112711.2757467-3-Akshay.Gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-02 16:17:29 +02:00
Akshay Gupta
82e1288701 misc: amd-sbi: Add check to probe only SBRMI devices
AMD OOB devices are differentiated by their Instance ID, with SBRMI
assigned Instance ID 1. Since the device ID match does not consider
the Instance ID, add an explicit check to restrict probing to only
the SBRMI device and exclude other OOB devices.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com>
Link: https://patch.msgid.link/20260318112711.2757467-2-Akshay.Gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-02 16:17:29 +02:00
Akshay Gupta
b5e7fb3981 misc: amd-sbi: Add revision support for AMD Venice platform
The AMD Venice platform uses revision 0x31 and a two-byte register
address size. Add the revision to the CPUID and MCAMSR protocol
functions to ensure correct protocol identification.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com>
Link: https://patch.msgid.link/20260318112711.2757467-1-Akshay.Gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-02 16:17:29 +02:00
Akshay Gupta
ac7460c603 misc: amd-sbi: Address CPUID extended function bits
According to the UAPI header (amd-apml.h), the CPUID extended function
capability is indicated by bits [55:48], but the driver currently
checks bits [63:56]. Adjust the driver to use bits [55:48] so that
extended function capability is detected correctly.

Fixes: bb13a84ed6 ("misc: amd-sbi: Add support for CPUID protocol")
Tested-by: Prathima L K <Prathima.Lk@amd.com>
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com>
Link: https://patch.msgid.link/20260318094706.2623258-1-Akshay.Gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-02 16:17:25 +02:00
Arnd Bergmann
663eb8763c i3c: simplify combined i3c/i2c dependencies
All combined i2c/i3c drivers appear to suffer from the same link
time problem when CONFIG_I3C is set to 'm':

arm-linux-gnueabi-ld: drivers/iio/magnetometer/mmc5633.o: in function `mmc5633_i3c_driver_init':
mmc5633.c:(.init.text+0x30): undefined reference to `i3c_driver_register_with_owner'

This was previously fixed every time by marking individual
drivers as 'depends on I2C; depends on I3C || !I3C', but this gets
tedious and is somewhat confusing.

Add a Kconfig symbol 'I3C_OR_I2C' to help replace those dependencies,
and use this in all the existing drivers that had already fixed it
as well as the new mmc5633 driver.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260204164216.544409-1-arnd@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-02-27 16:33:07 +01:00
Greg Kroah-Hartman
c428900703 Merge 6.18-rc3 into char-misc-next
We need the fixes in here, and it resolves a merge conflict in:
	drivers/misc/amd-sbi/Kconfig

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-27 07:48:19 +01:00
Jean Delvare
70ad06df73 misc: amd-sbi: Clarify that this is a BMC driver
Add a sentence to the driver description to clarify that the sbrmi-i2c
driver is intended to run on the BMC and not on the managed node. Add
platform dependencies accordingly.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Link: https://lore.kernel.org/r/5c9f7100-0e59-4237-a252-43c3ee4802a2@amd.com
Link: https://patch.msgid.link/20251016155040.0e86c102@endymion
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 08:02:57 +02:00
Akshay Gupta
18e4a02963 misc: amd-sbi: Extend support for MCAMSR protocol for rev 0x21
- MCAMSR protocol for revision 0x21 is updated to include the
  extended thread supported by the platform.
- This modifies the existing protocol to include additional byte
  to provide high thread number.
- New input structure is defined to address this, as the hardware
  protocol is tightly coupled with the input structure length

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-6-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Akshay Gupta
87816eb470 misc: amd-sbi: Extend support for CPUID protocol for rev 0x21
- CPUID protocol for revision 0x21 is updated to include the
  extended thread supported by the platform.
- This modifies the existing protocol to include additional byte
  to provide high thread number.
- New input structure is defined to address this, as the hardware
  protocol is tightly coupled with the input structure length

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-5-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Akshay Gupta
dd68c06380 misc: amd-sbi: CPUID/MCAMSR protocol for Revision 0x21
- CPUID and MCAMSR protocol for newer platform with revision
  0x21 and later is modified as per two byte register address size.
- Modify the CPUID and MCAMSR protocol to return error, "-EOPNOTSUPP",
  for revision 0x21.
- Next set of patches will add support for CPUID and MCAMSR for Turin and
  later platforms.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-4-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Akshay Gupta
45392fd439 misc: amd-sbi: Add support for Turin platform
- RMI registers addresses in AMD new platforms are 2 bytes,
  on previous processors the address size is 1 byte.
- Implement logic to identify register address size at runtime.
- The identification is done in first transaction using the
  Revision register.
- The revision register can be read using 1 byte in both, older and
  newer platforms.
- However, sending 1 byte on later platform can cause unrecoverable error.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-3-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Akshay Gupta
5c7dddd736 misc: amd-sbi: Add support for SB-RMI over I3C
AMD EPYC platforms with zen5 and later support APML(SB-RMI)
connection to the BMC over I3C bus for faster data transfer
up to 12.5 Mhz.
I2C and I3C is supported in same file using module_i3c_i2c_driver()
with probe based on dts entry.
AMD APML I3C devices support static address for backward compatibility to I2C.
I3C static address can be used to assign I3C device dynamic address.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-2-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Akshay Gupta
b9a7c95991 misc: amd-sbi: Add helper function to prepare I3C support
New AMD processors support APML connection over I3C.
Move the code, common for both I2C and I3C to new helper
function, "sbrmi_common_probe()"
While at it, renaming the static structure regmap_config "sbrmi_i2c_regmap_config"
to "sbrmi_regmap_config" to avoid confusion.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://patch.msgid.link/20250915103649.1705078-1-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-22 07:59:57 +02:00
Max Kellermann
5f8f84e286 drivers/misc/amd-sbi/Kconfig: select REGMAP_I2C
Without CONFIG_REGMAP, rmi-i2c.c fails to build because struct
regmap_config is not defined:

 drivers/misc/amd-sbi/rmi-i2c.c: In function ‘sbrmi_i2c_probe’:
 drivers/misc/amd-sbi/rmi-i2c.c:57:16: error: variable ‘sbrmi_i2c_regmap_config’ has initializer but incomplete type
    57 |         struct regmap_config sbrmi_i2c_regmap_config = {
       |                ^~~~~~~~~~~~~

Additionally, CONFIG_REGMAP_I2C is needed for devm_regmap_init_i2c():

 ld: drivers/misc/amd-sbi/rmi-i2c.o: in function `sbrmi_i2c_probe':
 drivers/misc/amd-sbi/rmi-i2c.c:69:(.text+0x1c0): undefined reference to `__devm_regmap_init_i2c'

Fixes: 013f7e7131 ("misc: amd-sbi: Use regmap subsystem")
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Tested-by: Akshay Gupta <Akshay.Gupta@amd.com>
Reviewed-by: Akshay Gupta <Akshay.Gupta@amd.com>
Link: https://lore.kernel.org/r/20250829091442.1112106-1-max.kellermann@ionos.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-06 16:00:50 +02:00
Akshay Gupta
16ad3ee51f misc: amd-sbi: Explicitly clear in/out arg "mb_in_out"
- New AMD processor will support different input/output for same command.
- In some scenarios the input value is not cleared, which will be added to
  output before reporting the data.
- Clearing input explicitly will be a cleaner and safer approach.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250716110729.2193725-3-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16 15:02:45 +02:00
Akshay Gupta
bbb4013947 misc: amd-sbi: Address copy_to/from_user() warning reported in smatch
Smatch warnings are reported for below commit,

Commit bb13a84ed6 ("misc: amd-sbi: Add support for CPUID protocol")
from Apr 28, 2025 (linux-next), leads to the following Smatch static
checker warning:

drivers/misc/amd-sbi/rmi-core.c:376 apml_rmi_reg_xfer() warn: maybe return -EFAULT instead of the bytes remaining?
drivers/misc/amd-sbi/rmi-core.c:394 apml_mailbox_xfer() warn: maybe return -EFAULT instead of the bytes remaining?
drivers/misc/amd-sbi/rmi-core.c:411 apml_cpuid_xfer() warn: maybe return -EFAULT instead of the bytes remaining?
drivers/misc/amd-sbi/rmi-core.c:428 apml_mcamsr_xfer() warn: maybe return -EFAULT instead of the bytes remaining?

copy_to/from_user() returns number of bytes, not copied.
In case data not copied, return "-EFAULT".
Additionally, fixes the "-EPROTOTYPE" error return as intended.

Fixes: 35ac2034db ("misc: amd-sbi: Add support for AMD_SBI IOCTL")
Fixes: bb13a84ed6 ("misc: amd-sbi: Add support for CPUID protocol")
Fixes: 69b1ba83d2 ("misc: amd-sbi: Add support for read MCA register protocol")
Fixes: cf141287b7 ("misc: amd-sbi: Add support for register xfer")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/aDVyO8ByVsceybk9@stanley.mountain/
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250716110729.2193725-2-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16 15:02:45 +02:00
Akshay Gupta
e108b0a5d3 misc: amd-sbi: Address potential integer overflow issue reported in smatch
Smatch warnings are reported for below commit,

Commit bb13a84ed6 ("misc: amd-sbi: Add support for CPUID protocol")
from Apr 28, 2025 (linux-next), leads to the following Smatch static
checker warning:

drivers/misc/amd-sbi/rmi-core.c:132 rmi_cpuid_read() warn: bitwise OR is zero '0xffffffff00000000 & 0xffff'
drivers/misc/amd-sbi/rmi-core.c:132 rmi_cpuid_read() warn: potential integer overflow from user 'msg->cpu_in_out << 32'
drivers/misc/amd-sbi/rmi-core.c:213 rmi_mca_msr_read() warn: bitwise OR is zero '0xffffffff00000000 & 0xffff'
drivers/misc/amd-sbi/rmi-core.c:213 rmi_mca_msr_read() warn: potential integer overflow from user 'msg->mcamsr_in_out << 32'

CPUID & MCAMSR thread data from input is available at byte 4 & 5, this
patch fixes to copy the user data correctly in the argument.
Previously, CPUID and MCAMSR data is return only for thread 0.

Fixes: bb13a84ed6 ("misc: amd-sbi: Add support for CPUID protocol")
Fixes: 69b1ba83d2 ("misc: amd-sbi: Add support for read MCA register protocol")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/aDVyO8ByVsceybk9@stanley.mountain/
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250716110729.2193725-1-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-16 15:02:45 +02:00
Akshay Gupta
cf141287b7 misc: amd-sbi: Add support for register xfer
- Provide user register access over IOCTL.
  Both register read and write are supported.
- APML interface does not provide a synchronization method. By defining,
  a register access path, we use APML modules and library for
  all APML transactions. Without having to use external tools such as
  i2c-tools, which may cause race conditions.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-10-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:41 +02:00
Akshay Gupta
69b1ba83d2 misc: amd-sbi: Add support for read MCA register protocol
- AMD provides custom protocol to read Machine Check Architecture(MCA)
  registers over sideband. The information is accessed for range of
  MCA registers by passing register address and thread ID to the protocol.
  MCA register read command using the register address to access
  Core::X86::Msr::MCG_CAP which determines the number of MCA banks.
  Access is read-only

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-9-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:41 +02:00
Akshay Gupta
bb13a84ed6 misc: amd-sbi: Add support for CPUID protocol
- AMD provides custom protocol to read Processor feature
  capabilities and configuration information through side band.
  The information is accessed by providing CPUID Function,
  extended function and thread ID to the protocol.
  Undefined function returns 0.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-8-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
35ac2034db misc: amd-sbi: Add support for AMD_SBI IOCTL
The present sbrmi module only support reporting power via hwmon.
However, AMD data center range of processors support various
system management functionality using custom protocols defined in
Advanced Platform Management Link (APML) specification.

Register a miscdevice, which creates a device /dev/sbrmiX with an IOCTL
interface for the user space to invoke the APML Mailbox protocol, which
is already defined in sbrmi_mailbox_xfer().

The APML protocols depend on a set of RMI registers. Having an IOCTL
as a single entry point will help in providing synchronization among
these protocols as multiple transactions on RMI register set may
create race condition.
Support for other protocols will be added in subsequent patches.

APML mailbox protocol returns additional error codes written by
SMU firmware in the out-bound register 0x37. These errors include,
invalid core, message not supported over platform and
others. This additional error codes can be used to provide more
details to user space.

Open-sourced and widely used https://github.com/amd/esmi_oob_library
will continue to provide user-space programmable API.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-7-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
587d2c6251 misc: amd-sbi: Optimize the wait condition for mailbox command completion
- optimize the wait condition to indicate command completion
  by replacing the do while loop with regmap subsystem API
  regmap_read_poll_timeout()

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-6-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
013f7e7131 misc: amd-sbi: Use regmap subsystem
- regmap subsystem provides multiple benefits over direct smbus APIs
- subsystem adds another abstraction layer on top of struct i2c_client to
  make it easy to read or write registers.
- The subsystem can be helpful in following cases
  - Different types of bus (i2c/i3c), we have plans to support i3c.
  - Different Register address size (1byte/2byte)

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-5-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
f4dc640663 misc: amd-sbi: Move hwmon device sensor as separate entity
- Move hwmon device sensor to misc as only power is reported through
  hwmon sensor.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-4-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
43470595e7 misc: amd-sbi: Move protocol functionality to core file
- This is done to utilize the protocol functionality into
  other domains.
- Increase the scalability of the module with different bus(i2c/i3c)

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-3-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Akshay Gupta
e156586764 hwmon/misc: amd-sbi: Move core sbrmi from hwmon to misc
This is done to support other functionality provided by the SBRMI, which
does not fit in the hwmon subsystem.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20250428063034.2145566-2-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00