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Revision 8e37395c3a5dceff62a5010ebbbc107f4145935c authored by Linus Torvalds on 20 October 2021, 16:13:22 UTC, committed by Linus Torvalds on 20 October 2021, 16:13:22 UTC 
Merge tag 'sound-5.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
 
Pull sound fixes from Takashi Iwai:
 "Again it became bigger than wished, unfortunately, as this contains
  quite a few ASoC fixes that came up a bit late. It also includes yet
  more HD- and USB-audio quirks: I decided to merge them now, as those
  are for stable, and we'll need them sooner or later.

  Although the volumes are a bit high, all changes are device-specific
  (and reasonably small) fixes, so it should be safe for the late rc"

* tag 'sound-5.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Fix microphone sound on Jieli webcam.
  ALSA: hda/realtek: Fixes HP Spectre x360 15-eb1xxx speakers
  ALSA: usb-audio: Provide quirk for Sennheiser GSP670 Headset
  ALSA: hda/realtek: Add quirk for Clevo PC50HS
  ALSA: usb-audio: add Schiit Hel device to quirk table
  ASoC: wm8960: Fix clock configuration on slave mode
  ASoC: cs42l42: Ensure 0dB full scale volume is used for headsets
  ASoC: soc-core: fix null-ptr-deref in snd_soc_del_component_unlocked()
  ASoC: codec: wcd938x: Add irq config support
  ASoC: DAPM: Fix missing kctl change notifications
  ASoC: Intel: bytcht_es8316: Utilize dev_err_probe() to avoid log saturation
  ASoC: Intel: bytcht_es8316: Switch to use gpiod_get_optional()
  ASoC: Intel: bytcht_es8316: Use temporary variable for struct device
  ASoC: Intel: bytcht_es8316: Get platform data via dev_get_platdata()
  ASoC: wcd938x: Fix jack detection issue
  ASoC: nau8824: Fix headphone vs headset, button-press detection no longer working
  ASoC: cs4341: Add SPI device ID table
  ASoC: pcm179x: Add missing entries SPI to device ID table
  ASoC: fsl_xcvr: Fix channel swap issue with ARC
  ASoC: pcm512x: Mend accesses to the I2S_1 and I2S_2 registers
2 parent s 6da52de + 2966492
Raw File
sbrmi.rst 
.. SPDX-License-Identifier: GPL-2.0-or-later

Kernel driver sbrmi
===================

Supported hardware:

  * Sideband Remote Management Interface (SB-RMI) compliant AMD SoC
    device connected to the BMC via the APML.

    Prefix: 'sbrmi'

    Addresses scanned: This driver doesn't support address scanning.

    To instantiate this driver on an AMD CPU with SB-RMI
    support, the i2c bus number would be the bus connected from the board
    management controller (BMC) to the CPU.
    The SMBus address is really 7 bits. Some vendors and the SMBus
    specification show the address as 8 bits, left justified with the R/W
    bit as a write (0) making bit 0. Some vendors use only the 7 bits
    to describe the address.
    As mentioned in AMD's APML specification, The SB-RMI address is
    normally 78h(0111 100W) or 3Ch(011 1100) for socket 0 and 70h(0111 000W)
    or 38h(011 1000) for socket 1, but it could vary based on hardware
    address select pins.

    Datasheet: The SB-RMI interface and protocol along with the Advanced
               Platform Management Link (APML) Specification is available
               as part of the open source SoC register reference at:

               https://www.amd.com/en/support/tech-docs?keyword=55898

Author: Akshay Gupta <akshay.gupta@amd.com>

Description
-----------

The APML provides a way to communicate with the SB Remote Management interface
(SB-RMI) module from the external SMBus master that can be used to report socket
power on AMD platforms using mailbox command and resembles a typical 8-pin remote
power sensor's I2C interface to BMC.

This driver implements current power with power cap and power cap max.

sysfs-Interface
---------------
Power sensors can be queried and set via the standard ``hwmon`` interface
on ``sysfs``, under the directory ``/sys/class/hwmon/hwmonX`` for some value
of ``X`` (search for the ``X`` such that ``/sys/class/hwmon/hwmonX/name`` has
content ``sbrmi``)

================ ===== ========================================================
Name             Perm   Description
================ ===== ========================================================
power1_input     RO    Current Power consumed
power1_cap       RW    Power limit can be set between 0 and power1_cap_max
power1_cap_max   RO    Maximum powerlimit calculated and reported by the SMU FW
================ ===== ========================================================

The following example show how the 'Power' attribute from the i2c-addresses
can be monitored using the userspace utilities like ``sensors`` binary::

  # sensors
  sbrmi-i2c-1-38
  Adapter: bcm2835 I2C adapter
  power1:       61.00 W (cap = 225.00 W)

  sbrmi-i2c-1-3c
  Adapter: bcm2835 I2C adapter
  power1:       28.39 W (cap = 224.77 W)
  #

Also, Below shows how get and set the values from sysfs entries individually::
  # cat /sys/class/hwmon/hwmon1/power1_cap_max
  225000000

  # echo 180000000 > /sys/class/hwmon/hwmon1/power1_cap
  # cat /sys/class/hwmon/hwmon1/power1_cap
  180000000
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