[PATCH v4 0/7] cpufreq support for Raspberry Pi

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: stefan.wahren@i2se.com, linux-kernel@vger.kernel.org
Cc: mbrugger@suse.de, viresh.kumar@linaro.org, rjw@rjwysocki.net,
	sboyd@kernel.org, eric@anholt.net, f.fainelli@gmail.com,
	bcm-kernel-feedback-list@broadcom.com, ptesarik@suse.com,
	linux-rpi-kernel@lists.infradead.org, ssuloev@orpaltech.com,
	linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	mturquette@baylibre.com, linux-pm@vger.kernel.org,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Subject: [PATCH v4 0/7] cpufreq support for Raspberry Pi
Date: Wed, 12 Jun 2019 20:24:52 +0200	[thread overview]
Message-ID: <20190612182500.4097-1-nsaenzjulienne@suse.de> (raw)

Hi all,
this aims at adding cpufreq support to the Raspberry Pi family of
boards.

The series first factors out 'pllb' from clk-bcm2385 and creates a new
clk driver that operates it over RPi's firmware interface[1]. We are
forced to do so as the firmware 'owns' the pll and we're not allowed to
change through the register interface directly as we might race with the
over-temperature and under-voltage protections provided by the firmware.

Next it creates a minimal cpufreq driver that populates the CPU's opp
table, and registers cpufreq-dt. Which is needed as the firmware
controls the max and min frequencies available.

This was tested on a RPi3b+ and RPI2b, both using multi_v7_defconfig and
arm64's defconfig.

That's all,
kind regards,
Nicolas

[1] https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface

---

Changes since v3:
  - Fix sparse warnings in clk-raspberrypi.c
  - Minor cleanups

Changes since v2:
  - Fixed configs to match Stefan's comments
  - Round OPP frequencies
  - Rebase onto linux-next
  - Minor cleanups & checkpatch.pl

Changes since v1:
  - Enabled by default on the whole family of devices
  - Added/Fixed module support
  - clk device now registered by firmware driver
  - raspberrypi-cpufreq device now registered by clk driver
  - Reimplemented clk rounding unsing determine_rate()
  - Enabled in configs for arm and arm64

Changes since RFC:
  - Move firmware clk device into own driver

Nicolas Saenz Julienne (7):
  clk: bcm2835: remove pllb
  clk: bcm283x: add driver interfacing with Raspberry Pi's firmware
  firmware: raspberrypi: register clk device
  cpufreq: add driver for Raspberry Pi
  clk: raspberrypi: register platform device for raspberrypi-cpufreq
  ARM: defconfig: enable cpufreq driver for RPi
  arm64: defconfig: enable cpufreq support for RPi3

 arch/arm/configs/bcm2835_defconfig    |   9 +
 arch/arm/configs/multi_v7_defconfig   |   2 +
 arch/arm64/configs/defconfig          |   2 +
 drivers/clk/bcm/Kconfig               |   7 +
 drivers/clk/bcm/Makefile              |   1 +
 drivers/clk/bcm/clk-bcm2835.c         |  28 +--
 drivers/clk/bcm/clk-raspberrypi.c     | 315 ++++++++++++++++++++++++++
 drivers/cpufreq/Kconfig.arm           |   8 +
 drivers/cpufreq/Makefile              |   1 +
 drivers/cpufreq/raspberrypi-cpufreq.c |  97 ++++++++
 drivers/firmware/raspberrypi.c        |  10 +
 11 files changed, 456 insertions(+), 24 deletions(-)
 create mode 100644 drivers/clk/bcm/clk-raspberrypi.c
 create mode 100644 drivers/cpufreq/raspberrypi-cpufreq.c

-- 
2.21.0