linux-kernel - [PATCH v5 0/2] Clock based PWM output driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220212162342.72646-1-nikita@trvn.ru>
Date:   Sat, 12 Feb 2022 21:23:40 +0500
From:   Nikita Travkin <nikita@...n.ru>
To:     thierry.reding@...il.com, lee.jones@...aro.org
Cc:     u.kleine-koenig@...gutronix.de, robh+dt@...nel.org,
        sboyd@...nel.org, krzk@...nel.org, linus.walleij@...aro.org,
        masneyb@...tation.org, sean.anderson@...o.com,
        linux-pwm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        ~postmarketos/upstreaming@...ts.sr.ht,
        Nikita Travkin <nikita@...n.ru>
Subject: [PATCH v5 0/2] Clock based PWM output driver

This series introduces an "adapter" driver that allows PWM consumers
to control clock outputs with duty-cycle control.

Some platforms (e.g. some Qualcomm chipsets) have "General Purpose"
clocks that can be muxed to GPIO outputs and used as PWM outputs.
Those outputs may be connected to various peripherals such as
leds in display backlight or haptic feedback motor driver.

To avoid re-implementing every single PWM consumer driver with clk
support (like in [1]) and don't put the burden of providing the PWM
sources on the clock drivers (as was proposed in [2]), clk based
pwm controller driver is introduced.

There is an existing driver that provides the opposite function
in drivers/clk/clk-pwm.c with a compatible "pwm-clock" so the new
driver uses the opposite naming scheme: drivers/pwm/pwm-clk.c
and compatible "clk-pwm".

Changes in v2:
 - Fix filename in the DT schema.
 - Address Uwe's review comments.
Changes in v3:
 - Fix node pattern in the core pwm schema.
 - Address Uwe's review comments.
Changes in v4:
 - Drop the (incorrect) pwm schema change.
 - Use generic node name in the dt bindings example.
Changes in v5:
 - Correct required properties.
 - add missed returns.

Nikita Travkin (2):
  dt-bindings: pwm: Document clk based PWM controller
  pwm: Add clock based PWM output driver

 .../devicetree/bindings/pwm/clk-pwm.yaml      |  46 ++++++
 drivers/pwm/Kconfig                           |  10 ++
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-clk.c                         | 139 ++++++++++++++++++
 4 files changed, 196 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/clk-pwm.yaml
 create mode 100644 drivers/pwm/pwm-clk.c

-- 
2.34.1