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{ "id": 2227082, "url": "http://patchwork.ozlabs.org/api/covers/2227082/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pwm/cover/cover.1776932336.git.andrea.porta@suse.com/", "project": { "id": 38, "url": "http://patchwork.ozlabs.org/api/projects/38/?format=api", "name": "Linux PWM development", "link_name": "linux-pwm", "list_id": "linux-pwm.vger.kernel.org", "list_email": "linux-pwm@vger.kernel.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<cover.1776932336.git.andrea.porta@suse.com>", "list_archive_url": null, "date": "2026-04-23T08:30:18", "name": "[v3,0/3] Add RP1 PWM controller support", "submitter": { "id": 88172, "url": "http://patchwork.ozlabs.org/api/people/88172/?format=api", "name": "Andrea della Porta", "email": "andrea.porta@suse.com" }, "mbox": "http://patchwork.ozlabs.org/project/linux-pwm/cover/cover.1776932336.git.andrea.porta@suse.com/mbox/", "series": [ { "id": 501159, "url": "http://patchwork.ozlabs.org/api/series/501159/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pwm/list/?series=501159", "date": "2026-04-23T08:30:20", "name": "Add RP1 PWM controller support", "version": 3, "mbox": "http://patchwork.ozlabs.org/series/501159/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2227082/comments/", "headers": { "Return-Path": "\n <linux-pwm+bounces-8672-incoming=patchwork.ozlabs.org@vger.kernel.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linux-pwm@vger.kernel.org" ], "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=suse.com header.i=@suse.com header.a=rsa-sha256\n header.s=google header.b=ESfXel+i;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; 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This is necessary to operate the\ncooling fan connected to one of the PWM channels.\n\nThe tachometer pin for the fan speed is managed by the firmware \nrunning on the RP1's M-core. It uses the PHASE2 register\nto report the RPM, which is then exported by this driver via\nsyscon registers. A subsequent patch will add a new device\nand driver to read the RPM and export this value via hwmon.\n \nSubsequent patches will also add the CPU thermal zone, which\nacts as a consumer of the PWM device.\n\nBest regards,\nAndrea\n\nCHANGES in V3:\n\n- Refactored all the register macros. They now have RP1_PWM_ prefix\n and follow the register name.\n- Dropped the tab alignment in front of struct declarations (use a space\n instead).\n- Added a check in tohw() to test (and bail out quickly) in case that\n period_length_ns is zero.\n- Probing now returns an error if clk_rate > 1 GHz.\n- Added a check on minimum period ticks. Return 1 to signal round-up.\n- Fixed inverted polarity detection on edge cases.\n- Fixed rounding errors (in both tohwi() and fromhw()) in inverted\n polarity calculations.\n- Dropped a redundant check on period >= duty.\n- Replaced memset by inline struct init.\n- Disabling a channel now is faster, skipping the duty/period/polarity\n setup.\n- Fixed an error string (s/Fail/Failed)\n- Used %pe to signal error string instead of an integer.\n- Added several new sections to the Limitations paragraph to better\n explain what will happen on edge cases.\n- Maximum period is now U32_MAX-1 to allow 100% duty cycle on all\n selectable periods.\n- The hw period register now takes into account for the extra tick at\n the end of the period (subtracted one to wfhw->period_ticks in tohw\n and added 1 in fromhw).\n- Added .remove() callback to free resources even if the driver is\n not unbindable/unloadable, to avoid accumulating tech debt.\n\n\nNaushir Patuck (2):\n dt-bindings: pwm: Add Raspberry Pi RP1 PWM controller\n pwm: rp1: Add RP1 PWM controller driver\n\nStanimir Varbanov (1):\n arm64: dts: broadcom: rpi-5: Add RP1 PWM node\n\n .../bindings/pwm/raspberrypi,rp1-pwm.yaml | 54 +++\n .../boot/dts/broadcom/bcm2712-rpi-5-b.dts | 12 +\n arch/arm64/boot/dts/broadcom/rp1-common.dtsi | 10 +\n drivers/pwm/Kconfig | 9 +\n drivers/pwm/Makefile | 1 +\n drivers/pwm/pwm-rp1.c | 414 ++++++++++++++++++\n 6 files changed, 500 insertions(+)\n create mode 100644 Documentation/devicetree/bindings/pwm/raspberrypi,rp1-pwm.yaml\n create mode 100644 drivers/pwm/pwm-rp1.c" }