From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5E2411FBCA7; Thu, 5 Mar 2026 19:48:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772740084; cv=none; b=rXMXZrjh/FyHaeWnrbTsywyyPc2tN5xsiDH62JHwZti0OC24cXLhmsYVoWQcZX6MRrgImvIC5TPX+L57lNIs07ltibU3p+HK6YthG5VW75amuz/5aMz7ZYbYquM+es8MFk9nNmheu4or3Xs4hEatqLLHUhTMiyuBxV0Titu+UvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772740084; c=relaxed/simple; bh=wZTLuyIEzm0W/hvy9SmyHAmJORCVKTwCpy+lEu9Hxfg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jEOJjb7/qIts5WO9pe0/bk1oiStb9OtEusaSLlsQTGmvfaREGlkt5ujNUmtk3xDZ9wupZmE8Zoc6NMcsVByDsRTuaztVFFsi63aQMJ1PTCsmbullYUs4SVieiXD09BUQm9W49ZLBkfape4UXlcY5ubR0CiAysOAyiUTObsyL+wk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N6fv/+UF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N6fv/+UF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1860AC116C6; Thu, 5 Mar 2026 19:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772740083; bh=wZTLuyIEzm0W/hvy9SmyHAmJORCVKTwCpy+lEu9Hxfg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N6fv/+UF75GoUFJmF74hgsDzLXFIS6z5CTRJbvXHJ3Qi6dnVI9ZIZI15mMR1PBZbp hPo6ckU1c0azIoJ0f4lT8pvUqO+jZrkKrGCYGnWpsxbTkMjxSSPIaihdConMSSy9Ex 95cDP/hjRfj9JVk9NGDOWaxXwD+wI17AdMl+SRO4LabN7mPSmTCGApI04oeGGp0/BF IkuZ1GSs+ec9q/jV0/sNqZhjeR1eORpmPiEYe2DUMCWzMCfc7A4dWPTqJ/1hXb+mFZ kx0DsiNRvA6ay/h3kqQkAEPMMNHXl1Bnn+YHZHXSWV3oa+MoDfg5pJGWWXnj/nOGTj YUQnM69ICR1Vw== From: "Rafael J. Wysocki" To: Tzung-Bi Shih Cc: chrome-platform@lists.linux.dev, LKML , Linux ACPI , Benson Leung , Enric Balletbo i Serra , Ravi Chandra Sadineni Subject: [PATCH v2 6/6] platform/chrome: wilco_ec: event: Convert to a platform driver Date: Thu, 05 Mar 2026 20:46:19 +0100 Message-ID: <9600287.CDJkKcVGEf@rafael.j.wysocki> Organization: Linux Kernel Development In-Reply-To: <6259948.lOV4Wx5bFT@rafael.j.wysocki> References: <6259948.lOV4Wx5bFT@rafael.j.wysocki> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="UTF-8" From: "Rafael J. Wysocki" In all cases in which a struct acpi_driver is used for binding a driver to an ACPI device object, a corresponding platform device is created by the ACPI core and that device is regarded as a proper representation of underlying hardware. Accordingly, a struct platform_driver should be used by driver code to bind to that device. There are multiple reasons why drivers should not bind directly to ACPI device objects [1]. Overall, it is better to bind drivers to platform devices than to their ACPI companions, so convert the ChromeOS Wilco Embedded Controller event ACPI driver to a platform one. While this is not expected to alter functionality, it changes sysfs layout and so it will be visible to user space. Link: https://lore.kernel.org/all/2396510.ElGaqSPkdT@rafael.j.wysocki/ [1] Signed-off-by: Rafael J. Wysocki --- v1 -> v2: No changes --- drivers/platform/chrome/wilco_ec/event.c | 66 ++++++++++++------------ 1 file changed, 34 insertions(+), 32 deletions(-) diff --git a/drivers/platform/chrome/wilco_ec/event.c b/drivers/platform/chrome/wilco_ec/event.c index f4500dd05f93..b6e935badc0e 100644 --- a/drivers/platform/chrome/wilco_ec/event.c +++ b/drivers/platform/chrome/wilco_ec/event.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include #include @@ -198,7 +199,7 @@ struct event_device_data { /** * enqueue_events() - Place EC events in queue to be read by userspace. - * @adev: Device the events came from. + * @dev: Device the events came from. * @buf: Buffer of event data. * @length: Length of event data buffer. * @@ -209,9 +210,9 @@ struct event_device_data { * * Return: 0 on success or negative error code on failure. */ -static int enqueue_events(struct acpi_device *adev, const u8 *buf, u32 length) +static int enqueue_events(struct device *dev, const u8 *buf, u32 length) { - struct event_device_data *dev_data = adev->driver_data; + struct event_device_data *dev_data = dev_get_drvdata(dev); struct ec_event *event, *queue_event, *old_event; size_t num_words, event_size; u32 offset = 0; @@ -222,14 +223,14 @@ static int enqueue_events(struct acpi_device *adev, const u8 *buf, u32 length) num_words = ec_event_num_words(event); event_size = ec_event_size(event); if (num_words > EC_ACPI_MAX_EVENT_WORDS) { - dev_err(&adev->dev, "Too many event words: %zu > %d\n", + dev_err(dev, "Too many event words: %zu > %d\n", num_words, EC_ACPI_MAX_EVENT_WORDS); return -EOVERFLOW; } /* Ensure event does not overflow the available buffer */ if ((offset + event_size) > length) { - dev_err(&adev->dev, "Event exceeds buffer: %zu > %d\n", + dev_err(dev, "Event exceeds buffer: %zu > %d\n", offset + event_size, length); return -EOVERFLOW; } @@ -262,12 +263,13 @@ static int enqueue_events(struct acpi_device *adev, const u8 *buf, u32 length) static void event_device_notify(acpi_handle handle, u32 value, void *data) { struct acpi_buffer event_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; - struct acpi_device *adev = data; + struct device *dev = data; + struct acpi_device *adev = ACPI_COMPANION(dev); union acpi_object *obj; acpi_status status; if (value != EC_ACPI_NOTIFY_EVENT) { - dev_err(&adev->dev, "Invalid event: 0x%08x\n", value); + dev_err(dev, "Invalid event: 0x%08x\n", value); return; } @@ -275,31 +277,31 @@ static void event_device_notify(acpi_handle handle, u32 value, void *data) status = acpi_evaluate_object(adev->handle, EC_ACPI_GET_EVENT, NULL, &event_buffer); if (ACPI_FAILURE(status)) { - dev_err(&adev->dev, "Error executing ACPI method %s()\n", + dev_err(dev, "Error executing ACPI method %s()\n", EC_ACPI_GET_EVENT); return; } obj = (union acpi_object *)event_buffer.pointer; if (!obj) { - dev_err(&adev->dev, "Nothing returned from %s()\n", + dev_err(dev, "Nothing returned from %s()\n", EC_ACPI_GET_EVENT); return; } if (obj->type != ACPI_TYPE_BUFFER) { - dev_err(&adev->dev, "Invalid object returned from %s()\n", + dev_err(dev, "Invalid object returned from %s()\n", EC_ACPI_GET_EVENT); kfree(obj); return; } if (obj->buffer.length < sizeof(struct ec_event)) { - dev_err(&adev->dev, "Invalid buffer length %d from %s()\n", + dev_err(dev, "Invalid buffer length %d from %s()\n", obj->buffer.length, EC_ACPI_GET_EVENT); kfree(obj); return; } - enqueue_events(adev, obj->buffer.pointer, obj->buffer.length); + enqueue_events(dev, obj->buffer.pointer, obj->buffer.length); kfree(obj); } @@ -434,8 +436,8 @@ static void hangup_device(struct event_device_data *dev_data) } /** - * event_device_add() - Callback when creating a new device. - * @adev: ACPI device that we will be receiving events from. + * event_device_probe() - Callback when creating a new device. + * @pdev: Platform device that we will be receiving events from. * * This finds a free minor number for the device, allocates and initializes * some device data, and creates a new device and char dev node. @@ -447,7 +449,7 @@ static void hangup_device(struct event_device_data *dev_data) * * Return: 0 on success, negative error code on failure. */ -static int event_device_add(struct acpi_device *adev) +static int event_device_probe(struct platform_device *pdev) { struct event_device_data *dev_data; int error, minor; @@ -455,7 +457,7 @@ static int event_device_add(struct acpi_device *adev) minor = ida_alloc_max(&event_ida, EVENT_MAX_DEV-1, GFP_KERNEL); if (minor < 0) { error = minor; - dev_err(&adev->dev, "Failed to find minor number: %d\n", error); + dev_err(&pdev->dev, "Failed to find minor number: %d\n", error); return error; } @@ -466,7 +468,7 @@ static int event_device_add(struct acpi_device *adev) } /* Initialize the device data. */ - adev->driver_data = dev_data; + platform_set_drvdata(pdev, dev_data); dev_data->events = event_queue_new(queue_size); if (!dev_data->events) { kfree(dev_data); @@ -492,8 +494,9 @@ static int event_device_add(struct acpi_device *adev) goto free_dev_data; /* Install an ACPI notify handler. */ - error = acpi_dev_install_notify_handler(adev, ACPI_DEVICE_NOTIFY, - event_device_notify, adev); + error = acpi_dev_install_notify_handler(ACPI_COMPANION(&pdev->dev), + ACPI_DEVICE_NOTIFY, + event_device_notify, &pdev->dev); if (error) goto free_cdev; @@ -508,12 +511,12 @@ static int event_device_add(struct acpi_device *adev) return error; } -static void event_device_remove(struct acpi_device *adev) +static void event_device_remove(struct platform_device *pdev) { - struct event_device_data *dev_data = adev->driver_data; + struct event_device_data *dev_data = platform_get_drvdata(pdev); - acpi_dev_remove_notify_handler(adev, ACPI_DEVICE_NOTIFY, - event_device_notify); + acpi_dev_remove_notify_handler(ACPI_COMPANION(&pdev->dev), + ACPI_DEVICE_NOTIFY, event_device_notify); cdev_device_del(&dev_data->cdev, &dev_data->dev); ida_free(&event_ida, MINOR(dev_data->dev.devt)); hangup_device(dev_data); @@ -525,13 +528,12 @@ static const struct acpi_device_id event_acpi_ids[] = { }; MODULE_DEVICE_TABLE(acpi, event_acpi_ids); -static struct acpi_driver event_driver = { - .name = DRV_NAME, - .class = DRV_NAME, - .ids = event_acpi_ids, - .ops = { - .add = event_device_add, - .remove = event_device_remove, +static struct platform_driver event_driver = { + .probe = event_device_probe, + .remove = event_device_remove, + .driver = { + .name = DRV_NAME, + .acpi_match_table = event_acpi_ids, }, }; @@ -554,7 +556,7 @@ static int __init event_module_init(void) } event_major = MAJOR(dev_num); - ret = acpi_bus_register_driver(&event_driver); + ret = platform_driver_register(&event_driver); if (ret < 0) { pr_err(DRV_NAME ": Failed registering driver: %d\n", ret); goto unregister_region; @@ -572,7 +574,7 @@ static int __init event_module_init(void) static void __exit event_module_exit(void) { - acpi_bus_unregister_driver(&event_driver); + platform_driver_unregister(&event_driver); unregister_chrdev_region(MKDEV(event_major, 0), EVENT_MAX_DEV); class_unregister(&event_class); ida_destroy(&event_ida); -- 2.51.0