From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 980ACC636CD for ; Fri, 10 Feb 2023 08:04:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2A27710EC8D; Fri, 10 Feb 2023 08:04:09 +0000 (UTC) Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by gabe.freedesktop.org (Postfix) with ESMTPS id A8E5710EC55 for ; Fri, 10 Feb 2023 04:51:07 +0000 (UTC) Received: by mail-pg1-x530.google.com with SMTP id s8so2950917pgg.11 for ; Thu, 09 Feb 2023 20:51:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=tEls10WodkspsIvZIvxa4LCxo5R1yCy5xPl31tNRCfY=; b=AI5OkR5ngOdIYwA82Bd2NHyMJ+O2BLu1AlHUiAUk5u2mES8050ILPnIi34V/HwnVmn UCnnl/NNHpnSFBN3X0R580Y09W5YGDjQXorCqi2JWHAwRM3mAVXKAyPB7q7B66d3DoWt zBvfn3AmAyRezdi5kNYRSaoRxCZe3u4hC11prURWNE0PK6ZNCw5117fr7UHA3ZhhHI6z ua9y3dmza6fdLajFD3iCgQy+ca3vadxm1QgxmG6b53N46lfItM+tP6BzFu/BuB6LbEC1 2TmnClABN6Fxc12v6c0kbWm8LL7Al2NDRYIr/vhwsP9jpjc8vOPXdePVWan8RRrIxgG1 ma/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tEls10WodkspsIvZIvxa4LCxo5R1yCy5xPl31tNRCfY=; b=kqRLmxJ4wx1DKNnHF7V8btSeHYW0QytMxwCHBaVtXqrA4ysYTUfh1ETM/vrFuh5xB/ 8YGlcMowJHXcBWMe9BADT+GW2fALbGSvDj6MUMQTkqfdcGrGmQflKbF++jf0H1Esan0H NbrXJOrYQS374V/FznslZRmFQ3USRWutDpBVDwo1sCcWzEuBaZWdomPFNuWSw8d5VZyd w92JCHefU+0klWmovoOQQil8nddgdbBanEz6+FB5SbF5V7+aOrVrjAwnON0kUv1mFvMs 099BdmBQaGFq90RxobRsuqfnbk6je+mYIu+Nr+hY0q/ODOjkZta6B7zIa/Zm7KXlrpcT Mw+Q== X-Gm-Message-State: AO0yUKVitXEqRa6v6+EE9d95GnkD8ufM9kcMyKwboFXEbC8V8wXghtF5 YZ8Z1c1LQKHJ56y4p07XuY8= X-Google-Smtp-Source: AK7set+I/CPPxHXAhf5qBsL4mcZeaWR1Cid3atIIseLpDh1NtpOroP8ski833jPHpzXBgHHcqOiaLw== X-Received: by 2002:a62:15d3:0:b0:5a8:4db3:266e with SMTP id 202-20020a6215d3000000b005a84db3266emr3828885pfv.10.1676004667360; Thu, 09 Feb 2023 20:51:07 -0800 (PST) Received: from localhost.localdomain ([202.53.32.211]) by smtp.gmail.com with ESMTPSA id t13-20020a62ea0d000000b0057fec210d33sm2269218pfh.152.2023.02.09.20.50.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Feb 2023 20:51:07 -0800 (PST) From: Orlando Chamberlain To: platform-driver-x86@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org Subject: [RFC PATCH 7/9] apple-gmux: add sysfs interface Date: Fri, 10 Feb 2023 15:48:24 +1100 Message-Id: <20230210044826.9834-8-orlandoch.dev@gmail.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230210044826.9834-1-orlandoch.dev@gmail.com> References: <20230210044826.9834-1-orlandoch.dev@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Fri, 10 Feb 2023 08:04:04 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Pan, Xinhui" , Lijo Lazar , Rander Wang , YiPeng Chai , Mario Limonciello , David Airlie , Pierre-Louis Bossart , Evan Quan , Ranjani Sridharan , Yong Zhi , Aun-Ali Zaidi , Andrey Grodzovsky , Bokun Zhang , Orlando Chamberlain , Mark Gross , Hans de Goede , Kerem Karabay , Jaroslav Kysela , Jack Xiao , Kai Vehmanen , Somalapuram Amaranath , Takashi Iwai , Aditya Garg , Daniel Vetter , =?UTF-8?q?Amadeusz=20S=C5=82awi=C5=84ski?= , Alex Deucher , =?UTF-8?q?Christian=20K=C3=B6nig?= , Hawking Zhang Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Allow reading gmux ports from userspace. When the unsafe module parameter allow_user_writes is true, writing 1 byte values is also allowed. For example: cd /sys/bus/acpi/devices/APP000B:00/physical_node/ echo 4 > gmux_selected_port cat gmux_selected_port_data | xxd -p Will show the gmux version information (00000005 in this case) Signed-off-by: Orlando Chamberlain --- drivers/platform/x86/apple-gmux.c | 129 ++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index c38d6ef0c15a..756059d48393 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -66,6 +66,11 @@ struct apple_gmux_data { enum vga_switcheroo_client_id switch_state_external; enum vga_switcheroo_state power_state; struct completion powerchange_done; + +#ifdef CONFIG_SYSFS + /* sysfs data */ + int selected_port; +#endif /* CONFIG_SYSFS */ }; static struct apple_gmux_data *apple_gmux_data; @@ -651,6 +656,121 @@ static void gmux_notify_handler(acpi_handle device, u32 value, void *context) complete(&gmux_data->powerchange_done); } +/** + * DOC: Sysfs Interface + * + * gmux ports can be read from userspace as a sysfs interface. For example: + * + * # echo 4 > /sys/bus/acpi/devices/APP000B:00/physical_node/gmux_selected_port + * # cat /sys/bus/acpi/devices/APP000B:00/physical_node/gmux_selected_port_data | xxd -p + * 00000005 + * + * Reads 4 bytes from port 4 (GMUX_PORT_VERSION_MAJOR). + * + * Single byte writes are also supported, however this must be enabled with the + * unsafe allow_user_writes module parameter. + * + */ + +#ifdef CONFIG_SYSFS + +static bool allow_user_writes; +module_param_unsafe(allow_user_writes, bool, 0); +MODULE_PARM_DESC(allow_user_writes, "Allow userspace to write to gmux ports (default: false) (bool)"); + +static ssize_t gmux_selected_port_store(struct device *dev, + struct device_attribute *attr, const char *sysfsbuf, size_t count) +{ + struct apple_gmux_data *gmux_data = dev_get_drvdata(dev); + u8 port; + + if (kstrtou8(sysfsbuf, 10, &port) < 0) + return -EINVAL; + + /* On pio gmux's, make sure the user doesn't access too high of a port. */ + if ((gmux_data->config == &apple_gmux_pio) && + port > (gmux_data->iolen - 4)) + return -EINVAL; + + gmux_data->selected_port = port; + return count; +} + +static ssize_t gmux_selected_port_show(struct device *dev, + struct device_attribute *attr, char *sysfsbuf) +{ + struct apple_gmux_data *gmux_data = dev_get_drvdata(dev); + + return sysfs_emit(sysfsbuf, "%d\n", gmux_data->selected_port); +} + +DEVICE_ATTR_RW(gmux_selected_port); + +static ssize_t gmux_selected_port_data_store(struct device *dev, + struct device_attribute *attr, const char *sysfsbuf, size_t count) +{ + struct apple_gmux_data *gmux_data = dev_get_drvdata(dev); + + if (count == 1) + gmux_write8(gmux_data, gmux_data->selected_port, *sysfsbuf); + else + return -EINVAL; + + return count; +} + +static ssize_t gmux_selected_port_data_show(struct device *dev, + struct device_attribute *attr, char *sysfsbuf) +{ + struct apple_gmux_data *gmux_data = dev_get_drvdata(dev); + u32 data; + + data = gmux_read32(gmux_data, gmux_data->selected_port); + memcpy(sysfsbuf, &data, sizeof(data)); + + return sizeof(data); +} + +struct device_attribute dev_attr_gmux_selected_port_data_rw = __ATTR_RW(gmux_selected_port_data); +struct device_attribute dev_attr_gmux_selected_port_data_ro = __ATTR_RO(gmux_selected_port_data); + +static int gmux_init_sysfs(struct pnp_dev *pnp) +{ + int ret; + + ret = device_create_file(&pnp->dev, &dev_attr_gmux_selected_port); + if (ret) + return ret; + if (allow_user_writes) + ret = device_create_file(&pnp->dev, &dev_attr_gmux_selected_port_data_rw); + else + ret = device_create_file(&pnp->dev, &dev_attr_gmux_selected_port_data_ro); + if (ret) + device_remove_file(&pnp->dev, &dev_attr_gmux_selected_port); + return ret; +} + +static void gmux_fini_sysfs(struct pnp_dev *pnp) +{ + device_remove_file(&pnp->dev, &dev_attr_gmux_selected_port); + if (allow_user_writes) + device_remove_file(&pnp->dev, &dev_attr_gmux_selected_port_data_rw); + else + device_remove_file(&pnp->dev, &dev_attr_gmux_selected_port_data_ro); +} + +#else + +static int gmux_init_sysfs(struct pnp_dev *pnp) +{ + return 0; +} +static void gmux_fini_sysfs(struct pnp_dev *pnp) +{ +} + +#endif /* CONFIG_SYSFS */ + static int gmux_suspend(struct device *dev) { struct pnp_dev *pnp = to_pnp_dev(dev); @@ -846,8 +966,16 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) goto err_register_handler; } + ret = gmux_init_sysfs(pnp); + if (ret) { + pr_err("Failed to register gmux sysfs entries\n"); + goto err_sysfs; + } + return 0; +err_sysfs: + vga_switcheroo_unregister_handler(); err_register_handler: gmux_disable_interrupts(gmux_data); apple_gmux_data = NULL; @@ -877,6 +1005,7 @@ static void gmux_remove(struct pnp_dev *pnp) { struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); + gmux_fini_sysfs(pnp); vga_switcheroo_unregister_handler(); gmux_disable_interrupts(gmux_data); if (gmux_data->gpe >= 0) { -- 2.39.1