From patchwork Fri May 31 20:33:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 13682139 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD26F8004A; Fri, 31 May 2024 20:33:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717187634; cv=none; b=pUXFVePiqnywwoqbDG2/wnnVENESY9SCTdMSXf7FmlOSVelOowUQixATcdjTTHTR7pmimzWchYRafRvES/5774yRIkLJ1W9ce4moJ54/iDiWracey7K65eJ6wrAHnpy+jfkVxoeeKXbwyn/DBnHzqqZDTl2crbXZ+nm0CE2BvI0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717187634; c=relaxed/simple; bh=+7dtKjLD3lIwHtaoTxtl/YXckyVlH+3H9HrKHHp9Wyc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=R1Uo2BKa66+eKRfJHotVv2Bqe1+bmNiTr/qgRwTZ/GYMNiMGS9h3wMNQKZeTx7W/vUJD7YBDS//+V0wJtiiUPBGvyFNYFR8wFfwbJ3XuiM9Z4aC1hnki9CS5zEVCAPHW4pd3UobIV6v6XApiVGFP7n8+sV7intyxj4ueNT3f+ZA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=AcigV4IT; arc=none smtp.client-ip=209.85.210.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AcigV4IT" Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-702342c60dfso1524076b3a.2; Fri, 31 May 2024 13:33:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1717187631; x=1717792431; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=k9eRuoPFcU0MhFMvPhG+IPwfqxweonXAAsB8PwcsScg=; b=AcigV4ITvTtXUQ8Vr0OW4OA5ZTvrkKSp/HoebcxwOsXcAj6bfbtmCKhcmJDUUn7CSA URTtT9jpQmQto8s7MuxvFwSsll6KvCiHciHsVkc45NDF6YeQ15FTrQfxOyvYZF5ii6jG dlgBKDwRZRgapXMy3l1eNgJsJzlGnlBZvIlShulj5hiMGmtKjt0GnAwyK2hQxD2M2SKH j4qV4g+fOFQGHhldYM9d4m+y+F8BxfOoO6WcGefyrAkP66CTbcsq7wgkKUnAGuYaZxfg IbsksG31RViE1IJYsUjFuCx9AY/Xpc79wt7csMJ0jSv++MzD9CErvr+9wZHb+u7OYZ/T PdBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717187631; x=1717792431; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=k9eRuoPFcU0MhFMvPhG+IPwfqxweonXAAsB8PwcsScg=; b=tcHprLFygiFgpMcKakaN8ZWzhzrIVgQc/GpYDW1aH/8tclGs+JMnFuhAoQCqVM0SEy 2M8WbfBBhI5jD3TPKj2blkmQv4DVSRhZYbRKMaB53kEGRi1eoHqX82Se+9f3HeGWpXOR bK14YKUeGQu6q7KKFxv0dnxLXaI7TOFReKV6ITG3mKlD0mFqukFmAmFN9klhuin6IHPO lT8ZsfBOQx83CUxtU+C5+whTJzKPs/4GWs5Pp7Jty137onZdeg8e+mTVrnhLf2aM5qdA sxnDHPzD0apU/+f5ikoc+mwj8ZtR1GA7IJubqUS8ojhawrF1lJgESWkvDuTpY0Nj4I+5 UNmQ== X-Gm-Message-State: AOJu0YyjHcXqzhozPQnk8GU19riBksTDBKOTLkNfGi7wkYSY3KQXrNwE JPog5XRrrp9sJhg4NzaWJg/lQvtwNkgHGSoiaKB+HD8hTiV8rxAXCMF1kg== X-Google-Smtp-Source: AGHT+IEebwQED0LbomUMxHV3/JtMtP6ifv2HoXK9xr07GSDVXZFNqgT2x9iCT0AY25eoI+Q2Nd0/kQ== X-Received: by 2002:a05:6a00:1a86:b0:702:2749:608b with SMTP id d2e1a72fcca58-702477bb6a7mr3438898b3a.1.1717187631553; Fri, 31 May 2024 13:33:51 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-702423cb6fasm1767556b3a.8.2024.05.31.13.33.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 May 2024 13:33:50 -0700 (PDT) Sender: Guenter Roeck From: Guenter Roeck To: linux-hwmon@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nuno Sa , Radu Sabau , Guenter Roeck Subject: [PATCH v2 1/2] hwmon: Add PEC attribute support to hardware monitoring core Date: Fri, 31 May 2024 13:33:45 -0700 Message-Id: <20240531203346.1396055-2-linux@roeck-us.net> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240531203346.1396055-1-linux@roeck-us.net> References: <20240531203346.1396055-1-linux@roeck-us.net> Precedence: bulk X-Mailing-List: linux-hwmon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Several hardware monitoring chips optionally support Packet Error Checking (PEC). For some chips, PEC support can be enabled simply by setting I2C_CLIENT_PEC in the i2c client data structure. Others require chip specific code to enable or disable PEC support. Introduce hwmon_chip_pec and HWMON_C_PEC to simplify adding configurable PEC support for hardware monitoring drivers. A driver can set HWMON_C_PEC in its chip information data to indicate PEC support. If a chip requires chip specific code to enable or disable PEC support, the driver only needs to implement support for the hwmon_chip_pec attribute to its write function. Packet Error Checking is only supported for SMBus devices. HWMON_C_PEC must therefore only be set by a driver if the parent device is an I2C device. Attempts to set HWMON_C_PEC on any other device type is not supported and rejected. The code calls i2c_check_functionality() to check if PEC is supported by the I2C/SMBus controller. This function is only available if CONFIG_I2C is enabled. For this reason, the added code needs to depend on CONFIG_I2C. Cc: Radu Sabau Acked-by: Nuno Sa Signed-off-by: Guenter Roeck --- v2: Use sysfs_emit() Return -EINVAL if the parent device is not an i2c client device Added code needs to be enclosed in "#ifdef(CONFIG_I2C)" Added Nuno's Acked-by: tag. drivers/hwmon/Kconfig | 1 + drivers/hwmon/hwmon.c | 147 +++++++++++++++++++++++++++++++++++++----- include/linux/hwmon.h | 2 + 3 files changed, 134 insertions(+), 16 deletions(-) diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index e14ae18a973b..7f384a2494c9 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -6,6 +6,7 @@ menuconfig HWMON tristate "Hardware Monitoring support" depends on HAS_IOMEM + depends on I2C || I2C=n default y help Hardware monitoring devices let you monitor the hardware health diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c index 3b259c425ab7..894cbe992bdf 100644 --- a/drivers/hwmon/hwmon.c +++ b/drivers/hwmon/hwmon.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -309,6 +310,114 @@ static int hwmon_attr_base(enum hwmon_sensor_types type) return 1; } +#if IS_ENABLED(CONFIG_I2C) + +/* + * PEC support + * + * The 'pec' attribute is attached to I2C client devices. It is only provided + * if the i2c controller supports PEC. + * + * The mutex ensures that PEC configuration between i2c device and the hardware + * is consistent. Use a single mutex because attribute writes are supposed to be + * rare, and maintaining a separate mutex for each hardware monitoring device + * would add substantial complexity to the driver for little if any gain. + * + * The hardware monitoring device is identified as child of the i2c client + * device. This assumes that only a single hardware monitoring device is + * attached to an i2c client device. + */ + +static DEFINE_MUTEX(hwmon_pec_mutex); + +static int hwmon_match_device(struct device *dev, void *data) +{ + return dev->class == &hwmon_class; +} + +static ssize_t pec_show(struct device *dev, struct device_attribute *dummy, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + + return sysfs_emit(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC)); +} + +static ssize_t pec_store(struct device *dev, struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct hwmon_device *hwdev; + struct device *hdev; + bool val; + int err; + + err = kstrtobool(buf, &val); + if (err < 0) + return err; + + hdev = device_find_child(dev, NULL, hwmon_match_device); + if (!hdev) + return -ENODEV; + + mutex_lock(&hwmon_pec_mutex); + + /* + * If there is no write function, we assume that chip specific + * handling is not required. + */ + hwdev = to_hwmon_device(hdev); + if (hwdev->chip->ops->write) { + err = hwdev->chip->ops->write(hdev, hwmon_chip, hwmon_chip_pec, 0, val); + if (err && err != -EOPNOTSUPP) + goto unlock; + } + + if (!val) + client->flags &= ~I2C_CLIENT_PEC; + else + client->flags |= I2C_CLIENT_PEC; + + err = count; +unlock: + mutex_unlock(&hwmon_pec_mutex); + put_device(hdev); + + return err; +} + +static DEVICE_ATTR_RW(pec); + +static void hwmon_remove_pec(void *dev) +{ + device_remove_file(dev, &dev_attr_pec); +} + +static int hwmon_pec_register(struct device *hdev) +{ + struct i2c_client *client = i2c_verify_client(hdev->parent); + int err; + + if (!client) + return -EINVAL; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) + return 0; + + err = device_create_file(&client->dev, &dev_attr_pec); + if (err) + return err; + + return devm_add_action_or_reset(hdev, hwmon_remove_pec, &client->dev); +} + +#else /* CONFIG_I2C */ +static int hwmon_pec_register(struct device *hdev) +{ + return -EINVAL; +} +#endif /* CONFIG_I2C */ + /* sysfs attribute management */ static ssize_t hwmon_attr_show(struct device *dev, @@ -397,10 +506,6 @@ static struct attribute *hwmon_genattr(const void *drvdata, const char *name; bool is_string = is_string_attr(type, attr); - /* The attribute is invisible if there is no template string */ - if (!template) - return ERR_PTR(-ENOENT); - mode = ops->is_visible(drvdata, type, attr, index); if (!mode) return ERR_PTR(-ENOENT); @@ -712,8 +817,8 @@ static int hwmon_genattrs(const void *drvdata, attr = __ffs(attr_mask); attr_mask &= ~BIT(attr); - if (attr >= template_size) - return -EINVAL; + if (attr >= template_size || !templates[attr]) + continue; /* attribute is invisible */ a = hwmon_genattr(drvdata, info->type, attr, i, templates[attr], ops); if (IS_ERR(a)) { @@ -849,16 +954,26 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata, INIT_LIST_HEAD(&hwdev->tzdata); if (hdev->of_node && chip && chip->ops->read && - chip->info[0]->type == hwmon_chip && - (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) { - err = hwmon_thermal_register_sensors(hdev); - if (err) { - device_unregister(hdev); - /* - * Don't worry about hwdev; hwmon_dev_release(), called - * from device_unregister(), will free it. - */ - goto ida_remove; + chip->info[0]->type == hwmon_chip) { + u32 config = chip->info[0]->config[0]; + + if (config & HWMON_C_REGISTER_TZ) { + err = hwmon_thermal_register_sensors(hdev); + if (err) { + device_unregister(hdev); + /* + * Don't worry about hwdev; hwmon_dev_release(), + * called from device_unregister(), will free it. + */ + goto ida_remove; + } + } + if (config & HWMON_C_PEC) { + err = hwmon_pec_register(hdev); + if (err) { + device_unregister(hdev); + goto ida_remove; + } } } diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h index edf96f249eb5..e94314760aab 100644 --- a/include/linux/hwmon.h +++ b/include/linux/hwmon.h @@ -45,6 +45,7 @@ enum hwmon_chip_attributes { hwmon_chip_power_samples, hwmon_chip_temp_samples, hwmon_chip_beep_enable, + hwmon_chip_pec, }; #define HWMON_C_TEMP_RESET_HISTORY BIT(hwmon_chip_temp_reset_history) @@ -60,6 +61,7 @@ enum hwmon_chip_attributes { #define HWMON_C_POWER_SAMPLES BIT(hwmon_chip_power_samples) #define HWMON_C_TEMP_SAMPLES BIT(hwmon_chip_temp_samples) #define HWMON_C_BEEP_ENABLE BIT(hwmon_chip_beep_enable) +#define HWMON_C_PEC BIT(hwmon_chip_pec) enum hwmon_temp_attributes { hwmon_temp_enable,