From patchwork Fri May 25 19:24:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Wahren X-Patchwork-Id: 10428377 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 30DC7601D5 for ; Fri, 25 May 2018 19:26:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1DC53297B1 for ; Fri, 25 May 2018 19:26:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12229297C2; Fri, 25 May 2018 19:26:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07D47297B1 for ; Fri, 25 May 2018 19:26:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968140AbeEYT0g (ORCPT ); Fri, 25 May 2018 15:26:36 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:44339 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968127AbeEYT0f (ORCPT ); Fri, 25 May 2018 15:26:35 -0400 Received: from localhost.localdomain ([37.4.249.126]) by mrelayeu.kundenserver.de (mreue105 [212.227.15.183]) with ESMTPSA (Nemesis) id 0MhD7J-1fiW3k2NX7-00MOWb; Fri, 25 May 2018 21:25:29 +0200 From: Stefan Wahren To: Jean Delvare , Guenter Roeck , Jonathan Corbet , Eric Anholt Cc: Florian Fainelli , Ray Jui , Scott Branden , Phil Elwell , bcm-kernel-feedback-list@broadcom.com, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, Stefan Wahren , =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= Subject: [PATCH V3 2/6] hwmon: Add support for RPi voltage sensor Date: Fri, 25 May 2018 21:24:35 +0200 Message-Id: <1527276279-23876-3-git-send-email-stefan.wahren@i2se.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1527276279-23876-1-git-send-email-stefan.wahren@i2se.com> References: <1527276279-23876-1-git-send-email-stefan.wahren@i2se.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:Q2u9O3TFTCj1TsMi1wEr0Q0v9IzUOMqTIKK6jALFiCiXboBGa/z thUGLuCOBjMsdYeqrqLyoqzyXor052sLZuESepT7gx6Yjvpvz90DYynLvC1PaTu2waORIsd xp6GdI2y8TsIEptFerbVyZCgBPD0EVA+ZT9j+RwD7IaYZAyTOJdjYpqACpNiOaEiOsB8b9w WYCtnB49US1CQ0cWlANCQ== X-UI-Out-Filterresults: notjunk:1; V01:K0:NicsPBZwB9o=:MvfkrzSGr0k5PGEc1DE4Iv Wn9W2DxDpOTaL4evzsrqEYtZmehWr9xqg+ASSqRJTg/b7reQMsLo0omcTWrfGJvyOPFXfJbZk s6xiTANljA2qmUwETJkuIMqzDbgo9itzKa7g5NKhtxFvXeOXQGYVbPLRAlC9rGlT8Gku11rKu ZXCAM62AkT/Rb/A9oisO65ig2VDI+42uYXcz0Jqwa7a9oFqLbzxvzp6H0fGNP0eNOhEkUgAtx tuvnHyxcDOfTc9deL6ZCJtyC8XJaurHFjJb580zgJ/lfbkg12oQnytHNXvSRgAPvPCviSC1Vt 1Q2ke68/XuRbJGeroezqtu55XDGE+A9CxBEglabhdXFbAcj4i5jbo4w1C18hxzxkU6tIs+WnQ 1NFym56dLvzTu2w3BtkrDduiFfz5BB+tAhWAPcmzDot3qHk4oywDkNlYZtaW4dyvRyC1rsRIC tFp+JHxsOVhvFdfh0IBFvrYkyiu0B9gmejQQEy/EE2cOQkrW3Nw3XM9M6x8kH6hNUvNmoNRux VilfuxiQbHSQ0MRVLiIA7ktJONPIjXCZC4hMlMPsqUHF9mHdUxS7tKgNOs4GOs8E6zCTLYxjM YsyXF9l+V9aLArTCEk+bRVHbO7SYiDbTyfdUP8fqKvGa0HCRylN7Qz7VLk7t4la6ILceGrwUV 0TJm+ghmKfLrbz0noOXxbbFLkPVf678VKOEfgFxSIBmciH81a4NoCdAsqI6hM+e4FnhPX5LAC eeVh8D/G+1TqX1gnmby6RNKbhm8Mrk2qLOrJ7bNoDgxhSJpsxg+Ad6nxCBh14dQ2ZIKGa3h34 dcP6f4U Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently there is no easy way to detect undervoltage conditions on a remote Raspberry Pi. This hwmon driver retrieves the state of the undervoltage sensor via mailbox interface. The handling based on Noralf's modifications to the downstream firmware driver. In case of an undervoltage condition only an entry is written to the kernel log. CC: "Noralf Trønnes" Signed-off-by: Stefan Wahren Acked-by: Guenter Roeck --- Documentation/hwmon/raspberrypi-hwmon | 22 +++++ drivers/hwmon/Kconfig | 10 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/raspberrypi-hwmon.c | 166 ++++++++++++++++++++++++++++++++++ 4 files changed, 199 insertions(+) create mode 100644 Documentation/hwmon/raspberrypi-hwmon create mode 100644 drivers/hwmon/raspberrypi-hwmon.c diff --git a/Documentation/hwmon/raspberrypi-hwmon b/Documentation/hwmon/raspberrypi-hwmon new file mode 100644 index 0000000..3c92e2c --- /dev/null +++ b/Documentation/hwmon/raspberrypi-hwmon @@ -0,0 +1,22 @@ +Kernel driver raspberrypi-hwmon +=============================== + +Supported boards: + * Raspberry Pi A+ (via GPIO on SoC) + * Raspberry Pi B+ (via GPIO on SoC) + * Raspberry Pi 2 B (via GPIO on SoC) + * Raspberry Pi 3 B (via GPIO on port expander) + * Raspberry Pi 3 B+ (via PMIC) + +Author: Stefan Wahren + +Description +----------- + +This driver periodically polls a mailbox property of the VC4 firmware to detect +undervoltage conditions. + +Sysfs entries +------------- + +in0_lcrit_alarm Undervoltage alarm diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index f10840a..fdaab82 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1298,6 +1298,16 @@ config SENSORS_PWM_FAN This driver can also be built as a module. If so, the module will be called pwm-fan. +config SENSORS_RASPBERRYPI_HWMON + tristate "Raspberry Pi voltage monitor" + depends on RASPBERRYPI_FIRMWARE || COMPILE_TEST + help + If you say yes here you get support for voltage sensor on the + Raspberry Pi. + + This driver can also be built as a module. If so, the module + will be called raspberrypi-hwmon. + config SENSORS_SHT15 tristate "Sensiron humidity and temperature sensors. SHT15 and compat." depends on GPIOLIB || COMPILE_TEST diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index e7d52a3..a929770 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -141,6 +141,7 @@ obj-$(CONFIG_SENSORS_PC87427) += pc87427.o obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o obj-$(CONFIG_SENSORS_POWR1220) += powr1220.o obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o +obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o diff --git a/drivers/hwmon/raspberrypi-hwmon.c b/drivers/hwmon/raspberrypi-hwmon.c new file mode 100644 index 0000000..fb4e4a6 --- /dev/null +++ b/drivers/hwmon/raspberrypi-hwmon.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Raspberry Pi voltage sensor driver + * + * Based on firmware/raspberrypi.c by Noralf Trønnes + * + * Copyright (C) 2018 Stefan Wahren + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#define UNDERVOLTAGE_STICKY_BIT BIT(16) + +struct rpi_hwmon_data { + struct device *hwmon_dev; + struct rpi_firmware *fw; + u32 last_throttled; + struct delayed_work get_values_poll_work; +}; + +static void rpi_firmware_get_throttled(struct rpi_hwmon_data *data) +{ + u32 new_uv, old_uv, value; + int ret; + + /* Request firmware to clear sticky bits */ + value = 0xffff; + + ret = rpi_firmware_property(data->fw, RPI_FIRMWARE_GET_THROTTLED, + &value, sizeof(value)); + if (ret) { + dev_err_once(data->hwmon_dev, "Failed to get throttled (%d)\n", + ret); + return; + } + + new_uv = value & UNDERVOLTAGE_STICKY_BIT; + old_uv = data->last_throttled & UNDERVOLTAGE_STICKY_BIT; + data->last_throttled = value; + + if (new_uv == old_uv) + return; + + if (new_uv) + dev_crit(data->hwmon_dev, "Undervoltage detected!\n"); + else + dev_info(data->hwmon_dev, "Voltage normalised\n"); + + sysfs_notify(&data->hwmon_dev->kobj, NULL, "in0_lcrit_alarm"); +} + +static void get_values_poll(struct work_struct *work) +{ + struct rpi_hwmon_data *data; + + data = container_of(work, struct rpi_hwmon_data, + get_values_poll_work.work); + + rpi_firmware_get_throttled(data); + + /* + * We can't run faster than the sticky shift (100ms) since we get + * flipping in the sticky bits that are cleared. + */ + schedule_delayed_work(&data->get_values_poll_work, 2 * HZ); +} + +static int rpi_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct rpi_hwmon_data *data = dev_get_drvdata(dev); + + *val = !!(data->last_throttled & UNDERVOLTAGE_STICKY_BIT); + return 0; +} + +static umode_t rpi_is_visible(const void *_data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + return 0444; +} + +static const u32 rpi_in_config[] = { + HWMON_I_LCRIT_ALARM, + 0 +}; + +static const struct hwmon_channel_info rpi_in = { + .type = hwmon_in, + .config = rpi_in_config, +}; + +static const struct hwmon_channel_info *rpi_info[] = { + &rpi_in, + NULL +}; + +static const struct hwmon_ops rpi_hwmon_ops = { + .is_visible = rpi_is_visible, + .read = rpi_read, +}; + +static const struct hwmon_chip_info rpi_chip_info = { + .ops = &rpi_hwmon_ops, + .info = rpi_info, +}; + +static int rpi_hwmon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rpi_hwmon_data *data; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* Parent driver assure that firmware is correct */ + data->fw = dev_get_drvdata(dev->parent); + + /* Init throttled */ + ret = rpi_firmware_property(data->fw, RPI_FIRMWARE_GET_THROTTLED, + &data->last_throttled, + sizeof(data->last_throttled)); + + data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "rpi_volt", + data, + &rpi_chip_info, + NULL); + + INIT_DELAYED_WORK(&data->get_values_poll_work, get_values_poll); + platform_set_drvdata(pdev, data); + + if (!PTR_ERR_OR_ZERO(data->hwmon_dev)) + schedule_delayed_work(&data->get_values_poll_work, 2 * HZ); + + return PTR_ERR_OR_ZERO(data->hwmon_dev); +} + +static int rpi_hwmon_remove(struct platform_device *pdev) +{ + struct rpi_hwmon_data *data = platform_get_drvdata(pdev); + + cancel_delayed_work_sync(&data->get_values_poll_work); + + return 0; +} + +static struct platform_driver rpi_hwmon_driver = { + .probe = rpi_hwmon_probe, + .remove = rpi_hwmon_remove, + .driver = { + .name = "raspberrypi-hwmon", + }, +}; +module_platform_driver(rpi_hwmon_driver); + +MODULE_AUTHOR("Stefan Wahren "); +MODULE_DESCRIPTION("Raspberry Pi voltage sensor driver"); +MODULE_LICENSE("GPL v2");