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authorMatthias Brugger <mbrugger@suse.com>2018-10-10 17:59:05 +0200
committerMatthias Brugger <mbrugger@suse.com>2018-10-11 12:44:30 +0200
commit267a64cfd3f522efa05eafdf547db03f12704f1b (patch)
tree28dd9333e95249ad71cc0b6c1ecbaa5e8f8c1f98
parentc6c535a0884cf19dd26a5913f61fccd6890e14db (diff)
hwmon: Add support for RPi voltage sensor (bsc#1108468).
-rw-r--r--patches.drivers/hwmon-Add-support-for-RPi-voltage-sensor.patch266
-rw-r--r--series.conf1
2 files changed, 267 insertions, 0 deletions
diff --git a/patches.drivers/hwmon-Add-support-for-RPi-voltage-sensor.patch b/patches.drivers/hwmon-Add-support-for-RPi-voltage-sensor.patch
new file mode 100644
index 0000000000..7c3145dc66
--- /dev/null
+++ b/patches.drivers/hwmon-Add-support-for-RPi-voltage-sensor.patch
@@ -0,0 +1,266 @@
+From: Stefan Wahren <stefan.wahren@i2se.com>
+Date: Fri, 25 May 2018 21:24:35 +0200
+Subject: hwmon: Add support for RPi voltage sensor
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+Git-commit: 74d1e007915fab590f8be9dc647b19511260210c
+Patch-mainline: v4.19-rc1
+References: bsc#1108468
+
+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" <noralf@tronnes.org>
+Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
+Signed-off-by: Eric Anholt <eric@anholt.net>
+Acked-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Matthias Brugger <mbrugger@suse.com>
+---
+ 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 000000000000..3c92e2cb52d6
+--- /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 <stefan.wahren@i2se.com>
++
++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 f10840ad465c..195154178aff 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 && !RASPBERRYPI_FIRMWARE)
++ 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 e7d52a36e6c4..a9297703fd6e 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 000000000000..fb4e4a6bb1f6
+--- /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 <stefan.wahren@i2se.com>
++ */
++#include <linux/device.h>
++#include <linux/err.h>
++#include <linux/hwmon.h>
++#include <linux/module.h>
++#include <linux/platform_device.h>
++#include <linux/slab.h>
++#include <linux/workqueue.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
++
++#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 <stefan.wahren@i2se.com>");
++MODULE_DESCRIPTION("Raspberry Pi voltage sensor driver");
++MODULE_LICENSE("GPL v2");
+--
+2.19.0
+
diff --git a/series.conf b/series.conf
index 70daf8450d..9223966c49 100644
--- a/series.conf
+++ b/series.conf
@@ -17558,6 +17558,7 @@
patches.arch/ARM-imx-flag-failure-of-of_iomap.patch
patches.arch/ARM-exynos-Clear-global-variable-on-init-error-path.patch
patches.drivers/ARM-bcm2835-Add-GET_THROTTLED-firmware-property.patch
+ patches.drivers/hwmon-Add-support-for-RPi-voltage-sensor.patch
patches.drivers/soc-mediatek-pwrap-fix-cipher-init-setting-error.patch
patches.drivers/IB-hfi1-Invalid-NUMA-node-information-can-cause-a-di.patch
patches.drivers/fbdev-Distinguish-between-interlaced-and-progressive.patch