From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/hwmon/raspberrypi-hwmon.c | 148 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 drivers/hwmon/raspberrypi-hwmon.c (limited to 'drivers/hwmon/raspberrypi-hwmon.c') diff --git a/drivers/hwmon/raspberrypi-hwmon.c b/drivers/hwmon/raspberrypi-hwmon.c new file mode 100644 index 000000000..1650d3b4c --- /dev/null +++ b/drivers/hwmon/raspberrypi-hwmon.c @@ -0,0 +1,148 @@ +// 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 +#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"); + + hwmon_notify_event(data->hwmon_dev, hwmon_in, hwmon_in_lcrit_alarm, 0); +} + +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 struct hwmon_channel_info *rpi_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_LCRIT_ALARM), + 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); + + data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "rpi_volt", + data, + &rpi_chip_info, + NULL); + if (IS_ERR(data->hwmon_dev)) + return PTR_ERR(data->hwmon_dev); + + ret = devm_delayed_work_autocancel(dev, &data->get_values_poll_work, + get_values_poll); + if (ret) + return ret; + platform_set_drvdata(pdev, data); + + schedule_delayed_work(&data->get_values_poll_work, 2 * HZ); + + return 0; +} + +static struct platform_driver rpi_hwmon_driver = { + .probe = rpi_hwmon_probe, + .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"); +MODULE_ALIAS("platform:raspberrypi-hwmon"); -- cgit v1.2.3