^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Raspberry Pi voltage sensor driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Based on firmware/raspberrypi.c by Noralf Trønnes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Copyright (C) 2018 Stefan Wahren <stefan.wahren@i2se.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/hwmon.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/workqueue.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <soc/bcm2835/raspberrypi-firmware.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define UNDERVOLTAGE_STICKY_BIT BIT(16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) struct rpi_hwmon_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct device *hwmon_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) struct rpi_firmware *fw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) u32 last_throttled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct delayed_work get_values_poll_work;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) static void rpi_firmware_get_throttled(struct rpi_hwmon_data *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) u32 new_uv, old_uv, value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /* Request firmware to clear sticky bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) value = 0xffff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) ret = rpi_firmware_property(data->fw, RPI_FIRMWARE_GET_THROTTLED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) &value, sizeof(value));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) dev_err_once(data->hwmon_dev, "Failed to get throttled (%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) new_uv = value & UNDERVOLTAGE_STICKY_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) old_uv = data->last_throttled & UNDERVOLTAGE_STICKY_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) data->last_throttled = value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) if (new_uv == old_uv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (new_uv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) dev_crit(data->hwmon_dev, "Undervoltage detected!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) dev_info(data->hwmon_dev, "Voltage normalised\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) sysfs_notify(&data->hwmon_dev->kobj, NULL, "in0_lcrit_alarm");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) static void get_values_poll(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) struct rpi_hwmon_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) data = container_of(work, struct rpi_hwmon_data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) get_values_poll_work.work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) rpi_firmware_get_throttled(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * We can't run faster than the sticky shift (100ms) since we get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * flipping in the sticky bits that are cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) schedule_delayed_work(&data->get_values_poll_work, 2 * HZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) static int rpi_read(struct device *dev, enum hwmon_sensor_types type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) u32 attr, int channel, long *val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) struct rpi_hwmon_data *data = dev_get_drvdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) *val = !!(data->last_throttled & UNDERVOLTAGE_STICKY_BIT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) static umode_t rpi_is_visible(const void *_data, enum hwmon_sensor_types type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) u32 attr, int channel)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return 0444;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static const struct hwmon_channel_info *rpi_info[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) HWMON_CHANNEL_INFO(in,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) HWMON_I_LCRIT_ALARM),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) static const struct hwmon_ops rpi_hwmon_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) .is_visible = rpi_is_visible,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) .read = rpi_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) static const struct hwmon_chip_info rpi_chip_info = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) .ops = &rpi_hwmon_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) .info = rpi_info,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static int rpi_hwmon_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) struct rpi_hwmon_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) /* Parent driver assure that firmware is correct */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) data->fw = dev_get_drvdata(dev->parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "rpi_volt",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) &rpi_chip_info,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) INIT_DELAYED_WORK(&data->get_values_poll_work, get_values_poll);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) platform_set_drvdata(pdev, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (!PTR_ERR_OR_ZERO(data->hwmon_dev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) schedule_delayed_work(&data->get_values_poll_work, 2 * HZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) return PTR_ERR_OR_ZERO(data->hwmon_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static int rpi_hwmon_remove(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) struct rpi_hwmon_data *data = platform_get_drvdata(pdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) cancel_delayed_work_sync(&data->get_values_poll_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) static struct platform_driver rpi_hwmon_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) .probe = rpi_hwmon_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) .remove = rpi_hwmon_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) .name = "raspberrypi-hwmon",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) module_platform_driver(rpi_hwmon_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) MODULE_AUTHOR("Stefan Wahren <wahrenst@gmx.net>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) MODULE_DESCRIPTION("Raspberry Pi voltage sensor driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) MODULE_LICENSE("GPL v2");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) MODULE_ALIAS("platform:raspberrypi-hwmon");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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