diff --git a/Documentation/hwmon/raspberrypi-hwmon.rst b/Documentation/hwmon/raspberrypi-hwmon.rst index 8038ade36490a..db315184b8616 100644 --- a/Documentation/hwmon/raspberrypi-hwmon.rst +++ b/Documentation/hwmon/raspberrypi-hwmon.rst @@ -20,6 +20,17 @@ undervoltage conditions. Sysfs entries ------------- -======================= ================== +======================= ====================================================== +in0_input Core voltage in millivolts +in1_input SDRAM controller voltage in millivolts +in2_input SDRAM I/O voltage in millivolts +in3_input SDRAM PHY voltage in millivolts +in0_label "core" +in1_label "sdram_c" +in2_label "sdram_i" +in3_label "sdram_p" in0_lcrit_alarm Undervoltage alarm -======================= ================== +======================= ====================================================== + +The voltage inputs and labels are only exposed if the firmware reports support +for the corresponding voltage ID. diff --git a/drivers/hwmon/raspberrypi-hwmon.c b/drivers/hwmon/raspberrypi-hwmon.c index a2938881ccd2f..a458a858b0ac5 100644 --- a/drivers/hwmon/raspberrypi-hwmon.c +++ b/drivers/hwmon/raspberrypi-hwmon.c @@ -5,6 +5,7 @@ * Based on firmware/raspberrypi.c by Noralf Trønnes * * Copyright (C) 2018 Stefan Wahren + * Copyright (C) 2026 Shubham Chakraborty */ #include #include @@ -21,10 +22,18 @@ struct rpi_hwmon_data { struct device *hwmon_dev; struct rpi_firmware *fw; + u32 valid_inputs; u32 last_throttled; struct delayed_work get_values_poll_work; }; +static const char * const rpi_hwmon_labels[] = { + "core", + "sdram_c", + "sdram_i", + "sdram_p", +}; + static void rpi_firmware_get_throttled(struct rpi_hwmon_data *data) { u32 new_uv, old_uv, value; @@ -56,6 +65,22 @@ static void rpi_firmware_get_throttled(struct rpi_hwmon_data *data) hwmon_notify_event(data->hwmon_dev, hwmon_in, hwmon_in_lcrit_alarm, 0); } +static int rpi_firmware_get_voltage(struct rpi_hwmon_data *data, u32 id, + long *val) +{ + struct rpi_firmware_get_voltage_request packet = + RPI_FIRMWARE_GET_VOLTAGE_REQUEST(id); + int ret; + + ret = rpi_firmware_property(data->fw, RPI_FIRMWARE_GET_VOLTAGE, + &packet, sizeof(packet)); + if (ret) + return ret; + + *val = le32_to_cpu(packet.value) / 1000; + return 0; +} + static void get_values_poll(struct work_struct *work) { struct rpi_hwmon_data *data; @@ -77,19 +102,94 @@ static int rpi_read(struct device *dev, enum hwmon_sensor_types type, { struct rpi_hwmon_data *data = dev_get_drvdata(dev); - *val = !!(data->last_throttled & UNDERVOLTAGE_STICKY_BIT); + if (type == hwmon_in) { + switch (attr) { + case hwmon_in_input: + switch (channel) { + case 0: + return rpi_firmware_get_voltage(data, + RPI_FIRMWARE_VOLT_ID_CORE, + val); + case 1: + return rpi_firmware_get_voltage(data, + RPI_FIRMWARE_VOLT_ID_SDRAM_C, + val); + case 2: + return rpi_firmware_get_voltage(data, + RPI_FIRMWARE_VOLT_ID_SDRAM_I, + val); + case 3: + return rpi_firmware_get_voltage(data, + RPI_FIRMWARE_VOLT_ID_SDRAM_P, + val); + default: + return -EOPNOTSUPP; + } + case hwmon_in_lcrit_alarm: + if (channel == 0) { + *val = !!(data->last_throttled & UNDERVOLTAGE_STICKY_BIT); + return 0; + } + return -EOPNOTSUPP; + default: + return -EOPNOTSUPP; + } + } + + return -EOPNOTSUPP; +} + +static int rpi_read_string(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + if (type == hwmon_in && attr == hwmon_in_label) { + if (channel >= ARRAY_SIZE(rpi_hwmon_labels)) + return -EOPNOTSUPP; + + *str = rpi_hwmon_labels[channel]; + return 0; + } + + return -EOPNOTSUPP; +} + +static umode_t rpi_is_visible(const void *_data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + const struct rpi_hwmon_data *data = _data; + + if (type == hwmon_in) { + switch (attr) { + case hwmon_in_input: + case hwmon_in_label: + if (!(data->valid_inputs & BIT(channel))) + return 0; + return 0444; + case hwmon_in_lcrit_alarm: + if (channel == 0) + return 0444; + return 0; + default: + return 0; + } + } + return 0; } static const struct hwmon_channel_info * const rpi_info[] = { HWMON_CHANNEL_INFO(in, - HWMON_I_LCRIT_ALARM), + HWMON_I_INPUT | HWMON_I_LABEL | HWMON_I_LCRIT_ALARM, + HWMON_I_INPUT | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LABEL), NULL }; static const struct hwmon_ops rpi_hwmon_ops = { - .visible = 0444, + .is_visible = rpi_is_visible, .read = rpi_read, + .read_string = rpi_read_string, }; static const struct hwmon_chip_info rpi_chip_info = { @@ -101,6 +201,7 @@ static int rpi_hwmon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct rpi_hwmon_data *data; + long voltage; int ret; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); @@ -110,6 +211,26 @@ static int rpi_hwmon_probe(struct platform_device *pdev) /* Parent driver assure that firmware is correct */ data->fw = dev_get_drvdata(dev->parent); + ret = rpi_firmware_get_voltage(data, RPI_FIRMWARE_VOLT_ID_CORE, + &voltage); + if (!ret) + data->valid_inputs |= BIT(0); + + ret = rpi_firmware_get_voltage(data, RPI_FIRMWARE_VOLT_ID_SDRAM_C, + &voltage); + if (!ret) + data->valid_inputs |= BIT(1); + + ret = rpi_firmware_get_voltage(data, RPI_FIRMWARE_VOLT_ID_SDRAM_I, + &voltage); + if (!ret) + data->valid_inputs |= BIT(2); + + ret = rpi_firmware_get_voltage(data, RPI_FIRMWARE_VOLT_ID_SDRAM_P, + &voltage); + if (!ret) + data->valid_inputs |= BIT(3); + data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "rpi_volt", data, &rpi_chip_info, @@ -159,6 +280,7 @@ static struct platform_driver rpi_hwmon_driver = { module_platform_driver(rpi_hwmon_driver); MODULE_AUTHOR("Stefan Wahren "); +MODULE_AUTHOR("Shubham Chakraborty "); MODULE_DESCRIPTION("Raspberry Pi voltage sensor driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:raspberrypi-hwmon");