1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/hwmon/cgbc-hwmon.c b/drivers/hwmon/cgbc-hwmon.c
new file mode 100644
index 000000000000..772f44d56ccf
--- /dev/null
+++ b/drivers/hwmon/cgbc-hwmon.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * cgbc-hwmon - Congatec Board Controller hardware monitoring driver
+ *
+ * Copyright (C) 2024 Thomas Richard <thomas.richard@bootlin.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/mfd/cgbc.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define CGBC_HWMON_CMD_SENSOR		0x77
+#define CGBC_HWMON_CMD_SENSOR_DATA_SIZE	0x05
+
+#define CGBC_HWMON_TYPE_MASK	GENMASK(6, 5)
+#define CGBC_HWMON_ID_MASK	GENMASK(4, 0)
+#define CGBC_HWMON_ACTIVE_BIT	BIT(7)
+
+struct cgbc_hwmon_sensor {
+	enum hwmon_sensor_types type;
+	bool active;
+	unsigned int index;
+	unsigned int channel;
+	const char *label;
+};
+
+struct cgbc_hwmon_data {
+	struct cgbc_device_data *cgbc;
+	unsigned int nb_sensors;
+	struct cgbc_hwmon_sensor *sensors;
+};
+
+enum cgbc_sensor_types {
+	CGBC_HWMON_TYPE_TEMP = 1,
+	CGBC_HWMON_TYPE_IN,
+	CGBC_HWMON_TYPE_FAN
+};
+
+static const char * const cgbc_hwmon_labels_temp[] = {
+	"CPU Temperature",
+	"Box Temperature",
+	"Ambient Temperature",
+	"Board Temperature",
+	"Carrier Temperature",
+	"Chipset Temperature",
+	"Video Temperature",
+	"Other Temperature",
+	"TOPDIM Temperature",
+	"BOTTOMDIM Temperature",
+};
+
+static const struct {
+	enum hwmon_sensor_types type;
+	const char *label;
+} cgbc_hwmon_labels_in[] = {
+	{ hwmon_in, "CPU Voltage" },
+	{ hwmon_in, "DC Runtime Voltage" },
+	{ hwmon_in, "DC Standby Voltage" },
+	{ hwmon_in, "CMOS Battery Voltage" },
+	{ hwmon_in, "Battery Voltage" },
+	{ hwmon_in, "AC Voltage" },
+	{ hwmon_in, "Other Voltage" },
+	{ hwmon_in, "5V Voltage" },
+	{ hwmon_in, "5V Standby Voltage" },
+	{ hwmon_in, "3V3 Voltage" },
+	{ hwmon_in, "3V3 Standby Voltage" },
+	{ hwmon_in, "VCore A Voltage" },
+	{ hwmon_in, "VCore B Voltage" },
+	{ hwmon_in, "12V Voltage" },
+	{ hwmon_curr, "DC Current" },
+	{ hwmon_curr, "5V Current" },
+	{ hwmon_curr, "12V Current" },
+};
+
+#define CGBC_HWMON_NB_IN_SENSORS	14
+
+static const char * const cgbc_hwmon_labels_fan[] = {
+	"CPU Fan",
+	"Box Fan",
+	"Ambient Fan",
+	"Chipset Fan",
+	"Video Fan",
+	"Other Fan",
+};
+
+static int cgbc_hwmon_cmd(struct cgbc_device_data *cgbc, u8 index, u8 *data)
+{
+	u8 cmd[2] = {CGBC_HWMON_CMD_SENSOR, index};
+
+	return cgbc_command(cgbc, cmd, sizeof(cmd), data, CGBC_HWMON_CMD_SENSOR_DATA_SIZE, NULL);
+}
+
+static int cgbc_hwmon_probe_sensors(struct device *dev, struct cgbc_hwmon_data *hwmon)
+{
+	struct cgbc_device_data *cgbc = hwmon->cgbc;
+	struct cgbc_hwmon_sensor *sensor = hwmon->sensors;
+	u8 data[CGBC_HWMON_CMD_SENSOR_DATA_SIZE], nb_sensors, i;
+	int ret;
+
+	ret = cgbc_hwmon_cmd(cgbc, 0, &data[0]);
+	if (ret)
+		return ret;
+
+	nb_sensors = data[0];
+
+	hwmon->sensors = devm_kzalloc(dev, sizeof(*hwmon->sensors) * nb_sensors, GFP_KERNEL);
+	sensor = hwmon->sensors;
+
+	for (i = 0; i < nb_sensors; i++) {
+		enum cgbc_sensor_types type;
+		unsigned int channel;
+
+		/*
+		 * No need to request data for the first sensor.
+		 * We got data for the first sensor when we ask the number of sensors to the Board
+		 * Controller.
+		 */
+		if (i) {
+			ret = cgbc_hwmon_cmd(cgbc, i, &data[0]);
+			if (ret)
+				return ret;
+		}
+
+		type = FIELD_GET(CGBC_HWMON_TYPE_MASK, data[1]);
+		channel = FIELD_GET(CGBC_HWMON_ID_MASK, data[1]) - 1;
+
+		if (type == CGBC_HWMON_TYPE_TEMP && channel < ARRAY_SIZE(cgbc_hwmon_labels_temp)) {
+			sensor->type = hwmon_temp;
+			sensor->label = cgbc_hwmon_labels_temp[channel];
+		} else if (type == CGBC_HWMON_TYPE_IN &&
+			   channel < ARRAY_SIZE(cgbc_hwmon_labels_in)) {
+			/*
+			 * The Board Controller doesn't differentiate current and voltage sensors.
+			 * Get the sensor type from cgbc_hwmon_labels_in[channel].type instead.
+			 */
+			sensor->type = cgbc_hwmon_labels_in[channel].type;
+			sensor->label = cgbc_hwmon_labels_in[channel].label;
+		} else if (type == CGBC_HWMON_TYPE_FAN &&
+			   channel < ARRAY_SIZE(cgbc_hwmon_labels_fan)) {
+			sensor->type = hwmon_fan;
+			sensor->label = cgbc_hwmon_labels_fan[channel];
+		} else {
+			dev_warn(dev, "Board Controller returned an unknown sensor (type=%d, channel=%d), ignore it",
+				 type, channel);
+			continue;
+		}
+
+		sensor->active = FIELD_GET(CGBC_HWMON_ACTIVE_BIT, data[1]);
+		sensor->channel = channel;
+		sensor->index = i;
+		sensor++;
+		hwmon->nb_sensors++;
+	}
+
+	return 0;
+}
+
+static struct cgbc_hwmon_sensor *cgbc_hwmon_find_sensor(struct cgbc_hwmon_data *hwmon,
+							enum hwmon_sensor_types type, int channel)
+{
+	struct cgbc_hwmon_sensor *sensor = NULL;
+	int i;
+
+	/*
+	 * The Board Controller doesn't differentiate current and voltage sensors.
+	 * The channel value (from the Board Controller point of view) shall be computed for current
+	 * sensors.
+	 */
+	if (type == hwmon_curr)
+		channel += CGBC_HWMON_NB_IN_SENSORS;
+
+	for (i = 0; i < hwmon->nb_sensors; i++) {
+		if (hwmon->sensors[i].type == type && hwmon->sensors[i].channel == channel) {
+			sensor = &hwmon->sensors[i];
+			break;
+		}
+	}
+
+	return sensor;
+}
+
+static int cgbc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
+			   long *val)
+{
+	struct cgbc_hwmon_data *hwmon = dev_get_drvdata(dev);
+	struct cgbc_hwmon_sensor *sensor = cgbc_hwmon_find_sensor(hwmon, type, channel);
+	struct cgbc_device_data *cgbc = hwmon->cgbc;
+	u8 data[CGBC_HWMON_CMD_SENSOR_DATA_SIZE];
+	int ret;
+
+	ret = cgbc_hwmon_cmd(cgbc, sensor->index, &data[0]);
+	if (ret)
+		return ret;
+
+	*val = (data[3] << 8) | data[2];
+
+	/*
+	 * For the Board Controller 1lsb = 0.1 degree centigrade.
+	 * Other units are as expected.
+	 */
+	if (sensor->type == hwmon_temp)
+		*val *= 100;
+
+	return 0;
+}
+
+static umode_t cgbc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
+				     int channel)
+{
+	struct cgbc_hwmon_data *data = (struct cgbc_hwmon_data *)_data;
+	struct cgbc_hwmon_sensor *sensor;
+
+	sensor = cgbc_hwmon_find_sensor(data, type, channel);
+	if (!sensor)
+		return 0;
+
+	return sensor->active ? 0444 : 0;
+}
+
+static int cgbc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+				  int channel, const char **str)
+{
+	struct cgbc_hwmon_data *hwmon = dev_get_drvdata(dev);
+	struct cgbc_hwmon_sensor *sensor = cgbc_hwmon_find_sensor(hwmon, type, channel);
+
+	*str = sensor->label;
+
+	return 0;
+}
+
+static const struct hwmon_channel_info * const cgbc_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL),
+	HWMON_CHANNEL_INFO(curr,
+			   HWMON_C_INPUT | HWMON_C_LABEL, HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL),
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL, HWMON_F_INPUT | HWMON_F_LABEL),
+	NULL
+};
+
+static const struct hwmon_ops cgbc_hwmon_ops = {
+	.is_visible = cgbc_hwmon_is_visible,
+	.read = cgbc_hwmon_read,
+	.read_string = cgbc_hwmon_read_string,
+};
+
+static const struct hwmon_chip_info cgbc_chip_info = {
+	.ops = &cgbc_hwmon_ops,
+	.info = cgbc_hwmon_info,
+};
+
+static int cgbc_hwmon_probe(struct platform_device *pdev)
+{
+	struct cgbc_device_data *cgbc = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct cgbc_hwmon_data *data;
+	struct device *hwmon_dev;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->cgbc = cgbc;
+
+	ret = cgbc_hwmon_probe_sensors(dev, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to probe sensors");
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, "cgbc_hwmon", data, &cgbc_chip_info,
+							 NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct platform_driver cgbc_hwmon_driver = {
+	.driver = {
+		.name = "cgbc-hwmon",
+	},
+	.probe = cgbc_hwmon_probe,
+};
+
+module_platform_driver(cgbc_hwmon_driver);
+
+MODULE_AUTHOR("Thomas Richard <thomas.richard@bootlin.com>");
+MODULE_DESCRIPTION("Congatec Board Controller Hardware Monitoring Driver");
+MODULE_LICENSE("GPL");