[PATCH] hwmon: add POWER-Z driver

From: Thomas Weißschuh
Date: Thu Aug 31 2023 - 04:45:32 EST


POWER-Z is a series of devices to monitor power characteristics of USB-C
connections and display those on a on-device display.
Some of the devices, notably KM002C and KM003C, contain an additional
port which exposes the measurements via USB.

This is a driver for this monitor port.

It was developed and tested with the KM003C.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
MAINTAINERS | 6 ++
drivers/hwmon/Kconfig | 10 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/powerz.c | 258 +++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 275 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4e3419c04f27..12bcf14597c4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4795,6 +4795,12 @@ X: drivers/char/ipmi/
X: drivers/char/random.c
X: drivers/char/tpm/

+CHARGERLAB POWER-Z HARDWARE MONITOR DRIVER
+M: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
+L: linux-hwmon@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/hwmon/powerz.c
+
CHECKPATCH
M: Andy Whitcroft <apw@xxxxxxxxxxxxx>
M: Joe Perches <joe@xxxxxxxxxxx>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index ec38c8892158..a055f9cdef16 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -839,6 +839,16 @@ config SENSORS_JC42
This driver can also be built as a module. If so, the module
will be called jc42.

+config SENSORS_POWERZ
+ tristate "ChargerLAB POWER-Z USB-C tester");
+ depends on USB
+ help
+ If you say yes here you get support for ChargerLAB POWER-Z series of
+ USB-C charging testers.
+
+ This driver can also be built as a module. If so, the module
+ will be called powerz.
+
config SENSORS_POWR1220
tristate "Lattice POWR1220 Power Monitoring"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 4ac9452b5430..019189500e5d 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -176,6 +176,7 @@ obj-$(CONFIG_SENSORS_OXP) += oxp-sensors.o
obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
+obj-$(CONFIG_SENSORS_POWERZ) += powerz.o
obj-$(CONFIG_SENSORS_POWR1220) += powr1220.o
obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o
obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o
diff --git a/drivers/hwmon/powerz.c b/drivers/hwmon/powerz.c
new file mode 100644
index 000000000000..898ab4c2516d
--- /dev/null
+++ b/drivers/hwmon/powerz.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/completion.h>
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#define DRIVER_NAME "powerz"
+#define POWERZ_EP_CMD_OUT 0x01
+#define POWERZ_EP_DATA_IN 0x81
+
+struct powerz_sensor_data {
+ u8 _unknown_1[8];
+ __le32 Vbus;
+ __le32 Ibus;
+ __le32 Vbus_avg;
+ __le32 Ibus_avg;
+ u8 _unknown_2[8];
+ u8 temp[2];
+ __le16 cc1;
+ __le16 cc2;
+ __le16 dp;
+ __le16 dm;
+ u8 _unknown_3[6];
+} __packed;
+
+struct powerz_priv {
+ struct device *hwmon_dev;
+ struct usb_interface *intf;
+};
+
+static const struct hwmon_channel_info * const powerz_info[] = {
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LABEL | HWMON_I_AVERAGE,
+ 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_AVERAGE),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_LABEL),
+ NULL
+};
+
+static umode_t powerz_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ return 0444;
+}
+
+static int powerz_read_string(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ if (type == hwmon_curr && attr == hwmon_curr_label)
+ *str = "bus";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 0)
+ *str = "bus";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 1)
+ *str = "cc1";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 2)
+ *str = "cc2";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 3)
+ *str = "dp";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 4)
+ *str = "dm";
+ else if (type == hwmon_temp && attr == hwmon_temp_label)
+ *str = "temp";
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+struct powerz_usb_ctx {
+ char transfer_buffer[64];
+ struct completion completion;
+ int status;
+};
+
+static void powerz_usb_data_complete(struct urb *urb)
+{
+ struct powerz_usb_ctx *ctx = urb->context;
+
+ ctx->status = 0;
+ complete(&ctx->completion);
+}
+
+static void powerz_usb_cmd_complete(struct urb *urb)
+{
+ struct powerz_usb_ctx *ctx = urb->context;
+ int ret;
+
+ usb_fill_bulk_urb(urb, urb->dev, usb_rcvbulkpipe(urb->dev, POWERZ_EP_DATA_IN),
+ ctx->transfer_buffer, sizeof(ctx->transfer_buffer),
+ powerz_usb_data_complete, ctx);
+
+ ret = usb_submit_urb(urb, GFP_ATOMIC);
+ if (ret) {
+ usb_free_urb(urb);
+ ctx->status = ret;
+ complete(&ctx->completion);
+ }
+}
+
+static struct powerz_sensor_data *powerz_read_data(struct usb_device *udev,
+ struct powerz_usb_ctx *ctx)
+{
+ struct urb *urb;
+ int r;
+
+ ctx->status = -ETIMEDOUT;
+ init_completion(&ctx->completion);
+
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb)
+ return ERR_PTR(-ENOMEM);
+
+ ctx->transfer_buffer[0] = 0x0c;
+ ctx->transfer_buffer[1] = 0x00;
+ ctx->transfer_buffer[2] = 0x02;
+ ctx->transfer_buffer[3] = 0x00;
+
+ usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, POWERZ_EP_CMD_OUT),
+ ctx->transfer_buffer, 4, powerz_usb_cmd_complete, ctx);
+ r = usb_submit_urb(urb, GFP_KERNEL);
+ if (r) {
+ usb_free_urb(urb);
+ return ERR_PTR(r);
+ }
+
+ if (!wait_for_completion_interruptible_timeout(&ctx->completion, msecs_to_jiffies(5))) {
+ usb_kill_urb(urb);
+ usb_free_urb(urb);
+ return ERR_PTR(-EIO);
+ }
+
+ if (ctx->status) {
+ usb_free_urb(urb);
+ return ERR_PTR(ctx->status);
+ }
+
+ if (urb->actual_length < (sizeof(struct powerz_sensor_data))) {
+ usb_free_urb(urb);
+ return ERR_PTR(-EIO);
+ }
+
+ usb_free_urb(urb);
+ return (struct powerz_sensor_data *)(ctx->transfer_buffer);
+}
+
+static int powerz_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ struct usb_interface *intf = to_usb_interface(dev->parent);
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct powerz_sensor_data *data;
+ struct powerz_usb_ctx *ctx;
+
+ ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ data = powerz_read_data(udev, ctx);
+ if (IS_ERR(data)) {
+ kfree(ctx);
+ return PTR_ERR(data);
+ }
+
+ if (type == hwmon_curr && attr == hwmon_curr_input)
+ *val = ((s32)le32_to_cpu(data->Ibus)) / 1000;
+ else if (type == hwmon_curr && attr == hwmon_curr_average)
+ *val = ((s32)le32_to_cpu(data->Ibus_avg)) / 1000;
+ else if (type == hwmon_in && attr == hwmon_in_input && channel == 0)
+ *val = le32_to_cpu(data->Vbus) / 1000;
+ else if (type == hwmon_in && attr == hwmon_in_average && channel == 0)
+ *val = le32_to_cpu(data->Vbus_avg) / 1000;
+ else if (type == hwmon_in && attr == hwmon_in_input && channel == 1)
+ *val = le16_to_cpu(data->cc1) / 10;
+ else if (type == hwmon_in && attr == hwmon_in_input && channel == 2)
+ *val = le16_to_cpu(data->cc2) / 10;
+ else if (type == hwmon_in && attr == hwmon_in_input && channel == 3)
+ *val = le16_to_cpu(data->dp) / 10;
+ else if (type == hwmon_in && attr == hwmon_in_input && channel == 4)
+ *val = le16_to_cpu(data->dm) / 10;
+ else if (type == hwmon_temp && attr == hwmon_temp_input)
+ *val = ((long)data->temp[1]) * 2000 + ((long)data->temp[0]) * 1000 / 128;
+ else
+ return -EINVAL;
+
+ kfree(ctx);
+
+ return 0;
+}
+
+static const struct hwmon_ops powerz_hwmon_ops = {
+ .is_visible = powerz_is_visible,
+ .read = powerz_read,
+ .read_string = powerz_read_string,
+};
+
+static const struct hwmon_chip_info powerz_chip_info = {
+ .ops = &powerz_hwmon_ops,
+ .info = powerz_info,
+};
+
+static int powerz_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct powerz_priv *priv;
+ struct device *parent;
+ const char *name;
+ int ret;
+
+ parent = &intf->dev;
+
+ priv = devm_kzalloc(parent, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ name = devm_hwmon_sanitize_name(parent, udev->product ?: DRIVER_NAME);
+ priv->hwmon_dev = hwmon_device_register_with_info(parent, name,
+ priv,
+ &powerz_chip_info,
+ NULL);
+ ret = PTR_ERR_OR_ZERO(priv->hwmon_dev);
+ priv->intf = intf;
+ usb_set_intfdata(intf, priv);
+
+ return ret;
+}
+
+static void powerz_disconnect(struct usb_interface *intf)
+{
+ struct powerz_priv *priv = usb_get_intfdata(intf);
+
+ hwmon_device_unregister(priv->hwmon_dev);
+}
+
+static const struct usb_device_id powerz_id_table[] = {
+ { USB_DEVICE_INTERFACE_NUMBER(0x5FC9, 0x0063, 0x00) }, /* ChargerLAB POWER-Z KM003C */
+ { }
+};
+MODULE_DEVICE_TABLE(usb, powerz_id_table);
+
+static struct usb_driver powerz_driver = {
+ .name = DRIVER_NAME,
+ .id_table = powerz_id_table,
+ .probe = powerz_probe,
+ .disconnect = powerz_disconnect,
+};
+module_usb_driver(powerz_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Thomas Weißschuh <linux@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("ChargerLAB POWER-Z USB-C tester");

---
base-commit: b97d64c722598ffed42ece814a2cb791336c6679
change-id: 20230831-powerz-2ccb978a8e57

Best regards,
--
Thomas Weißschuh <linux@xxxxxxxxxxxxxx>