On 9/1/23 15:36, Thomas Weißschuh wrote:
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>
---
Changes in v3:
- CC linux-usb list
- address Guenters review comments
- simplify hwmon chip name
- drop member "intf" from struct powerz_priv
- use devm-APIs
- return EOPNOTSUPP for invalid channels
- rework if-else chaining in read functions
- integrate transfer context into struct powerz_priv
- simplify logic and return value of powerz_read_data
- fix naming of struct powerz_sensor_data members
- explicitly include all necessary header files
- add doc
- simplify URB completion callbacks a bit
- fix indentation
- add support for VDD channel
- add support for VBUS/IBUS min/max as printed on the device itself
- allocate single URB as part of struct powerz_priv
- kill in-flight URBs on disconnect
- Link to v2: https://lore.kernel.org/r/20230831-powerz-v2-1-5c62c53debd4@xxxxxxxxxxxxxx
Changes in v2:
- fix syntax error in Kconfig
- avoid double free of urb in case of failure
- Link to v1: https://lore.kernel.org/r/20230831-powerz-v1-1-03979e519f52@xxxxxxxxxxxxxx
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/powerz.rst | 27 ++++ > MAINTAINERS | 7 +
drivers/hwmon/Kconfig | 10 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/powerz.c | 288 +++++++++++++++++++++++++++++++++++++++++
6 files changed, 334 insertions(+)
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 88dadea85cfc..10a54644557d 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -178,6 +178,7 @@ Hardware Monitoring Kernel Drivers
peci-cputemp
peci-dimmtemp
pmbus
+ powerz
powr1220
pxe1610
pwm-fan
diff --git a/Documentation/hwmon/powerz.rst b/Documentation/hwmon/powerz.rst
new file mode 100644
index 000000000000..530fff68ca6e
--- /dev/null
+++ b/Documentation/hwmon/powerz.rst
@@ -0,0 +1,27 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver POWERZ
+====================
+
+Supported chips:
+
+ * ChargerLAB POWER-Z KM003C
+
+ Prefix: 'powerz'
+
+ Addresses scanned: -
+
+Author:
+
+ - Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
+
+Description
+-----------
+
+This driver implements support for the ChargerLAB POWER-Z USB-C power testing
+family.
+
+The device communicates with the custom protocol over USB.
+
+The channel labels exposed via hwmon match the labels used by the on-device
+display and the official POWER-Z PC software.
diff --git a/MAINTAINERS b/MAINTAINERS
index fcbb106aaa57..153c6fe0a725 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4795,6 +4795,13 @@ 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: Documentation/hwmon/powerz.rst
+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..12af9f9cfd9f 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..6209339e5414
--- /dev/null
+++ b/drivers/hwmon/powerz.c
@@ -0,0 +1,288 @@
+// 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/device.h>
+#include <linux/hwmon.h>
+#include <linux/lockdep.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/usb.h>
+
+#define DRIVER_NAME "powerz"
+#define POWERZ_EP_CMD_OUT 0x01
+#define POWERZ_EP_DATA_IN 0x81
+
+/* as printed on the device itself */
+#define POWERZ_MAX_VOLTAGE 50000
+#define POWERZ_MAX_CURRENT 6000
+
+struct powerz_sensor_data {
+ u8 _unknown_1[8];
+ __le32 V_bus;
+ __le32 I_bus;
+ __le32 V_bus_avg;
+ __le32 I_bus_avg;
+ u8 _unknown_2[8];
+ u8 temp[2];
+ __le16 V_cc1;
+ __le16 V_cc2;
+ __le16 V_dp;
+ __le16 V_dm;
+ __le16 V_dd;
+ u8 _unknown_3[4];
+} __packed;
+
+struct powerz_priv {
+ char transfer_buffer[64]; /* first member to satisfy DMA alignment */
+ struct mutex mutex;
+ struct completion completion;
+ struct urb *urb;
+ int status;
+};
+
+static const struct hwmon_channel_info *const powerz_info[] = {
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LABEL | HWMON_I_AVERAGE |
+ HWMON_I_MIN | HWMON_I_MAX,
+ 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_AVERAGE |
+ HWMON_C_MIN | HWMON_I_MAX),
+ 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 = "IBUS";
+ } else if (type == hwmon_in && attr == hwmon_in_label) {
+ if (channel == 0)
+ *str = "VBUS";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 1)
+ *str = "VCC1";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 2)
+ *str = "VCC2";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 3)
+ *str = "VDP";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 4)
+ *str = "VDM";
+ else if (type == hwmon_in && attr == hwmon_in_label && channel == 5)
+ *str = "VDD";
All those repeated "type == hwmon_in && attr == hwmon_in_label" checks are
unnecessary. Note that this could be much simpler written as
const char *in_labels[] = {
"VBUS", "VCC1", "VCC2", "VDP", "VDM", "VDD"
};
...
*str = in_labels[channel];
but I'll leave that up to you.
+ else
+ return -EOPNOTSUPP;
+ } else if (type == hwmon_temp && attr == hwmon_temp_label) {
+ *str = "TEMP";
+ } else {
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static void powerz_usb_data_complete(struct urb *urb)
+{
+ struct powerz_priv *priv = urb->context;
+
+ complete(&priv->completion);
+}
+
+static void powerz_usb_cmd_complete(struct urb *urb)
+{
+ struct powerz_priv *priv = urb->context;
+
+ usb_fill_bulk_urb(urb, urb->dev,
+ usb_rcvbulkpipe(urb->dev, POWERZ_EP_DATA_IN),
+ priv->transfer_buffer, sizeof(priv->transfer_buffer),
+ powerz_usb_data_complete, priv);
+
+ priv->status = usb_submit_urb(urb, GFP_ATOMIC);
+ if (priv->status)
+ complete(&priv->completion);
+}
+
+static int powerz_read_data(struct usb_device *udev, struct powerz_priv *priv)
+{
+ int ret;
+
+ lockdep_assert_held(&priv->mutex);
+
This is a local function, so this check is unnecessary.
It is well known that the lock is held when this function is called.
+ priv->status = -ETIMEDOUT;
+ reinit_completion(&priv->completion);
+
+ priv->transfer_buffer[0] = 0x0c;
+ priv->transfer_buffer[1] = 0x00;
+ priv->transfer_buffer[2] = 0x02;
+ priv->transfer_buffer[3] = 0x00;
+
+ usb_fill_bulk_urb(priv->urb, udev, usb_sndbulkpipe(udev, POWERZ_EP_CMD_OUT),
+ priv->transfer_buffer, 4, powerz_usb_cmd_complete,
+ priv);
+ ret = usb_submit_urb(priv->urb, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ if (!wait_for_completion_interruptible_timeout
+ (&priv->completion, msecs_to_jiffies(5))) {
+ usb_kill_urb(priv->urb);
+ return -EIO;
+ }
+
+ if (priv->urb->actual_length < sizeof(struct powerz_sensor_data))
+ return -EIO;
+
+ return priv->status;
+}
+
+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_priv *priv = usb_get_intfdata(intf);
+ struct powerz_sensor_data *data;
+ int ret;
+
+ if (!priv)
+ return -EIO; /* disconnected */
+
+ mutex_lock(&priv->mutex);
+ ret = powerz_read_data(udev, priv);
+ if (ret)
+ goto out;
+
+ data = (struct powerz_sensor_data *)priv->transfer_buffer;
+
+ if (type == hwmon_curr) {
+ if (attr == hwmon_curr_input)
+ *val = ((s32)le32_to_cpu(data->I_bus)) / 1000;
+ else if (attr == hwmon_curr_average)
+ *val = ((s32)le32_to_cpu(data->I_bus_avg)) / 1000;
Just wondering ... does this device really report current in micro-amps ?
+ else if (attr == hwmon_curr_min)
+ *val = -POWERZ_MAX_CURRENT;
+ else if (attr == hwmon_curr_max)
+ *val = POWERZ_MAX_CURRENT;
I just noticed that. Please drop limits if they are constants.
That is not the idea with limit attributes; they should only
be provided if they are supported/reported by the chip/device,
not if they are constants (yes, I know, there are some drivers
reporting such constants, but that doesn't make it better or
acceptable).
+ else
+ ret = -EOPNOTSUPP;
+ } else if (type == hwmon_in) {
+ if (attr == hwmon_in_input) {
+ if (channel == 0)
+ *val = le32_to_cpu(data->V_bus) / 1000;
and voltage in micro-volt ? Just asking, because I don't think I have
ever seen that.
+ else if (channel == 1)
+ *val = le16_to_cpu(data->V_cc1) / 10;
+ else if (channel == 2)
+ *val = le16_to_cpu(data->V_cc2) / 10;
+ else if (channel == 3)
+ *val = le16_to_cpu(data->V_dp) / 10;
+ else if (channel == 4)
+ *val = le16_to_cpu(data->V_dm) / 10;
+ else if (channel == 5)
+ *val = le16_to_cpu(data->V_dd) / 10;
+ else
+ ret = -EOPNOTSUPP;
+ } else if (attr == hwmon_in_average && channel == 0) {
+ *val = le32_to_cpu(data->V_bus_avg) / 1000;
+ } else if (attr == hwmon_in_min && channel == 0) {
+ *val = -POWERZ_MAX_VOLTAGE;
+ } else if (attr == hwmon_in_max && channel == 0) {
+ *val = POWERZ_MAX_VOLTAGE;
+ } else {
There are more repeated checks (for channel == 0) here. Not that it matters,
because the constants should not bre reported anyway. Also, I do wonder if
hwmon_in_min == -POWERZ_MAX_VOLTAGE is really correct.
+ ret = -EOPNOTSUPP;
+ }
+ } else if (type == hwmon_temp && attr == hwmon_temp_input) {
+ *val =
+ ((long)data->temp[1]) * 2000 +
+ ((long)data->temp[0]) * 1000 / 128;
I guess this is really ((data->temp[1] << 8) + data->temp[0]) * 1000 / 128,
which might be easier to understand, but good enough. The typecasts are
unnecessary, though.
+ } else {
+ ret = -EOPNOTSUPP;
+ }
+
+out:
+ mutex_unlock(&priv->mutex);
+ return ret;
+}
+
+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 powerz_priv *priv;
+ struct device *hwmon_dev;
+ struct device *parent;
+
+ parent = &intf->dev;
+
+ priv = devm_kzalloc(parent, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!priv->urb)
+ return -ENOMEM;
+ mutex_init(&priv->mutex);
+ priv->status = -ETIMEDOUT;
I don't see why this would be needed here.
+ init_completion(&priv->completion);
+
+ hwmon_dev =
+ devm_hwmon_device_register_with_info(parent, DRIVER_NAME, priv,
+ &powerz_chip_info, NULL);
+ usb_set_intfdata(intf, priv);
+
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static void powerz_disconnect(struct usb_interface *intf)
+{
+ struct powerz_priv *priv = usb_get_intfdata(intf);
+
+ mutex_lock(&priv->mutex);
+ usb_kill_urb(priv->urb);
+ usb_free_urb(priv->urb);
+ mutex_unlock(&priv->mutex);
+}
+
+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: 29aa98d0fe013e2ab62aae4266231b7fb05d47a2
change-id: 20230831-powerz-2ccb978a8e57
Best regards,
