hwmon: add Corsair Commander Pro driver

This is v7 of a driver for the Corsair Commander Pro.
It provides sysfs attributes for:
- Reading fan speed
- Reading temp sensors
- Reading voltage values
- Writing pwm and reading last written pwm
- Reading fan and temp connection status

It is an usb driver, so it needs to be ignored by usbhid.
The Corsair Commander Pro is a fan controller and provides
no means for user interaction.
The two device numbers are there, because there is a slightly
different version of the same device. (Only difference
seem to be in some presets.)

Squashed:
 hwmon: (corsair-cpro) add fan_target

 This adds fan_target entries to the corsair-cpro driver.
 Reading the attribute from the device does not seem possible, so
 it returns the last set value (same as pwm).

 send_usb_cmd now has one more argument, which is needed for the
 fan_target command.

 hwmon: corsair-cpro: Change to HID driver

 This changes corsair-cpro to a hid driver using hid reports.
Signed-off-by: Marius Zachmann <mail@mariuszachmann.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200626055936.4441-1-mail@mariuszachmann.de
Link: https://lore.kernel.org/r/20200709141413.30790-1-mail@mariuszachmann.de
[groeck: Squashed follow-up patches to avoid changes in HID code]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/corsair-cpro.rst

+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver corsair-cpro
+==========================
+
+Supported devices:
+
+  * Corsair Commander Pro
+  * Corsair Commander Pro (1000D)
+
+Author: Marius Zachmann
+
+Description
+-----------
+
+This driver implements the sysfs interface for the Corsair Commander Pro.
+The Corsair Commander Pro is a USB device with 6 fan connectors,
+4 temperature sensor connectors and 2 Corsair LED connectors.
+It can read the voltage levels on the SATA power connector.
+
+Usage Notes
+-----------
+
+Since it is a USB device, hotswapping is possible. The device is autodetected.
+
+Sysfs entries
+-------------
+
+======================= =====================================================================
+in0_input		Voltage on SATA 12v
+in1_input		Voltage on SATA 5v
+in2_input		Voltage on SATA 3.3v
+temp[1-4]_input		Temperature on connected temperature sensors
+fan[1-6]_input		Connected fan rpm.
+fan[1-6]_label		Shows fan type as detected by the device.
+fan[1-6]_target		Sets fan speed target rpm.
+			When reading, it reports the last value if it was set by the driver.
+			Otherwise returns 0.
+pwm[1-6]		Sets the fan speed. Values from 0-255.
+			When reading, it reports the last value if it was set by the driver.
+			Otherwise returns 0.
+======================= =====================================================================

Documentation/hwmon/index.rst

@@ -47,6 +47,7 @@ Hardware Monitoring Kernel Drivers
    bel-pfe
    bt1-pvt
    coretemp
+   corsair-cpro
    da9052
    da9055
    dell-smm-hwmon

MAINTAINERS

@@ -4401,6 +4401,12 @@ S:	Maintained
 F:	Documentation/hwmon/coretemp.rst
 F:	drivers/hwmon/coretemp.c
 
+CORSAIR-CPRO HARDWARE MONITOR DRIVER
+M:	Marius  <mail@mariuszachmann.de>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	drivers/hwmon/corsair-cpro.c
+
 COSA/SRP SYNC SERIAL DRIVER
 M:	Jan "Yenya" Kasprzak <kas@fi.muni.cz>
 S:	Maintained

drivers/hwmon/Kconfig

@@ -439,6 +439,16 @@ config SENSORS_BT1_PVT_ALARMS
 	  the data conversion will be periodically performed and the data will be
 	  saved in the internal driver cache.
 
+config SENSORS_CORSAIR_CPRO
+	tristate "Corsair Commander Pro controller"
+	depends on HID
+	help
+	  If you say yes here you get support for the Corsair Commander Pro
+	  controller.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called corsair-cpro.
+
 config SENSORS_DRIVETEMP
 	tristate "Hard disk drives with temperature sensors"
 	depends on SCSI && ATA

drivers/hwmon/Makefile

@@ -56,6 +56,7 @@ obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
 obj-$(CONFIG_SENSORS_BT1_PVT)	+= bt1-pvt.o
 obj-$(CONFIG_SENSORS_CORETEMP)	+= coretemp.o
+obj-$(CONFIG_SENSORS_CORSAIR_CPRO) += corsair-cpro.o
 obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
 obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
 obj-$(CONFIG_SENSORS_DELL_SMM)	+= dell-smm-hwmon.o

drivers/hwmon/corsair-cpro.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * corsair-cpro.c - Linux driver for Corsair Commander Pro
+ * Copyright (C) 2020 Marius Zachmann <mail@mariuszachmann.de>
+ *
+ * This driver uses hid reports to communicate with the device to allow hidraw userspace drivers
+ * still being used. The device does not use report ids. When using hidraw and this driver
+ * simultaniously, reports could be switched.
+ */
+
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/hid.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define USB_VENDOR_ID_CORSAIR			0x1b1c
+#define USB_PRODUCT_ID_CORSAIR_COMMANDERPRO	0x0c10
+#define USB_PRODUCT_ID_CORSAIR_1000D		0x1d00
+
+#define OUT_BUFFER_SIZE		63
+#define IN_BUFFER_SIZE		16
+#define LABEL_LENGTH		11
+#define REQ_TIMEOUT		300
+
+#define CTL_GET_TMP_CNCT	0x10	/*
+					 * returns in bytes 1-4 for each temp sensor:
+					 * 0 not connected
+					 * 1 connected
+					 */
+#define CTL_GET_TMP		0x11	/*
+					 * send: byte 1 is channel, rest zero
+					 * rcv:  returns temp for channel in centi-degree celsius
+					 * in bytes 1 and 2
+					 * returns 17 in byte 0 if no sensor is connected
+					 */
+#define CTL_GET_VOLT		0x12	/*
+					 * send: byte 1 is rail number: 0 = 12v, 1 = 5v, 2 = 3.3v
+					 * rcv:  returns millivolt in bytes 1,2
+					 */
+#define CTL_GET_FAN_CNCT	0x20	/*
+					 * returns in bytes 1-6 for each fan:
+					 * 0 not connected
+					 * 1 3pin
+					 * 2 4pin
+					 */
+#define CTL_GET_FAN_RPM		0x21	/*
+					 * send: byte 1 is channel, rest zero
+					 * rcv:  returns rpm in bytes 1,2
+					 */
+#define CTL_SET_FAN_FPWM	0x23	/*
+					 * set fixed pwm
+					 * send: byte 1 is fan number
+					 * send: byte 2 is percentage from 0 - 100
+					 */
+#define CTL_SET_FAN_TARGET	0x24	/*
+					 * set target rpm
+					 * send: byte 1 is fan number
+					 * send: byte 2-3 is target
+					 * device accepts all values from 0x00 - 0xFFFF
+					 */
+
+#define NUM_FANS		6
+#define NUM_TEMP_SENSORS	4
+
+struct ccp_device {
+	struct hid_device *hdev;
+	struct device *hwmon_dev;
+	struct completion wait_input_report;
+	struct mutex mutex; /* whenever buffer is used, lock before send_usb_cmd */
+	u8 *buffer;
+	int pwm[6];
+	int target[6];
+	DECLARE_BITMAP(temp_cnct, NUM_TEMP_SENSORS);
+	DECLARE_BITMAP(fan_cnct, NUM_FANS);
+	char fan_label[6][LABEL_LENGTH];
+};
+
+/* send command, check for error in response, response in ccp->buffer */
+static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2, u8 byte3)
+{
+	unsigned long t;
+	int ret;
+
+	memset(ccp->buffer, 0x00, OUT_BUFFER_SIZE);
+	ccp->buffer[0] = command;
+	ccp->buffer[1] = byte1;
+	ccp->buffer[2] = byte2;
+	ccp->buffer[3] = byte3;
+
+	reinit_completion(&ccp->wait_input_report);
+
+	ret = hid_hw_output_report(ccp->hdev, ccp->buffer, OUT_BUFFER_SIZE);
+	if (ret < 0)
+		return ret;
+
+	t = wait_for_completion_timeout(&ccp->wait_input_report, msecs_to_jiffies(REQ_TIMEOUT));
+	if (!t)
+		return -ETIMEDOUT;
+
+	/* first byte of response is error code */
+	if (ccp->buffer[0] != 0x00) {
+		hid_dbg(ccp->hdev, "device response error: %d", ccp->buffer[0]);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int ccp_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size)
+{
+	struct ccp_device *ccp = hid_get_drvdata(hdev);
+
+	/* only copy buffer when requested */
+	if (completion_done(&ccp->wait_input_report))
+		return 0;
+
+	memcpy(ccp->buffer, data, min(IN_BUFFER_SIZE, size));
+	complete(&ccp->wait_input_report);
+
+	return 0;
+}
+
+/* requests and returns single data values depending on channel */
+static int get_data(struct ccp_device *ccp, int command, int channel)
+{
+	int ret;
+
+	mutex_lock(&ccp->mutex);
+
+	ret = send_usb_cmd(ccp, command, channel, 0, 0);
+	if (ret)
+		goto out_unlock;
+
+	ret = (ccp->buffer[1] << 8) + ccp->buffer[2];
+
+out_unlock:
+	mutex_unlock(&ccp->mutex);
+	return ret;
+}
+
+static int set_pwm(struct ccp_device *ccp, int channel, long val)
+{
+	int ret;
+
+	if (val < 0 || val > 255)
+		return -EINVAL;
+
+	ccp->pwm[channel] = val;
+
+	/* The Corsair Commander Pro uses values from 0-100 */
+	val = DIV_ROUND_CLOSEST(val * 100, 255);
+
+	mutex_lock(&ccp->mutex);
+
+	ret = send_usb_cmd(ccp, CTL_SET_FAN_FPWM, channel, val, 0);
+
+	mutex_unlock(&ccp->mutex);
+	return ret;
+}
+
+static int set_target(struct ccp_device *ccp, int channel, long val)
+{
+	int ret;
+
+	val = clamp_val(val, 0, 0xFFFF);
+	ccp->target[channel] = val;
+
+	mutex_lock(&ccp->mutex);
+
+	ret = send_usb_cmd(ccp, CTL_SET_FAN_TARGET, channel, val >> 8, val);
+
+	mutex_unlock(&ccp->mutex);
+	return ret;
+}
+
+static int ccp_read_string(struct device *dev, enum hwmon_sensor_types type,
+			   u32 attr, int channel, const char **str)
+{
+	struct ccp_device *ccp = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_label:
+			*str = ccp->fan_label[channel];
+			return 0;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static int ccp_read(struct device *dev, enum hwmon_sensor_types type,
+		    u32 attr, int channel, long *val)
+{
+	struct ccp_device *ccp = dev_get_drvdata(dev);
+	int ret;
+
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			ret = get_data(ccp, CTL_GET_TMP, channel);
+			if (ret < 0)
+				return ret;
+			*val = ret * 10;
+			return 0;
+		default:
+			break;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			ret = get_data(ccp, CTL_GET_FAN_RPM, channel);
+			if (ret < 0)
+				return ret;
+			*val = ret;
+			return 0;
+		case hwmon_fan_target:
+			/* how to read target values from the device is unknown */
+			/* driver returns last set value or 0			*/
+			*val = ccp->target[channel];
+			return 0;
+		default:
+			break;
+		}
+		break;
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			/* how to read pwm values from the device is currently unknown */
+			/* driver returns last set value or 0		               */
+			*val = ccp->pwm[channel];
+			return 0;
+		default:
+			break;
+		}
+		break;
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			ret = get_data(ccp, CTL_GET_VOLT, channel);
+			if (ret < 0)
+				return ret;
+			*val = ret;
+			return 0;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+};
+
+static int ccp_write(struct device *dev, enum hwmon_sensor_types type,
+		     u32 attr, int channel, long val)
+{
+	struct ccp_device *ccp = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			return set_pwm(ccp, channel, val);
+		default:
+			break;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_target:
+			return set_target(ccp, channel, val);
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+};
+
+static umode_t ccp_is_visible(const void *data, enum hwmon_sensor_types type,
+			      u32 attr, int channel)
+{
+	const struct ccp_device *ccp = data;
+
+	switch (type) {
+	case hwmon_temp:
+		if (!test_bit(channel, ccp->temp_cnct))
+			break;
+
+		switch (attr) {
+		case hwmon_temp_input:
+			return 0444;
+		case hwmon_temp_label:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	case hwmon_fan:
+		if (!test_bit(channel, ccp->fan_cnct))
+			break;
+
+		switch (attr) {
+		case hwmon_fan_input:
+			return 0444;
+		case hwmon_fan_label:
+			return 0444;
+		case hwmon_fan_target:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	case hwmon_pwm:
+		if (!test_bit(channel, ccp->fan_cnct))
+			break;
+
+		switch (attr) {
+		case hwmon_pwm_input:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+};
+
+static const struct hwmon_ops ccp_hwmon_ops = {
+	.is_visible = ccp_is_visible,
+	.read = ccp_read,
+	.read_string = ccp_read_string,
+	.write = ccp_write,
+};
+
+static const struct hwmon_channel_info *ccp_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_REGISTER_TZ),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT
+			   ),
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_TARGET
+			   ),
+	HWMON_CHANNEL_INFO(pwm,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT
+			   ),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT
+			   ),
+	NULL
+};
+
+static const struct hwmon_chip_info ccp_chip_info = {
+	.ops = &ccp_hwmon_ops,
+	.info = ccp_info,
+};
+
+/* read fan connection status and set labels */
+static int get_fan_cnct(struct ccp_device *ccp)
+{
+	int channel;
+	int mode;
+	int ret;
+
+	ret = send_usb_cmd(ccp, CTL_GET_FAN_CNCT, 0, 0, 0);
+	if (ret)
+		return ret;
+
+	for (channel = 0; channel < NUM_FANS; channel++) {
+		mode = ccp->buffer[channel + 1];
+		if (mode == 0)
+			continue;
+
+		set_bit(channel, ccp->fan_cnct);
+
+		switch (mode) {
+		case 1:
+			scnprintf(ccp->fan_label[channel], LABEL_LENGTH,
+				  "fan%d 3pin", channel + 1);
+			break;
+		case 2:
+			scnprintf(ccp->fan_label[channel], LABEL_LENGTH,
+				  "fan%d 4pin", channel + 1);
+			break;
+		default:
+			scnprintf(ccp->fan_label[channel], LABEL_LENGTH,
+				  "fan%d other", channel + 1);
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/* read temp sensor connection status */
+static int get_temp_cnct(struct ccp_device *ccp)
+{
+	int channel;
+	int mode;
+	int ret;
+
+	ret = send_usb_cmd(ccp, CTL_GET_TMP_CNCT, 0, 0, 0);
+	if (ret)
+		return ret;
+
+	for (channel = 0; channel < NUM_TEMP_SENSORS; channel++) {
+		mode = ccp->buffer[channel + 1];
+		if (mode == 0)
+			continue;
+
+		set_bit(channel, ccp->temp_cnct);
+	}
+
+	return 0;
+}
+
+static int ccp_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct ccp_device *ccp;
+	int ret;
+
+	ccp = devm_kzalloc(&hdev->dev, sizeof(*ccp), GFP_KERNEL);
+	if (!ccp)
+		return -ENOMEM;
+
+	ccp->buffer = devm_kmalloc(&hdev->dev, OUT_BUFFER_SIZE, GFP_KERNEL);
+	if (!ccp->buffer)
+		return -ENOMEM;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret)
+		return ret;
+
+	ret = hid_hw_open(hdev);
+	if (ret)
+		goto out_hw_stop;
+
+	ccp->hdev = hdev;
+	hid_set_drvdata(hdev, ccp);
+	mutex_init(&ccp->mutex);
+	init_completion(&ccp->wait_input_report);
+
+	hid_device_io_start(hdev);
+
+	/* temp and fan connection status only updates when device is powered on */
+	ret = get_temp_cnct(ccp);
+	if (ret)
+		goto out_hw_close;
+
+	ret = get_fan_cnct(ccp);
+	if (ret)
+		goto out_hw_close;
+	ccp->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, "corsaircpro",
+							 ccp, &ccp_chip_info, 0);
+	if (IS_ERR(ccp->hwmon_dev)) {
+		ret = PTR_ERR(ccp->hwmon_dev);
+		goto out_hw_close;
+	}
+
+	return 0;
+
+out_hw_close:
+	hid_hw_close(hdev);
+out_hw_stop:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void ccp_remove(struct hid_device *hdev)
+{
+	struct ccp_device *ccp = hid_get_drvdata(hdev);
+
+	hwmon_device_unregister(ccp->hwmon_dev);
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id ccp_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_COMMANDERPRO) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CORSAIR, USB_PRODUCT_ID_CORSAIR_1000D) },
+	{ }
+};
+
+static struct hid_driver ccp_driver = {
+	.name = "corsair-cpro",
+	.id_table = ccp_devices,
+	.probe = ccp_probe,
+	.remove = ccp_remove,
+	.raw_event = ccp_raw_event,
+};
+
+MODULE_DEVICE_TABLE(hid, ccp_devices);
+MODULE_LICENSE("GPL");
+
+static int __init ccp_init(void)
+{
+	return hid_register_driver(&ccp_driver);
+}
+
+static void __exit ccp_exit(void)
+{
+	hid_unregister_driver(&ccp_driver);
+}
+
+/*
+ * When compiling this driver as built-in, hwmon initcalls will get called before the
+ * hid driver and this driver would fail to register. late_initcall solves this.
+ */
+late_initcall(ccp_init);
+module_exit(ccp_exit);