[PATCH v5 0/2] Update ASUS WMI supported boards

[PATCH v5 0/2] Update ASUS WMI supported boards

[Denis Pauk]

Add support by WMI interface privided by Asus for B550/X570 boards: 
* PRIME X570-PRO,
* ROG CROSSHAIR VIII HERO
* ROG CROSSHAIR VIII DARK HERO
* ROG CROSSHAIR VIII FORMULA
* ROG STRIX X570-E GAMING
* ROG STRIX B550-E GAMING

Add support by WMI interface privided by Asus for X370/X470/
B450/X399 boards:
* ROG CROSSHAIR VI HERO,
* PRIME X399-A,
* PRIME X470-PRO,
* ROG CROSSHAIR VI EXTREME,
* ROG CROSSHAIR VI HERO (WI-FI AC),
* ROG CROSSHAIR VII HERO,
* ROG CROSSHAIR VII HERO (WI-FI),
* ROG STRIX B450-E GAMING,
* ROG STRIX B450-F GAMING,
* ROG STRIX B450-I GAMING,
* ROG STRIX X399-E GAMING,
* ROG STRIX X470-F GAMING,
* ROG STRIX X470-I GAMING,
* ROG ZENITH EXTREME,
* ROG ZENITH EXTREME ALPHA.

Fix warning reported by: kernel test robot.

Could you please review?

Signed-off-by: Denis Pauk <pauk.denis@gmail.com>
Signed-off-by: Ed Brindley <kernel@maidavale.org>
Signed-off-by: Eugene Shalygin <eugene.shalygin@gmail.com>

---
Changes in v5:
- Fixes build issue reported by kernel test robot with disabled ACPI_WMI.
- asus_wmi_sensors: Remove sensor->name check as always evaluated to true.

Changes in v4:
 - Implement wmi driver instead platform driver.
 - Update documentation with known issues.

Changes in v3:
 - Use MODULE_DEVICE_TABLE for match devices.
 - asus_wmi_ec_sensors: Use get_unaligned_be32 instead incorrectly used 
   get_unaligned_le32.
 - Add documentaion for drivers.

Changes in v2:
 - asus_wmi_ec_sensors: Rename asus_wmi_sensors to asus_wmi_ec_sensors for 
   B550/X570 boards.
 - asus_wmi_ec_sensors: Use utf8s_to_utf16s/utf16s_to_utf8s instead handmade 
   fuctions.
 - asus_wmi_ec_sensors: Use post increment.
 - asus_wmi_ec_sensors: Use get_unaligned* for convert values.
 - asus_wmi_ec_sensors: Use PTR_ERR_OR_ZERO.
 - asus_wmi_ec_sensors: Specify per-board sensors in a declarative way 
   (by Eugene Shalygin).
 - asus_wmi_sensors: Add support for X370/X470/B450/X399 boards.

---

Denis Pauk (2):
  hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.
  hwmon: (asus_wmi_sensors) Support X370 Asus WMI.

 Documentation/hwmon/asus_wmi_ec_sensors.rst |  35 ++
 Documentation/hwmon/asus_wmi_sensors.rst    |  74 +++
 MAINTAINERS                                 |   8 +
 drivers/hwmon/Kconfig                       |  22 +
 drivers/hwmon/Makefile                      |   2 +
 drivers/hwmon/asus_wmi_ec_sensors.c         | 648 ++++++++++++++++++++
 drivers/hwmon/asus_wmi_sensors.c            | 621 +++++++++++++++++++
 7 files changed, 1410 insertions(+)
 create mode 100644 Documentation/hwmon/asus_wmi_ec_sensors.rst
 create mode 100644 Documentation/hwmon/asus_wmi_sensors.rst
 create mode 100644 drivers/hwmon/asus_wmi_ec_sensors.c
 create mode 100644 drivers/hwmon/asus_wmi_sensors.c


base-commit: 39b483aa38995329326988cbc4077422bebc175a
-- 
2.33.0

[PATCH v5 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Denis Pauk]

Linux HWMON sensors driver for ASUS motherboards to read
sensors from the embedded controller.

Many ASUS motherboards do not publish all the available
sensors via the Super I/O chip but the missing ones are
available through the embedded controller (EC) registers.

This driver implements reading those sensor data via the
WMI method BREC, which is known to be present in all ASUS
motherboards based on the AMD 500 series chipsets (and
probably is available in other models too). The driver
needs to know exact register addresses for the sensors and
thus support for each motherboard has to be added explicitly.

The EC registers do not provide critical values for the
sensors and as such they are not published to the HWMON.

Supported motherboards:
* PRIME X570-PRO
* ROG CROSSHAIR VIII HERO
* ROG CROSSHAIR VIII DARK HERO
* ROG CROSSHAIR VIII FORMULA
* ROG STRIX X570-E GAMING
* ROG STRIX B550-E GAMING

Signed-off-by: Denis Pauk <pauk.denis@gmail.com>
Co-developed-by: Eugene Shalygin <eugene.shalygin@gmail.com>
Signed-off-by: Eugene Shalygin <eugene.shalygin@gmail.com>
Tested-by: Tor Vic <torvic9@mailbox.org>
Reported-by: kernel test robot <lkp@intel.com>

---
Changes in v5:
- Fixes build issue reported by kernel test robot with disabled ACPI_WMI.

Changes in v4:
 - implement wmi driver instead platform driver.

Changes in v3:
 - Use MODULE_DEVICE_TABLE for match devices.
 - Use get_unaligned_be32 instead incorrectly used get_unaligned_le32.
 - Add documentaion for driver.

Changes in v2:
 - Use utf8s_to_utf16s/utf16s_to_utf8s instead handmade fuctions.
 - Use post increment.
 - Use get_unaligned* for convert values.
 - Use PTR_ERR_OR_ZERO.
 - Specify per-board sensors in a declarative way (by Eugene Shalygin).
---
 Documentation/hwmon/asus_wmi_ec_sensors.rst |  35 ++
 MAINTAINERS                                 |   7 +
 drivers/hwmon/Kconfig                       |  11 +
 drivers/hwmon/Makefile                      |   1 +
 drivers/hwmon/asus_wmi_ec_sensors.c         | 648 ++++++++++++++++++++
 5 files changed, 702 insertions(+)
 create mode 100644 Documentation/hwmon/asus_wmi_ec_sensors.rst
 create mode 100644 drivers/hwmon/asus_wmi_ec_sensors.c

diff --git a/Documentation/hwmon/asus_wmi_ec_sensors.rst b/Documentation/hwmon/asus_wmi_ec_sensors.rst
new file mode 100644
index 000000000000..e4f603804a82
--- /dev/null
+++ b/Documentation/hwmon/asus_wmi_ec_sensors.rst
@@ -0,0 +1,35 @@
+Kernel driver asus-wmi-ec-sensors
+=================================
+
+Supported boards:
+ * PRIME X570-PRO,
+ * Pro WS X570-ACE,
+ * ROG CROSSHAIR VIII DARK HERO,
+ * ROG CROSSHAIR VIII FORMULA,
+ * ROG CROSSHAIR VIII HERO,
+ * ROG STRIX B550-E GAMING,
+ * ROG STRIX X570-E GAMING.
+
+Authors:
+        Eugene Shalygin <eugene.shalygin@gmail.com>
+
+Description:
+------------
+ASUS mainboards publish hardware monitoring information via Super I/O
+chip and the ACPI embedded controller (EC) registers. Some of the sensors
+are only available via the EC.
+
+ASUS WMI interface provides a method (BREC) to read data from EC registers,
+which is utilized by this driver to publish those sensor readings to the
+HWMON system. The driver is aware of and reads the following sensors:
+
+1. Chipset (PCH) temperature
+2. CPU package temperature
+3. Motherboard temperature
+4. Readings from the T_Sensor header
+5. VRM temperature
+6. CPU_Opt fan RPM
+7. Chipset fan RPM
+8. Readings from the "Water flow meter" header (RPM)
+9. Readings from the "Water In" and "Water Out" temperature headers
+10. CPU current
diff --git a/MAINTAINERS b/MAINTAINERS
index cc5eaf4e65dc..05448435991d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2937,6 +2937,13 @@ W:	http://acpi4asus.sf.net
 F:	drivers/platform/x86/asus*.c
 F:	drivers/platform/x86/eeepc*.c
 
+ASUS WMI HARDWARE MONITOR DRIVER
+M:	Eugene Shalygin <eugene.shalygin@gmail.com>
+M:	Denis Pauk <pauk.denis@gmail.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	drivers/hwmon/asus_wmi_ec_sensors.c
+
 ASUS WIRELESS RADIO CONTROL DRIVER
 M:	João Paulo Rechi Vita <jprvita@gmail.com>
 L:	platform-driver-x86@vger.kernel.org
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 7fde4c6e1e7f..430a438432a0 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2215,6 +2215,17 @@ config SENSORS_ATK0110
 	  This driver can also be built as a module. If so, the module
 	  will be called asus_atk0110.
 
+config SENSORS_ASUS_WMI_EC
+	tristate "ASUS WMI B550/X570"
+	help
+	  If you say yes here you get support for the ACPI embedded controller
+	  hardware monitoring interface found in B550/X570 ASUS motherboards.
+	  This driver will provide readings of fans, voltages and temperatures
+	  through the system firmware.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called asus_wmi_sensors_ec.
+
 endif # ACPI
 
 endif # HWMON
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index baee6a8d4dd1..aae2ff5c7335 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_HWMON_VID)		+= hwmon-vid.o
 # APCI drivers
 obj-$(CONFIG_SENSORS_ACPI_POWER) += acpi_power_meter.o
 obj-$(CONFIG_SENSORS_ATK0110)	+= asus_atk0110.o
+obj-$(CONFIG_SENSORS_ASUS_WMI_EC)	+= asus_wmi_ec_sensors.o
 
 # Native drivers
 # asb100, then w83781d go first, as they can override other drivers' addresses.
diff --git a/drivers/hwmon/asus_wmi_ec_sensors.c b/drivers/hwmon/asus_wmi_ec_sensors.c
new file mode 100644
index 000000000000..f9d8a0be7bea
--- /dev/null
+++ b/drivers/hwmon/asus_wmi_ec_sensors.c
@@ -0,0 +1,648 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * HWMON driver for ASUS B550/X570 motherboards that publish sensor
+ * values via the embedded controller registers.
+ *
+ * Copyright (C) 2021 Eugene Shalygin <eugene.shalygin@gmail.com>
+ * Copyright (C) 2018-2019 Ed Brindley <kernel@maidavale.org>
+ *
+ * EC provides:
+ * Chipset temperature,
+ * CPU temperature,
+ * Motherboard temperature,
+ * T_Sensor temperature,
+ * VRM  temperature,
+ * Water In temperature,
+ * Water Out temperature,
+ * CPU Optional Fan RPM,
+ * Chipset Fan RPM,
+ * Water Flow Fan RPM,
+ * CPU current.
+ *
+ */
+#include <asm/unaligned.h>
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/nls.h>
+#include <linux/units.h>
+#include <linux/wmi.h>
+
+#define ASUSWMI_MONITORING_GUID		"466747A0-70EC-11DE-8A39-0800200C9A66"
+#define ASUSWMI_METHODID_BLOCK_READ_EC		0x42524543 /* BREC */
+
+#define ASUS_WMI_BLOCK_READ_REGISTERS_MAX 0x10 /* from the ASUS DSDT source */
+/* from the ASUS_WMI_BLOCK_READ_REGISTERS_MAX value */
+#define ASUS_WMI_MAX_BUF_LEN 0x80
+#define MAX_SENSOR_LABEL_LENGTH 0x10
+
+static u32 hwmon_attributes[] = {
+	[hwmon_chip] = HWMON_C_REGISTER_TZ,
+	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
+	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
+	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
+	[hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL,
+};
+
+struct asus_wmi_ec_sensor_address {
+	u8 index;
+	u8 bank;
+	u8 size;
+};
+
+#define MAKE_SENSOR_ADDRESS(size_i, bank_i, index_i) \
+	{ .size = size_i,\
+	   .bank = bank_i,\
+	   .index = index_i}
+
+struct ec_sensor_info {
+	char label[MAX_SENSOR_LABEL_LENGTH];
+	enum hwmon_sensor_types type;
+	struct asus_wmi_ec_sensor_address addr;
+};
+
+#define EC_SENSOR(sensor_label, sensor_type, size, bank, index) \
+	{ .label = sensor_label,\
+	.type = sensor_type, \
+	.addr = MAKE_SENSOR_ADDRESS(size, bank, index) \
+	}
+
+enum known_ec_sensor {
+	SENSOR_TEMP_CHIPSET,
+	SENSOR_TEMP_CPU,
+	SENSOR_TEMP_MB,
+	SENSOR_TEMP_T_SENSOR,
+	SENSOR_TEMP_VRM,
+	SENSOR_FAN_CPU_OPT,
+	SENSOR_FAN_CHIPSET,
+	SENSOR_FAN_WATER_FLOW,
+	SENSOR_CURR_CPU,
+	SENSOR_TEMP_WATER_IN,
+	SENSOR_TEMP_WATER_OUT,
+	SENSOR_MAX
+};
+
+/*
+ * All the known sensors for ASUS EC controllers
+ */
+static const struct ec_sensor_info known_ec_sensors[] = {
+	[SENSOR_TEMP_CHIPSET] = EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
+	[SENSOR_TEMP_CPU] = EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
+	[SENSOR_TEMP_MB] = EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
+	[SENSOR_TEMP_T_SENSOR] = EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
+	[SENSOR_TEMP_VRM] = EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
+	[SENSOR_FAN_CPU_OPT] = EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xb0),
+	[SENSOR_FAN_CHIPSET] = EC_SENSOR("Chipset", hwmon_fan, 2, 0x00, 0xb4),
+	[SENSOR_FAN_WATER_FLOW] = EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xbc),
+	[SENSOR_CURR_CPU] = EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
+	[SENSOR_TEMP_WATER_IN] = EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x00),
+	[SENSOR_TEMP_WATER_OUT] = EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x01),
+};
+
+struct asus_wmi_data {
+	const enum known_ec_sensor known_board_sensors[SENSOR_MAX + 1];
+};
+
+/* boards with EC support */
+static struct asus_wmi_data sensors_board_PW_X570_P = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB, SENSOR_TEMP_VRM,
+		SENSOR_FAN_CHIPSET,
+		SENSOR_MAX
+	},
+};
+
+static struct asus_wmi_data sensors_board_PW_X570_A = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB, SENSOR_TEMP_VRM,
+		SENSOR_FAN_CHIPSET,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+static struct asus_wmi_data sensors_board_R_C8H = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
+		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
+		SENSOR_TEMP_WATER_IN, SENSOR_TEMP_WATER_OUT,
+		SENSOR_FAN_CPU_OPT, SENSOR_FAN_CHIPSET, SENSOR_FAN_WATER_FLOW,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+/* Same as Hero but without chipset fan */
+static struct asus_wmi_data sensors_board_R_C8DH = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
+		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
+		SENSOR_TEMP_WATER_IN, SENSOR_TEMP_WATER_OUT,
+		SENSOR_FAN_CPU_OPT, SENSOR_FAN_WATER_FLOW,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+/* Same as Hero but without water */
+static struct asus_wmi_data sensors_board_R_C8F = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
+		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
+		SENSOR_FAN_CPU_OPT, SENSOR_FAN_CHIPSET,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+static struct asus_wmi_data sensors_board_RS_B550_E_G = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
+		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
+		SENSOR_FAN_CPU_OPT,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+static struct asus_wmi_data sensors_board_RS_X570_E_G = {
+	.known_board_sensors = {
+		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
+		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
+		SENSOR_FAN_CHIPSET,
+		SENSOR_CURR_CPU,
+		SENSOR_MAX
+	},
+};
+
+static struct asus_wmi_data *board_sensors;
+
+static int __init asus_wmi_dmi_matched(const struct dmi_system_id *d)
+{
+	board_sensors = d->driver_data;
+	return 0;
+}
+
+#define DMI_EXACT_MATCH_ASUS_BOARD_NAME(name, sensors) \
+	{ \
+		.callback = asus_wmi_dmi_matched, \
+		.matches = { \
+			DMI_EXACT_MATCH(DMI_BOARD_VENDOR, \
+					"ASUSTeK COMPUTER INC."), \
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, name), \
+		}, \
+		.driver_data = sensors, \
+	}
+
+static const struct dmi_system_id asus_wmi_ec_dmi_table[] = {
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X570-PRO", &sensors_board_PW_X570_P),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("Pro WS X570-ACE", &sensors_board_PW_X570_A),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII DARK HERO", &sensors_board_R_C8DH),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII FORMULA", &sensors_board_R_C8F),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII HERO", &sensors_board_R_C8H),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B550-E GAMING", &sensors_board_RS_B550_E_G),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X570-E GAMING", &sensors_board_RS_X570_E_G),
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, asus_wmi_ec_dmi_table);
+
+struct ec_sensor {
+	enum known_ec_sensor info_index;
+	u32 cached_value;
+};
+
+/**
+ * struct asus_wmi_ec_info - sensor info.
+ * @sensors: list of sensors.
+ * @read_arg: UTF-16 string to pass to BRxx() WMI function.
+ * @read_buffer: decoded output from WMI result.
+ * @nr_sensors: number of board EC sensors.
+ * @nr_registers: number of EC registers to read (sensor might span more than
+ *                         1 register).
+ * @last_updated: in jiffies.
+ */
+struct asus_wmi_ec_info {
+	struct ec_sensor sensors[SENSOR_MAX];
+	char read_arg[((ASUS_WMI_BLOCK_READ_REGISTERS_MAX * 4) + 1) * 2];
+	u8 read_buffer[ASUS_WMI_BLOCK_READ_REGISTERS_MAX];
+	unsigned int nr_sensors;
+	unsigned int nr_registers;
+	unsigned long last_updated;
+};
+
+struct asus_wmi_sensors {
+	/* lock access to instrnal cache */
+	struct mutex lock;
+	struct asus_wmi_ec_info ec;
+};
+
+static int asus_wmi_ec_fill_board_sensors(struct asus_wmi_ec_info *ec)
+{
+	const enum known_ec_sensor *bsi;
+	struct ec_sensor *s = ec->sensors;
+	int i;
+
+	if (!board_sensors)
+		return -ENODEV;
+
+	bsi = board_sensors->known_board_sensors;
+	ec->nr_sensors = 0;
+	ec->nr_registers = 0;
+
+	for (i = 0; i < SENSOR_MAX && bsi[i] != SENSOR_MAX; i++) {
+		s[i].info_index = bsi[i];
+		s[i].cached_value = 0;
+		ec->nr_sensors++;
+		ec->nr_registers += known_ec_sensors[bsi[i]].addr.size;
+	}
+
+	return 0;
+}
+
+/*
+ * The next four functions converts to/from BRxx string argument format
+ * The format of the string is as follows:
+ * The string consists of two-byte UTF-16 characters
+ * The value of the very first byte int the string is equal to the total length
+ * of the next string in bytes, thus excluding the first two-byte character
+ * The rest of the string encodes pairs of (bank, index) pairs, where both
+ * values are byte-long (0x00 to 0xFF)
+ * Numbers are encoded as UTF-16 hex values
+ */
+static void asus_wmi_ec_decode_reply_buffer(const u8 *inp, u8 *out)
+{
+	unsigned int len = ACPI_MIN(ASUS_WMI_MAX_BUF_LEN, inp[0] / 4);
+	char buffer[ASUS_WMI_MAX_BUF_LEN * 2];
+	const char *pos = buffer;
+	const u8 *data = inp + 2;
+	unsigned int i;
+
+	utf16s_to_utf8s((wchar_t *)data, len * 2,  UTF16_LITTLE_ENDIAN, buffer, len * 2);
+
+	for (i = 0; i < len; i++, pos += 2)
+		out[i] = (hex_to_bin(pos[0]) << 4) + hex_to_bin(pos[1]);
+}
+
+static void asus_wmi_ec_encode_registers(u16 *registers, u8 len, char *out)
+{
+	char buffer[ASUS_WMI_MAX_BUF_LEN * 2];
+	char *pos = buffer;
+	unsigned int i;
+	u8 byte;
+
+	*out++ = len * 8;
+	*out++ = 0;
+
+	for (i = 0; i < len; i++) {
+		byte = registers[i] >> 8;
+		*pos = hex_asc_hi(byte);
+		pos++;
+		*pos = hex_asc_lo(byte);
+		pos++;
+		byte = registers[i];
+		*pos = hex_asc_hi(byte);
+		pos++;
+		*pos = hex_asc_lo(byte);
+		pos++;
+	}
+
+	utf8s_to_utf16s(buffer, len * 4, UTF16_LITTLE_ENDIAN, (wchar_t *)out, len * 4);
+}
+
+static void asus_wmi_ec_make_block_read_query(struct asus_wmi_ec_info *ec)
+{
+	u16 registers[ASUS_WMI_BLOCK_READ_REGISTERS_MAX];
+	const struct ec_sensor_info *si;
+	int i, j, register_idx = 0;
+
+	/*
+	 * if we can get values for all the registers in a single query,
+	 * the query will not change from call to call
+	 */
+	if (ec->nr_registers <= ASUS_WMI_BLOCK_READ_REGISTERS_MAX &&
+	    ec->read_arg[0] > 0) {
+		/* no need to update */
+		return;
+	}
+
+	for (i = 0; i < ec->nr_sensors; i++) {
+		si = &known_ec_sensors[ec->sensors[i].info_index];
+		for (j = 0; j < si->addr.size;
+		     j++, register_idx++) {
+			registers[register_idx] = (si->addr.bank << 8) + si->addr.index + j;
+		}
+	}
+
+	asus_wmi_ec_encode_registers(registers, ec->nr_registers, ec->read_arg);
+}
+
+static int asus_wmi_ec_block_read(u32 method_id, char *query, u8 *out)
+{
+#if IS_ENABLED(CONFIG_ACPI_WMI)
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER,
+				      NULL };
+	struct acpi_buffer input;
+	union acpi_object *obj;
+	acpi_status status;
+
+	/* the first byte of the BRxx() argument string has to be the string size */
+	input.length = (acpi_size)query[0] + 2;
+	input.pointer = query;
+	status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0, method_id, &input,
+				     &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_BUFFER) {
+		if (!obj)
+			acpi_os_free(output.pointer);
+
+		return -EIO;
+	}
+	asus_wmi_ec_decode_reply_buffer(obj->buffer.pointer, out);
+	acpi_os_free(output.pointer);
+	return 0;
+#else
+	return -EOPNOTSUPP;
+#endif
+}
+
+static int asus_wmi_ec_update_ec_sensors(struct asus_wmi_ec_info *ec)
+{
+	const struct ec_sensor_info *si;
+	struct ec_sensor *s;
+
+	int status;
+	u8 i_sensor, read_reg_ct;
+
+	asus_wmi_ec_make_block_read_query(ec);
+	status = asus_wmi_ec_block_read(ASUSWMI_METHODID_BLOCK_READ_EC,
+					ec->read_arg,
+					ec->read_buffer);
+	if (status)
+		return status;
+
+	read_reg_ct = 0;
+	for (i_sensor = 0; i_sensor < ec->nr_sensors; i_sensor++) {
+		s = &ec->sensors[i_sensor];
+		si = &known_ec_sensors[s->info_index];
+
+		switch (si->addr.size) {
+		case 1:
+			s->cached_value = ec->read_buffer[read_reg_ct];
+			break;
+		case 2:
+			s->cached_value = get_unaligned_be16(&ec->read_buffer[read_reg_ct]);
+			break;
+		case 4:
+			s->cached_value = get_unaligned_be32(&ec->read_buffer[read_reg_ct]);
+			break;
+		default:
+			s->cached_value =  0;
+		}
+		read_reg_ct += si->addr.size;
+	}
+	return 0;
+}
+
+static int asus_wmi_ec_scale_sensor_value(u32 value, int data_type)
+{
+	switch (data_type) {
+	case hwmon_curr:
+	case hwmon_temp:
+	case hwmon_in:
+		return value * KILO;
+	default:
+		return value;
+	}
+}
+
+static int asus_wmi_ec_find_sensor_index(const struct asus_wmi_ec_info *ec,
+					 enum hwmon_sensor_types type, int channel)
+{
+	int i;
+
+	for (i = 0; i < ec->nr_sensors; i++) {
+		if (known_ec_sensors[ec->sensors[i].info_index].type == type) {
+			if (channel == 0)
+				return i;
+
+			channel--;
+		}
+	}
+	return -EINVAL;
+}
+
+static int asus_wmi_ec_get_cached_value_or_update(int sensor_index,
+						  struct asus_wmi_sensors *state,
+						  u32 *value)
+{
+	int ret;
+
+	if (time_after(jiffies, state->ec.last_updated + HZ)) {
+		ret = asus_wmi_ec_update_ec_sensors(&state->ec);
+		if (ret)
+			return ret;
+
+		state->ec.last_updated = jiffies;
+	}
+
+	*value = state->ec.sensors[sensor_index].cached_value;
+	return 0;
+}
+
+/*
+ * Now follow the functions that implement the hwmon interface
+ */
+
+static int asus_wmi_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+				  u32 attr, int channel, long *val)
+{
+	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
+	int ret, sidx, info_index;
+	u32 value = 0;
+
+	sidx = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
+	if (sidx < 0)
+		return sidx;
+
+	mutex_lock(&sensor_data->lock);
+	ret = asus_wmi_ec_get_cached_value_or_update(sidx, sensor_data, &value);
+	mutex_unlock(&sensor_data->lock);
+	if (ret)
+		return ret;
+
+	info_index = sensor_data->ec.sensors[sidx].info_index;
+	*val = asus_wmi_ec_scale_sensor_value(value,
+					      known_ec_sensors[info_index].type);
+
+	return ret;
+}
+
+static int asus_wmi_ec_hwmon_read_string(struct device *dev,
+					 enum hwmon_sensor_types type, u32 attr,
+					 int channel, const char **str)
+{
+	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
+	int sensor_index;
+
+	sensor_index = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
+	*str = known_ec_sensors[sensor_data->ec.sensors[sensor_index].info_index].label;
+
+	return 0;
+}
+
+static umode_t asus_wmi_ec_hwmon_is_visible(const void *drvdata,
+					    enum hwmon_sensor_types type, u32 attr,
+					    int channel)
+{
+	int index;
+	const struct asus_wmi_sensors *sensor_data = drvdata;
+
+	index = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
+
+	return index == 0xff ? 0 : 0444;
+}
+
+static int asus_wmi_hwmon_add_chan_info(struct hwmon_channel_info *asus_wmi_hwmon_chan,
+					struct device *dev, int num,
+					enum hwmon_sensor_types type, u32 config)
+{
+	u32 *cfg;
+
+	cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return -ENOMEM;
+
+	asus_wmi_hwmon_chan->type = type;
+	asus_wmi_hwmon_chan->config = cfg;
+	memset32(cfg, config, num);
+
+	return 0;
+}
+
+static const struct hwmon_ops asus_wmi_ec_hwmon_ops = {
+	.is_visible = asus_wmi_ec_hwmon_is_visible,
+	.read = asus_wmi_ec_hwmon_read,
+	.read_string = asus_wmi_ec_hwmon_read_string,
+};
+
+static struct hwmon_chip_info asus_wmi_ec_chip_info = {
+	.ops = &asus_wmi_ec_hwmon_ops,
+};
+
+static int asus_wmi_ec_configure_sensor_setup(struct device *dev,
+					      struct asus_wmi_sensors *sensor_data)
+{
+	struct hwmon_channel_info *asus_wmi_hwmon_chan;
+	const struct hwmon_channel_info **ptr_asus_wmi_ci;
+	int nr_count[hwmon_max] = { 0 }, nr_types = 0;
+	const struct hwmon_chip_info *chip_info;
+	const struct ec_sensor_info *si;
+	enum hwmon_sensor_types type;
+	struct device *hwdev;
+	int i, ret;
+
+	ret = asus_wmi_ec_fill_board_sensors(&sensor_data->ec);
+	if (ret)
+		return ret;
+
+	if (!sensor_data->ec.nr_sensors)
+		return -ENODEV;
+
+	for (i = 0; i < sensor_data->ec.nr_sensors; i++) {
+		si = &known_ec_sensors[sensor_data->ec.sensors[i].info_index];
+		if (!nr_count[si->type])
+			nr_types++;
+		nr_count[si->type]++;
+	}
+
+	if (nr_count[hwmon_temp]) {
+		nr_count[hwmon_chip]++;
+		nr_types++;
+	}
+
+	asus_wmi_hwmon_chan = devm_kcalloc(dev, nr_types,
+					   sizeof(*asus_wmi_hwmon_chan),
+					   GFP_KERNEL);
+	if (!asus_wmi_hwmon_chan)
+		return -ENOMEM;
+
+	ptr_asus_wmi_ci = devm_kcalloc(dev, nr_types + 1,
+				       sizeof(*ptr_asus_wmi_ci), GFP_KERNEL);
+	if (!ptr_asus_wmi_ci)
+		return -ENOMEM;
+
+	asus_wmi_ec_chip_info.info = ptr_asus_wmi_ci;
+	chip_info = &asus_wmi_ec_chip_info;
+
+	for (type = 0; type < hwmon_max; type++) {
+		if (!nr_count[type])
+			continue;
+
+		ret = asus_wmi_hwmon_add_chan_info(asus_wmi_hwmon_chan, dev,
+						   nr_count[type], type,
+						   hwmon_attributes[type]);
+		if (ret)
+			return ret;
+
+		*ptr_asus_wmi_ci++ = asus_wmi_hwmon_chan++;
+	}
+
+	dev_dbg(dev, "board has %d EC sensors that span %d registers",
+		sensor_data->ec.nr_sensors,
+		sensor_data->ec.nr_registers);
+
+	hwdev = devm_hwmon_device_register_with_info(dev, KBUILD_MODNAME,
+						     sensor_data, chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(hwdev);
+}
+
+static int asus_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+	struct asus_wmi_sensors *sensor_data;
+	struct device *dev = &wdev->dev;
+
+	if (!dmi_check_system(asus_wmi_ec_dmi_table))
+		return -ENODEV;
+
+	sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
+				   GFP_KERNEL);
+	if (!sensor_data)
+		return -ENOMEM;
+
+	mutex_init(&sensor_data->lock);
+
+	dev_set_drvdata(dev, sensor_data);
+
+	/* ec init */
+	return asus_wmi_ec_configure_sensor_setup(dev,
+						  sensor_data);
+}
+
+static const struct wmi_device_id asus_ec_wmi_id_table[] = {
+	{ ASUSWMI_MONITORING_GUID, NULL },
+	{ }
+};
+
+static struct wmi_driver asus_sensors_wmi_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+	},
+	.id_table = asus_ec_wmi_id_table,
+	.probe = asus_wmi_probe,
+};
+module_wmi_driver(asus_sensors_wmi_driver);
+
+MODULE_AUTHOR("Ed Brindley <kernel@maidavale.org>");
+MODULE_AUTHOR("Eugene Shalygin <eugene.shalygin@gmail.com>");
+MODULE_DESCRIPTION("Asus WMI Sensors Driver");
+MODULE_LICENSE("GPL");
-- 
2.33.0

[PATCH v5 2/2] hwmon: (asus_wmi_sensors) Support X370 Asus WMI.

[Denis Pauk]

Provides a Linux kernel module "asus_wmi_sensors" that provides sensor
readouts via ASUS' WMI interface present in the UEFI of
X370/X470/B450/X399 Ryzen motherboards.

Supported motherboards:
* ROG CROSSHAIR VI HERO,
* PRIME X399-A,
* PRIME X470-PRO,
* ROG CROSSHAIR VI EXTREME,
* ROG CROSSHAIR VI HERO (WI-FI AC),
* ROG CROSSHAIR VII HERO,
* ROG CROSSHAIR VII HERO (WI-FI),
* ROG STRIX B450-E GAMING,
* ROG STRIX B450-F GAMING,
* ROG STRIX B450-I GAMING,
* ROG STRIX X399-E GAMING,
* ROG STRIX X470-F GAMING,
* ROG STRIX X470-I GAMING,
* ROG ZENITH EXTREME,
* ROG ZENITH EXTREME ALPHA.

Signed-off-by: Denis Pauk <pauk.denis@gmail.com>
Co-developed-by: Ed Brindley <kernel@maidavale.org>
Signed-off-by: Ed Brindley <kernel@maidavale.org>
Reported-by: kernel test robot <lkp@intel.com>

---
Changes in v5:
- Fixes build issue reported by kernel test robot with disabled ACPI_WMI.
- Remove sensor->name check as always eevaluated to true.

Changes in v4:
- Implement wmi driver instead platform driver.
- Update documentation.

Changes in v3:
- Use MODULE_DEVICE_TABLE for match devices.
- Add documentaion for driver.

Changes in v2:
- Add module for boards with support of WMI interface returned sensor name and
  value of sensor..
---
 Documentation/hwmon/asus_wmi_sensors.rst |  74 +++
 MAINTAINERS                              |   1 +
 drivers/hwmon/Kconfig                    |  11 +
 drivers/hwmon/Makefile                   |   1 +
 drivers/hwmon/asus_wmi_sensors.c         | 621 +++++++++++++++++++++++
 5 files changed, 708 insertions(+)
 create mode 100644 Documentation/hwmon/asus_wmi_sensors.rst
 create mode 100644 drivers/hwmon/asus_wmi_sensors.c

diff --git a/Documentation/hwmon/asus_wmi_sensors.rst b/Documentation/hwmon/asus_wmi_sensors.rst
new file mode 100644
index 000000000000..e32bfb74289f
--- /dev/null
+++ b/Documentation/hwmon/asus_wmi_sensors.rst
@@ -0,0 +1,74 @@
+Kernel driver asus-wmi-sensors
+=================================
+
+Supported boards:
+ * PRIME X399-A,
+ * PRIME X470-PRO,
+ * ROG CROSSHAIR VI EXTREME,
+ * ROG CROSSHAIR VI HERO,
+ * ROG CROSSHAIR VI HERO (WI-FI AC),
+ * ROG CROSSHAIR VII HERO,
+ * ROG CROSSHAIR VII HERO (WI-FI),
+ * ROG STRIX B450-E GAMING,
+ * ROG STRIX B450-F GAMING,
+ * ROG STRIX B450-I GAMING,
+ * ROG STRIX X399-E GAMING,
+ * ROG STRIX X470-F GAMING,
+ * ROG STRIX X470-I GAMING,
+ * ROG ZENITH EXTREME,
+ * ROG ZENITH EXTREME ALPHA.
+
+Authors:
+        Ed Brindley <kernel@maidavale.org>
+
+Description:
+------------
+ASUS mainboards publish hardware monitoring information via WMI interface.
+
+ASUS WMI interface provides a methods to get list of sensors and values of
+such, which is utilized by this driver to publish those sensor readings to the
+HWMON system. The driver is aware of and reads the following sensors:
+ * CPU Core Voltage,
+ * CPU SOC Voltage,
+ * DRAM Voltage,
+ * VDDP Voltage,
+ * 1.8V PLL Voltage,
+ * +12V Voltage,
+ * +5V Voltage,
+ * 3VSB Voltage,
+ * VBAT Voltage,
+ * AVCC3 Voltage,
+ * SB 1.05V Voltage,
+ * CPU Core Voltage,
+ * CPU SOC Voltage,
+ * DRAM Voltage,
+ * CPU Fan RPM,
+ * Chassis Fan 1 RPM,
+ * Chassis Fan 2 RPM,
+ * Chassis Fan 3 RPM,
+ * HAMP Fan RPM,
+ * Water Pump RPM,
+ * CPU OPT RPM,
+ * Water Flow RPM,
+ * AIO Pump RPM,
+ * CPU Temperature,
+ * CPU Socket Temperature,
+ * Motherboard Temperature,
+ * Chipset Temperature,
+ * Tsensor 1 Temperature,
+ * CPU VRM Temperature,
+ * Water In,
+ * Water Out,
+ * CPU VRM Output Current.
+
+Known Issues:
+* The WMI implementation in some of Asus' BIOSes is buggy. This can result in
+   fans stopping, fans getting stuck at max speed, or temperature readouts
+   getting stuck. This is not an issue with the driver, but the BIOS. The Prime
+   X470 Pro seems particularly bad for this. The more frequently the WMI
+   interface is polled the greater the potential for this to happen. Until you
+   have subjected your computer to an extended soak test while polling the
+   sensors frequently, don't leave you computer unattended. Upgrading to new
+   BIOS version with method version greater than or equal to two should
+   rectify the issue.
+* A few boards report 12v voltages to be ~10v.
diff --git a/MAINTAINERS b/MAINTAINERS
index 05448435991d..46036c184330 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2943,6 +2943,7 @@ M:	Denis Pauk <pauk.denis@gmail.com>
 L:	linux-hwmon@vger.kernel.org
 S:	Maintained
 F:	drivers/hwmon/asus_wmi_ec_sensors.c
+F:	drivers/hwmon/asus_wmi_sensors.c
 
 ASUS WIRELESS RADIO CONTROL DRIVER
 M:	João Paulo Rechi Vita <jprvita@gmail.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 430a438432a0..461328c4b00a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2215,6 +2215,17 @@ config SENSORS_ATK0110
 	  This driver can also be built as a module. If so, the module
 	  will be called asus_atk0110.
 
+config SENSORS_ASUS_WMI
+	tristate "ASUS WMI X370/X470/B450/X399"
+	help
+	  If you say yes here you get support for the ACPI hardware monitoring
+	  interface found in X370/X470/B450/X399 ASUS motherboards. This driver
+	  will provide readings of fans, voltages and temperatures through the system
+	  firmware.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called asus_wmi_sensors.
+
 config SENSORS_ASUS_WMI_EC
 	tristate "ASUS WMI B550/X570"
 	help
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index aae2ff5c7335..656a6191a0f8 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_HWMON_VID)		+= hwmon-vid.o
 # APCI drivers
 obj-$(CONFIG_SENSORS_ACPI_POWER) += acpi_power_meter.o
 obj-$(CONFIG_SENSORS_ATK0110)	+= asus_atk0110.o
+obj-$(CONFIG_SENSORS_ASUS_WMI)	+= asus_wmi_sensors.o
 obj-$(CONFIG_SENSORS_ASUS_WMI_EC)	+= asus_wmi_ec_sensors.o
 
 # Native drivers
diff --git a/drivers/hwmon/asus_wmi_sensors.c b/drivers/hwmon/asus_wmi_sensors.c
new file mode 100644
index 000000000000..a45fbec4e319
--- /dev/null
+++ b/drivers/hwmon/asus_wmi_sensors.c
@@ -0,0 +1,621 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * HWMON driver for ASUS motherboards that provides sensor readouts via WMI
+ * interface present in the UEFI of the X370/X470/B450/X399 Ryzen motherboards.
+ *
+ * Copyright (C) 2018-2019 Ed Brindley <kernel@maidavale.org>
+ *
+ * WMI interface provides:
+ * CPU Core Voltage,
+ * CPU SOC Voltage,
+ * DRAM Voltage,
+ * VDDP Voltage,
+ * 1.8V PLL Voltage,
+ * +12V Voltage,
+ * +5V Voltage,
+ * 3VSB Voltage,
+ * VBAT Voltage,
+ * AVCC3 Voltage,
+ * SB 1.05V Voltage,
+ * CPU Core Voltage,
+ * CPU SOC Voltage,
+ * DRAM Voltage,
+ * CPU Fan RPM,
+ * Chassis Fan 1 RPM,
+ * Chassis Fan 2 RPM,
+ * Chassis Fan 3 RPM,
+ * HAMP Fan RPM,
+ * Water Pump RPM,
+ * CPU OPT RPM,
+ * Water Flow RPM,
+ * AIO Pump RPM,
+ * CPU Temperature,
+ * CPU Socket Temperature,
+ * Motherboard Temperature,
+ * Chipset Temperature,
+ * Tsensor 1 Temperature,
+ * CPU VRM Temperature,
+ * Water In,
+ * Water Out,
+ * CPU VRM Output Current.
+ *
+ */
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/units.h>
+#include <linux/wmi.h>
+
+#define ASUSWMI_MONITORING_GUID		"466747A0-70EC-11DE-8A39-0800200C9A66"
+#define ASUSWMI_METHODID_GET_VALUE	0x52574543
+#define ASUSWMI_METHODID_UPDATE_BUFFER	0x51574543
+#define ASUSWMI_METHODID_GET_INFO	0x50574543
+#define ASUSWMI_METHODID_GET_NUMBER		0x50574572
+#define ASUSWMI_METHODID_GET_VERSION		0x50574574
+
+#define ASUS_WMI_MAX_STR_SIZE	32
+
+#define DMI_EXACT_MATCH_ASUS_BOARD_NAME(name) \
+	{ \
+		.matches = { \
+			DMI_EXACT_MATCH(DMI_BOARD_VENDOR, \
+					"ASUSTeK COMPUTER INC."), \
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, name), \
+		}, \
+	}
+
+static const struct dmi_system_id asus_wmi_dmi_table[] = {
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X399-A"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X470-PRO"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VI EXTREME"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VI HERO"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VI HERO (WI-FI AC)"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VII HERO"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VII HERO (WI-FI)"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-E GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-F GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B450-I GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X399-E GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X470-F GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X470-I GAMING"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG ZENITH EXTREME"),
+	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG ZENITH EXTREME ALPHA"),
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, asus_wmi_dmi_table);
+
+enum asus_wmi_sensor_class {
+	VOLTAGE = 0x0,
+	TEMPERATURE_C = 0x1,
+	FAN_RPM = 0x2,
+	CURRENT = 0x3,
+	WATER_FLOW = 0x4,
+};
+
+enum asus_wmi_location {
+	CPU = 0x0,
+	CPU_SOC = 0x1,
+	DRAM = 0x2,
+	MOTHERBOARD = 0x3,
+	CHIPSET = 0x4,
+	AUX = 0x5,
+	VRM = 0x6,
+	COOLER = 0x7
+};
+
+enum asus_wmi_type {
+	SIGNED_INT = 0x0,
+	UNSIGNED_INT = 0x1,
+	SCALED = 0x3,
+};
+
+enum asus_wmi_source {
+	SIO = 0x1,
+	EC = 0x2
+};
+
+static enum hwmon_sensor_types asus_data_types[] = {
+	[VOLTAGE] = hwmon_in,
+	[TEMPERATURE_C] = hwmon_temp,
+	[FAN_RPM] = hwmon_fan,
+	[CURRENT] = hwmon_curr,
+	[WATER_FLOW] = hwmon_fan,
+};
+
+static u32 hwmon_attributes[] = {
+	[hwmon_chip] = HWMON_C_REGISTER_TZ,
+	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
+	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
+	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
+	[hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL,
+};
+
+/**
+ * struct asus_wmi_sensor_info - sensor info.
+ * @id: sensor id.
+ * @data_type: sensor class e.g. voltage, temp etc.
+ * @location: sensor location.
+ * @name: sensor name.
+ * @source: sensor source.
+ * @type: sensor type signed, unsigned etc.
+ * @cached_value: cached sensor value.
+ */
+struct asus_wmi_sensor_info {
+	u32 id;
+	int data_type;
+	int location;
+	char name[ASUS_WMI_MAX_STR_SIZE];
+	int source;
+	int type;
+	u32 cached_value;
+};
+
+struct asus_wmi_wmi_info {
+	u8 buffer;
+	unsigned long source_last_updated[3];	/* in jiffies */
+	int sensor_count;
+
+	const struct asus_wmi_sensor_info **info[hwmon_max];
+	struct asus_wmi_sensor_info **info_by_id;
+};
+
+struct asus_wmi_sensors {
+	/* lock access to instrnal cache */
+	struct mutex lock;
+	struct asus_wmi_wmi_info wmi;
+};
+
+/*
+ * Universal method for calling WMI method
+ */
+static int asus_wmi_call_method(u32 method_id, u32 *args, struct acpi_buffer *output)
+{
+#if IS_ENABLED(CONFIG_ACPI_WMI)
+	struct acpi_buffer input = {(acpi_size) sizeof(*args), args };
+	acpi_status status;
+
+	status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0, method_id, &input, output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return 0;
+#else
+	return -EOPNOTSUPP;
+#endif
+}
+
+/*
+ * Gets the version of the ASUS sensors interface implemented
+ */
+static int asus_wmi_get_version(u32 *version)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	u32 args[] = {0, 0, 0};
+	union acpi_object *obj;
+	int err;
+
+	err = asus_wmi_call_method(ASUSWMI_METHODID_GET_VERSION, args, &output);
+	if (err)
+		return err;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_INTEGER)
+		return -EIO;
+
+	*version = obj->integer.value;
+
+	return 0;
+}
+
+/*
+ * Gets the number of sensor items
+ */
+static int asus_wmi_get_item_count(u32 *count)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	u32 args[] = {0, 0, 0};
+	union acpi_object *obj;
+	int err;
+
+	err = asus_wmi_call_method(ASUSWMI_METHODID_GET_NUMBER, args, &output);
+	if (err)
+		return err;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_INTEGER)
+		return -EIO;
+
+	*count = obj->integer.value;
+
+	return 0;
+}
+
+static int asus_wmi_hwmon_add_chan_info(struct hwmon_channel_info *asus_wmi_hwmon_chan,
+					struct device *dev, int num,
+					enum hwmon_sensor_types type, u32 config)
+{
+	u32 *cfg;
+
+	cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return -ENOMEM;
+
+	asus_wmi_hwmon_chan->type = type;
+	asus_wmi_hwmon_chan->config = cfg;
+	memset32(cfg, config, num);
+
+	return 0;
+}
+
+/*
+ * For a given sensor item returns details e.g. type (voltage/temperature/fan speed etc), bank etc
+ */
+static int asus_wmi_sensor_info(int index, struct asus_wmi_sensor_info *s)
+{
+	union acpi_object name_obj, data_type_obj, location_obj, source_obj, type_obj;
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	u32 args[] = {index, 0};
+	union acpi_object *obj;
+	int err;
+
+	err = asus_wmi_call_method(ASUSWMI_METHODID_GET_INFO, args, &output);
+	if (err)
+		return err;
+
+	s->id = index;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE)
+		return -EIO;
+
+	if (obj->package.count != 5)
+		return 1;
+
+	name_obj = obj->package.elements[0];
+
+	if (name_obj.type != ACPI_TYPE_STRING)
+		return 1;
+
+	strncpy(s->name, name_obj.string.pointer, sizeof(s->name) - 1);
+
+	data_type_obj = obj->package.elements[1];
+
+	if (data_type_obj.type != ACPI_TYPE_INTEGER)
+		return 1;
+
+	s->data_type = data_type_obj.integer.value;
+
+	location_obj = obj->package.elements[2];
+
+	if (location_obj.type != ACPI_TYPE_INTEGER)
+		return 1;
+
+	s->location = location_obj.integer.value;
+
+	source_obj = obj->package.elements[3];
+
+	if (source_obj.type != ACPI_TYPE_INTEGER)
+		return 1;
+
+	s->source = source_obj.integer.value;
+
+	type_obj = obj->package.elements[4];
+
+	if (type_obj.type != ACPI_TYPE_INTEGER)
+		return 1;
+
+	s->type = type_obj.integer.value;
+
+	return 0;
+}
+
+static int asus_wmi_update_buffer(u8 source)
+{
+	u32 args[] = {source, 0};
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	return asus_wmi_call_method(ASUSWMI_METHODID_UPDATE_BUFFER, args, &output);
+}
+
+static int asus_wmi_get_sensor_value(u8 index, u32 *value)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	u32 args[] = {index, 0};
+	union acpi_object *obj;
+	int err;
+
+	err = asus_wmi_call_method(ASUSWMI_METHODID_GET_VALUE, args, &output);
+	if (err)
+		return err;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_INTEGER)
+		return -EIO;
+
+	*value = obj->integer.value;
+
+	return 0;
+}
+
+static void asus_wmi_update_values_for_source(u8 source, struct asus_wmi_sensors *sensor_data)
+{
+	int ret = 0;
+	int value = 0;
+	int i;
+	struct asus_wmi_sensor_info *sensor;
+
+	for (i = 0; i < sensor_data->wmi.sensor_count; i++) {
+		sensor = sensor_data->wmi.info_by_id[i];
+		if (sensor && sensor->source == source) {
+			ret = asus_wmi_get_sensor_value(sensor->id, &value);
+			if (!ret)
+				sensor->cached_value = value;
+		}
+	}
+}
+
+static int asus_wmi_scale_sensor_value(u32 value, int data_type)
+{
+	/* FAN_RPM and WATER_FLOW don't need scaling */
+	switch (data_type) {
+	case VOLTAGE:
+		return DIV_ROUND_CLOSEST(value, 1000);
+	case TEMPERATURE_C:
+		return value * 1000;
+	case CURRENT:
+		return value * 1000;
+	}
+	return value;
+}
+
+static int asus_wmi_get_cached_value_or_update(const struct asus_wmi_sensor_info *sensor,
+					       struct asus_wmi_sensors *sensor_data,
+					       u32 *value)
+{
+	int ret;
+
+	if (time_after(jiffies, sensor_data->wmi.source_last_updated[sensor->source] + HZ)) {
+		ret = asus_wmi_update_buffer(sensor->source);
+		if (ret)
+			return -EIO;
+
+		sensor_data->wmi.buffer = sensor->source;
+
+		asus_wmi_update_values_for_source(sensor->source, sensor_data);
+		sensor_data->wmi.source_last_updated[sensor->source] = jiffies;
+	}
+
+	*value = sensor->cached_value;
+	return 0;
+}
+
+/*
+ * Now follow the functions that implement the hwmon interface
+ */
+
+static int asus_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			       u32 attr, int channel, long *val)
+{
+	int ret;
+	u32 value = 0;
+	const struct asus_wmi_sensor_info *sensor;
+
+	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
+
+	sensor = *(sensor_data->wmi.info[type] + channel);
+
+	mutex_lock(&sensor_data->lock);
+	ret = asus_wmi_get_cached_value_or_update(sensor, sensor_data, &value);
+	mutex_unlock(&sensor_data->lock);
+	if (!ret)
+		*val = asus_wmi_scale_sensor_value(value, sensor->data_type);
+
+	return ret;
+}
+
+static int asus_wmi_hwmon_read_string(struct device *dev,
+				      enum hwmon_sensor_types type, u32 attr,
+				      int channel, const char **str)
+{
+	const struct asus_wmi_sensor_info *sensor;
+	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
+
+	sensor = *(sensor_data->wmi.info[type] + channel);
+	*str = sensor->name;
+
+	return 0;
+}
+
+static umode_t asus_wmi_hwmon_is_visible(const void *drvdata,
+					 enum hwmon_sensor_types type, u32 attr,
+					 int channel)
+{
+	const struct asus_wmi_sensor_info *sensor;
+	const struct asus_wmi_sensors *sensor_data = drvdata;
+
+	sensor = *(sensor_data->wmi.info[type] + channel);
+	if (sensor)
+		return 0444;
+
+	return 0;
+}
+
+static const struct hwmon_ops asus_wmi_hwmon_ops = {
+	.is_visible = asus_wmi_hwmon_is_visible,
+	.read = asus_wmi_hwmon_read,
+	.read_string = asus_wmi_hwmon_read_string,
+};
+
+static struct hwmon_chip_info asus_wmi_chip_info = {
+	.ops = &asus_wmi_hwmon_ops,
+	.info = NULL,
+};
+
+static int asus_wmi_configure_sensor_setup(struct device *dev,
+					   struct asus_wmi_sensors *sensor_data)
+{
+	int err;
+	int i, idx;
+	int nr_count[hwmon_max] = {0}, nr_types = 0;
+	struct device *hwdev;
+	struct hwmon_channel_info *asus_wmi_hwmon_chan;
+	struct asus_wmi_sensor_info *temp_sensor;
+	enum hwmon_sensor_types type;
+	const struct hwmon_channel_info **ptr_asus_wmi_ci;
+	const struct hwmon_chip_info *chip_info;
+
+	sensor_data->wmi.buffer = -1;
+	temp_sensor = devm_kcalloc(dev, 1, sizeof(*temp_sensor), GFP_KERNEL);
+	if (!temp_sensor)
+		return -ENOMEM;
+
+	for (i = 0; i < sensor_data->wmi.sensor_count; i++) {
+		err = asus_wmi_sensor_info(i, temp_sensor);
+		if (err)
+			return -EINVAL;
+
+		switch (temp_sensor->data_type) {
+		case TEMPERATURE_C:
+		case VOLTAGE:
+		case CURRENT:
+		case FAN_RPM:
+		case WATER_FLOW:
+			type = asus_data_types[temp_sensor->data_type];
+			if (!nr_count[type])
+				nr_types++;
+			nr_count[type]++;
+			break;
+		}
+	}
+
+	if (nr_count[hwmon_temp])
+		nr_count[hwmon_chip]++, nr_types++;
+
+	asus_wmi_hwmon_chan = devm_kcalloc(dev, nr_types,
+					   sizeof(*asus_wmi_hwmon_chan),
+					   GFP_KERNEL);
+	if (!asus_wmi_hwmon_chan)
+		return -ENOMEM;
+
+	ptr_asus_wmi_ci = devm_kcalloc(dev, nr_types + 1,
+				       sizeof(*ptr_asus_wmi_ci), GFP_KERNEL);
+	if (!ptr_asus_wmi_ci)
+		return -ENOMEM;
+
+	asus_wmi_chip_info.info = ptr_asus_wmi_ci;
+	chip_info = &asus_wmi_chip_info;
+
+	sensor_data->wmi.info_by_id = devm_kcalloc(dev, sensor_data->wmi.sensor_count,
+						   sizeof(*sensor_data->wmi.info_by_id),
+						   GFP_KERNEL);
+
+	if (!sensor_data->wmi.info_by_id)
+		return -ENOMEM;
+
+	for (type = 0; type < hwmon_max; type++) {
+		if (!nr_count[type])
+			continue;
+
+		asus_wmi_hwmon_add_chan_info(asus_wmi_hwmon_chan, dev,
+					     nr_count[type], type,
+					     hwmon_attributes[type]);
+		*ptr_asus_wmi_ci++ = asus_wmi_hwmon_chan++;
+
+		sensor_data->wmi.info[type] = devm_kcalloc(dev,
+							   nr_count[type],
+							   sizeof(*sensor_data->wmi.info),
+							   GFP_KERNEL);
+		if (!sensor_data->wmi.info[type])
+			return -ENOMEM;
+	}
+
+	for (i = sensor_data->wmi.sensor_count - 1; i >= 0 ; i--) {
+		temp_sensor = devm_kzalloc(dev, sizeof(*temp_sensor), GFP_KERNEL);
+		if (!temp_sensor)
+			return -ENOMEM;
+
+		err = asus_wmi_sensor_info(i, temp_sensor);
+		if (err)
+			continue;
+
+		switch (temp_sensor->data_type) {
+		case TEMPERATURE_C:
+		case VOLTAGE:
+		case CURRENT:
+		case FAN_RPM:
+		case WATER_FLOW:
+			type = asus_data_types[temp_sensor->data_type];
+			idx = --nr_count[type];
+			*(sensor_data->wmi.info[type] + idx) = temp_sensor;
+			sensor_data->wmi.info_by_id[i] = temp_sensor;
+			break;
+		}
+	}
+
+	dev_dbg(dev, "board has %d sensors",
+		sensor_data->wmi.sensor_count);
+
+	hwdev = devm_hwmon_device_register_with_info(dev, KBUILD_MODNAME,
+						     sensor_data, chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(hwdev);
+}
+
+static int asus_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+	struct asus_wmi_sensors *sensor_data;
+	struct device *dev = &wdev->dev;
+	u32 version = 0;
+
+	if (!dmi_check_system(asus_wmi_dmi_table))
+		return -ENODEV;
+
+	sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
+				   GFP_KERNEL);
+	if (!sensor_data)
+		return -ENOMEM;
+
+	if (asus_wmi_get_version(&version))
+		return -ENODEV;
+
+	if (asus_wmi_get_item_count(&sensor_data->wmi.sensor_count))
+		return -ENODEV;
+
+	if (sensor_data->wmi.sensor_count  <= 0 || version < 2) {
+		dev_info(dev, "version: %u with %d sensors is unsupported\n",
+			 version, sensor_data->wmi.sensor_count);
+
+		return -ENODEV;
+	}
+
+	mutex_init(&sensor_data->lock);
+
+	dev_set_drvdata(dev, sensor_data);
+
+	return asus_wmi_configure_sensor_setup(dev,
+					       sensor_data);
+}
+
+static const struct wmi_device_id asus_wmi_id_table[] = {
+	{ ASUSWMI_MONITORING_GUID, NULL },
+	{ }
+};
+
+static struct wmi_driver asus_sensors_wmi_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+	},
+	.id_table = asus_wmi_id_table,
+	.probe = asus_wmi_probe,
+};
+module_wmi_driver(asus_sensors_wmi_driver);
+
+MODULE_AUTHOR("Ed Brindley <kernel@maidavale.org>");
+MODULE_DESCRIPTION("Asus WMI Sensors Driver");
+MODULE_LICENSE("GPL");
-- 
2.33.0

Re: [PATCH v5 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Guenter Roeck]

On 10/11/21 12:55 PM, Denis Pauk wrote:
> Linux HWMON sensors driver for ASUS motherboards to read
> sensors from the embedded controller.
> 
> Many ASUS motherboards do not publish all the available
> sensors via the Super I/O chip but the missing ones are
> available through the embedded controller (EC) registers.
> 
> This driver implements reading those sensor data via the
> WMI method BREC, which is known to be present in all ASUS
> motherboards based on the AMD 500 series chipsets (and
> probably is available in other models too). The driver
> needs to know exact register addresses for the sensors and
> thus support for each motherboard has to be added explicitly.
> 
> The EC registers do not provide critical values for the
> sensors and as such they are not published to the HWMON.
> 
> Supported motherboards:
> * PRIME X570-PRO
> * ROG CROSSHAIR VIII HERO
> * ROG CROSSHAIR VIII DARK HERO
> * ROG CROSSHAIR VIII FORMULA
> * ROG STRIX X570-E GAMING
> * ROG STRIX B550-E GAMING
> 
> Signed-off-by: Denis Pauk <pauk.denis@gmail.com>
> Co-developed-by: Eugene Shalygin <eugene.shalygin@gmail.com>
> Signed-off-by: Eugene Shalygin <eugene.shalygin@gmail.com>
> Tested-by: Tor Vic <torvic9@mailbox.org>
> Reported-by: kernel test robot <lkp@intel.com>
> 
> ---
> Changes in v5:
> - Fixes build issue reported by kernel test robot with disabled ACPI_WMI.
> 
> Changes in v4:
>   - implement wmi driver instead platform driver.
> 
> Changes in v3:
>   - Use MODULE_DEVICE_TABLE for match devices.
>   - Use get_unaligned_be32 instead incorrectly used get_unaligned_le32.
>   - Add documentaion for driver.
> 
> Changes in v2:
>   - Use utf8s_to_utf16s/utf16s_to_utf8s instead handmade fuctions.
>   - Use post increment.
>   - Use get_unaligned* for convert values.
>   - Use PTR_ERR_OR_ZERO.
>   - Specify per-board sensors in a declarative way (by Eugene Shalygin).
> ---
>   Documentation/hwmon/asus_wmi_ec_sensors.rst |  35 ++

This also needs to be added to index.rst in the same directory.

>   MAINTAINERS                                 |   7 +
>   drivers/hwmon/Kconfig                       |  11 +
>   drivers/hwmon/Makefile                      |   1 +
>   drivers/hwmon/asus_wmi_ec_sensors.c         | 648 ++++++++++++++++++++
>   5 files changed, 702 insertions(+)
>   create mode 100644 Documentation/hwmon/asus_wmi_ec_sensors.rst
>   create mode 100644 drivers/hwmon/asus_wmi_ec_sensors.c
> 
> diff --git a/Documentation/hwmon/asus_wmi_ec_sensors.rst b/Documentation/hwmon/asus_wmi_ec_sensors.rst
> new file mode 100644
> index 000000000000..e4f603804a82
> --- /dev/null
> +++ b/Documentation/hwmon/asus_wmi_ec_sensors.rst
> @@ -0,0 +1,35 @@
> +Kernel driver asus-wmi-ec-sensors
> +=================================
> +
> +Supported boards:
> + * PRIME X570-PRO,
> + * Pro WS X570-ACE,
> + * ROG CROSSHAIR VIII DARK HERO,
> + * ROG CROSSHAIR VIII FORMULA,
> + * ROG CROSSHAIR VIII HERO,
> + * ROG STRIX B550-E GAMING,
> + * ROG STRIX X570-E GAMING.
> +
> +Authors:
> +        Eugene Shalygin <eugene.shalygin@gmail.com>
> +
> +Description:
> +------------
> +ASUS mainboards publish hardware monitoring information via Super I/O
> +chip and the ACPI embedded controller (EC) registers. Some of the sensors
> +are only available via the EC.
> +
> +ASUS WMI interface provides a method (BREC) to read data from EC registers,
> +which is utilized by this driver to publish those sensor readings to the
> +HWMON system. The driver is aware of and reads the following sensors:
> +
> +1. Chipset (PCH) temperature
> +2. CPU package temperature
> +3. Motherboard temperature
> +4. Readings from the T_Sensor header
> +5. VRM temperature
> +6. CPU_Opt fan RPM
> +7. Chipset fan RPM
> +8. Readings from the "Water flow meter" header (RPM)
> +9. Readings from the "Water In" and "Water Out" temperature headers
> +10. CPU current
> diff --git a/MAINTAINERS b/MAINTAINERS
> index cc5eaf4e65dc..05448435991d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2937,6 +2937,13 @@ W:	http://acpi4asus.sf.net
>   F:	drivers/platform/x86/asus*.c
>   F:	drivers/platform/x86/eeepc*.c
>   
> +ASUS WMI HARDWARE MONITOR DRIVER
> +M:	Eugene Shalygin <eugene.shalygin@gmail.com>
> +M:	Denis Pauk <pauk.denis@gmail.com>
> +L:	linux-hwmon@vger.kernel.org
> +S:	Maintained
> +F:	drivers/hwmon/asus_wmi_ec_sensors.c
> +
>   ASUS WIRELESS RADIO CONTROL DRIVER
>   M:	João Paulo Rechi Vita <jprvita@gmail.com>
>   L:	platform-driver-x86@vger.kernel.org
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 7fde4c6e1e7f..430a438432a0 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -2215,6 +2215,17 @@ config SENSORS_ATK0110
>   	  This driver can also be built as a module. If so, the module
>   	  will be called asus_atk0110.
>   
> +config SENSORS_ASUS_WMI_EC
> +	tristate "ASUS WMI B550/X570"
> +	help
> +	  If you say yes here you get support for the ACPI embedded controller
> +	  hardware monitoring interface found in B550/X570 ASUS motherboards.
> +	  This driver will provide readings of fans, voltages and temperatures
> +	  through the system firmware.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called asus_wmi_sensors_ec.
> +
>   endif # ACPI
>   
>   endif # HWMON
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index baee6a8d4dd1..aae2ff5c7335 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_HWMON_VID)		+= hwmon-vid.o
>   # APCI drivers
>   obj-$(CONFIG_SENSORS_ACPI_POWER) += acpi_power_meter.o
>   obj-$(CONFIG_SENSORS_ATK0110)	+= asus_atk0110.o
> +obj-$(CONFIG_SENSORS_ASUS_WMI_EC)	+= asus_wmi_ec_sensors.o
>   
>   # Native drivers
>   # asb100, then w83781d go first, as they can override other drivers' addresses.
> diff --git a/drivers/hwmon/asus_wmi_ec_sensors.c b/drivers/hwmon/asus_wmi_ec_sensors.c
> new file mode 100644
> index 000000000000..f9d8a0be7bea
> --- /dev/null
> +++ b/drivers/hwmon/asus_wmi_ec_sensors.c
> @@ -0,0 +1,648 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * HWMON driver for ASUS B550/X570 motherboards that publish sensor
> + * values via the embedded controller registers.
> + *
> + * Copyright (C) 2021 Eugene Shalygin <eugene.shalygin@gmail.com>
> + * Copyright (C) 2018-2019 Ed Brindley <kernel@maidavale.org>
> + *
> + * EC provides:
> + * Chipset temperature,
> + * CPU temperature,
> + * Motherboard temperature,
> + * T_Sensor temperature,
> + * VRM  temperature,
> + * Water In temperature,
> + * Water Out temperature,
> + * CPU Optional Fan RPM,
> + * Chipset Fan RPM,
> + * Water Flow Fan RPM,
> + * CPU current.
> + *
> + */
> +#include <asm/unaligned.h>
> +#include <linux/acpi.h>
> +#include <linux/dmi.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/init.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/nls.h>
> +#include <linux/units.h>
> +#include <linux/wmi.h>
> +
> +#define ASUSWMI_MONITORING_GUID		"466747A0-70EC-11DE-8A39-0800200C9A66"
> +#define ASUSWMI_METHODID_BLOCK_READ_EC		0x42524543 /* BREC */
> +
> +#define ASUS_WMI_BLOCK_READ_REGISTERS_MAX 0x10 /* from the ASUS DSDT source */
> +/* from the ASUS_WMI_BLOCK_READ_REGISTERS_MAX value */
> +#define ASUS_WMI_MAX_BUF_LEN 0x80
> +#define MAX_SENSOR_LABEL_LENGTH 0x10
> +
> +static u32 hwmon_attributes[] = {
> +	[hwmon_chip] = HWMON_C_REGISTER_TZ,
> +	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
> +	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
> +	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
> +	[hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL,
> +};
> +
> +struct asus_wmi_ec_sensor_address {
> +	u8 index;
> +	u8 bank;
> +	u8 size;
> +};
> +
> +#define MAKE_SENSOR_ADDRESS(size_i, bank_i, index_i) \
> +	{ .size = size_i,\
> +	   .bank = bank_i,\
> +	   .index = index_i}
> +
> +struct ec_sensor_info {
> +	char label[MAX_SENSOR_LABEL_LENGTH];
> +	enum hwmon_sensor_types type;
> +	struct asus_wmi_ec_sensor_address addr;
> +};
> +
> +#define EC_SENSOR(sensor_label, sensor_type, size, bank, index) \
> +	{ .label = sensor_label,\
> +	.type = sensor_type, \
> +	.addr = MAKE_SENSOR_ADDRESS(size, bank, index) \
> +	}
> +
> +enum known_ec_sensor {
> +	SENSOR_TEMP_CHIPSET,
> +	SENSOR_TEMP_CPU,
> +	SENSOR_TEMP_MB,
> +	SENSOR_TEMP_T_SENSOR,
> +	SENSOR_TEMP_VRM,
> +	SENSOR_FAN_CPU_OPT,
> +	SENSOR_FAN_CHIPSET,
> +	SENSOR_FAN_WATER_FLOW,
> +	SENSOR_CURR_CPU,
> +	SENSOR_TEMP_WATER_IN,
> +	SENSOR_TEMP_WATER_OUT,
> +	SENSOR_MAX
> +};
> +
> +/*
> + * All the known sensors for ASUS EC controllers
> + */
> +static const struct ec_sensor_info known_ec_sensors[] = {
> +	[SENSOR_TEMP_CHIPSET] = EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
> +	[SENSOR_TEMP_CPU] = EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
> +	[SENSOR_TEMP_MB] = EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
> +	[SENSOR_TEMP_T_SENSOR] = EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
> +	[SENSOR_TEMP_VRM] = EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
> +	[SENSOR_FAN_CPU_OPT] = EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xb0),
> +	[SENSOR_FAN_CHIPSET] = EC_SENSOR("Chipset", hwmon_fan, 2, 0x00, 0xb4),
> +	[SENSOR_FAN_WATER_FLOW] = EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xbc),
> +	[SENSOR_CURR_CPU] = EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
> +	[SENSOR_TEMP_WATER_IN] = EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x00),
> +	[SENSOR_TEMP_WATER_OUT] = EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x01),
> +};
> +
> +struct asus_wmi_data {
> +	const enum known_ec_sensor known_board_sensors[SENSOR_MAX + 1];
> +};
> +
> +/* boards with EC support */
> +static struct asus_wmi_data sensors_board_PW_X570_P = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB, SENSOR_TEMP_VRM,
> +		SENSOR_FAN_CHIPSET,
> +		SENSOR_MAX
> +	},
> +};
> +
> +static struct asus_wmi_data sensors_board_PW_X570_A = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB, SENSOR_TEMP_VRM,
> +		SENSOR_FAN_CHIPSET,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +static struct asus_wmi_data sensors_board_R_C8H = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
> +		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
> +		SENSOR_TEMP_WATER_IN, SENSOR_TEMP_WATER_OUT,
> +		SENSOR_FAN_CPU_OPT, SENSOR_FAN_CHIPSET, SENSOR_FAN_WATER_FLOW,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +/* Same as Hero but without chipset fan */
> +static struct asus_wmi_data sensors_board_R_C8DH = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
> +		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
> +		SENSOR_TEMP_WATER_IN, SENSOR_TEMP_WATER_OUT,
> +		SENSOR_FAN_CPU_OPT, SENSOR_FAN_WATER_FLOW,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +/* Same as Hero but without water */
> +static struct asus_wmi_data sensors_board_R_C8F = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
> +		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
> +		SENSOR_FAN_CPU_OPT, SENSOR_FAN_CHIPSET,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +static struct asus_wmi_data sensors_board_RS_B550_E_G = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
> +		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
> +		SENSOR_FAN_CPU_OPT,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +static struct asus_wmi_data sensors_board_RS_X570_E_G = {
> +	.known_board_sensors = {
> +		SENSOR_TEMP_CHIPSET, SENSOR_TEMP_CPU, SENSOR_TEMP_MB,
> +		SENSOR_TEMP_T_SENSOR, SENSOR_TEMP_VRM,
> +		SENSOR_FAN_CHIPSET,
> +		SENSOR_CURR_CPU,
> +		SENSOR_MAX
> +	},
> +};
> +
> +static struct asus_wmi_data *board_sensors;
> +
> +static int __init asus_wmi_dmi_matched(const struct dmi_system_id *d)
> +{
> +	board_sensors = d->driver_data;
> +	return 0;
> +}
> +
> +#define DMI_EXACT_MATCH_ASUS_BOARD_NAME(name, sensors) \
> +	{ \
> +		.callback = asus_wmi_dmi_matched, \
> +		.matches = { \
> +			DMI_EXACT_MATCH(DMI_BOARD_VENDOR, \
> +					"ASUSTeK COMPUTER INC."), \
> +			DMI_EXACT_MATCH(DMI_BOARD_NAME, name), \
> +		}, \
> +		.driver_data = sensors, \
> +	}
> +
> +static const struct dmi_system_id asus_wmi_ec_dmi_table[] = {
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("PRIME X570-PRO", &sensors_board_PW_X570_P),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("Pro WS X570-ACE", &sensors_board_PW_X570_A),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII DARK HERO", &sensors_board_R_C8DH),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII FORMULA", &sensors_board_R_C8F),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG CROSSHAIR VIII HERO", &sensors_board_R_C8H),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX B550-E GAMING", &sensors_board_RS_B550_E_G),
> +	DMI_EXACT_MATCH_ASUS_BOARD_NAME("ROG STRIX X570-E GAMING", &sensors_board_RS_X570_E_G),
> +	{}
> +};
> +MODULE_DEVICE_TABLE(dmi, asus_wmi_ec_dmi_table);
> +
> +struct ec_sensor {
> +	enum known_ec_sensor info_index;
> +	u32 cached_value;
> +};
> +
> +/**
> + * struct asus_wmi_ec_info - sensor info.
> + * @sensors: list of sensors.
> + * @read_arg: UTF-16 string to pass to BRxx() WMI function.
> + * @read_buffer: decoded output from WMI result.
> + * @nr_sensors: number of board EC sensors.
> + * @nr_registers: number of EC registers to read (sensor might span more than
> + *                         1 register).
> + * @last_updated: in jiffies.
> + */
> +struct asus_wmi_ec_info {
> +	struct ec_sensor sensors[SENSOR_MAX];
> +	char read_arg[((ASUS_WMI_BLOCK_READ_REGISTERS_MAX * 4) + 1) * 2];
> +	u8 read_buffer[ASUS_WMI_BLOCK_READ_REGISTERS_MAX];
> +	unsigned int nr_sensors;
> +	unsigned int nr_registers;
> +	unsigned long last_updated;
> +};
> +
> +struct asus_wmi_sensors {
> +	/* lock access to instrnal cache */

internal ?

> +	struct mutex lock;
> +	struct asus_wmi_ec_info ec;
> +};
> +
> +static int asus_wmi_ec_fill_board_sensors(struct asus_wmi_ec_info *ec)
> +{
> +	const enum known_ec_sensor *bsi;
> +	struct ec_sensor *s = ec->sensors;
> +	int i;
> +
> +	if (!board_sensors)
> +		return -ENODEV;
> +
> +	bsi = board_sensors->known_board_sensors;
> +	ec->nr_sensors = 0;
> +	ec->nr_registers = 0;
> +
> +	for (i = 0; i < SENSOR_MAX && bsi[i] != SENSOR_MAX; i++) {
> +		s[i].info_index = bsi[i];
> +		s[i].cached_value = 0;
> +		ec->nr_sensors++;
> +		ec->nr_registers += known_ec_sensors[bsi[i]].addr.size;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * The next four functions converts to/from BRxx string argument format
> + * The format of the string is as follows:
> + * The string consists of two-byte UTF-16 characters
> + * The value of the very first byte int the string is equal to the total length
> + * of the next string in bytes, thus excluding the first two-byte character
> + * The rest of the string encodes pairs of (bank, index) pairs, where both
> + * values are byte-long (0x00 to 0xFF)
> + * Numbers are encoded as UTF-16 hex values
> + */
> +static void asus_wmi_ec_decode_reply_buffer(const u8 *inp, u8 *out)
> +{
> +	unsigned int len = ACPI_MIN(ASUS_WMI_MAX_BUF_LEN, inp[0] / 4);
> +	char buffer[ASUS_WMI_MAX_BUF_LEN * 2];
> +	const char *pos = buffer;
> +	const u8 *data = inp + 2;
> +	unsigned int i;
> +
> +	utf16s_to_utf8s((wchar_t *)data, len * 2,  UTF16_LITTLE_ENDIAN, buffer, len * 2);
> +
> +	for (i = 0; i < len; i++, pos += 2)
> +		out[i] = (hex_to_bin(pos[0]) << 4) + hex_to_bin(pos[1]);
> +}
> +
> +static void asus_wmi_ec_encode_registers(u16 *registers, u8 len, char *out)
> +{
> +	char buffer[ASUS_WMI_MAX_BUF_LEN * 2];
> +	char *pos = buffer;
> +	unsigned int i;
> +	u8 byte;
> +
> +	*out++ = len * 8;
> +	*out++ = 0;
> +
> +	for (i = 0; i < len; i++) {
> +		byte = registers[i] >> 8;
> +		*pos = hex_asc_hi(byte);
> +		pos++;
> +		*pos = hex_asc_lo(byte);
> +		pos++;
> +		byte = registers[i];
> +		*pos = hex_asc_hi(byte);
> +		pos++;
> +		*pos = hex_asc_lo(byte);
> +		pos++;
> +	}
> +
> +	utf8s_to_utf16s(buffer, len * 4, UTF16_LITTLE_ENDIAN, (wchar_t *)out, len * 4);
> +}
> +
> +static void asus_wmi_ec_make_block_read_query(struct asus_wmi_ec_info *ec)
> +{
> +	u16 registers[ASUS_WMI_BLOCK_READ_REGISTERS_MAX];
> +	const struct ec_sensor_info *si;
> +	int i, j, register_idx = 0;
> +
> +	/*
> +	 * if we can get values for all the registers in a single query,
> +	 * the query will not change from call to call
> +	 */
> +	if (ec->nr_registers <= ASUS_WMI_BLOCK_READ_REGISTERS_MAX &&
> +	    ec->read_arg[0] > 0) {
> +		/* no need to update */
> +		return;
> +	}
> +
> +	for (i = 0; i < ec->nr_sensors; i++) {
> +		si = &known_ec_sensors[ec->sensors[i].info_index];
> +		for (j = 0; j < si->addr.size;
> +		     j++, register_idx++) {
> +			registers[register_idx] = (si->addr.bank << 8) + si->addr.index + j;
> +		}
> +	}
> +
> +	asus_wmi_ec_encode_registers(registers, ec->nr_registers, ec->read_arg);
> +}
> +
> +static int asus_wmi_ec_block_read(u32 method_id, char *query, u8 *out)
> +{
> +#if IS_ENABLED(CONFIG_ACPI_WMI)
> +	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER,
> +				      NULL };
> +	struct acpi_buffer input;
> +	union acpi_object *obj;
> +	acpi_status status;
> +
> +	/* the first byte of the BRxx() argument string has to be the string size */
> +	input.length = (acpi_size)query[0] + 2;
> +	input.pointer = query;
> +	status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0, method_id, &input,
> +				     &output);
> +	if (ACPI_FAILURE(status))
> +		return -EIO;
> +
> +	obj = output.pointer;
> +	if (!obj || obj->type != ACPI_TYPE_BUFFER) {
> +		if (!obj)
> +			acpi_os_free(output.pointer);

This code looks wrong. With obj == output.pointer, output.pointer
is always NULL here. This should be
		if (obj)
			acpi_os_free(obj);
but then since acpi_os_free() calls free(), which does
a NULL pointer check,
		acpi_os_free(obj);
should be just as good.

> +
> +		return -EIO;
> +	}
> +	asus_wmi_ec_decode_reply_buffer(obj->buffer.pointer, out);
> +	acpi_os_free(output.pointer);
> +	return 0;
> +#else
> +	return -EOPNOTSUPP;
> +#endif
> +}
> +
> +static int asus_wmi_ec_update_ec_sensors(struct asus_wmi_ec_info *ec)
> +{
> +	const struct ec_sensor_info *si;
> +	struct ec_sensor *s;
> +

This empty line is confusing; it suggests the end of the variable list
which is not the case. Please drop.

> +	int status;
> +	u8 i_sensor, read_reg_ct;
> +
> +	asus_wmi_ec_make_block_read_query(ec);
> +	status = asus_wmi_ec_block_read(ASUSWMI_METHODID_BLOCK_READ_EC,
> +					ec->read_arg,
> +					ec->read_buffer);
> +	if (status)
> +		return status;
> +
> +	read_reg_ct = 0;
> +	for (i_sensor = 0; i_sensor < ec->nr_sensors; i_sensor++) {
> +		s = &ec->sensors[i_sensor];
> +		si = &known_ec_sensors[s->info_index];
> +
> +		switch (si->addr.size) {
> +		case 1:
> +			s->cached_value = ec->read_buffer[read_reg_ct];
> +			break;
> +		case 2:
> +			s->cached_value = get_unaligned_be16(&ec->read_buffer[read_reg_ct]);
> +			break;
> +		case 4:
> +			s->cached_value = get_unaligned_be32(&ec->read_buffer[read_reg_ct]);
> +			break;
> +		default:
> +			s->cached_value =  0;
> +		}
> +		read_reg_ct += si->addr.size;
> +	}
> +	return 0;
> +}
> +
> +static int asus_wmi_ec_scale_sensor_value(u32 value, int data_type)
> +{
> +	switch (data_type) {
> +	case hwmon_curr:
> +	case hwmon_temp:
> +	case hwmon_in:
> +		return value * KILO;
> +	default:
> +		return value;
> +	}
> +}
> +
> +static int asus_wmi_ec_find_sensor_index(const struct asus_wmi_ec_info *ec,
> +					 enum hwmon_sensor_types type, int channel)
> +{
> +	int i;
> +
> +	for (i = 0; i < ec->nr_sensors; i++) {
> +		if (known_ec_sensors[ec->sensors[i].info_index].type == type) {
> +			if (channel == 0)
> +				return i;
> +
> +			channel--;
> +		}
> +	}
> +	return -EINVAL;
> +}
> +
> +static int asus_wmi_ec_get_cached_value_or_update(int sensor_index,
> +						  struct asus_wmi_sensors *state,
> +						  u32 *value)
> +{
> +	int ret;
> +
> +	if (time_after(jiffies, state->ec.last_updated + HZ)) {
> +		ret = asus_wmi_ec_update_ec_sensors(&state->ec);
> +		if (ret)
> +			return ret;
> +
> +		state->ec.last_updated = jiffies;
> +	}
> +
> +	*value = state->ec.sensors[sensor_index].cached_value;
> +	return 0;
> +}
> +
> +/*
> + * Now follow the functions that implement the hwmon interface
> + */
> +
> +static int asus_wmi_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +				  u32 attr, int channel, long *val)
> +{
> +	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
> +	int ret, sidx, info_index;
> +	u32 value = 0;
> +
> +	sidx = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
> +	if (sidx < 0)
> +		return sidx;
> +
> +	mutex_lock(&sensor_data->lock);
> +	ret = asus_wmi_ec_get_cached_value_or_update(sidx, sensor_data, &value);
> +	mutex_unlock(&sensor_data->lock);
> +	if (ret)
> +		return ret;
> +
> +	info_index = sensor_data->ec.sensors[sidx].info_index;
> +	*val = asus_wmi_ec_scale_sensor_value(value,
> +					      known_ec_sensors[info_index].type);
> +
> +	return ret;
> +}
> +
> +static int asus_wmi_ec_hwmon_read_string(struct device *dev,
> +					 enum hwmon_sensor_types type, u32 attr,
> +					 int channel, const char **str)
> +{
> +	struct asus_wmi_sensors *sensor_data = dev_get_drvdata(dev);
> +	int sensor_index;
> +
> +	sensor_index = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
> +	*str = known_ec_sensors[sensor_data->ec.sensors[sensor_index].info_index].label;
> +
> +	return 0;
> +}
> +
> +static umode_t asus_wmi_ec_hwmon_is_visible(const void *drvdata,
> +					    enum hwmon_sensor_types type, u32 attr,
> +					    int channel)
> +{
> +	int index;
> +	const struct asus_wmi_sensors *sensor_data = drvdata;
> +
> +	index = asus_wmi_ec_find_sensor_index(&sensor_data->ec, type, channel);
> +
> +	return index == 0xff ? 0 : 0444;
> +}
> +
> +static int asus_wmi_hwmon_add_chan_info(struct hwmon_channel_info *asus_wmi_hwmon_chan,
> +					struct device *dev, int num,
> +					enum hwmon_sensor_types type, u32 config)
> +{
> +	u32 *cfg;
> +
> +	cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
> +	if (!cfg)
> +		return -ENOMEM;
> +
> +	asus_wmi_hwmon_chan->type = type;
> +	asus_wmi_hwmon_chan->config = cfg;
> +	memset32(cfg, config, num);
> +
> +	return 0;
> +}
> +
> +static const struct hwmon_ops asus_wmi_ec_hwmon_ops = {
> +	.is_visible = asus_wmi_ec_hwmon_is_visible,
> +	.read = asus_wmi_ec_hwmon_read,
> +	.read_string = asus_wmi_ec_hwmon_read_string,
> +};
> +
> +static struct hwmon_chip_info asus_wmi_ec_chip_info = {
> +	.ops = &asus_wmi_ec_hwmon_ops,
> +};
> +
> +static int asus_wmi_ec_configure_sensor_setup(struct device *dev,
> +					      struct asus_wmi_sensors *sensor_data)
> +{
> +	struct hwmon_channel_info *asus_wmi_hwmon_chan;
> +	const struct hwmon_channel_info **ptr_asus_wmi_ci;
> +	int nr_count[hwmon_max] = { 0 }, nr_types = 0;
> +	const struct hwmon_chip_info *chip_info;
> +	const struct ec_sensor_info *si;
> +	enum hwmon_sensor_types type;
> +	struct device *hwdev;
> +	int i, ret;
> +
> +	ret = asus_wmi_ec_fill_board_sensors(&sensor_data->ec);
> +	if (ret)
> +		return ret;
> +
> +	if (!sensor_data->ec.nr_sensors)
> +		return -ENODEV;
> +
> +	for (i = 0; i < sensor_data->ec.nr_sensors; i++) {
> +		si = &known_ec_sensors[sensor_data->ec.sensors[i].info_index];
> +		if (!nr_count[si->type])
> +			nr_types++;
> +		nr_count[si->type]++;
> +	}
> +
> +	if (nr_count[hwmon_temp]) {
> +		nr_count[hwmon_chip]++;
> +		nr_types++;
> +	}
> +
> +	asus_wmi_hwmon_chan = devm_kcalloc(dev, nr_types,
> +					   sizeof(*asus_wmi_hwmon_chan),
> +					   GFP_KERNEL);
> +	if (!asus_wmi_hwmon_chan)
> +		return -ENOMEM;
> +
> +	ptr_asus_wmi_ci = devm_kcalloc(dev, nr_types + 1,
> +				       sizeof(*ptr_asus_wmi_ci), GFP_KERNEL);
> +	if (!ptr_asus_wmi_ci)
> +		return -ENOMEM;
> +
> +	asus_wmi_ec_chip_info.info = ptr_asus_wmi_ci;
> +	chip_info = &asus_wmi_ec_chip_info;
> +
> +	for (type = 0; type < hwmon_max; type++) {
> +		if (!nr_count[type])
> +			continue;
> +
> +		ret = asus_wmi_hwmon_add_chan_info(asus_wmi_hwmon_chan, dev,
> +						   nr_count[type], type,
> +						   hwmon_attributes[type]);
> +		if (ret)
> +			return ret;
> +
> +		*ptr_asus_wmi_ci++ = asus_wmi_hwmon_chan++;
> +	}
> +
> +	dev_dbg(dev, "board has %d EC sensors that span %d registers",
> +		sensor_data->ec.nr_sensors,
> +		sensor_data->ec.nr_registers);
> +
> +	hwdev = devm_hwmon_device_register_with_info(dev, KBUILD_MODNAME,
> +						     sensor_data, chip_info, NULL);
> +
> +	return PTR_ERR_OR_ZERO(hwdev);
> +}
> +
> +static int asus_wmi_probe(struct wmi_device *wdev, const void *context)
> +{
> +	struct asus_wmi_sensors *sensor_data;
> +	struct device *dev = &wdev->dev;
> +
> +	if (!dmi_check_system(asus_wmi_ec_dmi_table))
> +		return -ENODEV;
> +
> +	sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
> +				   GFP_KERNEL);
> +	if (!sensor_data)
> +		return -ENOMEM;
> +
> +	mutex_init(&sensor_data->lock);
> +
> +	dev_set_drvdata(dev, sensor_data);
> +
> +	/* ec init */
> +	return asus_wmi_ec_configure_sensor_setup(dev,
> +						  sensor_data);
> +}
> +
> +static const struct wmi_device_id asus_ec_wmi_id_table[] = {
> +	{ ASUSWMI_MONITORING_GUID, NULL },
> +	{ }
> +};
> +
> +static struct wmi_driver asus_sensors_wmi_driver = {
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +	},
> +	.id_table = asus_ec_wmi_id_table,
> +	.probe = asus_wmi_probe,
> +};
> +module_wmi_driver(asus_sensors_wmi_driver);
> +
> +MODULE_AUTHOR("Ed Brindley <kernel@maidavale.org>");
> +MODULE_AUTHOR("Eugene Shalygin <eugene.shalygin@gmail.com>");
> +MODULE_DESCRIPTION("Asus WMI Sensors Driver");
> +MODULE_LICENSE("GPL");
> 

Re: [PATCH v5 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Eugene Shalygin]

Hi, Denis,

> +       for (i_sensor = 0; i_sensor < ec->nr_sensors; i_sensor++) {
> +               s = &ec->sensors[i_sensor];
> +               si = &known_ec_sensors[s->info_index];
> +
> +               switch (si->addr.size) {
> +               case 1:
> +                       s->cached_value = ec->read_buffer[read_reg_ct];
> +                       break;
> +               case 2:
> +                       s->cached_value = get_unaligned_be16(&ec->read_buffer[read_reg_ct]);
> +                       break;
> +               case 4:
> +                       s->cached_value = get_unaligned_be32(&ec->read_buffer[read_reg_ct]);
> +                       break;
> +               default:
> +                       s->cached_value =  0;
> +               }
> +               read_reg_ct += si->addr.size;

There is at least one more sensor hiding in the EC address space: the
south bridge voltage. And it seems its value is not an integer, so the
conversion to mV will not be a simple get_unaligned_xx() call when we
locate and add it. Thus, I would suggest extracting this switch in a
separate function to make the future modification simpler. Something
like the following:

static inline u32 get_sensor_value(const struct ec_sensor_info *si, u8
*data) // si for the data encoding scheme
{
    switch (si->addr.components.size) {
    case 1:
        return *data;
    case 2:
        return get_unaligned_be16(data);
    case 4:
        return get_unaligned_be32(data);
    }
}

static void update_sensor_values(struct ec_sensors_data *ec, u8 *data)
{
    const struct ec_sensor_info *si;
    struct ec_sensor *s;

    for (s = ec->sensors; s != ec->sensors + ec->nr_sensors; s++) {
        si = &known_ec_sensors[s->info_index];
        s->cached_value = get_sensor_value(si, data);
        data += si->addr.components.size;
    }
}

Additionally, this would simplify update_ec_sensors() body:

mutex_lock(&ec->lock);
make_asus_wmi_block_read_query(ec);
status = asus_ec_block_read(dev, METHODID_BLOCK_READ_EC, ec->read_arg,
    buffer);

if (!status) {
    update_sensor_values(ec, buffer);
}
mutex_unlock(&ec->lock);


Eugene