[PATCH v7 0/2] Update ASUS WMI supported boards

[PATCH v7 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.

I have changed code to use dmi_first_match for directly without callbacks 
get sensors list defined for board, added "depends on ACPI_WMI" for 
both modules and added additional check for input buffer in 
asus_wmi_ec_decode_reply_buffer..

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 v7:
- Use  for directly get sensors list by board.
- Add depends on ACPI_WMI to Kconfig.
- Add response buffer size check in asus_wmi_ec_decode_reply_buffer.
- Clean up defines names.

Changes in v6:
- asus_wmi_ec_sensors: Generate query for all sensors on sensors setup
- asus_wmi_ec_sensors: Move binary to sensor value logic to separate 
  get_sensor_value (by Eugene Shalygin)
- asus_wmi_ec_sensors: Use acpi_os_free without NULL pointer check.
- Add asus_wmi_sensor to documentation index.
- Add asus_wmi_ec_sensor to documentation index.

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 +++
 Documentation/hwmon/index.rst               |   2 +
 MAINTAINERS                                 |   8 +
 drivers/hwmon/Kconfig                       |  24 +
 drivers/hwmon/Makefile                      |   2 +
 drivers/hwmon/asus_wmi_ec_sensors.c         | 632 ++++++++++++++++++++
 drivers/hwmon/asus_wmi_sensors.c            | 617 +++++++++++++++++++
 8 files changed, 1394 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: be68c4dcc659172af86e875c25d26c6a114b1afc
-- 
2.33.0

[PATCH v7 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
* Pro WS X570-ACE
* 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>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reported-by: kernel test robot <lkp@intel.com>

---
Changes in v7:
- Use dmi_first_match for directly get sensors list by board.
- Add depends on ACPI_WMI to Kconfig.
- Add response buffer size check in asus_wmi_ec_decode_reply_buffer.
- Clean up defines names.

Changes in v6:
- Generate query for all sensors on sensors setup
- Move binary to sensor value logic to separate get_sensor_value
  (by Eugene Shalygin)
- Add asus_wmi_ec_sensor to documentation index.
- Use acpi_os_free without NULL pointer check.

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 ++
 Documentation/hwmon/index.rst               |   1 +
 MAINTAINERS                                 |   7 +
 drivers/hwmon/Kconfig                       |  12 +
 drivers/hwmon/Makefile                      |   1 +
 drivers/hwmon/asus_wmi_ec_sensors.c         | 632 ++++++++++++++++++++
 6 files changed, 688 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/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 7046bf1870d9..23deb1a1202f 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -43,6 +43,7 @@ Hardware Monitoring Kernel Drivers
    asb100
    asc7621
    aspeed-pwm-tacho
+   asus_wmi_ec_sensors
    bcm54140
    bel-pfe
    bpa-rs600
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..01b6338d70ff 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2215,6 +2215,18 @@ 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"
+	depends on ACPI_WMI
+	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..7080c3085920
--- /dev/null
+++ b/drivers/hwmon/asus_wmi_ec_sensors.c
@@ -0,0 +1,632 @@
+// 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"
+/* BLOCK_READ_EC */
+#define	ASUSWMI_METHODID_BREC	0x42524543
+/* from the ASUS DSDT source */
+#define	ASUSWMI_BREC_REGISTERS_MAX	0x10
+#define	ASUSWMI_MAX_BUF_LEN	0x80
+#define	SENSOR_LABEL_LEN	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[SENSOR_LABEL_LEN];
+	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
+	},
+};
+
+#define	DMI_EXACT_MATCH_ASUS_BOARD_NAME(name, sensors) \
+	{ \
+		.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[((ASUSWMI_BREC_REGISTERS_MAX * 4) + 1) * 2];
+	u8 read_buffer[ASUSWMI_BREC_REGISTERS_MAX];
+	unsigned int nr_sensors;
+	unsigned int nr_registers;
+	unsigned long last_updated;
+};
+
+struct asus_wmi_sensors {
+	/* lock access to internal 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;
+
+	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, u32 length)
+{
+	char buffer[ASUSWMI_MAX_BUF_LEN * 2];
+	const char *pos = buffer;
+	const u8 *data = inp + 2;
+	unsigned int i;
+	u32 len;
+
+	len = min3((u32)ASUSWMI_MAX_BUF_LEN, (length - 2) / 4, (u32)inp[0] / 4);
+
+	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[ASUSWMI_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[ASUSWMI_BREC_REGISTERS_MAX];
+	const struct ec_sensor_info *si;
+	int i, j, register_idx = 0;
+
+	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)
+{
+	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) {
+		acpi_os_free(obj);
+		return -EIO;
+	}
+	asus_wmi_ec_decode_reply_buffer(obj->buffer.pointer, out, obj->buffer.length);
+	acpi_os_free(obj);
+	return 0;
+}
+
+static inline u32 get_sensor_value(const struct ec_sensor_info *si, u8 *data)
+{
+	switch (si->addr.size) {
+	case 1:
+		return *data;
+	case 2:
+		return get_unaligned_be16(data);
+	case 4:
+		return get_unaligned_be32(data);
+	default:
+		return 0;
+	}
+}
+
+static void asus_wmi_ec_update_ec_sensors(struct asus_wmi_ec_info *ec)
+{
+	const struct ec_sensor_info *si;
+	u8 i_sensor;
+	struct ec_sensor *s;
+	u8 *data;
+
+	data = ec->read_buffer;
+	for (i_sensor = 0; i_sensor < ec->nr_sensors; i_sensor++) {
+		s = &ec->sensors[i_sensor];
+		si = &known_ec_sensors[s->info_index];
+		s->cached_value = get_sensor_value(si, data);
+		data += si->addr.size;
+	}
+}
+
+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_block_read(ASUSWMI_METHODID_BREC,
+					     state->ec.read_arg,
+					     state->ec.read_buffer);
+		if (ret)
+			return ret;
+
+		asus_wmi_ec_update_ec_sensors(&state->ec);
+		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,
+					      const enum known_ec_sensor *bsi)
+{
+	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, bsi);
+	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++;
+	}
+
+	/*
+	 * if we can get values for all the registers in a single query,
+	 * the query will not change from call to call
+	 */
+	asus_wmi_ec_make_block_read_query(&sensor_data->ec);
+
+	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 asus_wmi_data *board_sensors;
+	const enum known_ec_sensor *bsi;
+	const struct dmi_system_id *dmi_id;
+	struct device *dev = &wdev->dev;
+
+	dmi_id = dmi_first_match(asus_wmi_ec_dmi_table);
+	if (!dmi_id)
+		return -ENODEV;
+
+	board_sensors = dmi_id->driver_data;
+	if (!board_sensors)
+		return -ENODEV;
+
+	bsi = board_sensors->known_board_sensors;
+
+	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, bsi);
+}
+
+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 v7 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 v7:
- Add depends on ACPI_WMI to Kconfig.
- Clean up defines names.

Changes in v6:
- Add asus_wmi_sensor to documentation index.

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 +++
 Documentation/hwmon/index.rst            |   1 +
 MAINTAINERS                              |   1 +
 drivers/hwmon/Kconfig                    |  12 +
 drivers/hwmon/Makefile                   |   1 +
 drivers/hwmon/asus_wmi_sensors.c         | 617 +++++++++++++++++++++++
 6 files changed, 706 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/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 23deb1a1202f..6dca9df9d24a 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -44,6 +44,7 @@ Hardware Monitoring Kernel Drivers
    asc7621
    aspeed-pwm-tacho
    asus_wmi_ec_sensors
+   asus_wmi_sensors
    bcm54140
    bel-pfe
    bpa-rs600
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 01b6338d70ff..f4e53d02d3d7 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2215,6 +2215,18 @@ 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"
+	depends on ACPI_WMI
+	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"
 	depends on ACPI_WMI
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..5f255b5fe4d6
--- /dev/null
+++ b/drivers/hwmon/asus_wmi_sensors.c
@@ -0,0 +1,617 @@
+// 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 internal 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)
+{
+	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;
+}
+
+/*
+ * 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 v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Andy Shevchenko]

On Fri, Oct 15, 2021 at 8:58 AM Denis Pauk <pauk.denis@gmail.com> 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
> * Pro WS X570-ACE
> * ROG CROSSHAIR VIII HERO
> * ROG CROSSHAIR VIII DARK HERO
> * ROG CROSSHAIR VIII FORMULA
> * ROG STRIX X570-E GAMING
> * ROG STRIX B550-E GAMING

...

> Reported-by: kernel test robot <lkp@intel.com>

New code can't be reported as regression. Or what did you mean by that?

...

> +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>

reST has a special keyword for that.

...

> +/*
> + * 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.

> + *

Redundant line.

> + */

> +#include <asm/unaligned.h>

The common rule is to go from generic to particular, hence
linux/*
followed by
asm/*
followed by local subsystem / local headers like
linux/hwmon*

with a blank line between each group.

> +#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>

...

> +/* BLOCK_READ_EC */

Not sure what this means, but...

> +#define        ASUSWMI_METHODID_BREC   0x42524543

...above has definitely an ASCII combination in hex format, care to
decode it in the comment?

...

> +/* from the ASUS DSDT source */

Keep the same style for all comments, i.e. here "From ..."

...

> +#define        MAKE_SENSOR_ADDRESS(size_i, bank_i, index_i) \
> +       { .size = size_i,\
> +          .bank = bank_i,\
> +          .index = index_i}

You should choose one style for all macros. Here is one, there is
another... I would recommend to use one of

#define ... { \
... \
}

or

#define ... \
{ \
... \
}

In the second case the indentation of the {} is defined by the
semantics of the macro: in case of function-like macro it starts from
the first column, in case of data structure filler usually with one
TAB.

...

> +/*
> + * All the known sensors for ASUS EC controllers
> + */

One line and "All known sensors..."

...

> +struct asus_wmi_ec_info {
> +       struct ec_sensor sensors[SENSOR_MAX];

> +       char read_arg[((ASUSWMI_BREC_REGISTERS_MAX * 4) + 1) * 2];

Too many parentheses.

> +       u8 read_buffer[ASUSWMI_BREC_REGISTERS_MAX];
> +       unsigned int nr_sensors;
> +       unsigned int nr_registers;
> +       unsigned long last_updated;
> +};

...

> +       for (i = 0; i < SENSOR_MAX && bsi[i] != SENSOR_MAX; i++) {
> +               s[i].info_index = bsi[i];

> +               s[i].cached_value = 0;

Isn't it filled by kzalloc() or alike?

> +               ec->nr_sensors++;
> +               ec->nr_registers += known_ec_sensors[bsi[i]].addr.size;
> +       }

...

> +/*
> + * 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

The comment above misses a lot of punctuation. Also it would be nice
to indent the list of items if any and so on.

> + */
> +static void asus_wmi_ec_decode_reply_buffer(const u8 *inp, u8 *out, u32 length)
> +{
> +       char buffer[ASUSWMI_MAX_BUF_LEN * 2];
> +       const char *pos = buffer;
> +       const u8 *data = inp + 2;
> +       unsigned int i;
> +       u32 len;

> +       len = min3((u32)ASUSWMI_MAX_BUF_LEN, (length - 2) / 4, (u32)inp[0] / 4);

Instead I would prefer to have to min_t() calls without adding castings.
Also might be useful to have a short comment explaining this choice.

> +       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]);

NIH hex2bin().

> +}

...

> +       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++;
> +       }

NIH bin2hex()

...

> +               for (j = 0; j < si->addr.size;
> +                    j++, register_idx++) {

One line.

> +                       registers[register_idx] = (si->addr.bank << 8) + si->addr.index + j;
> +               }

...

> +       /* the first byte of the BRxx() argument string has to be the string size */

Comment style.

...

> +       input.length = (acpi_size)query[0] + 2;

Why is casting needed?

...

> +       status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0, method_id, &input,
> +                                    &output);

Logically better to keep &input and &output on the same line, i.e.
second one here.

> +       obj = output.pointer;
> +       if (!obj || obj->type != ACPI_TYPE_BUFFER) {

> +               acpi_os_free(obj);

What's the point of calling acpi_os_free(obj) when you already know it's NULL?

On top of that is the acpi_os_free() high-level enough API for this?

> +               return -EIO;
> +       }
> +       asus_wmi_ec_decode_reply_buffer(obj->buffer.pointer, out, obj->buffer.length);

> +       acpi_os_free(obj);

Ditto.

...

> +       switch (data_type) {
> +       case hwmon_curr:
> +       case hwmon_temp:
> +       case hwmon_in:

> +               return value * KILO;

Thanks for using KILO, but do you think it's the correct one and not MILLI?
MILLI means that we got value in <units> and we would like to convert
it to <milliunits>.
KILO would mean the opposite, like we got in <milliunits> and we would
like to have <units>.

> +       default:
> +               return value;
> +       }

...

> +/*
> + * Now follow the functions that implement the hwmon interface
> + */

One line.

...

> +       int index;
> +       const struct asus_wmi_sensors *sensor_data = drvdata;

Here and elsewhere, perhaps reversed xmas tree order?

...

> +       int nr_count[hwmon_max] = { 0 }, nr_types = 0;

{} will work as well.

...

> +       /*
> +        * if we can get values for all the registers in a single query,
> +        * the query will not change from call to call

"If..."
And period at the end since it's a multi-line comment.

> +        */

...

> +       sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
> +                                  GFP_KERNEL);

One line?

...

> +       /* ec init */

Usefulness of this comment?

> +       return asus_wmi_ec_configure_sensor_setup(dev,
> +                                                 sensor_data, bsi);

One line?

...

> +       .driver = {

> +               .name = KBUILD_MODNAME,

It's kinda semi-ABI, please be not dependent on compile-time variables.

> +       },

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Guenter Roeck]

On 10/15/21 1:21 AM, Andy Shevchenko wrote:
> On Fri, Oct 15, 2021 at 8:58 AM Denis Pauk <pauk.denis@gmail.com> 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
>> * Pro WS X570-ACE
>> * ROG CROSSHAIR VIII HERO
>> * ROG CROSSHAIR VIII DARK HERO
>> * ROG CROSSHAIR VIII FORMULA
>> * ROG STRIX X570-E GAMING
>> * ROG STRIX B550-E GAMING
> 
> ...
> 
>> Reported-by: kernel test robot <lkp@intel.com>
> 
> New code can't be reported as regression. Or what did you mean by that?
> 
Some people include that after 0-day reported a bug in an earlier
revision of the patch. No idea why (it's like expecting submitters
to add "Reported-by:" for everyone providing code review feedback).

Guenter

> ...
> 
>> +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>
> 
> reST has a special keyword for that.
> 
> ...
> 
>> +/*
>> + * 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.
> 
>> + *
> 
> Redundant line.
> 
>> + */
> 
>> +#include <asm/unaligned.h>
> 
> The common rule is to go from generic to particular, hence
> linux/*
> followed by
> asm/*
> followed by local subsystem / local headers like
> linux/hwmon*
> 
> with a blank line between each group.
> 
>> +#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>
> 
> ...
> 
>> +/* BLOCK_READ_EC */
> 
> Not sure what this means, but...
> 
>> +#define        ASUSWMI_METHODID_BREC   0x42524543
> 
> ...above has definitely an ASCII combination in hex format, care to
> decode it in the comment?
> 
> ...
> 
>> +/* from the ASUS DSDT source */
> 
> Keep the same style for all comments, i.e. here "From ..."
> 
> ...
> 
>> +#define        MAKE_SENSOR_ADDRESS(size_i, bank_i, index_i) \
>> +       { .size = size_i,\
>> +          .bank = bank_i,\
>> +          .index = index_i}
> 
> You should choose one style for all macros. Here is one, there is
> another... I would recommend to use one of
> 
> #define ... { \
> ... \
> }
> 
> or
> 
> #define ... \
> { \
> ... \
> }
> 
> In the second case the indentation of the {} is defined by the
> semantics of the macro: in case of function-like macro it starts from
> the first column, in case of data structure filler usually with one
> TAB.
> 
> ...
> 
>> +/*
>> + * All the known sensors for ASUS EC controllers
>> + */
> 
> One line and "All known sensors..."
> 
> ...
> 
>> +struct asus_wmi_ec_info {
>> +       struct ec_sensor sensors[SENSOR_MAX];
> 
>> +       char read_arg[((ASUSWMI_BREC_REGISTERS_MAX * 4) + 1) * 2];
> 
> Too many parentheses.
> 
>> +       u8 read_buffer[ASUSWMI_BREC_REGISTERS_MAX];
>> +       unsigned int nr_sensors;
>> +       unsigned int nr_registers;
>> +       unsigned long last_updated;
>> +};
> 
> ...
> 
>> +       for (i = 0; i < SENSOR_MAX && bsi[i] != SENSOR_MAX; i++) {
>> +               s[i].info_index = bsi[i];
> 
>> +               s[i].cached_value = 0;
> 
> Isn't it filled by kzalloc() or alike?
> 
>> +               ec->nr_sensors++;
>> +               ec->nr_registers += known_ec_sensors[bsi[i]].addr.size;
>> +       }
> 
> ...
> 
>> +/*
>> + * 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
> 
> The comment above misses a lot of punctuation. Also it would be nice
> to indent the list of items if any and so on.
> 
>> + */
>> +static void asus_wmi_ec_decode_reply_buffer(const u8 *inp, u8 *out, u32 length)
>> +{
>> +       char buffer[ASUSWMI_MAX_BUF_LEN * 2];
>> +       const char *pos = buffer;
>> +       const u8 *data = inp + 2;
>> +       unsigned int i;
>> +       u32 len;
> 
>> +       len = min3((u32)ASUSWMI_MAX_BUF_LEN, (length - 2) / 4, (u32)inp[0] / 4);
> 
> Instead I would prefer to have to min_t() calls without adding castings.
> Also might be useful to have a short comment explaining this choice.
> 
>> +       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]);
> 
> NIH hex2bin().
> 
>> +}
> 
> ...
> 
>> +       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++;
>> +       }
> 
> NIH bin2hex()
> 
> ...
> 
>> +               for (j = 0; j < si->addr.size;
>> +                    j++, register_idx++) {
> 
> One line.
> 
>> +                       registers[register_idx] = (si->addr.bank << 8) + si->addr.index + j;
>> +               }
> 
> ...
> 
>> +       /* the first byte of the BRxx() argument string has to be the string size */
> 
> Comment style.
> 
> ...
> 
>> +       input.length = (acpi_size)query[0] + 2;
> 
> Why is casting needed?
> 
> ...
> 
>> +       status = wmi_evaluate_method(ASUSWMI_MONITORING_GUID, 0, method_id, &input,
>> +                                    &output);
> 
> Logically better to keep &input and &output on the same line, i.e.
> second one here.
> 
>> +       obj = output.pointer;
>> +       if (!obj || obj->type != ACPI_TYPE_BUFFER) {
> 
>> +               acpi_os_free(obj);
> 
> What's the point of calling acpi_os_free(obj) when you already know it's NULL?
> 
> On top of that is the acpi_os_free() high-level enough API for this?
> 
>> +               return -EIO;
>> +       }
>> +       asus_wmi_ec_decode_reply_buffer(obj->buffer.pointer, out, obj->buffer.length);
> 
>> +       acpi_os_free(obj);
> 
> Ditto.
> 
> ...
> 
>> +       switch (data_type) {
>> +       case hwmon_curr:
>> +       case hwmon_temp:
>> +       case hwmon_in:
> 
>> +               return value * KILO;
> 
> Thanks for using KILO, but do you think it's the correct one and not MILLI?
> MILLI means that we got value in <units> and we would like to convert
> it to <milliunits>.
> KILO would mean the opposite, like we got in <milliunits> and we would
> like to have <units>.
> 
>> +       default:
>> +               return value;
>> +       }
> 
> ...
> 
>> +/*
>> + * Now follow the functions that implement the hwmon interface
>> + */
> 
> One line.
> 
> ...
> 
>> +       int index;
>> +       const struct asus_wmi_sensors *sensor_data = drvdata;
> 
> Here and elsewhere, perhaps reversed xmas tree order?
> 
> ...
> 
>> +       int nr_count[hwmon_max] = { 0 }, nr_types = 0;
> 
> {} will work as well.
> 
> ...
> 
>> +       /*
>> +        * if we can get values for all the registers in a single query,
>> +        * the query will not change from call to call
> 
> "If..."
> And period at the end since it's a multi-line comment.
> 
>> +        */
> 
> ...
> 
>> +       sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
>> +                                  GFP_KERNEL);
> 
> One line?
> 
> ...
> 
>> +       /* ec init */
> 
> Usefulness of this comment?
> 
>> +       return asus_wmi_ec_configure_sensor_setup(dev,
>> +                                                 sensor_data, bsi);
> 
> One line?
> 
> ...
> 
>> +       .driver = {
> 
>> +               .name = KBUILD_MODNAME,
> 
> It's kinda semi-ABI, please be not dependent on compile-time variables.
> 
>> +       },
> 

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Eugene Shalygin]

Hi, Andy,


> > +#define        ASUSWMI_METHODID_BREC   0x42524543
>
> ...above has definitely an ASCII combination in hex format, care to
> decode it in the comment?

This is a constant from the WMI dispatch function, the number is a
four-letter ASCII-encoded method name, here BREC, which is already
noted in the define identifier. Is it needed to repeat that?

> > +       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]);
>
> NIH hex2bin().

Does it make sense to call hex2bin() with size = 1?

> > +       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++;
> > +       }
>
> NIH bin2hex()

bin2hex() can't output UTF-16LE characters, can it? It would need an
intermediate buffer and a call to convert ASCII (UTF-8) to UTF-16.


> > +       obj = output.pointer;
> > +       if (!obj || obj->type != ACPI_TYPE_BUFFER) {
>
> > +               acpi_os_free(obj);
>
> What's the point of calling acpi_os_free(obj) when you already know it's NULL?

The case when obj->type != ACPI_TYPE_BUFFER

Regards,
Eugene

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Eugene Shalygin]

Hi, Andy,

On Fri, 15 Oct 2021 at 16:37, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> I didn't get it. If there is a strong endianess expected the parameter
> should be __le16 or __be16, moreover it seems it missed the const
> qualifier. Any preparatory stuff should be done in the
> asus_wmi_ec_make_block_read_query() which prepares the input buffer,
> doesn't it?

We need to produce and parse a, roughly speaking, hex-BSTR to pass it
to the WMI function (save for its size parameter of 16 bits instead of
32 for the BSTR). bin/hex conversion functions accept/output UTF-8
strings and thus require an intermediate buffer and additional utf-8
<-> utf-16 conversion. Do you insist that a loop with a stride of 4 is
a homegrown library already?

> > > What's the point of calling acpi_os_free(obj) when you already know it's NULL?
> >
> > The case when obj->type != ACPI_TYPE_BUFFER
>
> Read my comment again, please.

I did it twice already and still can't understand. The WMI method can
return a string, for example, which is an error for our code, but the
buffer needs to be freed.

Regards,
Eugene

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[thomas]

On 2021-10-15T08:58+0300, Denis Pauk wrote:
> +/*
> + * 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, u32 length)
> +{
> +	char buffer[ASUSWMI_MAX_BUF_LEN * 2];
> +	const char *pos = buffer;
> +	const u8 *data = inp + 2;
> +	unsigned int i;
> +	u32 len;
> +
> +	len = min3((u32)ASUSWMI_MAX_BUF_LEN, (length - 2) / 4, (u32)inp[0] / 4);

This will still access out of bounds memory when length == 0.

> +
> +	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 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)

In both drivers there is function like this where the caller is responsible
for halding the mutex. Maybe the mutex could be handled by the function
directly.

> +{
> +	int ret;
> +
> +	if (time_after(jiffies, state->ec.last_updated + HZ)) {
> +		ret = asus_wmi_ec_block_read(ASUSWMI_METHODID_BREC,
> +					     state->ec.read_arg,
> +					     state->ec.read_buffer);
> +		if (ret)
> +			return ret;
> +
> +		asus_wmi_ec_update_ec_sensors(&state->ec);
> +		state->ec.last_updated = jiffies;
> +	}
> +
> +	*value = state->ec.sensors[sensor_index].cached_value;
> +	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;

Should this not check for index < 0?

> +}

> +static int asus_wmi_probe(struct wmi_device *wdev, const void *context)
> +{
> +	struct asus_wmi_sensors *sensor_data;
> +	struct asus_wmi_data *board_sensors;
> +	const enum known_ec_sensor *bsi;
> +	const struct dmi_system_id *dmi_id;
> +	struct device *dev = &wdev->dev;
> +
> +	dmi_id = dmi_first_match(asus_wmi_ec_dmi_table);
> +	if (!dmi_id)
> +		return -ENODEV;
> +
> +	board_sensors = dmi_id->driver_data;
> +	if (!board_sensors)
> +		return -ENODEV;
> +
> +	bsi = board_sensors->known_board_sensors;
> +
> +	sensor_data = devm_kzalloc(dev, sizeof(struct asus_wmi_sensors),
> +				   GFP_KERNEL);

sizeof(*sensor_data);

> +	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, bsi);
> +}

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Andy Shevchenko]

On Fri, Oct 15, 2021 at 5:26 PM Eugene Shalygin
<eugene.shalygin@gmail.com> wrote:

...

> > > +#define        ASUSWMI_METHODID_BREC   0x42524543
> >
> > ...above has definitely an ASCII combination in hex format, care to
> > decode it in the comment?
>
> This is a constant from the WMI dispatch function, the number is a
> four-letter ASCII-encoded method name, here BREC, which is already
> noted in the define identifier. Is it needed to repeat that?

Method name and signature might be different, I tend to ask to add a
comment, simple /* BREC */ at the end of line would suffice.

...

> > > +       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]);
> >
> > NIH hex2bin().
>
> Does it make sense to call hex2bin() with size = 1?

Definitely. We don't want homegrown copies of library APIs.

...

> > > +       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++;
> > > +       }
> >
> > NIH bin2hex()
>
> bin2hex() can't output UTF-16LE characters, can it? It would need an
> intermediate buffer and a call to convert ASCII (UTF-8) to UTF-16.

I didn't get it. If there is a strong endianess expected the parameter
should be __le16 or __be16, moreover it seems it missed the const
qualifier. Any preparatory stuff should be done in the
asus_wmi_ec_make_block_read_query() which prepares the input buffer,
doesn't it?

So, replace homegwon library APIs.

...

> > > +       obj = output.pointer;
> > > +       if (!obj || obj->type != ACPI_TYPE_BUFFER) {
> >
> > > +               acpi_os_free(obj);
> >
> > What's the point of calling acpi_os_free(obj) when you already know it's NULL?
>
> The case when obj->type != ACPI_TYPE_BUFFER

Read my comment again, please.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Andy Shevchenko]

On Fri, Oct 15, 2021 at 8:36 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Fri, Oct 15, 2021 at 5:26 PM Eugene Shalygin
> <eugene.shalygin@gmail.com> wrote:

...

> > bin2hex() can't output UTF-16LE characters, can it? It would need an
> > intermediate buffer and a call to convert ASCII (UTF-8) to UTF-16.
>
> I didn't get it. If there is a strong endianess expected the parameter
> should be __le16 or __be16, moreover it seems it missed the const
> qualifier. Any preparatory stuff should be done in the
> asus_wmi_ec_make_block_read_query() which prepares the input buffer,
> doesn't it?

I'm expecting a confusion here, so let me clarify:
1) in the current code the __le16/__be16 is missed, BUT
2) if you are going to prepare CPU endian buffer in the caller, the
u16 is correct, only const should be added.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Andy Shevchenko]

On Fri, Oct 15, 2021 at 5:49 PM Eugene Shalygin
<eugene.shalygin@gmail.com> wrote:
> On Fri, 15 Oct 2021 at 16:37, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

...

> > I didn't get it. If there is a strong endianess expected the parameter
> > should be __le16 or __be16, moreover it seems it missed the const
> > qualifier. Any preparatory stuff should be done in the
> > asus_wmi_ec_make_block_read_query() which prepares the input buffer,
> > doesn't it?
>
> We need to produce and parse a, roughly speaking, hex-BSTR to pass it
> to the WMI function (save for its size parameter of 16 bits instead of
> 32 for the BSTR). bin/hex conversion functions accept/output UTF-8
> strings and thus require an intermediate buffer and additional utf-8
> <-> utf-16 conversion. Do you insist that a loop with a stride of 4 is
> a homegrown library already?

The code deserves a very good comment. And even if you want to keep
functionality, replace homegrown library calls.

...

> > > > What's the point of calling acpi_os_free(obj) when you already know it's NULL?
> > >
> > > The case when obj->type != ACPI_TYPE_BUFFER
> >
> > Read my comment again, please.
>
> I did it twice already and still can't understand. The WMI method can
> return a string, for example, which is an error for our code, but the
> buffer needs to be freed.

You cut the context, but I think I meant

if (!obj)
  return -ENOMEM;
if (!obj->...) {
  free();
  return -EIO;
}

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v7 1/2] hwmon: (asus_wmi_ec_sensors) Support B550 Asus WMI.

[Denis Pauk]

Hi Andy,

On Fri, 15 Oct 2021 11:21:49 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
...
> 
> > Reported-by: kernel test robot <lkp@intel.com>  
> 
> New code can't be reported as regression. Or what did you mean by
> that?
> 
Just that i have applied changed recommended by test robot. I will
remove it.

> ...
> 
> > +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>  
> 
> reST has a special keyword for that.
> 
> ...
> 
Do you mean something like?
---
Authors:
    - Ed Brindley <kernel@maidavale.org>
---
I have found only such example in other Documentation/hwmon/* files.

Best regards,
    	Denis.