Re: [PATCH v7 3/3] hwmon: (nct6775) Support access via Asus WMI
From: Denis Pauk
Date: Thu Sep 16 2021 - 17:24:44 EST
On Thu, 16 Sep 2021 14:10:49 -0700
Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> On 9/16/21 1:22 PM, Denis Pauk wrote:
> > Support accessing the NCT677x via Asus WMI functions.
> >
> > On mainboards that support this way of accessing the chip, the
> > driver will usually not work without this option since in these
> > mainboards, ACPI will mark the I/O port as used.
> >
> > Code uses ACPI firmware interface to communicate with sensors with
> > ASUS motherboards:
> > * PRIME B460-PLUS,
> > * ROG CROSSHAIR VIII IMPACT,
> > * ROG STRIX B550-E GAMING,
> > * ROG STRIX B550-F GAMING,
> > * ROG STRIX B550-F GAMING (WI-FI),
> > * ROG STRIX Z490-I GAMING,
> > * TUF GAMING B550M-PLUS,
> > * TUF GAMING B550M-PLUS (WI-FI),
> > * TUF GAMING B550-PLUS,
> > * TUF GAMING X570-PLUS,
> > * TUF GAMING X570-PRO (WI-FI).
> >
> > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204807
> > Signed-off-by: Denis Pauk <pauk.denis@xxxxxxxxx>
> > Co-developed-by: Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx>
> > Tested-by: Pär Ekholm <pehlm@xxxxxxxxxxx>
> > Tested-by: <to.eivind@xxxxxxxxx>
> > Tested-by: Artem S. Tashkinov <aros@xxxxxxx>
> > Tested-by: Vittorio Roberto Alfieri <me@xxxxxxxxxxx>
> > Tested-by: Sahan Fernando <sahan.h.fernando@xxxxxxxxx>
> > Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
> > Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> >
> > ---
> > Changes in v7:
> > - Remove unrequred & 0xff with int8 variables.
> > - Make ASUSWMI_UNSUPPORTED_METHOD as default value for WMI
> > responce, before run wmi_evaluate_method().
> > - Rename ASUSWMI_MGMT2_GUID to ASUSWMI_MONITORING_GUID.
> > - Replace checks of 'err != -EINVAL' with 'err >= 0' for
> > match_string result.
> >
> > Changes in v6:
> > - Minimaze codes inside code inside defined(CONFIG_ACPI_WMI).
> >
> > Changes in v5:
> > - Use IS_ENABLED(CONFIG_ACPI_WMI) instead
> > defined(CONFIG_ACPI_WMI)
> >
> > Changes in v4:
> > - Fix build without ACPI WMI.
> >
> > Changes in v3:
> > - Remove unrequired type conversions.
> > - Save result of match_string before check.
> >
> > Changes in v2:
> > - Split changes to separate patches.
> > - Limit WMI usage by DMI_BOARD_NAME in checked ASUS motherboards.
> > ---
> > drivers/hwmon/Kconfig | 1 +
> > drivers/hwmon/nct6775.c | 230
> > ++++++++++++++++++++++++++++++++++++---- 2 files changed, 210
> > insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index e3675377bc5d..9eefb1014b53 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -1423,6 +1423,7 @@ config SENSORS_NCT6683
> > config SENSORS_NCT6775
> > tristate "Nuvoton NCT6775F and compatibles"
> > depends on !PPC
> > + depends on ACPI_WMI || ACPI_WMI=n
> > select HWMON_VID
> > help
> > If you say yes here you get support for the hardware
> > monitoring diff --git a/drivers/hwmon/nct6775.c
> > b/drivers/hwmon/nct6775.c index 4253eed7f5b0..46262d9d3bd9 100644
> > --- a/drivers/hwmon/nct6775.c
> > +++ b/drivers/hwmon/nct6775.c
> > @@ -55,6 +55,7 @@
> > #include <linux/dmi.h>
> > #include <linux/io.h>
> > #include <linux/nospec.h>
> > +#include <linux/wmi.h>
> > #include "lm75.h"
> >
> > #define USE_ALTERNATE
> > @@ -132,10 +133,13 @@ MODULE_PARM_DESC(fan_debounce, "Enable
> > debouncing for fan RPM signal"); #define SIO_ID_MASK
> > 0xFFF8
> > enum pwm_enable { off, manual, thermal_cruise, speed_cruise, sf3,
> > sf4 }; +enum sensor_access { access_direct, access_asuswmi };
> >
> > struct nct6775_sio_data {
> > int sioreg;
> > + int ld;
> > enum kinds kind;
> > + enum sensor_access access;
> >
> > /* superio_() callbacks */
> > void (*sio_outb)(struct nct6775_sio_data *sio_data, int
> > reg, int val); @@ -145,6 +149,90 @@ struct nct6775_sio_data {
> > void (*sio_exit)(struct nct6775_sio_data *sio_data);
> > };
> >
> > +#define ASUSWMI_MONITORING_GUID
> > "466747A0-70EC-11DE-8A39-0800200C9A66" +#define
> > ASUSWMI_METHODID_RSIO 0x5253494F +#define
> > ASUSWMI_METHODID_WSIO 0x5753494F +#define
> > ASUSWMI_METHODID_RHWM 0x5248574D +#define
> > ASUSWMI_METHODID_WHWM 0x5748574D +#define
> > ASUSWMI_UNSUPPORTED_METHOD 0xFFFFFFFE +
> > +static int asuswmi_evaluate_method(u32 method_id, u8 bank, u8 reg,
> > u8 val, u32 *retval) +{
What do you thin about rename asuswmi_evaluate_method() to
asuswmi_monitoring_method()? I have found that kernel already have
asus_wmi_evaluate_method() that has used different method GUID, so
looks as make sense to use different function name. It uses different
constants with different names/values and does not intersect with this
one.
> > +#if IS_ENABLED(CONFIG_ACPI_WMI)
> > + u32 args = bank | (reg << 8) | (val << 16);
> > + struct acpi_buffer input = { (acpi_size) sizeof(args),
> > &args };
> > + struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> > + acpi_status status;
> > + union acpi_object *obj;
> > + u32 tmp = ASUSWMI_UNSUPPORTED_METHOD;
> > +
> > + 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_INTEGER)
> > + tmp = obj->integer.value;
> > +
> > + if (retval)
> > + *retval = tmp;
> > +
> > + kfree(obj);
> > +
> > + if (tmp == ASUSWMI_UNSUPPORTED_METHOD)
> > + return -ENODEV;
> > + return 0;
> > +#else
> > + return -EOPNOTSUPP;
> > +#endif
> > +}
> > +
> > +static inline int nct6775_asuswmi_write(u8 bank, u8 reg, u8 val)
> > +{
> > + return asuswmi_evaluate_method(ASUSWMI_METHODID_WHWM, bank,
> > + reg,
> > val, NULL); +}
> > +
> > +static inline int nct6775_asuswmi_read(u8 bank, u8 reg, u8 *val)
> > +{
> > + u32 tmp = 0;
> > + int ret = asuswmi_evaluate_method(ASUSWMI_METHODID_RHWM,
> > bank,
> > + reg, 0, &tmp);
> > + *val = tmp;
> > + return ret;
> > +}
> > +
> > +static int superio_wmi_inb(struct nct6775_sio_data *sio_data, int
> > reg) +{
> > + int tmp;
> > +
> > + asuswmi_evaluate_method(ASUSWMI_METHODID_RSIO,
> > sio_data->ld,
> > + reg, 0, &tmp);
> > + return tmp;
> > +}
> > +
> > +static void superio_wmi_outb(struct nct6775_sio_data *sio_data,
> > int reg, int val) +{
> > + asuswmi_evaluate_method(ASUSWMI_METHODID_WSIO,
> > sio_data->ld,
> > + reg, val, NULL);
> > +}
> > +
> > +static void superio_wmi_select(struct nct6775_sio_data *sio_data,
> > int ld) +{
> > + sio_data->ld = ld;
> > +}
> > +
> > +static int superio_wmi_enter(struct nct6775_sio_data *sio_data)
> > +{
> > + return 0;
> > +}
> > +
> > +static void superio_wmi_exit(struct nct6775_sio_data *sio_data)
> > +{
> > +}
> > +
> > static void superio_outb(struct nct6775_sio_data *sio_data, int
> > reg, int val) {
> > int ioreg = sio_data->sioreg;
> > @@ -207,6 +295,7 @@ static void superio_exit(struct
> > nct6775_sio_data *sio_data)
> > #define NCT6775_REG_BANK 0x4E
> > #define NCT6775_REG_CONFIG 0x40
> > +#define NCT6775_PORT_CHIPID 0x58
> >
> > /*
> > * Not currently used:
> > @@ -1423,6 +1512,45 @@ static bool is_word_sized(struct
> > nct6775_data *data, u16 reg) return false;
> > }
> >
> > +static inline void nct6775_wmi_set_bank(struct nct6775_data *data,
> > u16 reg) +{
> > + u8 bank = reg >> 8;
> > +
> > + data->bank = bank;
> > +}
> > +
> > +static u16 nct6775_wmi_read_value(struct nct6775_data *data, u16
> > reg) +{
> > + int res, word_sized = is_word_sized(data, reg);
> > + u8 tmp;
> > +
> > + nct6775_wmi_set_bank(data, reg);
> > +
> > + nct6775_asuswmi_read(data->bank, reg, &tmp);
> > + res = tmp;
> > + if (word_sized) {
> > + nct6775_asuswmi_read(data->bank, (reg & 0xff) + 1,
> > &tmp);
>
> I just realized that all error returns from the wmi access methods
> are ignored. Why ?
Good question, I will check and add checks for all cases. Thank you.
>
> > + res = (res << 8) + tmp;
> > + }
> > + return res;
> > +}
> > +
> > +static int nct6775_wmi_write_value(struct nct6775_data *data, u16
> > reg, u16 value) +{
> > + int word_sized = is_word_sized(data, reg);
> > +
> > + nct6775_wmi_set_bank(data, reg);
> > +
> > + if (word_sized) {
> > + nct6775_asuswmi_write(data->bank, reg & 0xff,
> > value >> 8);
> > + nct6775_asuswmi_write(data->bank, (reg & 0xff) +
> > 1, value);
> > + } else {
> > + nct6775_asuswmi_write(data->bank, reg & 0xff,
> > value);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > /*
> > * On older chips, only registers 0x50-0x5f are banked.
> > * On more recent chips, all registers are banked.
> > @@ -3818,10 +3946,12 @@ static int nct6775_probe(struct
> > platform_device *pdev) struct device *hwmon_dev;
> > int num_attr_groups = 0;
> >
> > - res = platform_get_resource(pdev, IORESOURCE_IO, 0);
> > - if (!devm_request_region(&pdev->dev, res->start,
> > IOREGION_LENGTH,
> > - DRVNAME))
> > - return -EBUSY;
> > + if (sio_data->access == access_direct) {
> > + res = platform_get_resource(pdev, IORESOURCE_IO,
> > 0);
> > + if (!devm_request_region(&pdev->dev, res->start,
> > IOREGION_LENGTH,
> > + DRVNAME))
> > + return -EBUSY;
> > + }
> >
> > data = devm_kzalloc(&pdev->dev, sizeof(struct
> > nct6775_data), GFP_KERNEL);
> > @@ -3830,9 +3960,16 @@ static int nct6775_probe(struct
> > platform_device *pdev)
> > data->kind = sio_data->kind;
> > data->sioreg = sio_data->sioreg;
> > - data->addr = res->start;
> > - data->read_value = nct6775_read_value;
> > - data->write_value = nct6775_write_value;
> > +
> > + if (sio_data->access == access_direct) {
> > + data->addr = res->start;
> > + data->read_value = nct6775_read_value;
> > + data->write_value = nct6775_write_value;
> > + } else {
> > + data->read_value = nct6775_wmi_read_value;
> > + data->write_value = nct6775_wmi_write_value;
> > + }
> > +
> > mutex_init(&data->update_lock);
> > data->name = nct6775_device_names[data->kind];
> > data->bank = 0xff; /* Force initial bank
> > selection */ @@ -4743,6 +4880,7 @@ static int __init
> > nct6775_find(int sioaddr, struct nct6775_sio_data *sio_data) int
> > err; int addr;
> >
> > + sio_data->access = access_direct;
> > sio_data->sioreg = sioaddr;
> >
> > err = sio_data->sio_enter(sio_data);
> > @@ -4837,6 +4975,23 @@ static int __init nct6775_find(int sioaddr,
> > struct nct6775_sio_data *sio_data) */
> > static struct platform_device *pdev[2];
> >
> > +static const char * const asus_wmi_boards[] = {
> > + "PRIME B460-PLUS",
> > + "ROG CROSSHAIR VIII DARK HERO",
> > + "ROG CROSSHAIR VIII HERO",
> > + "ROG CROSSHAIR VIII IMPACT",
> > + "ROG STRIX B550-E GAMING",
> > + "ROG STRIX B550-F GAMING",
> > + "ROG STRIX B550-F GAMING (WI-FI)",
> > + "ROG STRIX Z490-I GAMING",
> > + "TUF GAMING B550M-PLUS",
> > + "TUF GAMING B550M-PLUS (WI-FI)",
> > + "TUF GAMING B550-PLUS",
> > + "TUF GAMING X570-PLUS",
> > + "TUF GAMING X570-PLUS (WI-FI)",
> > + "TUF GAMING X570-PRO (WI-FI)",
> > +};
> > +
> > static int __init sensors_nct6775_init(void)
> > {
> > int i, err;
> > @@ -4845,11 +5000,32 @@ static int __init sensors_nct6775_init(void)
> > struct resource res;
> > struct nct6775_sio_data sio_data;
> > int sioaddr[2] = { 0x2e, 0x4e };
> > + enum sensor_access access = access_direct;
> > + const char *board_vendor, *board_name;
> > + u8 tmp;
> >
> > err = platform_driver_register(&nct6775_driver);
> > if (err)
> > return err;
> >
> > + board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
> > + board_name = dmi_get_system_info(DMI_BOARD_NAME);
> > +
> > + if (board_name && board_vendor &&
> > + !strcmp(board_vendor, "ASUSTeK COMPUTER INC.")) {
> > + err = match_string(asus_wmi_boards,
> > ARRAY_SIZE(asus_wmi_boards),
> > + board_name);
> > + if (err >= 0) {
> > + /* if reading chip id via WMI succeeds,
> > use WMI */
> > + if (!nct6775_asuswmi_read(0,
> > NCT6775_PORT_CHIPID, &tmp)) {
> > + pr_info("Using Asus WMI to access
> > %#x chip.\n", tmp);
> > + access = access_asuswmi;
> > + } else {
> > + pr_err("Can't read ChipID by Asus
> > WMI.\n");
> > + }
> > + }
> > + }
> > +
> > /*
> > * initialize sio_data->kind and sio_data->sioreg.
> > *
> > @@ -4870,6 +5046,16 @@ static int __init sensors_nct6775_init(void)
> >
> > found = true;
> >
> > + sio_data.access = access;
> > +
> > + if (access == access_asuswmi) {
> > + sio_data.sio_outb = superio_wmi_outb;
> > + sio_data.sio_inb = superio_wmi_inb;
> > + sio_data.sio_select = superio_wmi_select;
> > + sio_data.sio_enter = superio_wmi_enter;
> > + sio_data.sio_exit = superio_wmi_exit;
> > + }
> > +
> > pdev[i] = platform_device_alloc(DRVNAME, address);
> > if (!pdev[i]) {
> > err = -ENOMEM;
> > @@ -4881,23 +5067,25 @@ static int __init sensors_nct6775_init(void)
> > if (err)
> > goto exit_device_put;
> >
> > - memset(&res, 0, sizeof(res));
> > - res.name = DRVNAME;
> > - res.start = address + IOREGION_OFFSET;
> > - res.end = address + IOREGION_OFFSET +
> > IOREGION_LENGTH - 1;
> > - res.flags = IORESOURCE_IO;
> > + if (sio_data.access == access_direct) {
> > + memset(&res, 0, sizeof(res));
> > + res.name = DRVNAME;
> > + res.start = address + IOREGION_OFFSET;
> > + res.end = address + IOREGION_OFFSET +
> > IOREGION_LENGTH - 1;
> > + res.flags = IORESOURCE_IO;
> > +
> > + err = acpi_check_resource_conflict(&res);
> > + if (err) {
> > + platform_device_put(pdev[i]);
> > + pdev[i] = NULL;
> > + continue;
> > + }
> >
> > - err = acpi_check_resource_conflict(&res);
> > - if (err) {
> > - platform_device_put(pdev[i]);
> > - pdev[i] = NULL;
> > - continue;
> > + err =
> > platform_device_add_resources(pdev[i], &res, 1);
> > + if (err)
> > + goto exit_device_put;
> > }
> >
> > - err = platform_device_add_resources(pdev[i], &res,
> > 1);
> > - if (err)
> > - goto exit_device_put;
> > -
> > /* platform_device_add calls probe() */
> > err = platform_device_add(pdev[i]);
> > if (err)
> >
>