Re: [PATCH] hwmon: add in watchdog for nct6686
From: Guenter Roeck
Date: Tue Aug 15 2023 - 11:38:16 EST
On Tue, Aug 15, 2023 at 07:55:15AM -0400, David Ober wrote:
> This change adds in the watchdog timer support for the nct6686
> chip so that it can be used on the Lenovo m90n IOT device
>
> Signed-off-by: David Ober <dober6023@xxxxxxxxx>
> ---
> Documentation/hwmon/nct6683.rst | 5 +-
> drivers/hwmon/nct6683.c | 247 ++++++++++++++++++++++++++++++--
This should be a separate driver in drivers/watchdog/, and sneaking
in support for a new vendor with the above description is inappropriate
anyway. Besides, why would the watchdog only work for Lenovo ?
Guenter
> 2 files changed, 242 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/hwmon/nct6683.rst b/Documentation/hwmon/nct6683.rst
> index 2e1408d174bd..7421bc444365 100644
> --- a/Documentation/hwmon/nct6683.rst
> +++ b/Documentation/hwmon/nct6683.rst
> @@ -3,7 +3,7 @@ Kernel driver nct6683
>
> Supported chips:
>
> - * Nuvoton NCT6683D/NCT6687D
> + * Nuvoton NCT6683D/NCT6686D/NCT6687D
>
> Prefix: 'nct6683'
>
> @@ -49,6 +49,8 @@ The driver has only been tested with the Intel firmware, and by default
> only instantiates on Intel boards. To enable it on non-Intel boards,
> set the 'force' module parameter to 1.
>
> +Implement the watchdog functionality of the NCT6686D eSIO chip
> +
> Tested Boards and Firmware Versions
> -----------------------------------
>
> @@ -63,4 +65,5 @@ Intel DH87MC NCT6683D EC firmware version 1.0 build 04/03/13
> Intel DB85FL NCT6683D EC firmware version 1.0 build 04/03/13
> ASRock X570 NCT6683D EC firmware version 1.0 build 06/28/19
> MSI B550 NCT6687D EC firmware version 1.0 build 05/07/20
> +LENOVO M90n-1 NCT6686D EC firmware version 9.0 build 04/21/21
> =============== ===============================================
> diff --git a/drivers/hwmon/nct6683.c b/drivers/hwmon/nct6683.c
> index f673f7d07941..eb95b91c4d39 100644
> --- a/drivers/hwmon/nct6683.c
> +++ b/drivers/hwmon/nct6683.c
> @@ -24,15 +24,16 @@
> #include <linux/acpi.h>
> #include <linux/delay.h>
> #include <linux/err.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> #include <linux/init.h>
> #include <linux/io.h>
> #include <linux/jiffies.h>
> -#include <linux/hwmon.h>
> -#include <linux/hwmon-sysfs.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> +#include <linux/watchdog.h>
>
> enum kinds { nct6683, nct6686, nct6687 };
>
> @@ -73,6 +74,34 @@ static const char * const nct6683_chip_names[] = {
> #define SIO_NCT6687_ID 0xd590
> #define SIO_ID_MASK 0xFFF0
>
> +#define WDT_CFG 0x828 /* W/O Lock Watchdog Register */
> +#define WDT_CNT 0x829 /* R/W Watchdog Timer Register */
> +#define WDT_STS 0x82A /* R/O Watchdog Status Register */
> +#define WDT_STS_EVT_POS (0)
> +#define WDT_STS_EVT_MSK (0x3 << WDT_STS_EVT_POS)
> +#define WDT_SOFT_EN 0x87 /* Enable soft watchdog timer */
> +#define WDT_SOFT_DIS 0xAA /* Disable soft watchdog timer */
> +
> +#define WATCHDOG_TIMEOUT 60 /* 1 minute default timeout */
> +
> +/* The timeout range is 1-255 seconds */
> +#define MIN_TIMEOUT 1
> +#define MAX_TIMEOUT 255
> +
> +static int timeout;
> +module_param(timeout, int, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
> + __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +static int early_disable;
> +module_param(early_disable, int, 0);
> +MODULE_PARM_DESC(early_disable, "Disable watchdog at boot time (default=0)");
> +
> static inline void
> superio_outb(int ioreg, int reg, int val)
> {
> @@ -171,10 +200,10 @@ superio_exit(int ioreg)
>
> #define NCT6683_REG_CUSTOMER_ID 0x602
> #define NCT6683_CUSTOMER_ID_INTEL 0x805
> +#define NCT6683_CUSTOMER_ID_LENOVO 0x1101
> #define NCT6683_CUSTOMER_ID_MITAC 0xa0e
> #define NCT6683_CUSTOMER_ID_MSI 0x201
> -#define NCT6683_CUSTOMER_ID_MSI2 0x200
> -#define NCT6683_CUSTOMER_ID_ASROCK 0xe2c
> +#define NCT6683_CUSTOMER_ID_ASROCK 0xe2c
> #define NCT6683_CUSTOMER_ID_ASROCK2 0xe1b
>
> #define NCT6683_REG_BUILD_YEAR 0x604
> @@ -183,6 +212,9 @@ superio_exit(int ioreg)
> #define NCT6683_REG_SERIAL 0x607
> #define NCT6683_REG_VERSION_HI 0x608
> #define NCT6683_REG_VERSION_LO 0x609
> +#define NCT6686_PAGE_REG_OFFSET 0
> +#define NCT6686_ADDR_REG_OFFSET 1
> +#define NCT6686_DATA_REG_OFFSET 2
>
> #define NCT6683_REG_CR_CASEOPEN 0xe8
> #define NCT6683_CR_CASEOPEN_MASK (1 << 7)
> @@ -304,6 +336,7 @@ struct nct6683_data {
>
> struct device *hwmon_dev;
> const struct attribute_group *groups[6];
> + struct watchdog_device wdt;
>
> int temp_num; /* number of temperature attributes */
> u8 temp_index[NCT6683_NUM_REG_MON];
> @@ -518,6 +551,39 @@ static void nct6683_write(struct nct6683_data *data, u16 reg, u16 value)
> outb_p(value & 0xff, data->addr + EC_DATA_REG);
> }
>
> +static inline void nct6686_wdt_set_bank(int base_addr, u16 reg)
> +{
> + outb_p(0xFF, base_addr + NCT6686_PAGE_REG_OFFSET);
> + outb_p(reg >> 8, base_addr + NCT6686_PAGE_REG_OFFSET);
> +}
> +
> +/* Not strictly necessary, but play it safe for now */
> +static inline void nct6686_wdt_reset_bank(int base_addr, u16 reg)
> +{
> + if (reg & 0xff00)
> + outb_p(0xFF, base_addr + NCT6686_PAGE_REG_OFFSET);
> +}
> +
> +static u8 nct6686_read(struct nct6683_data *data, u16 reg)
> +{
> + u8 res;
> +
> + nct6686_wdt_set_bank(data->addr, reg);
> + outb_p(reg & 0xff, data->addr + NCT6686_ADDR_REG_OFFSET);
> + res = inb_p(data->addr + NCT6686_DATA_REG_OFFSET);
> +
> + nct6686_wdt_reset_bank(data->addr, reg);
> + return res;
> +}
> +
> +static void nct6686_write(struct nct6683_data *data, u16 reg, u8 value)
> +{
> + nct6686_wdt_set_bank(data->addr, reg);
> + outb_p(reg & 0xff, data->addr + NCT6686_ADDR_REG_OFFSET);
> + outb_p(value & 0xff, data->addr + NCT6686_DATA_REG_OFFSET);
> + nct6686_wdt_reset_bank(data->addr, reg);
> +}
> +
> static int get_in_reg(struct nct6683_data *data, int nr, int index)
> {
> int ch = data->in_index[index];
> @@ -680,11 +746,12 @@ static umode_t nct6683_in_is_visible(struct kobject *kobj,
> int nr = index % 4; /* attribute */
>
> /*
> - * Voltage limits exist for Intel boards,
> + * Voltage limits exist for Intel and Lenovo boards,
> * but register location and encoding is unknown
> */
> if ((nr == 2 || nr == 3) &&
> - data->customer_id == NCT6683_CUSTOMER_ID_INTEL)
> + (data->customer_id == NCT6683_CUSTOMER_ID_INTEL ||
> + data->customer_id == NCT6683_CUSTOMER_ID_LENOVO))
> return 0;
>
> return attr->mode;
> @@ -1186,6 +1253,139 @@ static void nct6683_setup_sensors(struct nct6683_data *data)
> }
> }
>
> +/*
> + * Watchdog Functions
> + */
> +static int nct6686_wdt_enable(struct watchdog_device *wdog, bool enable)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdog);
> +
> + u_char reg;
> +
> + mutex_lock(&data->update_lock);
> + reg = nct6686_read(data, WDT_CFG);
> +
> + if (enable) {
> + nct6686_write(data, WDT_CFG, reg | 0x3);
> + mutex_unlock(&data->update_lock);
> + return 0;
> + }
> +
> + nct6686_write(data, WDT_CFG, reg & ~BIT(0));
> + mutex_unlock(&data->update_lock);
> +
> + return 0;
> +}
> +
> +static int nct6686_wdt_set_time(struct watchdog_device *wdog)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdog);
> +
> + mutex_lock(&data->update_lock);
> + nct6686_write(data, WDT_CNT, wdog->timeout);
> + mutex_unlock(&data->update_lock);
> +
> + if (wdog->timeout) {
> + nct6686_wdt_enable(wdog, true);
> + return 0;
> + }
> +
> + nct6686_wdt_enable(wdog, false);
> + return 0;
> +}
> +
> +static int nct6686_wdt_start(struct watchdog_device *wdt)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdt);
> + u_char reg;
> +
> + nct6686_wdt_set_time(wdt);
> +
> + /* Enable soft watchdog timer */
> + mutex_lock(&data->update_lock);
> + /* reset trigger status */
> + reg = nct6686_read(data, WDT_STS);
> + nct6686_write(data, WDT_STS, reg & ~WDT_STS_EVT_MSK);
> + mutex_unlock(&data->update_lock);
> + return 0;
> +}
> +
> +static int nct6686_wdt_stop(struct watchdog_device *wdt)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdt);
> +
> + mutex_lock(&data->update_lock);
> + nct6686_write(data, WDT_CFG, WDT_SOFT_DIS);
> + mutex_unlock(&data->update_lock);
> + return 0;
> +}
> +
> +static int nct6686_wdt_set_timeout(struct watchdog_device *wdt,
> + unsigned int timeout)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdt);
> +
> + wdt->timeout = timeout;
> + mutex_lock(&data->update_lock);
> + nct6686_write(data, WDT_CNT, timeout);
> + mutex_unlock(&data->update_lock);
> + return 0;
> +}
> +
> +static int nct6686_wdt_ping(struct watchdog_device *wdt)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdt);
> + int timeout;
> +
> + /*
> + * Note:
> + * NCT6686 does not support refreshing WDT_TIMER_REG register when
> + * the watchdog is active. Please disable watchdog before feeding
> + * the watchdog and enable it again.
> + */
> + /* Disable soft watchdog timer */
> + nct6686_wdt_enable(wdt, false);
> +
> + /* feed watchdog */
> + timeout = wdt->timeout;
> + mutex_lock(&data->update_lock);
> + nct6686_write(data, WDT_CNT, timeout);
> + mutex_unlock(&data->update_lock);
> +
> + /* Enable soft watchdog timer */
> + nct6686_wdt_enable(wdt, true);
> + return 0;
> +}
> +
> +static unsigned int nct6686_wdt_get_timeleft(struct watchdog_device *wdt)
> +{
> + struct nct6683_data *data = watchdog_get_drvdata(wdt);
> + int ret;
> +
> + mutex_lock(&data->update_lock);
> + ret = nct6686_read(data, WDT_CNT);
> + mutex_unlock(&data->update_lock);
> + if (ret < 0)
> + return 0;
> +
> + return ret;
> +}
> +
> +static const struct watchdog_info nct6686_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> + WDIOF_MAGICCLOSE,
> + .identity = "nct6686 watchdog",
> +};
> +
> +static const struct watchdog_ops nct6686_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = nct6686_wdt_start,
> + .stop = nct6686_wdt_stop,
> + .ping = nct6686_wdt_ping,
> + .set_timeout = nct6686_wdt_set_timeout,
> + .get_timeleft = nct6686_wdt_get_timeleft,
> +};
> +
> static int nct6683_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -1195,7 +1395,9 @@ static int nct6683_probe(struct platform_device *pdev)
> struct device *hwmon_dev;
> struct resource *res;
> int groups = 0;
> + int ret;
> char build[16];
> + u_char reg;
>
> res = platform_get_resource(pdev, IORESOURCE_IO, 0);
> if (!devm_request_region(dev, res->start, IOREGION_LENGTH, DRVNAME))
> @@ -1215,14 +1417,14 @@ static int nct6683_probe(struct platform_device *pdev)
>
> /* By default only instantiate driver if the customer ID is known */
> switch (data->customer_id) {
> + case NCT6683_CUSTOMER_ID_LENOVO:
> + break;
> case NCT6683_CUSTOMER_ID_INTEL:
> break;
> case NCT6683_CUSTOMER_ID_MITAC:
> break;
> case NCT6683_CUSTOMER_ID_MSI:
> break;
> - case NCT6683_CUSTOMER_ID_MSI2:
> - break;
> case NCT6683_CUSTOMER_ID_ASROCK:
> break;
> case NCT6683_CUSTOMER_ID_ASROCK2:
> @@ -1294,7 +1496,34 @@ static int nct6683_probe(struct platform_device *pdev)
>
> hwmon_dev = devm_hwmon_device_register_with_groups(dev,
> nct6683_device_names[data->kind], data, data->groups);
> - return PTR_ERR_OR_ZERO(hwmon_dev);
> +
> + ret = PTR_ERR_OR_ZERO(hwmon_dev);
> + if (ret)
> + return ret;
> +
> + if (data->kind == nct6686 && data->customer_id == NCT6683_CUSTOMER_ID_LENOVO) {
> + /* Watchdog initialization */
> + data->wdt.ops = &nct6686_wdt_ops;
> + data->wdt.info = &nct6686_wdt_info;
> +
> + data->wdt.timeout = WATCHDOG_TIMEOUT; /* Set default timeout */
> + data->wdt.min_timeout = MIN_TIMEOUT;
> + data->wdt.max_timeout = MAX_TIMEOUT;
> + data->wdt.parent = &pdev->dev;
> +
> + watchdog_init_timeout(&data->wdt, timeout, &pdev->dev);
> + watchdog_set_nowayout(&data->wdt, nowayout);
> + watchdog_set_drvdata(&data->wdt, data);
> +
> + /* reset trigger status */
> + reg = nct6686_read(data, WDT_STS);
> + nct6686_write(data, WDT_STS, reg & ~WDT_STS_EVT_MSK);
> +
> + watchdog_stop_on_unregister(&data->wdt);
> +
> + return devm_watchdog_register_device(dev, &data->wdt);
> + }
> + return ret;
> }
>
> #ifdef CONFIG_PM
> --
> 2.34.1
>