watchdog: w83627hf_wdt: Add quirk for Inves system

On some systems, the NCT6791D comes with a companion chip and the
watchdog function is in this companion chip. We must use a different
unlocking sequence to access the companion chip.

Use DMI strings to identify such system and adjust the unlocking
sequence automatically.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/w83627hf_wdt.c b/drivers/watchdog/w83627hf_wdt.c
index 4b9365d..3a49ba9 100644 (file)
--- a/drivers/watchdog/w83627hf_wdt.c
+++ b/drivers/watchdog/w83627hf_wdt.c
@@ -38,6 +38,7 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/dmi.h>
 
 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
 #define WATCHDOG_TIMEOUT 60            /* 60 sec default timeout */
@@ -46,6 +47,8 @@ static int wdt_io;
 static int cr_wdt_timeout;     /* WDT timeout register */
 static int cr_wdt_control;     /* WDT control register */
 static int cr_wdt_csr;         /* WDT control & status register */
+static int wdt_cfg_enter = 0x87;/* key to unlock configuration space */
+static int wdt_cfg_leave = 0xAA;/* key to lock configuration space */
 
 enum chips { w83627hf, w83627s, w83697hf, w83697ug, w83637hf, w83627thf,
             w83687thf, w83627ehf, w83627dhg, w83627uhg, w83667hg, w83627dhg_p,
@@ -130,8 +133,8 @@ static int superio_enter(void)
        if (!request_muxed_region(wdt_io, 2, WATCHDOG_NAME))
                return -EBUSY;
 
-       outb_p(0x87, WDT_EFER); /* Enter extended function mode */
-       outb_p(0x87, WDT_EFER); /* Again according to manual */
+       outb_p(wdt_cfg_enter, WDT_EFER); /* Enter extended function mode */
+       outb_p(wdt_cfg_enter, WDT_EFER); /* Again according to manual */
 
        return 0;
 }
@@ -143,7 +146,7 @@ static void superio_select(int ld)
 
 static void superio_exit(void)
 {
-       outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
+       outb_p(wdt_cfg_leave, WDT_EFER); /* Leave extended function mode */
        release_region(wdt_io, 2);
 }
 
@@ -430,6 +433,32 @@ static int wdt_find(int addr)
        return ret;
 }
 
+/*
+ * On some systems, the NCT6791D comes with a companion chip and the
+ * watchdog function is in this companion chip. We must use a different
+ * unlocking sequence to access the companion chip.
+ */
+static int __init wdt_use_alt_key(const struct dmi_system_id *d)
+{
+       wdt_cfg_enter = 0x88;
+       wdt_cfg_leave = 0xBB;
+
+       return 0;
+}
+
+static const struct dmi_system_id wdt_dmi_table[] __initconst = {
+       {
+               .matches = {
+                       DMI_EXACT_MATCH(DMI_SYS_VENDOR, "INVES"),
+                       DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "CTS"),
+                       DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "INVES"),
+                       DMI_EXACT_MATCH(DMI_BOARD_NAME, "SHARKBAY"),
+               },
+               .callback = wdt_use_alt_key,
+       },
+       {}
+};
+
 static int __init wdt_init(void)
 {
        int ret;
@@ -459,6 +488,9 @@ static int __init wdt_init(void)
                "NCT6102",
        };
 
+       /* Apply system-specific quirks */
+       dmi_check_system(wdt_dmi_table);
+
        wdt_io = 0x2e;
        chip = wdt_find(0x2e);
        if (chip < 0) {