hwmon: (it87) Add support for second Super-IO chip

The Super-IO chip can also reside at SIO address 0x4e, and there can be
two Super-IO chips in the system. Add support for it.

Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 4840f2d..f877cc9 100644 (file)
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -78,9 +78,10 @@ static unsigned short force_id;
 module_param(force_id, ushort, 0);
 MODULE_PARM_DESC(force_id, "Override the detected device ID");
 
-static struct platform_device *it87_pdev;
+static struct platform_device *it87_pdev[2];
 
 #define        REG_2E  0x2e    /* The register to read/write */
+#define        REG_4E  0x4e    /* Secondary register to read/write */
 
 #define        DEV     0x07    /* Register: Logical device select */
 #define PME    0x04    /* The device with the fan registers in it */
@@ -130,7 +131,7 @@ static inline int superio_enter(int ioreg)
        outb(0x87, ioreg);
        outb(0x01, ioreg);
        outb(0x55, ioreg);
-       outb(0x55, ioreg);
+       outb(ioreg == REG_4E ? 0xaa : 0x55, ioreg);
        return 0;
 }
 
@@ -2892,7 +2893,7 @@ static struct it87_data *it87_update_device(struct device *dev)
        return data;
 }
 
-static int __init it87_device_add(unsigned short address,
+static int __init it87_device_add(int index, unsigned short address,
                                  const struct it87_sio_data *sio_data)
 {
        struct platform_device *pdev;
@@ -2931,7 +2932,7 @@ static int __init it87_device_add(unsigned short address,
                goto exit_device_put;
        }
 
-       it87_pdev = pdev;
+       it87_pdev[index] = pdev;
        return 0;
 
 exit_device_put:
@@ -2941,30 +2942,48 @@ exit_device_put:
 
 static int __init sm_it87_init(void)
 {
-       int err;
-       unsigned short isa_address = 0;
+       int sioaddr[2] = { REG_2E, REG_4E };
        struct it87_sio_data sio_data;
+       unsigned short isa_address;
+       bool found = false;
+       int i, err;
 
-       memset(&sio_data, 0, sizeof(struct it87_sio_data));
-       err = it87_find(REG_2E, &isa_address, &sio_data);
-       if (err)
-               return err;
        err = platform_driver_register(&it87_driver);
        if (err)
                return err;
 
-       err = it87_device_add(isa_address, &sio_data);
-       if (err) {
-               platform_driver_unregister(&it87_driver);
-               return err;
+       for (i = 0; i < ARRAY_SIZE(sioaddr); i++) {
+               memset(&sio_data, 0, sizeof(struct it87_sio_data));
+               isa_address = 0;
+               err = it87_find(sioaddr[i], &isa_address, &sio_data);
+               if (err || isa_address == 0)
+                       continue;
+
+               err = it87_device_add(i, isa_address, &sio_data);
+               if (err)
+                       goto exit_dev_unregister;
+               found = true;
        }
 
+       if (!found) {
+               err = -ENODEV;
+               goto exit_unregister;
+       }
        return 0;
+
+exit_dev_unregister:
+       /* NULL check handled by platform_device_unregister */
+       platform_device_unregister(it87_pdev[0]);
+exit_unregister:
+       platform_driver_unregister(&it87_driver);
+       return err;
 }
 
 static void __exit sm_it87_exit(void)
 {
-       platform_device_unregister(it87_pdev);
+       /* NULL check handled by platform_device_unregister */
+       platform_device_unregister(it87_pdev[1]);
+       platform_device_unregister(it87_pdev[0]);
        platform_driver_unregister(&it87_driver);
 }