hwmon: (nct6775) Re-enable logical device mapping for NCT6791 during resume

After a suspend/resume cycle, the NCT6791 is back to its original BIOS
programming. In this state, HWMON IO access may be locked.
Re-enable it during resume.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index cf811c1..8686e96 100644 (file)
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -3936,6 +3936,18 @@ static int nct6775_probe(struct platform_device *pdev)
        return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+static void nct6791_enable_io_mapping(int sioaddr)
+{
+       int val;
+
+       val = superio_inb(sioaddr, NCT6791_REG_HM_IO_SPACE_LOCK_ENABLE);
+       if (val & 0x10) {
+               pr_info("Enabling hardware monitor logical device mappings.\n");
+               superio_outb(sioaddr, NCT6791_REG_HM_IO_SPACE_LOCK_ENABLE,
+                            val & ~0x10);
+       }
+}
+
 #ifdef CONFIG_PM
 static int nct6775_suspend(struct device *dev)
 {
@@ -3955,11 +3967,20 @@ static int nct6775_suspend(struct device *dev)
 static int nct6775_resume(struct device *dev)
 {
        struct nct6775_data *data = dev_get_drvdata(dev);
-       int i, j;
+       int i, j, err = 0;
 
        mutex_lock(&data->update_lock);
        data->bank = 0xff;              /* Force initial bank selection */
 
+       if (data->kind == nct6791) {
+               err = superio_enter(data->sioreg);
+               if (err)
+                       goto abort;
+
+               nct6791_enable_io_mapping(data->sioreg);
+               superio_exit(data->sioreg);
+       }
+
        /* Restore limits */
        for (i = 0; i < data->in_num; i++) {
                if (!(data->have_in & (1 << i)))
@@ -3996,11 +4017,12 @@ static int nct6775_resume(struct device *dev)
                nct6775_write_value(data, NCT6775_REG_FANDIV2, data->fandiv2);
        }
 
+abort:
        /* Force re-reading all values */
        data->valid = false;
        mutex_unlock(&data->update_lock);
 
-       return 0;
+       return err;
 }
 
 static const struct dev_pm_ops nct6775_dev_pm_ops = {
@@ -4088,15 +4110,9 @@ static int __init nct6775_find(int sioaddr, struct nct6775_sio_data *sio_data)
                pr_warn("Forcibly enabling Super-I/O. Sensor is probably unusable.\n");
                superio_outb(sioaddr, SIO_REG_ENABLE, val | 0x01);
        }
-       if (sio_data->kind == nct6791) {
-               val = superio_inb(sioaddr, NCT6791_REG_HM_IO_SPACE_LOCK_ENABLE);
-               if (val & 0x10) {
-                       pr_info("Enabling hardware monitor logical device mappings.\n");
-                       superio_outb(sioaddr,
-                                    NCT6791_REG_HM_IO_SPACE_LOCK_ENABLE,
-                                    val & ~0x10);
-               }
-       }
+
+       if (sio_data->kind == nct6791)
+               nct6791_enable_io_mapping(sioaddr);
 
        superio_exit(sioaddr);
        pr_info("Found %s or compatible chip at %#x:%#x\n",