hwmon: (nct6775) Add power management support

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

1 files changed, 86 insertions, 0 deletions

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index ffb56bb8c27d..56d7652d303b 100644
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -511,6 +511,12 @@ struct nct6775_data {
         u16 have_temp;
         u16 have_temp_fixed;
         u16 have_in;
+#ifdef CONFIG_PM
+        /* Remember extra register values over suspend/resume */
+        u8 vbat;
+        u8 fandiv1;
+        u8 fandiv2;
+#endif
 };
 
 struct nct6775_sio_data {
@@ -2270,10 +2276,90 @@ static int nct6775_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_PM
+static int nct6775_suspend(struct device *dev)
+{
+        struct nct6775_data *data = nct6775_update_device(dev);
+        struct nct6775_sio_data *sio_data = dev->platform_data;
+
+        mutex_lock(&data->update_lock);
+        data->vbat = nct6775_read_value(data, data->REG_VBAT);
+        if (sio_data->kind == nct6775) {
+                data->fandiv1 = nct6775_read_value(data, NCT6775_REG_FANDIV1);
+                data->fandiv2 = nct6775_read_value(data, NCT6775_REG_FANDIV2);
+        }
+        mutex_unlock(&data->update_lock);
+
+        return 0;
+}
+
+static int nct6775_resume(struct device *dev)
+{
+        struct nct6775_data *data = dev_get_drvdata(dev);
+        struct nct6775_sio_data *sio_data = dev->platform_data;
+        int i, j;
+
+        mutex_lock(&data->update_lock);
+        data->bank = 0xff;              /* Force initial bank selection */
+
+        /* Restore limits */
+        for (i = 0; i < data->in_num; i++) {
+                if (!(data->have_in & (1 << i)))
+                        continue;
+
+                nct6775_write_value(data, data->REG_IN_MINMAX[0][i],
+                                    data->in[i][1]);
+                nct6775_write_value(data, data->REG_IN_MINMAX[1][i],
+                                    data->in[i][2]);
+        }
+
+        for (i = 0; i < 5; i++) {
+                if (!(data->has_fan_min & (1 << i)))
+                        continue;
+
+                nct6775_write_value(data, data->REG_FAN_MIN[i],
+                                    data->fan_min[i]);
+        }
+
+        for (i = 0; i < NUM_TEMP; i++) {
+                if (!(data->have_temp & (1 << i)))
+                        continue;
+
+                for (j = 1; j < 4; j++)
+                        if (data->reg_temp[j][i])
+                                nct6775_write_temp(data, data->reg_temp[j][i],
+                                                   data->temp[j][i]);
+        }
+
+        /* Restore other settings */
+        nct6775_write_value(data, data->REG_VBAT, data->vbat);
+        if (sio_data->kind == nct6775) {
+                nct6775_write_value(data, NCT6775_REG_FANDIV1, data->fandiv1);
+                nct6775_write_value(data, NCT6775_REG_FANDIV2, data->fandiv2);
+        }
+
+        /* Force re-reading all values */
+        data->valid = false;
+        mutex_unlock(&data->update_lock);
+
+        return 0;
+}
+
+static const struct dev_pm_ops nct6775_dev_pm_ops = {
+        .suspend = nct6775_suspend,
+        .resume = nct6775_resume,
+};
+
+#define NCT6775_DEV_PM_OPS      (&nct6775_dev_pm_ops)
+#else
+#define NCT6775_DEV_PM_OPS      NULL
+#endif /* CONFIG_PM */
+
 static struct platform_driver nct6775_driver = {
         .driver = {
                 .owner  = THIS_MODULE,
                 .name   = DRVNAME,
+                .pm     = NCT6775_DEV_PM_OPS,
         },
         .probe          = nct6775_probe,
         .remove         = nct6775_remove,