hwmon: (nct6775) Add power management support

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

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,