bnxt_en: Use non-standard attribute to expose shutdown temperature

Implement the sysfs attributes directly in the driver for
shutdown threshold temperature and pass an extra attribute group
to the hwmon core when registering the hwmon device.

Link: https://lore.kernel.org/netdev/[email protected]/
 Cc: Jean Delvare <[email protected]>
 Cc: Guenter Roeck <[email protected]>
 Cc: [email protected]
Reviewed-by: Andy Gospodarek <[email protected]>
Signed-off-by: Kalesh AP <[email protected]>
Signed-off-by: Michael Chan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Kalesh AP

drivers/net/ethernet/broadcom/bnxt/bnxt_hwmon.c

@@ -131,6 +131,57 @@ static const struct hwmon_chip_info bnxt_hwmon_chip_info = {
 	.info   = bnxt_hwmon_info,
 };
 
+static ssize_t temp1_shutdown_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct bnxt *bp = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", bp->shutdown_thresh_temp * 1000);
+}
+
+static ssize_t temp1_shutdown_alarm_show(struct device *dev,
+					 struct device_attribute *attr, char *buf)
+{
+	struct bnxt *bp = dev_get_drvdata(dev);
+	u8 temp;
+	int rc;
+
+	rc = bnxt_hwrm_temp_query(bp, &temp);
+	if (rc)
+		return -EIO;
+
+	return sysfs_emit(buf, "%u\n", temp >= bp->shutdown_thresh_temp);
+}
+
+static DEVICE_ATTR_RO(temp1_shutdown);
+static DEVICE_ATTR_RO(temp1_shutdown_alarm);
+
+static struct attribute *bnxt_temp_extra_attrs[] = {
+	&dev_attr_temp1_shutdown.attr,
+	&dev_attr_temp1_shutdown_alarm.attr,
+	NULL,
+};
+
+static umode_t bnxt_temp_extra_attrs_visible(struct kobject *kobj,
+					     struct attribute *attr, int index)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct bnxt *bp = dev_get_drvdata(dev);
+
+	/* Shutdown temperature setting in NVM is optional */
+	if (!(bp->fw_cap & BNXT_FW_CAP_THRESHOLD_TEMP_SUPPORTED) ||
+	    !bp->shutdown_thresh_temp)
+		return 0;
+
+	return attr->mode;
+}
+
+static const struct attribute_group bnxt_temp_extra_group = {
+	.attrs		= bnxt_temp_extra_attrs,
+	.is_visible	= bnxt_temp_extra_attrs_visible,
+};
+__ATTRIBUTE_GROUPS(bnxt_temp_extra);
+
 void bnxt_hwmon_uninit(struct bnxt *bp)
 {
 	if (bp->hwmon_dev) {
@@ -156,7 +207,8 @@ void bnxt_hwmon_init(struct bnxt *bp)
 
 	bp->hwmon_dev = hwmon_device_register_with_info(&pdev->dev,
 							DRV_MODULE_NAME, bp,
-							&bnxt_hwmon_chip_info, NULL);
+							&bnxt_hwmon_chip_info,
+							bnxt_temp_extra_groups);
 	if (IS_ERR(bp->hwmon_dev)) {
 		bp->hwmon_dev = NULL;
 		dev_warn(&pdev->dev, "Cannot register hwmon device\n");