firmware: raspberrypi: Add backward compatible get_throttled

Avoid a hard userspace ABI change by adding a compatible get_throttled
sysfs entry. Its value is now feed by the GET_THROTTLED requests of the
new hwmon driver. The first access to get_throttled will generate
a warning.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>

drivers/firmware/raspberrypi.c

@@ -33,6 +33,7 @@ struct rpi_firmware {
  u32 enabled;
 
  struct kref consumers;
+ u32 get_throttled;
 };
 
 static struct platform_device *g_pdev;
@@ -178,6 +179,12 @@ int rpi_firmware_property(struct rpi_firmware *fw,
 
  kfree(data);
 
+ if ((tag == RPI_FIRMWARE_GET_THROTTLED) &&
+ memcmp(&fw->get_throttled, tag_data, sizeof(fw->get_throttled))) {
+ memcpy(&fw->get_throttled, tag_data, sizeof(fw->get_throttled));
+ sysfs_notify(&fw->cl.dev->kobj, NULL, "get_throttled");
+ }
+
  return ret;
 }
 EXPORT_SYMBOL_GPL(rpi_firmware_property);
@@ -202,6 +209,27 @@ static int rpi_firmware_notify_reboot(struct notifier_block *nb,
  return 0;
 }
 
+static ssize_t get_throttled_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rpi_firmware *fw = dev_get_drvdata(dev);
+
+ WARN_ONCE(1, "deprecated, use hwmon sysfs instead\n");
+
+ return sprintf(buf, "%x\n", fw->get_throttled);
+}
+
+static DEVICE_ATTR_RO(get_throttled);
+
+static struct attribute *rpi_firmware_dev_attrs[] = {
+ &dev_attr_get_throttled.attr,
+ NULL,
+};
+
+static const struct attribute_group rpi_firmware_dev_group = {
+ .attrs = rpi_firmware_dev_attrs,
+};
+
 static void
 rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
 {
@@ -231,6 +259,11 @@ rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
 
  rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
  -1, NULL, 0);
+
+ if (!IS_ERR_OR_NULL(rpi_hwmon)) {
+ if (devm_device_add_group(dev, &rpi_firmware_dev_group))
+ dev_err(dev, "Failed to create get_trottled attr\n");
+ }
 }
 
 static void rpi_register_clk_driver(struct device *dev)