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>

diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
index 48d724a..2a9edea 100644 (file)
--- a/drivers/firmware/raspberrypi.c
+++ b/drivers/firmware/raspberrypi.c
@@ -31,6 +31,7 @@ struct rpi_firmware {
        u32 enabled;
 
        struct kref consumers;
+       u32 get_throttled;
 };
 
 static struct platform_device *g_pdev;
@@ -176,6 +177,12 @@ 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);
@@ -200,6 +207,27 @@ 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)
 {
@@ -229,6 +257,11 @@ 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)