This patch has been created from AVM's opensrc packages:

    diff -durN --no-dereference 6660.07.21 6660.07.22  > this.patch

--- linux-4.9/drivers/regulator/int34d9-regulator.c	2020-06-26 07:47:14.000000000 +0200
+++ linux-4.9/drivers/regulator/int34d9-regulator.c	2020-08-25 12:15:35.000000000 +0200
@@ -27,6 +27,14 @@
 #include <linux/gpio/consumer.h>
 #include <linux/regulator/int34d9-regulator.h>
 
+/* RCVNUM - Recovery Number Register
+ * Number of attempts to recover the system after a VR Fault occurred.
+ * Only bits [3:0] are changeable.
+ * Bits [7:4] are reserved.
+ */
+#define PUMA7_PMIC_RECOVER_COUNT 0x70
+#define PUMA7_PMIC_SHUTDOWN_REASON_REG 0x20
+
 static int puma7_pmic_lpm_bbu = PUMA7_PMIC_LPM_CFG_BBU;
 static int puma7_pmic_lpm_sb = PUMA7_PMIC_LPM_CFG_FAST_STANDBY;
 static int puma7_pmic_lpm_dsb = PUMA7_PMIC_LPM_CFG_DEEP_STANDBY;
@@ -66,6 +74,75 @@
    return ret_val;
 }
 
+static struct puma7_pmic *dev_to_puma7_pmic(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return i2c_get_clientdata(client);
+}
+
+static ssize_t pmic_shutdown_reason_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct puma7_pmic *pmic = dev_to_puma7_pmic(dev);
+	s32 reg_val;
+
+	reg_val = puma7_pmic_read(pmic, PUMA7_PMIC_SHUTDOWN_REASON_REG);
+	if (reg_val < 0) {
+		dev_err(dev, "Failed to read PMIC shutdown reason: %d\n",
+				reg_val);
+		return reg_val;
+	}
+
+	return sprintf(buf, "0x%02x\n", reg_val);
+}
+
+static ssize_t pmic_recover_count_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct puma7_pmic *pmic = dev_to_puma7_pmic(dev);
+	s32 reg_val;
+
+	reg_val = puma7_pmic_read(pmic, PUMA7_PMIC_RECOVER_COUNT);
+	if (reg_val < 0) {
+		dev_err(dev, "Failed to read PMIC counter: %d\n", reg_val);
+		return reg_val;
+	}
+
+	return sprintf(buf, "%d\n", reg_val);
+}
+
+static ssize_t pmic_recover_count_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct puma7_pmic *pmic = dev_to_puma7_pmic(dev);
+	u8 value;
+	s32 ret;
+
+	ret = sscanf(buf, "%hhu", &value);
+	if (ret != 1 || value > 0x0F)
+		return -EINVAL;
+
+	ret =  puma7_pmic_write(pmic, PUMA7_PMIC_RECOVER_COUNT, value);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RO(pmic_shutdown_reason);
+static DEVICE_ATTR_RW(pmic_recover_count);
+
+static struct attribute *pmic_attr_attrs[] = {
+	&dev_attr_pmic_shutdown_reason.attr,
+	&dev_attr_pmic_recover_count.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pmic_attr);
+
 static int puma7_pmic_regulator_is_enabled(struct regulator_dev *rdev)
 {
    struct puma7_pmic *pmic = rdev_get_drvdata(rdev);
@@ -435,6 +512,9 @@
 				ACPI_PUMA7_PMIC_DEVICE_NAME, pmic);
    }
 
+	if (sysfs_create_groups(&dev->kobj, pmic_attr_groups))
+		dev_err(dev, "Failed to create PMIC sysfs group!");
+
    if (ret == 0) {  
       /* configure the PMIC */
       if((ret = puma7_pmic_write(pmic, PUMA7_PMIC_LPMCTRL_REG, PUMA7_PMIC_LPM_CFG_ACTIVE)) < 0) {
@@ -489,6 +569,8 @@
       regulator_unregister(pmic->rdev[i]);
    }
 
+   sysfs_remove_groups(&client->dev.kobj, pmic_attr_groups);
+
    gpio_free(client->irq);
    return 0;
 }
@@ -509,11 +591,11 @@
 
 static struct i2c_driver puma7_pmic_driver = {
 	.probe = puma7_pmic_regulator_probe,
-   .remove = puma7_pmic_regulator_remove,
+	.remove = puma7_pmic_regulator_remove,
 	.driver		= {
 		.name	= ACPI_PUMA7_PMIC_DEVICE_NAME,
 		.owner	= THIS_MODULE,
-      .acpi_match_table = ACPI_PTR(puma7_pmic_acpi_match),
+		.acpi_match_table = ACPI_PTR(puma7_pmic_acpi_match),
 	},
 	.id_table	= puma7_pmic_id,
 };
@@ -534,4 +616,3 @@
 MODULE_DESCRIPTION("PUMA7 PMIC voltage regulator driver");
 MODULE_AUTHOR("Vinay Patel");
 MODULE_LICENSE("GPL v2");
-
--- linux-4.9/.kernelvariables	2020-10-15 09:35:52.000000000 +0200
+++ linux-4.9/.kernelvariables	2020-10-15 10:07:10.000000000 +0200
@@ -1,6 +1,6 @@
 # vim: set autoread filetype=make:
 #
-# Auto-generated at build-80781
+# Auto-generated at build-82278
 # while generating for Fritz_Box_HW252x
 #
 ARCH = x86