--- /dev/null
+// SPDX-License-Identifier: ISC
+/* Initialize Owl Emulation Devices
+ *
+ * Copyright (C) 2016 Christian Lamparter <chunkeey@gmail.com>
+ * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ *
+ * Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)
+ * need to be able to initialize the PCIe wifi device. Normally, this is done
+ * during the early stages as a pci quirk.
+ * However, this isn't possible for devices which have the init code for the
+ * Atheros chip stored on UBI Volume on NAND. Hence, this module can be used to
+ * initialize the chip when the user-space is ready to extract the init code.
+ */
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/completion.h>
+#include <linux/etherdevice.h>
+#include <linux/firmware.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/ath9k_platform.h>
+
+struct owl_ctx {
+       struct completion eeprom_load;
+};
+
+#define EEPROM_FILENAME_LEN 100
+
+#define AR5416_EEPROM_MAGIC 0xa55a
+
+static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data,
+                          size_t cal_len)
+{
+       void __iomem *mem;
+       const void *cal_end = (void *)cal_data + cal_len;
+       const struct {
+               u16 reg;
+               u16 low_val;
+               u16 high_val;
+       } __packed * data;
+       u16 cmd;
+       u32 bar0;
+       bool swap_needed = false;
+
+       if (*cal_data != AR5416_EEPROM_MAGIC) {
+               if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) {
+                       dev_err(&pdev->dev, "invalid calibration data\n");
+                       return -EINVAL;
+               }
+
+               dev_dbg(&pdev->dev, "calibration data needs swapping\n");
+               swap_needed = true;
+       }
+
+       dev_info(&pdev->dev, "fixup device configuration\n");
+
+       mem = pcim_iomap(pdev, 0, 0);
+       if (!mem) {
+               dev_err(&pdev->dev, "ioremap error\n");
+               return -EINVAL;
+       }
+
+       pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0);
+       pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0,
+                              pci_resource_start(pdev, 0));
+       pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+       cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+       pci_write_config_word(pdev, PCI_COMMAND, cmd);
+
+       /* set pointer to first reg address */
+       for (data = (const void *)(cal_data + 3);
+            (const void *)data <= cal_end && data->reg != (u16)~0;
+            data++) {
+               u32 val;
+               u16 reg;
+
+               reg = data->reg;
+               val = data->low_val;
+               val |= ((u32)data->high_val) << 16;
+
+               if (swap_needed) {
+                       reg = swab16(reg);
+                       val = swahb32(val);
+               }
+
+               __raw_writel(val, mem + reg);
+               usleep_range(100, 120);
+       }
+
+       pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+       cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
+       pci_write_config_word(pdev, PCI_COMMAND, cmd);
+
+       pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0);
+       pcim_iounmap(pdev, mem);
+
+       pci_disable_device(pdev);
+
+       return 0;
+}
+
+static void owl_fw_cb(const struct firmware *fw, void *context)
+{
+       struct pci_dev *pdev = (struct pci_dev *)context;
+       struct owl_ctx *ctx = (struct owl_ctx *)pci_get_drvdata(pdev);
+       struct pci_bus *bus;
+
+       complete(&ctx->eeprom_load);
+
+       if (!fw) {
+               dev_err(&pdev->dev, "no eeprom data received.\n");
+               goto release;
+       }
+
+       /* also note that we are doing *u16 operations on the file */
+       if (fw->size > 4096 || fw->size < 0x200 || (fw->size & 1) == 1) {
+               dev_err(&pdev->dev, "eeprom file has an invalid size.\n");
+               goto release;
+       }
+
+       if (ath9k_pci_fixup(pdev, (const u16 *)fw->data, fw->size))
+               goto release;
+
+       pci_lock_rescan_remove();
+       bus = pdev->bus;
+       pci_stop_and_remove_bus_device(pdev);
+       /* the device should come back with the proper
+        * ProductId. But we have to initiate a rescan.
+        */
+       pci_rescan_bus(bus);
+       pci_unlock_rescan_remove();
+
+release:
+       release_firmware(fw);
+}
+
+static const char *owl_get_eeprom_name(struct pci_dev *pdev)
+{
+       struct device *dev = &pdev->dev;
+       char *eeprom_name;
+
+       dev_dbg(dev, "using auto-generated eeprom filename\n");
+
+       eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL);
+       if (!eeprom_name)
+               return NULL;
+
+       /* this should match the pattern used in ath9k/init.c */
+       scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin",
+                 dev_name(dev));
+
+       return eeprom_name;
+}
+
+static int owl_probe(struct pci_dev *pdev,
+                    const struct pci_device_id *id)
+{
+       struct owl_ctx *ctx;
+       const char *eeprom_name;
+       int err = 0;
+
+       if (pcim_enable_device(pdev))
+               return -EIO;
+
+       pcim_pin_device(pdev);
+
+       eeprom_name = owl_get_eeprom_name(pdev);
+       if (!eeprom_name) {
+               dev_err(&pdev->dev, "no eeprom filename found.\n");
+               return -ENODEV;
+       }
+
+       ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return -ENOMEM;
+
+       init_completion(&ctx->eeprom_load);
+
+       pci_set_drvdata(pdev, ctx);
+       err = request_firmware_nowait(THIS_MODULE, true, eeprom_name,
+                                     &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb);
+       if (err)
+               dev_err(&pdev->dev, "failed to request caldata (%d).\n", err);
+
+       return err;
+}
+
+static void owl_remove(struct pci_dev *pdev)
+{
+       struct owl_ctx *ctx = pci_get_drvdata(pdev);
+
+       if (ctx) {
+               wait_for_completion(&ctx->eeprom_load);
+               pci_set_drvdata(pdev, NULL);
+       }
+}
+
+static const struct pci_device_id owl_pci_table[] = {
+       { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */
+       { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */
+       { },
+};
+MODULE_DEVICE_TABLE(pci, owl_pci_table);
+
+static struct pci_driver owl_driver = {
+       .name           = KBUILD_MODNAME,
+       .id_table       = owl_pci_table,
+       .probe          = owl_probe,
+       .remove         = owl_remove,
+};
+module_pci_driver(owl_driver);
+MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
+MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX");
+MODULE_LICENSE("Dual BSD/GPL");