OpenWrt – Rev 4
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/*
* Initialize Owl Emulation Devices
*
* Copyright (C) 2016 Christian Lamparter <chunkeey@googlemail.com>
* Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* 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 of booting linux, because the necessary init code
* is read from the memory mapped SPI and passed to pci_enable_ath9k_fixup.
* However,this isn't possible for devices which have the init code for the
* Atheros chip stored on NAND. Hence, this module can be used to initialze
* 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 != ~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);
}
#ifdef CONFIG_LANTIQ
val = swab32(val);
#endif
__raw_writel(val, mem + reg);
udelay(100);
}
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 ath9k_platform_data *pdata = dev_get_platdata(&pdev->dev);
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 > sizeof(pdata->eeprom_data) || fw->size < 0x200 ||
(fw->size & 1) == 1) {
dev_err(&pdev->dev, "eeprom file has an invalid size.\n");
goto release;
}
if (pdata) {
memcpy(pdata->eeprom_data, fw->data, fw->size);
/*
* eeprom has been successfully loaded - pass the data to ath9k
* but remove the eeprom_name, so it doesn't try to load it too.
*/
pdata->eeprom_name = NULL;
}
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;
struct ath9k_platform_data *pdata;
char *eeprom_name;
/* try the existing platform data first */
pdata = dev_get_platdata(dev);
if (pdata && pdata->eeprom_name)
return pdata->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 = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx) {
dev_err(&pdev->dev, "failed to alloc device context.\n");
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);
kfree(ctx);
}
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);
kfree(ctx);
}
}
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 = "owl-loader",
.id_table = owl_pci_table,
.probe = owl_probe,
.remove = owl_remove,
};
module_pci_driver(owl_driver);
MODULE_AUTHOR("Christian Lamparter <chunkeey@googlemail.com>");
MODULE_DESCRIPTION("Initializes Atheros' Owl Emulation devices");
MODULE_LICENSE("GPL v2");