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1// SPDX-License-Identifier: ISC2/* Initialize Owl Emulation Devices3 *4 * Copyright (C) 2016 Christian Lamparter <chunkeey@gmail.com>5 * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>6 *7 * Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)8 * need to be able to initialize the PCIe wifi device. Normally, this is done9 * during the early stages as a pci quirk.10 * However, this isn't possible for devices which have the init code for the11 * Atheros chip stored on UBI Volume on NAND. Hence, this module can be used to12 * initialize the chip when the user-space is ready to extract the init code.13 */14#include <linux/module.h>15#include <linux/completion.h>16#include <linux/etherdevice.h>17#include <linux/firmware.h>18#include <linux/pci.h>19#include <linux/delay.h>20#include <linux/platform_device.h>21#include <linux/ath9k_platform.h>22#include <linux/nvmem-consumer.h>23#include <linux/workqueue.h>24 25struct owl_ctx {26 struct pci_dev *pdev;27 struct completion eeprom_load;28 struct work_struct work;29 struct nvmem_cell *cell;30};31 32#define EEPROM_FILENAME_LEN 10033 34#define AR5416_EEPROM_MAGIC 0xa55a35 36static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data,37 size_t cal_len)38{39 void __iomem *mem;40 const void *cal_end = (void *)cal_data + cal_len;41 const struct {42 u16 reg;43 u16 low_val;44 u16 high_val;45 } __packed * data;46 u16 cmd;47 u32 bar0;48 bool swap_needed = false;49 50 /* also note that we are doing *u16 operations on the file */51 if (cal_len > 4096 || cal_len < 0x200 || (cal_len & 1) == 1) {52 dev_err(&pdev->dev, "eeprom has an invalid size.\n");53 return -EINVAL;54 }55 56 if (*cal_data != AR5416_EEPROM_MAGIC) {57 if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) {58 dev_err(&pdev->dev, "invalid calibration data\n");59 return -EINVAL;60 }61 62 dev_dbg(&pdev->dev, "calibration data needs swapping\n");63 swap_needed = true;64 }65 66 dev_info(&pdev->dev, "fixup device configuration\n");67 68 mem = pci_iomap(pdev, 0, 0);69 if (!mem) {70 dev_err(&pdev->dev, "ioremap error\n");71 return -EINVAL;72 }73 74 pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0);75 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0,76 pci_resource_start(pdev, 0));77 pci_read_config_word(pdev, PCI_COMMAND, &cmd);78 cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;79 pci_write_config_word(pdev, PCI_COMMAND, cmd);80 81 /* set pointer to first reg address */82 for (data = (const void *)(cal_data + 3);83 (const void *)data <= cal_end && data->reg != (u16)~0;84 data++) {85 u32 val;86 u16 reg;87 88 reg = data->reg;89 val = data->low_val;90 val |= ((u32)data->high_val) << 16;91 92 if (swap_needed) {93 reg = swab16(reg);94 val = swahb32(val);95 }96 97 iowrite32(val, mem + reg);98 usleep_range(100, 120);99 }100 101 pci_read_config_word(pdev, PCI_COMMAND, &cmd);102 cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);103 pci_write_config_word(pdev, PCI_COMMAND, cmd);104 105 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0);106 pci_iounmap(pdev, mem);107 108 pci_disable_device(pdev);109 110 return 0;111}112 113static void owl_rescan(struct pci_dev *pdev)114{115 struct pci_bus *bus = pdev->bus;116 117 pci_lock_rescan_remove();118 pci_stop_and_remove_bus_device(pdev);119 /* the device should come back with the proper120 * ProductId. But we have to initiate a rescan.121 */122 pci_rescan_bus(bus);123 pci_unlock_rescan_remove();124}125 126static void owl_fw_cb(const struct firmware *fw, void *context)127{128 struct owl_ctx *ctx = context;129 130 complete(&ctx->eeprom_load);131 132 if (fw) {133 ath9k_pci_fixup(ctx->pdev, (const u16 *)fw->data, fw->size);134 owl_rescan(ctx->pdev);135 } else {136 dev_err(&ctx->pdev->dev, "no eeprom data received.\n");137 }138 release_firmware(fw);139}140 141static const char *owl_get_eeprom_name(struct pci_dev *pdev)142{143 struct device *dev = &pdev->dev;144 char *eeprom_name;145 146 dev_dbg(dev, "using auto-generated eeprom filename\n");147 148 eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL);149 if (!eeprom_name)150 return NULL;151 152 /* this should match the pattern used in ath9k/init.c */153 scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin",154 dev_name(dev));155 156 return eeprom_name;157}158 159static void owl_nvmem_work(struct work_struct *work)160{161 struct owl_ctx *ctx = container_of(work, struct owl_ctx, work);162 void *buf;163 size_t len;164 165 complete(&ctx->eeprom_load);166 167 buf = nvmem_cell_read(ctx->cell, &len);168 if (!IS_ERR(buf)) {169 ath9k_pci_fixup(ctx->pdev, buf, len);170 kfree(buf);171 owl_rescan(ctx->pdev);172 } else {173 dev_err(&ctx->pdev->dev, "no nvmem data received.\n");174 }175}176 177static int owl_nvmem_probe(struct owl_ctx *ctx)178{179 int err;180 181 ctx->cell = devm_nvmem_cell_get(&ctx->pdev->dev, "calibration");182 if (IS_ERR(ctx->cell)) {183 err = PTR_ERR(ctx->cell);184 if (err == -ENOENT || err == -EOPNOTSUPP)185 return 1; /* not present, try firmware_request */186 187 return err;188 }189 190 INIT_WORK(&ctx->work, owl_nvmem_work);191 schedule_work(&ctx->work);192 193 return 0;194}195 196static int owl_probe(struct pci_dev *pdev,197 const struct pci_device_id *id)198{199 struct owl_ctx *ctx;200 const char *eeprom_name;201 int err = 0;202 203 if (pci_enable_device(pdev))204 return -EIO;205 206 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);207 if (!ctx)208 return -ENOMEM;209 210 init_completion(&ctx->eeprom_load);211 ctx->pdev = pdev;212 213 pci_set_drvdata(pdev, ctx);214 215 err = owl_nvmem_probe(ctx);216 if (err <= 0)217 return err;218 219 eeprom_name = owl_get_eeprom_name(pdev);220 if (!eeprom_name) {221 dev_err(&pdev->dev, "no eeprom filename found.\n");222 return -ENODEV;223 }224 225 err = request_firmware_nowait(THIS_MODULE, true, eeprom_name,226 &pdev->dev, GFP_KERNEL, ctx, owl_fw_cb);227 if (err)228 dev_err(&pdev->dev, "failed to request caldata (%d).\n", err);229 230 return err;231}232 233static void owl_remove(struct pci_dev *pdev)234{235 struct owl_ctx *ctx = pci_get_drvdata(pdev);236 237 if (ctx) {238 wait_for_completion(&ctx->eeprom_load);239 pci_set_drvdata(pdev, NULL);240 }241}242 243static const struct pci_device_id owl_pci_table[] = {244 { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */245 { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */246 { },247};248MODULE_DEVICE_TABLE(pci, owl_pci_table);249 250static struct pci_driver owl_driver = {251 .name = KBUILD_MODNAME,252 .id_table = owl_pci_table,253 .probe = owl_probe,254 .remove = owl_remove,255};256module_pci_driver(owl_driver);257MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");258MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX");259MODULE_LICENSE("Dual BSD/GPL");260