1 // SPDX-License-Identifier: ISC 2 /* Initialize Owl Emulation Devices 3 * 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 done 9 * during the early stages as a pci quirk. 10 * However, this isn't possible for devices which have the init code for the 11 * Atheros chip stored on UBI Volume on NAND. Hence, this module can be used to 12 * 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/nvmem-consumer.h> 22 #include <linux/workqueue.h> 23 24 struct owl_ctx { 25 struct pci_dev *pdev; 26 struct completion eeprom_load; 27 struct work_struct work; 28 struct nvmem_cell *cell; 29 }; 30 31 #define EEPROM_FILENAME_LEN 100 32 33 #define AR5416_EEPROM_MAGIC 0xa55a 34 35 static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data, 36 size_t cal_len) 37 { 38 void __iomem *mem; 39 const void *cal_end = (void *)cal_data + cal_len; 40 const struct { 41 u16 reg; 42 u16 low_val; 43 u16 high_val; 44 } __packed * data; 45 u16 cmd; 46 u32 bar0; 47 bool swap_needed = false; 48 49 /* also note that we are doing *u16 operations on the file */ 50 if (cal_len > 4096 || cal_len < 0x200 || (cal_len & 1) == 1) { 51 dev_err(&pdev->dev, "eeprom has an invalid size.\n"); 52 return -EINVAL; 53 } 54 55 if (*cal_data != AR5416_EEPROM_MAGIC) { 56 if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) { 57 dev_err(&pdev->dev, "invalid calibration data\n"); 58 return -EINVAL; 59 } 60 61 dev_dbg(&pdev->dev, "calibration data needs swapping\n"); 62 swap_needed = true; 63 } 64 65 dev_info(&pdev->dev, "fixup device configuration\n"); 66 67 mem = pci_iomap(pdev, 0, 0); 68 if (!mem) { 69 dev_err(&pdev->dev, "ioremap error\n"); 70 return -EINVAL; 71 } 72 73 pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0); 74 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, 75 pci_resource_start(pdev, 0)); 76 pci_read_config_word(pdev, PCI_COMMAND, &cmd); 77 cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY; 78 pci_write_config_word(pdev, PCI_COMMAND, cmd); 79 80 /* set pointer to first reg address */ 81 for (data = (const void *)(cal_data + 3); 82 (const void *)data <= cal_end && data->reg != (u16)~0; 83 data++) { 84 u32 val; 85 u16 reg; 86 87 reg = data->reg; 88 val = data->low_val; 89 val |= ((u32)data->high_val) << 16; 90 91 if (swap_needed) { 92 reg = swab16(reg); 93 val = swahb32(val); 94 } 95 96 iowrite32(val, mem + reg); 97 usleep_range(100, 120); 98 } 99 100 pci_read_config_word(pdev, PCI_COMMAND, &cmd); 101 cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY); 102 pci_write_config_word(pdev, PCI_COMMAND, cmd); 103 104 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0); 105 pci_iounmap(pdev, mem); 106 107 pci_disable_device(pdev); 108 109 return 0; 110 } 111 112 static void owl_rescan(struct pci_dev *pdev) 113 { 114 struct pci_bus *bus = pdev->bus; 115 116 pci_lock_rescan_remove(); 117 pci_stop_and_remove_bus_device(pdev); 118 /* the device should come back with the proper 119 * ProductId. But we have to initiate a rescan. 120 */ 121 pci_rescan_bus(bus); 122 pci_unlock_rescan_remove(); 123 } 124 125 static void owl_fw_cb(const struct firmware *fw, void *context) 126 { 127 struct owl_ctx *ctx = context; 128 129 complete(&ctx->eeprom_load); 130 131 if (fw) { 132 ath9k_pci_fixup(ctx->pdev, (const u16 *)fw->data, fw->size); 133 owl_rescan(ctx->pdev); 134 } else { 135 dev_err(&ctx->pdev->dev, "no eeprom data received.\n"); 136 } 137 release_firmware(fw); 138 } 139 140 static const char *owl_get_eeprom_name(struct pci_dev *pdev) 141 { 142 struct device *dev = &pdev->dev; 143 char *eeprom_name; 144 145 dev_dbg(dev, "using auto-generated eeprom filename\n"); 146 147 eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL); 148 if (!eeprom_name) 149 return NULL; 150 151 /* this should match the pattern used in ath9k/init.c */ 152 scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin", 153 dev_name(dev)); 154 155 return eeprom_name; 156 } 157 158 static void owl_nvmem_work(struct work_struct *work) 159 { 160 struct owl_ctx *ctx = container_of(work, struct owl_ctx, work); 161 void *buf; 162 size_t len; 163 164 complete(&ctx->eeprom_load); 165 166 buf = nvmem_cell_read(ctx->cell, &len); 167 if (!IS_ERR(buf)) { 168 ath9k_pci_fixup(ctx->pdev, buf, len); 169 kfree(buf); 170 owl_rescan(ctx->pdev); 171 } else { 172 dev_err(&ctx->pdev->dev, "no nvmem data received.\n"); 173 } 174 } 175 176 static int owl_nvmem_probe(struct owl_ctx *ctx) 177 { 178 int err; 179 180 ctx->cell = devm_nvmem_cell_get(&ctx->pdev->dev, "calibration"); 181 if (IS_ERR(ctx->cell)) { 182 err = PTR_ERR(ctx->cell); 183 if (err == -ENOENT || err == -EOPNOTSUPP) 184 return 1; /* not present, try firmware_request */ 185 186 return err; 187 } 188 189 INIT_WORK(&ctx->work, owl_nvmem_work); 190 schedule_work(&ctx->work); 191 192 return 0; 193 } 194 195 static int owl_probe(struct pci_dev *pdev, 196 const struct pci_device_id *id) 197 { 198 struct owl_ctx *ctx; 199 const char *eeprom_name; 200 int err = 0; 201 202 if (pci_enable_device(pdev)) 203 return -EIO; 204 205 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); 206 if (!ctx) 207 return -ENOMEM; 208 209 init_completion(&ctx->eeprom_load); 210 ctx->pdev = pdev; 211 212 pci_set_drvdata(pdev, ctx); 213 214 err = owl_nvmem_probe(ctx); 215 if (err <= 0) 216 return err; 217 218 eeprom_name = owl_get_eeprom_name(pdev); 219 if (!eeprom_name) { 220 dev_err(&pdev->dev, "no eeprom filename found.\n"); 221 return -ENODEV; 222 } 223 224 err = request_firmware_nowait(THIS_MODULE, true, eeprom_name, 225 &pdev->dev, GFP_KERNEL, ctx, owl_fw_cb); 226 if (err) 227 dev_err(&pdev->dev, "failed to request caldata (%d).\n", err); 228 229 return err; 230 } 231 232 static void owl_remove(struct pci_dev *pdev) 233 { 234 struct owl_ctx *ctx = pci_get_drvdata(pdev); 235 236 if (ctx) { 237 wait_for_completion(&ctx->eeprom_load); 238 pci_set_drvdata(pdev, NULL); 239 } 240 } 241 242 static const struct pci_device_id owl_pci_table[] = { 243 { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */ 244 { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */ 245 { }, 246 }; 247 MODULE_DEVICE_TABLE(pci, owl_pci_table); 248 249 static struct pci_driver owl_driver = { 250 .name = KBUILD_MODNAME, 251 .id_table = owl_pci_table, 252 .probe = owl_probe, 253 .remove = owl_remove, 254 }; 255 module_pci_driver(owl_driver); 256 MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>"); 257 MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX"); 258 MODULE_LICENSE("Dual BSD/GPL"); 259