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/ath9k_platform.h> 22 #include <linux/nvmem-consumer.h> 23 #include <linux/workqueue.h> 24 25 struct 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 100 33 34 #define AR5416_EEPROM_MAGIC 0xa55a 35 36 static 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 = pcim_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 pcim_iounmap(pdev, mem); 107 108 pci_disable_device(pdev); 109 110 return 0; 111 } 112 113 static 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 proper 120 * ProductId. But we have to initiate a rescan. 121 */ 122 pci_rescan_bus(bus); 123 pci_unlock_rescan_remove(); 124 } 125 126 static 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 } 140 141 static 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 } 158 159 static 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 } 176 177 static 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 } 195 196 static 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 (pcim_enable_device(pdev)) 204 return -EIO; 205 206 pcim_pin_device(pdev); 207 208 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); 209 if (!ctx) 210 return -ENOMEM; 211 212 init_completion(&ctx->eeprom_load); 213 ctx->pdev = pdev; 214 215 pci_set_drvdata(pdev, ctx); 216 217 err = owl_nvmem_probe(ctx); 218 if (err <= 0) 219 return err; 220 221 eeprom_name = owl_get_eeprom_name(pdev); 222 if (!eeprom_name) { 223 dev_err(&pdev->dev, "no eeprom filename found.\n"); 224 return -ENODEV; 225 } 226 227 err = request_firmware_nowait(THIS_MODULE, true, eeprom_name, 228 &pdev->dev, GFP_KERNEL, ctx, owl_fw_cb); 229 if (err) 230 dev_err(&pdev->dev, "failed to request caldata (%d).\n", err); 231 232 return err; 233 } 234 235 static void owl_remove(struct pci_dev *pdev) 236 { 237 struct owl_ctx *ctx = pci_get_drvdata(pdev); 238 239 if (ctx) { 240 wait_for_completion(&ctx->eeprom_load); 241 pci_set_drvdata(pdev, NULL); 242 } 243 } 244 245 static const struct pci_device_id owl_pci_table[] = { 246 { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */ 247 { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */ 248 { }, 249 }; 250 MODULE_DEVICE_TABLE(pci, owl_pci_table); 251 252 static struct pci_driver owl_driver = { 253 .name = KBUILD_MODNAME, 254 .id_table = owl_pci_table, 255 .probe = owl_probe, 256 .remove = owl_remove, 257 }; 258 module_pci_driver(owl_driver); 259 MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>"); 260 MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX"); 261 MODULE_LICENSE("Dual BSD/GPL"); 262