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/version.h> 16 #include <linux/completion.h> 17 #include <linux/etherdevice.h> 18 #include <linux/firmware.h> 19 #include <linux/pci.h> 20 #include <linux/delay.h> 21 #include <linux/platform_device.h> 22 #include <linux/ath9k_platform.h> 23 24 struct owl_ctx { 25 struct completion eeprom_load; 26 }; 27 28 #define EEPROM_FILENAME_LEN 100 29 30 #define AR5416_EEPROM_MAGIC 0xa55a 31 32 static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data, 33 size_t cal_len) 34 { 35 void __iomem *mem; 36 const void *cal_end = (void *)cal_data + cal_len; 37 const struct { 38 u16 reg; 39 u16 low_val; 40 u16 high_val; 41 } __packed * data; 42 u16 cmd; 43 u32 bar0; 44 bool swap_needed = false; 45 46 if (*cal_data != AR5416_EEPROM_MAGIC) { 47 if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) { 48 dev_err(&pdev->dev, "invalid calibration data\n"); 49 return -EINVAL; 50 } 51 52 dev_dbg(&pdev->dev, "calibration data needs swapping\n"); 53 swap_needed = true; 54 } 55 56 dev_info(&pdev->dev, "fixup device configuration\n"); 57 58 mem = pcim_iomap(pdev, 0, 0); 59 if (!mem) { 60 dev_err(&pdev->dev, "ioremap error\n"); 61 return -EINVAL; 62 } 63 64 pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0); 65 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, 66 pci_resource_start(pdev, 0)); 67 pci_read_config_word(pdev, PCI_COMMAND, &cmd); 68 cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY; 69 pci_write_config_word(pdev, PCI_COMMAND, cmd); 70 71 /* set pointer to first reg address */ 72 for (data = (const void *)(cal_data + 3); 73 (const void *)data <= cal_end && data->reg != (u16)~0; 74 data++) { 75 u32 val; 76 u16 reg; 77 78 reg = data->reg; 79 val = data->low_val; 80 val |= ((u32)data->high_val) << 16; 81 82 if (swap_needed) { 83 reg = swab16(reg); 84 val = swahb32(val); 85 } 86 87 __raw_writel(val, mem + reg); 88 usleep_range(100, 120); 89 } 90 91 pci_read_config_word(pdev, PCI_COMMAND, &cmd); 92 cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY); 93 pci_write_config_word(pdev, PCI_COMMAND, cmd); 94 95 pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0); 96 pcim_iounmap(pdev, mem); 97 98 pci_disable_device(pdev); 99 100 return 0; 101 } 102 103 static void owl_fw_cb(const struct firmware *fw, void *context) 104 { 105 struct pci_dev *pdev = (struct pci_dev *)context; 106 struct owl_ctx *ctx = (struct owl_ctx *)pci_get_drvdata(pdev); 107 struct pci_bus *bus; 108 109 complete(&ctx->eeprom_load); 110 111 if (!fw) { 112 dev_err(&pdev->dev, "no eeprom data received.\n"); 113 goto release; 114 } 115 116 /* also note that we are doing *u16 operations on the file */ 117 if (fw->size > 4096 || fw->size < 0x200 || (fw->size & 1) == 1) { 118 dev_err(&pdev->dev, "eeprom file has an invalid size.\n"); 119 goto release; 120 } 121 122 if (ath9k_pci_fixup(pdev, (const u16 *)fw->data, fw->size)) 123 goto release; 124 125 pci_lock_rescan_remove(); 126 bus = pdev->bus; 127 pci_stop_and_remove_bus_device(pdev); 128 /* the device should come back with the proper 129 * ProductId. But we have to initiate a rescan. 130 */ 131 pci_rescan_bus(bus); 132 pci_unlock_rescan_remove(); 133 134 release: 135 release_firmware(fw); 136 } 137 138 static const char *owl_get_eeprom_name(struct pci_dev *pdev) 139 { 140 struct device *dev = &pdev->dev; 141 char *eeprom_name; 142 143 dev_dbg(dev, "using auto-generated eeprom filename\n"); 144 145 eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL); 146 if (!eeprom_name) 147 return NULL; 148 149 /* this should match the pattern used in ath9k/init.c */ 150 scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin", 151 dev_name(dev)); 152 153 return eeprom_name; 154 } 155 156 static int owl_probe(struct pci_dev *pdev, 157 const struct pci_device_id *id) 158 { 159 struct owl_ctx *ctx; 160 const char *eeprom_name; 161 int err = 0; 162 163 if (pcim_enable_device(pdev)) 164 return -EIO; 165 166 pcim_pin_device(pdev); 167 168 eeprom_name = owl_get_eeprom_name(pdev); 169 if (!eeprom_name) { 170 dev_err(&pdev->dev, "no eeprom filename found.\n"); 171 return -ENODEV; 172 } 173 174 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); 175 if (!ctx) 176 return -ENOMEM; 177 178 init_completion(&ctx->eeprom_load); 179 180 pci_set_drvdata(pdev, ctx); 181 err = request_firmware_nowait(THIS_MODULE, true, eeprom_name, 182 &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb); 183 if (err) 184 dev_err(&pdev->dev, "failed to request caldata (%d).\n", err); 185 186 return err; 187 } 188 189 static void owl_remove(struct pci_dev *pdev) 190 { 191 struct owl_ctx *ctx = pci_get_drvdata(pdev); 192 193 if (ctx) { 194 wait_for_completion(&ctx->eeprom_load); 195 pci_set_drvdata(pdev, NULL); 196 } 197 } 198 199 static const struct pci_device_id owl_pci_table[] = { 200 { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */ 201 { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */ 202 { }, 203 }; 204 MODULE_DEVICE_TABLE(pci, owl_pci_table); 205 206 static struct pci_driver owl_driver = { 207 .name = KBUILD_MODNAME, 208 .id_table = owl_pci_table, 209 .probe = owl_probe, 210 .remove = owl_remove, 211 }; 212 module_pci_driver(owl_driver); 213 MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>"); 214 MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX"); 215 MODULE_LICENSE("Dual BSD/GPL"); 216