target/linux/generic/files/drivers/misc/owl-loader.c

   1 /*
   2  * Initialize Owl Emulation Devices
   3  *
   4  * Copyright (C) 2016 Christian Lamparter <chunkeey@googlemail.com>
   5  * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published
   9  * by the Free Software Foundation.
  10  *
  11  * Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)
  12  * need to be able to initialize the PCIe wifi device. Normally, this is done
  13  * during the early stages of booting linux, because the necessary init code
  14  * is read from the memory mapped SPI and passed to pci_enable_ath9k_fixup.
  15  * However,this isn't possible for devices which have the init code for the
  16  * Atheros chip stored on NAND. Hence, this module can be used to initialze
  17  * the chip when the user-space is ready to extract the init code.
  18  */
  19 #include <linux/module.h>
  20 #include <linux/version.h>
  21 #include <linux/completion.h>
  22 #include <linux/etherdevice.h>
  23 #include <linux/firmware.h>
  24 #include <linux/pci.h>
  25 #include <linux/delay.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/ath9k_platform.h>
  28
  29 struct owl_ctx {
  30         struct completion eeprom_load;
  31 };
  32
  33 #define EEPROM_FILENAME_LEN 100
  34
  35 #define AR5416_EEPROM_MAGIC 0xa55a
  36
  37 static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data,
  38                            size_t cal_len)
  39 {
  40         void __iomem *mem;
  41         const void *cal_end = (void *)cal_data + cal_len;
  42         const struct {
  43                 u16 reg;
  44                 u16 low_val;
  45                 u16 high_val;
  46         } __packed *data;
  47         u16 cmd;
  48         u32 bar0;
  49         bool swap_needed = false;
  50
  51         if (*cal_data != AR5416_EEPROM_MAGIC) {
  52                 if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) {
  53                         dev_err(&pdev->dev, "invalid calibration data\n");
  54                         return -EINVAL;
  55                 }
  56
  57                 dev_dbg(&pdev->dev, "calibration data needs swapping\n");
  58                 swap_needed = true;
  59         }
  60
  61         dev_info(&pdev->dev, "fixup device configuration\n");
  62
  63         mem = pcim_iomap(pdev, 0, 0);
  64         if (!mem) {
  65                 dev_err(&pdev->dev, "ioremap error\n");
  66                 return -EINVAL;
  67         }
  68
  69         pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0);
  70         pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0,
  71                                pci_resource_start(pdev, 0));
  72         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
  73         cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
  74         pci_write_config_word(pdev, PCI_COMMAND, cmd);
  75
  76         /* set pointer to first reg address */
  77         for (data = (const void *) (cal_data + 3);
  78              (const void *) data <= cal_end && data->reg != (u16)~0;
  79              data++) {
  80                 u32 val;
  81                 u16 reg;
  82
  83                 reg = data->reg;
  84                 val = data->low_val;
  85                 val |= ((u32)data->high_val) << 16;
  86
  87                 if (swap_needed) {
  88                         reg = swab16(reg);
  89                         val = swahb32(val);
  90                 }
  91
  92 #ifdef CONFIG_LANTIQ
  93                 val = swab32(val);
  94 #endif
  95
  96                 __raw_writel(val, mem + reg);
  97                 udelay(100);
  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         pcim_iounmap(pdev, mem);
 106
 107         pci_disable_device(pdev);
 108
 109         return 0;
 110 }
 111
 112 static void owl_fw_cb(const struct firmware *fw, void *context)
 113 {
 114         struct pci_dev *pdev = (struct pci_dev *) context;
 115         struct owl_ctx *ctx = (struct owl_ctx *) pci_get_drvdata(pdev);
 116         struct ath9k_platform_data *pdata = dev_get_platdata(&pdev->dev);
 117         struct pci_bus *bus;
 118
 119         complete(&ctx->eeprom_load);
 120
 121         if (!fw) {
 122                 dev_err(&pdev->dev, "no eeprom data received.\n");
 123                 goto release;
 124         }
 125
 126         /* also note that we are doing *u16 operations on the file */
 127         if (fw->size > sizeof(pdata->eeprom_data) || fw->size < 0x200 ||
 128             (fw->size & 1) == 1) {
 129                 dev_err(&pdev->dev, "eeprom file has an invalid size.\n");
 130                 goto release;
 131         }
 132
 133         if (pdata) {
 134                 memcpy(pdata->eeprom_data, fw->data, fw->size);
 135
 136                 /*
 137                  * eeprom has been successfully loaded - pass the data to ath9k
 138                  * but remove the eeprom_name, so it doesn't try to load it too.
 139                  */
 140                 pdata->eeprom_name = NULL;
 141         }
 142
 143         if (ath9k_pci_fixup(pdev, (const u16 *) fw->data, fw->size))
 144                 goto release;
 145
 146         pci_lock_rescan_remove();
 147         bus = pdev->bus;
 148         pci_stop_and_remove_bus_device(pdev);
 149         /*
 150          * the device should come back with the proper
 151          * ProductId. But we have to initiate a rescan.
 152          */
 153         pci_rescan_bus(bus);
 154         pci_unlock_rescan_remove();
 155
 156 release:
 157         release_firmware(fw);
 158 }
 159
 160 static const char *owl_get_eeprom_name(struct pci_dev *pdev)
 161 {
 162         struct device *dev = &pdev->dev;
 163         struct ath9k_platform_data *pdata;
 164         char *eeprom_name;
 165
 166         /* try the existing platform data first */
 167         pdata = dev_get_platdata(dev);
 168         if (pdata && pdata->eeprom_name)
 169                 return pdata->eeprom_name;
 170
 171         dev_dbg(dev, "using auto-generated eeprom filename\n");
 172
 173         eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL);
 174         if (!eeprom_name)
 175                 return NULL;
 176
 177         /* this should match the pattern used in ath9k/init.c */
 178         scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin",
 179                   dev_name(dev));
 180
 181         return eeprom_name;
 182 }
 183
 184 static int owl_probe(struct pci_dev *pdev,
 185                     const struct pci_device_id *id)
 186 {
 187         struct owl_ctx *ctx;
 188         const char *eeprom_name;
 189         int err = 0;
 190
 191         if (pcim_enable_device(pdev))
 192                 return -EIO;
 193
 194         pcim_pin_device(pdev);
 195
 196         eeprom_name = owl_get_eeprom_name(pdev);
 197         if (!eeprom_name) {
 198                 dev_err(&pdev->dev, "no eeprom filename found.\n");
 199                 return -ENODEV;
 200         }
 201
 202         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 203         if (!ctx) {
 204                 dev_err(&pdev->dev, "failed to alloc device context.\n");
 205                 return -ENOMEM;
 206         }
 207         init_completion(&ctx->eeprom_load);
 208
 209         pci_set_drvdata(pdev, ctx);
 210         err = request_firmware_nowait(THIS_MODULE, true, eeprom_name,
 211                                       &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb);
 212         if (err) {
 213                 dev_err(&pdev->dev, "failed to request caldata (%d).\n", err);
 214                 kfree(ctx);
 215         }
 216         return err;
 217 }
 218
 219 static void owl_remove(struct pci_dev *pdev)
 220 {
 221         struct owl_ctx *ctx = pci_get_drvdata(pdev);
 222
 223         if (ctx) {
 224                 wait_for_completion(&ctx->eeprom_load);
 225                 pci_set_drvdata(pdev, NULL);
 226                 kfree(ctx);
 227         }
 228 }
 229
 230 static const struct pci_device_id owl_pci_table[] = {
 231         { PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */
 232         { PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */
 233         { },
 234 };
 235 MODULE_DEVICE_TABLE(pci, owl_pci_table);
 236
 237 static struct pci_driver owl_driver = {
 238         .name           = "owl-loader",
 239         .id_table       = owl_pci_table,
 240         .probe          = owl_probe,
 241         .remove         = owl_remove,
 242 };
 243 module_pci_driver(owl_driver);
 244 MODULE_AUTHOR("Christian Lamparter <chunkeey@googlemail.com>");
 245 MODULE_DESCRIPTION("Initializes Atheros' Owl Emulation devices");
 246 MODULE_LICENSE("GPL v2");