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
ath9k_pci_fixup(struct pci_dev * pdev,const u16 * cal_data,size_t cal_len)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
owl_rescan(struct pci_dev * pdev)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
owl_fw_cb(const struct firmware * fw,void * context)126 static void owl_fw_cb(const struct firmware *fw, void *context)
127 {
128 struct owl_ctx *ctx = (struct owl_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
owl_get_eeprom_name(struct pci_dev * pdev)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
owl_nvmem_work(struct work_struct * work)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
owl_nvmem_probe(struct owl_ctx * ctx)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
owl_probe(struct pci_dev * pdev,const struct pci_device_id * id)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
owl_remove(struct pci_dev * pdev)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