1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3 * Copyright (C) 2005-2014, 2018-2019 Intel Corporation
4 */
5 #include <linux/types.h>
6 #include <linux/slab.h>
7 #include <linux/export.h>
8
9 #include "iwl-drv.h"
10 #include "iwl-debug.h"
11 #include "iwl-eeprom-read.h"
12 #include "iwl-io.h"
13 #include "iwl-prph.h"
14 #include "iwl-csr.h"
15
16 /*
17 * EEPROM access time values:
18 *
19 * Driver initiates EEPROM read by writing byte address << 1 to CSR_EEPROM_REG.
20 * Driver then polls CSR_EEPROM_REG for CSR_EEPROM_REG_READ_VALID_MSK (0x1).
21 * When polling, wait 10 uSec between polling loops, up to a maximum 5000 uSec.
22 * Driver reads 16-bit value from bits 31-16 of CSR_EEPROM_REG.
23 */
24 #define IWL_EEPROM_ACCESS_TIMEOUT 5000 /* uSec */
25
26 #define IWL_EEPROM_SEM_TIMEOUT 10 /* microseconds */
27 #define IWL_EEPROM_SEM_RETRY_LIMIT 1000 /* number of attempts (not time) */
28
29
30 /*
31 * The device's EEPROM semaphore prevents conflicts between driver and uCode
32 * when accessing the EEPROM; each access is a series of pulses to/from the
33 * EEPROM chip, not a single event, so even reads could conflict if they
34 * weren't arbitrated by the semaphore.
35 */
36
37 #define EEPROM_SEM_TIMEOUT 10 /* milliseconds */
38 #define EEPROM_SEM_RETRY_LIMIT 1000 /* number of attempts (not time) */
39
iwl_eeprom_acquire_semaphore(struct iwl_trans * trans)40 static int iwl_eeprom_acquire_semaphore(struct iwl_trans *trans)
41 {
42 u16 count;
43 int ret;
44
45 for (count = 0; count < EEPROM_SEM_RETRY_LIMIT; count++) {
46 /* Request semaphore */
47 iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
48 CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM);
49
50 /* See if we got it */
51 ret = iwl_poll_bit(trans, CSR_HW_IF_CONFIG_REG,
52 CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
53 CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
54 EEPROM_SEM_TIMEOUT);
55 if (ret >= 0) {
56 IWL_DEBUG_EEPROM(trans->dev,
57 "Acquired semaphore after %d tries.\n",
58 count+1);
59 return ret;
60 }
61 }
62
63 return ret;
64 }
65
iwl_eeprom_release_semaphore(struct iwl_trans * trans)66 static void iwl_eeprom_release_semaphore(struct iwl_trans *trans)
67 {
68 iwl_clear_bit(trans, CSR_HW_IF_CONFIG_REG,
69 CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM);
70 }
71
iwl_eeprom_verify_signature(struct iwl_trans * trans,bool nvm_is_otp)72 static int iwl_eeprom_verify_signature(struct iwl_trans *trans, bool nvm_is_otp)
73 {
74 u32 gp = iwl_read32(trans, CSR_EEPROM_GP) & CSR_EEPROM_GP_VALID_MSK;
75
76 IWL_DEBUG_EEPROM(trans->dev, "EEPROM signature=0x%08x\n", gp);
77
78 switch (gp) {
79 case CSR_EEPROM_GP_BAD_SIG_EEP_GOOD_SIG_OTP:
80 if (!nvm_is_otp) {
81 IWL_ERR(trans, "EEPROM with bad signature: 0x%08x\n",
82 gp);
83 return -ENOENT;
84 }
85 return 0;
86 case CSR_EEPROM_GP_GOOD_SIG_EEP_LESS_THAN_4K:
87 case CSR_EEPROM_GP_GOOD_SIG_EEP_MORE_THAN_4K:
88 if (nvm_is_otp) {
89 IWL_ERR(trans, "OTP with bad signature: 0x%08x\n", gp);
90 return -ENOENT;
91 }
92 return 0;
93 case CSR_EEPROM_GP_BAD_SIGNATURE_BOTH_EEP_AND_OTP:
94 default:
95 IWL_ERR(trans,
96 "bad EEPROM/OTP signature, type=%s, EEPROM_GP=0x%08x\n",
97 nvm_is_otp ? "OTP" : "EEPROM", gp);
98 return -ENOENT;
99 }
100 }
101
102 /******************************************************************************
103 *
104 * OTP related functions
105 *
106 ******************************************************************************/
107
iwl_set_otp_access_absolute(struct iwl_trans * trans)108 static void iwl_set_otp_access_absolute(struct iwl_trans *trans)
109 {
110 iwl_read32(trans, CSR_OTP_GP_REG);
111
112 iwl_clear_bit(trans, CSR_OTP_GP_REG,
113 CSR_OTP_GP_REG_OTP_ACCESS_MODE);
114 }
115
iwl_nvm_is_otp(struct iwl_trans * trans)116 static int iwl_nvm_is_otp(struct iwl_trans *trans)
117 {
118 u32 otpgp;
119
120 /* OTP only valid for CP/PP and after */
121 switch (trans->hw_rev & CSR_HW_REV_TYPE_MSK) {
122 case CSR_HW_REV_TYPE_NONE:
123 IWL_ERR(trans, "Unknown hardware type\n");
124 return -EIO;
125 case CSR_HW_REV_TYPE_5300:
126 case CSR_HW_REV_TYPE_5350:
127 case CSR_HW_REV_TYPE_5100:
128 case CSR_HW_REV_TYPE_5150:
129 return 0;
130 default:
131 otpgp = iwl_read32(trans, CSR_OTP_GP_REG);
132 if (otpgp & CSR_OTP_GP_REG_DEVICE_SELECT)
133 return 1;
134 return 0;
135 }
136 }
137
iwl_init_otp_access(struct iwl_trans * trans)138 static int iwl_init_otp_access(struct iwl_trans *trans)
139 {
140 int ret;
141
142 ret = iwl_finish_nic_init(trans, trans->trans_cfg);
143 if (ret)
144 return ret;
145
146 iwl_set_bits_prph(trans, APMG_PS_CTRL_REG,
147 APMG_PS_CTRL_VAL_RESET_REQ);
148 udelay(5);
149 iwl_clear_bits_prph(trans, APMG_PS_CTRL_REG,
150 APMG_PS_CTRL_VAL_RESET_REQ);
151
152 /*
153 * CSR auto clock gate disable bit -
154 * this is only applicable for HW with OTP shadow RAM
155 */
156 if (trans->trans_cfg->base_params->shadow_ram_support)
157 iwl_set_bit(trans, CSR_DBG_LINK_PWR_MGMT_REG,
158 CSR_RESET_LINK_PWR_MGMT_DISABLED);
159
160 return 0;
161 }
162
iwl_read_otp_word(struct iwl_trans * trans,u16 addr,__le16 * eeprom_data)163 static int iwl_read_otp_word(struct iwl_trans *trans, u16 addr,
164 __le16 *eeprom_data)
165 {
166 int ret = 0;
167 u32 r;
168 u32 otpgp;
169
170 iwl_write32(trans, CSR_EEPROM_REG,
171 CSR_EEPROM_REG_MSK_ADDR & (addr << 1));
172 ret = iwl_poll_bit(trans, CSR_EEPROM_REG,
173 CSR_EEPROM_REG_READ_VALID_MSK,
174 CSR_EEPROM_REG_READ_VALID_MSK,
175 IWL_EEPROM_ACCESS_TIMEOUT);
176 if (ret < 0) {
177 IWL_ERR(trans, "Time out reading OTP[%d]\n", addr);
178 return ret;
179 }
180 r = iwl_read32(trans, CSR_EEPROM_REG);
181 /* check for ECC errors: */
182 otpgp = iwl_read32(trans, CSR_OTP_GP_REG);
183 if (otpgp & CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK) {
184 /* stop in this case */
185 /* set the uncorrectable OTP ECC bit for acknowledgment */
186 iwl_set_bit(trans, CSR_OTP_GP_REG,
187 CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK);
188 IWL_ERR(trans, "Uncorrectable OTP ECC error, abort OTP read\n");
189 return -EINVAL;
190 }
191 if (otpgp & CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK) {
192 /* continue in this case */
193 /* set the correctable OTP ECC bit for acknowledgment */
194 iwl_set_bit(trans, CSR_OTP_GP_REG,
195 CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK);
196 IWL_ERR(trans, "Correctable OTP ECC error, continue read\n");
197 }
198 *eeprom_data = cpu_to_le16(r >> 16);
199 return 0;
200 }
201
202 /*
203 * iwl_is_otp_empty: check for empty OTP
204 */
iwl_is_otp_empty(struct iwl_trans * trans)205 static bool iwl_is_otp_empty(struct iwl_trans *trans)
206 {
207 u16 next_link_addr = 0;
208 __le16 link_value;
209 bool is_empty = false;
210
211 /* locate the beginning of OTP link list */
212 if (!iwl_read_otp_word(trans, next_link_addr, &link_value)) {
213 if (!link_value) {
214 IWL_ERR(trans, "OTP is empty\n");
215 is_empty = true;
216 }
217 } else {
218 IWL_ERR(trans, "Unable to read first block of OTP list.\n");
219 is_empty = true;
220 }
221
222 return is_empty;
223 }
224
225
226 /*
227 * iwl_find_otp_image: find EEPROM image in OTP
228 * finding the OTP block that contains the EEPROM image.
229 * the last valid block on the link list (the block _before_ the last block)
230 * is the block we should read and used to configure the device.
231 * If all the available OTP blocks are full, the last block will be the block
232 * we should read and used to configure the device.
233 * only perform this operation if shadow RAM is disabled
234 */
iwl_find_otp_image(struct iwl_trans * trans,u16 * validblockaddr)235 static int iwl_find_otp_image(struct iwl_trans *trans,
236 u16 *validblockaddr)
237 {
238 u16 next_link_addr = 0, valid_addr;
239 __le16 link_value = 0;
240 int usedblocks = 0;
241
242 /* set addressing mode to absolute to traverse the link list */
243 iwl_set_otp_access_absolute(trans);
244
245 /* checking for empty OTP or error */
246 if (iwl_is_otp_empty(trans))
247 return -EINVAL;
248
249 /*
250 * start traverse link list
251 * until reach the max number of OTP blocks
252 * different devices have different number of OTP blocks
253 */
254 do {
255 /* save current valid block address
256 * check for more block on the link list
257 */
258 valid_addr = next_link_addr;
259 next_link_addr = le16_to_cpu(link_value) * sizeof(u16);
260 IWL_DEBUG_EEPROM(trans->dev, "OTP blocks %d addr 0x%x\n",
261 usedblocks, next_link_addr);
262 if (iwl_read_otp_word(trans, next_link_addr, &link_value))
263 return -EINVAL;
264 if (!link_value) {
265 /*
266 * reach the end of link list, return success and
267 * set address point to the starting address
268 * of the image
269 */
270 *validblockaddr = valid_addr;
271 /* skip first 2 bytes (link list pointer) */
272 *validblockaddr += 2;
273 return 0;
274 }
275 /* more in the link list, continue */
276 usedblocks++;
277 } while (usedblocks <= trans->trans_cfg->base_params->max_ll_items);
278
279 /* OTP has no valid blocks */
280 IWL_DEBUG_EEPROM(trans->dev, "OTP has no valid blocks\n");
281 return -EINVAL;
282 }
283
284 /*
285 * iwl_read_eeprom - read EEPROM contents
286 *
287 * Load the EEPROM contents from adapter and return it
288 * and its size.
289 *
290 * NOTE: This routine uses the non-debug IO access functions.
291 */
iwl_read_eeprom(struct iwl_trans * trans,u8 ** eeprom,size_t * eeprom_size)292 int iwl_read_eeprom(struct iwl_trans *trans, u8 **eeprom, size_t *eeprom_size)
293 {
294 __le16 *e;
295 u32 gp = iwl_read32(trans, CSR_EEPROM_GP);
296 int sz;
297 int ret;
298 u16 addr;
299 u16 validblockaddr = 0;
300 u16 cache_addr = 0;
301 int nvm_is_otp;
302
303 if (!eeprom || !eeprom_size)
304 return -EINVAL;
305
306 nvm_is_otp = iwl_nvm_is_otp(trans);
307 if (nvm_is_otp < 0)
308 return nvm_is_otp;
309
310 sz = trans->trans_cfg->base_params->eeprom_size;
311 IWL_DEBUG_EEPROM(trans->dev, "NVM size = %d\n", sz);
312
313 e = kmalloc(sz, GFP_KERNEL);
314 if (!e)
315 return -ENOMEM;
316
317 ret = iwl_eeprom_verify_signature(trans, nvm_is_otp);
318 if (ret < 0) {
319 IWL_ERR(trans, "EEPROM not found, EEPROM_GP=0x%08x\n", gp);
320 goto err_free;
321 }
322
323 /* Make sure driver (instead of uCode) is allowed to read EEPROM */
324 ret = iwl_eeprom_acquire_semaphore(trans);
325 if (ret < 0) {
326 IWL_ERR(trans, "Failed to acquire EEPROM semaphore.\n");
327 goto err_free;
328 }
329
330 if (nvm_is_otp) {
331 ret = iwl_init_otp_access(trans);
332 if (ret) {
333 IWL_ERR(trans, "Failed to initialize OTP access.\n");
334 goto err_unlock;
335 }
336
337 iwl_write32(trans, CSR_EEPROM_GP,
338 iwl_read32(trans, CSR_EEPROM_GP) &
339 ~CSR_EEPROM_GP_IF_OWNER_MSK);
340
341 iwl_set_bit(trans, CSR_OTP_GP_REG,
342 CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK |
343 CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK);
344 /* traversing the linked list if no shadow ram supported */
345 if (!trans->trans_cfg->base_params->shadow_ram_support) {
346 ret = iwl_find_otp_image(trans, &validblockaddr);
347 if (ret)
348 goto err_unlock;
349 }
350 for (addr = validblockaddr; addr < validblockaddr + sz;
351 addr += sizeof(u16)) {
352 __le16 eeprom_data;
353
354 ret = iwl_read_otp_word(trans, addr, &eeprom_data);
355 if (ret)
356 goto err_unlock;
357 e[cache_addr / 2] = eeprom_data;
358 cache_addr += sizeof(u16);
359 }
360 } else {
361 /* eeprom is an array of 16bit values */
362 for (addr = 0; addr < sz; addr += sizeof(u16)) {
363 u32 r;
364
365 iwl_write32(trans, CSR_EEPROM_REG,
366 CSR_EEPROM_REG_MSK_ADDR & (addr << 1));
367
368 ret = iwl_poll_bit(trans, CSR_EEPROM_REG,
369 CSR_EEPROM_REG_READ_VALID_MSK,
370 CSR_EEPROM_REG_READ_VALID_MSK,
371 IWL_EEPROM_ACCESS_TIMEOUT);
372 if (ret < 0) {
373 IWL_ERR(trans,
374 "Time out reading EEPROM[%d]\n", addr);
375 goto err_unlock;
376 }
377 r = iwl_read32(trans, CSR_EEPROM_REG);
378 e[addr / 2] = cpu_to_le16(r >> 16);
379 }
380 }
381
382 IWL_DEBUG_EEPROM(trans->dev, "NVM Type: %s\n",
383 nvm_is_otp ? "OTP" : "EEPROM");
384
385 iwl_eeprom_release_semaphore(trans);
386
387 *eeprom_size = sz;
388 *eeprom = (u8 *)e;
389 return 0;
390
391 err_unlock:
392 iwl_eeprom_release_semaphore(trans);
393 err_free:
394 kfree(e);
395
396 return ret;
397 }
398 IWL_EXPORT_SYMBOL(iwl_read_eeprom);
399