1/******************************************************************************
2 *
3 * This file is provided under a dual BSD/GPLv2 license.  When using or
4 * redistributing this file, you may do so under either license.
5 *
6 * GPL LICENSE SUMMARY
7 *
8 * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
9 * Copyright(c) 2018 - 2019 Intel Corporation
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of version 2 of the GNU General Public License as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * The full GNU General Public License is included in this distribution
21 * in the file called COPYING.
22 *
23 * Contact Information:
24 *  Intel Linux Wireless <linuxwifi@intel.com>
25 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
26 *
27 * BSD LICENSE
28 *
29 * Copyright(c) 2005 - 2014 Intel Corporation. All rights reserved.
30 * Copyright(c) 2018 - 2019 Intel Corporation
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 *
37 *  * Redistributions of source code must retain the above copyright
38 *    notice, this list of conditions and the following disclaimer.
39 *  * Redistributions in binary form must reproduce the above copyright
40 *    notice, this list of conditions and the following disclaimer in
41 *    the documentation and/or other materials provided with the
42 *    distribution.
43 *  * Neither the name Intel Corporation nor the names of its
44 *    contributors may be used to endorse or promote products derived
45 *    from this software without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
48 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
49 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
50 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
51 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
52 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
53 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
54 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
55 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
56 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
57 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
58 *****************************************************************************/
59#include <linux/types.h>
60#include <linux/slab.h>
61#include <linux/export.h>
62
63#include "iwl-drv.h"
64#include "iwl-debug.h"
65#include "iwl-eeprom-read.h"
66#include "iwl-io.h"
67#include "iwl-prph.h"
68#include "iwl-csr.h"
69
70/*
71 * EEPROM access time values:
72 *
73 * Driver initiates EEPROM read by writing byte address << 1 to CSR_EEPROM_REG.
74 * Driver then polls CSR_EEPROM_REG for CSR_EEPROM_REG_READ_VALID_MSK (0x1).
75 * When polling, wait 10 uSec between polling loops, up to a maximum 5000 uSec.
76 * Driver reads 16-bit value from bits 31-16 of CSR_EEPROM_REG.
77 */
78#define IWL_EEPROM_ACCESS_TIMEOUT	5000 /* uSec */
79
80#define IWL_EEPROM_SEM_TIMEOUT		10   /* microseconds */
81#define IWL_EEPROM_SEM_RETRY_LIMIT	1000 /* number of attempts (not time) */
82
83
84/*
85 * The device's EEPROM semaphore prevents conflicts between driver and uCode
86 * when accessing the EEPROM; each access is a series of pulses to/from the
87 * EEPROM chip, not a single event, so even reads could conflict if they
88 * weren't arbitrated by the semaphore.
89 */
90
91#define	EEPROM_SEM_TIMEOUT 10		/* milliseconds */
92#define EEPROM_SEM_RETRY_LIMIT 1000	/* number of attempts (not time) */
93
94static int iwl_eeprom_acquire_semaphore(struct iwl_trans *trans)
95{
96	u16 count;
97	int ret;
98
99	for (count = 0; count < EEPROM_SEM_RETRY_LIMIT; count++) {
100		/* Request semaphore */
101		iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
102			    CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM);
103
104		/* See if we got it */
105		ret = iwl_poll_bit(trans, CSR_HW_IF_CONFIG_REG,
106				CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
107				CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
108				EEPROM_SEM_TIMEOUT);
109		if (ret >= 0) {
110			IWL_DEBUG_EEPROM(trans->dev,
111					 "Acquired semaphore after %d tries.\n",
112					 count+1);
113			return ret;
114		}
115	}
116
117	return ret;
118}
119
120static void iwl_eeprom_release_semaphore(struct iwl_trans *trans)
121{
122	iwl_clear_bit(trans, CSR_HW_IF_CONFIG_REG,
123		      CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM);
124}
125
126static int iwl_eeprom_verify_signature(struct iwl_trans *trans, bool nvm_is_otp)
127{
128	u32 gp = iwl_read32(trans, CSR_EEPROM_GP) & CSR_EEPROM_GP_VALID_MSK;
129
130	IWL_DEBUG_EEPROM(trans->dev, "EEPROM signature=0x%08x\n", gp);
131
132	switch (gp) {
133	case CSR_EEPROM_GP_BAD_SIG_EEP_GOOD_SIG_OTP:
134		if (!nvm_is_otp) {
135			IWL_ERR(trans, "EEPROM with bad signature: 0x%08x\n",
136				gp);
137			return -ENOENT;
138		}
139		return 0;
140	case CSR_EEPROM_GP_GOOD_SIG_EEP_LESS_THAN_4K:
141	case CSR_EEPROM_GP_GOOD_SIG_EEP_MORE_THAN_4K:
142		if (nvm_is_otp) {
143			IWL_ERR(trans, "OTP with bad signature: 0x%08x\n", gp);
144			return -ENOENT;
145		}
146		return 0;
147	case CSR_EEPROM_GP_BAD_SIGNATURE_BOTH_EEP_AND_OTP:
148	default:
149		IWL_ERR(trans,
150			"bad EEPROM/OTP signature, type=%s, EEPROM_GP=0x%08x\n",
151			nvm_is_otp ? "OTP" : "EEPROM", gp);
152		return -ENOENT;
153	}
154}
155
156/******************************************************************************
157 *
158 * OTP related functions
159 *
160******************************************************************************/
161
162static void iwl_set_otp_access_absolute(struct iwl_trans *trans)
163{
164	iwl_read32(trans, CSR_OTP_GP_REG);
165
166	iwl_clear_bit(trans, CSR_OTP_GP_REG,
167		      CSR_OTP_GP_REG_OTP_ACCESS_MODE);
168}
169
170static int iwl_nvm_is_otp(struct iwl_trans *trans)
171{
172	u32 otpgp;
173
174	/* OTP only valid for CP/PP and after */
175	switch (trans->hw_rev & CSR_HW_REV_TYPE_MSK) {
176	case CSR_HW_REV_TYPE_NONE:
177		IWL_ERR(trans, "Unknown hardware type\n");
178		return -EIO;
179	case CSR_HW_REV_TYPE_5300:
180	case CSR_HW_REV_TYPE_5350:
181	case CSR_HW_REV_TYPE_5100:
182	case CSR_HW_REV_TYPE_5150:
183		return 0;
184	default:
185		otpgp = iwl_read32(trans, CSR_OTP_GP_REG);
186		if (otpgp & CSR_OTP_GP_REG_DEVICE_SELECT)
187			return 1;
188		return 0;
189	}
190}
191
192static int iwl_init_otp_access(struct iwl_trans *trans)
193{
194	int ret;
195
196	ret = iwl_finish_nic_init(trans, trans->trans_cfg);
197	if (ret)
198		return ret;
199
200	iwl_set_bits_prph(trans, APMG_PS_CTRL_REG,
201			  APMG_PS_CTRL_VAL_RESET_REQ);
202	udelay(5);
203	iwl_clear_bits_prph(trans, APMG_PS_CTRL_REG,
204			    APMG_PS_CTRL_VAL_RESET_REQ);
205
206	/*
207	 * CSR auto clock gate disable bit -
208	 * this is only applicable for HW with OTP shadow RAM
209	 */
210	if (trans->trans_cfg->base_params->shadow_ram_support)
211		iwl_set_bit(trans, CSR_DBG_LINK_PWR_MGMT_REG,
212			    CSR_RESET_LINK_PWR_MGMT_DISABLED);
213
214	return 0;
215}
216
217static int iwl_read_otp_word(struct iwl_trans *trans, u16 addr,
218			     __le16 *eeprom_data)
219{
220	int ret = 0;
221	u32 r;
222	u32 otpgp;
223
224	iwl_write32(trans, CSR_EEPROM_REG,
225		    CSR_EEPROM_REG_MSK_ADDR & (addr << 1));
226	ret = iwl_poll_bit(trans, CSR_EEPROM_REG,
227				 CSR_EEPROM_REG_READ_VALID_MSK,
228				 CSR_EEPROM_REG_READ_VALID_MSK,
229				 IWL_EEPROM_ACCESS_TIMEOUT);
230	if (ret < 0) {
231		IWL_ERR(trans, "Time out reading OTP[%d]\n", addr);
232		return ret;
233	}
234	r = iwl_read32(trans, CSR_EEPROM_REG);
235	/* check for ECC errors: */
236	otpgp = iwl_read32(trans, CSR_OTP_GP_REG);
237	if (otpgp & CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK) {
238		/* stop in this case */
239		/* set the uncorrectable OTP ECC bit for acknowledgment */
240		iwl_set_bit(trans, CSR_OTP_GP_REG,
241			    CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK);
242		IWL_ERR(trans, "Uncorrectable OTP ECC error, abort OTP read\n");
243		return -EINVAL;
244	}
245	if (otpgp & CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK) {
246		/* continue in this case */
247		/* set the correctable OTP ECC bit for acknowledgment */
248		iwl_set_bit(trans, CSR_OTP_GP_REG,
249			    CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK);
250		IWL_ERR(trans, "Correctable OTP ECC error, continue read\n");
251	}
252	*eeprom_data = cpu_to_le16(r >> 16);
253	return 0;
254}
255
256/*
257 * iwl_is_otp_empty: check for empty OTP
258 */
259static bool iwl_is_otp_empty(struct iwl_trans *trans)
260{
261	u16 next_link_addr = 0;
262	__le16 link_value;
263	bool is_empty = false;
264
265	/* locate the beginning of OTP link list */
266	if (!iwl_read_otp_word(trans, next_link_addr, &link_value)) {
267		if (!link_value) {
268			IWL_ERR(trans, "OTP is empty\n");
269			is_empty = true;
270		}
271	} else {
272		IWL_ERR(trans, "Unable to read first block of OTP list.\n");
273		is_empty = true;
274	}
275
276	return is_empty;
277}
278
279
280/*
281 * iwl_find_otp_image: find EEPROM image in OTP
282 *   finding the OTP block that contains the EEPROM image.
283 *   the last valid block on the link list (the block _before_ the last block)
284 *   is the block we should read and used to configure the device.
285 *   If all the available OTP blocks are full, the last block will be the block
286 *   we should read and used to configure the device.
287 *   only perform this operation if shadow RAM is disabled
288 */
289static int iwl_find_otp_image(struct iwl_trans *trans,
290					u16 *validblockaddr)
291{
292	u16 next_link_addr = 0, valid_addr;
293	__le16 link_value = 0;
294	int usedblocks = 0;
295
296	/* set addressing mode to absolute to traverse the link list */
297	iwl_set_otp_access_absolute(trans);
298
299	/* checking for empty OTP or error */
300	if (iwl_is_otp_empty(trans))
301		return -EINVAL;
302
303	/*
304	 * start traverse link list
305	 * until reach the max number of OTP blocks
306	 * different devices have different number of OTP blocks
307	 */
308	do {
309		/* save current valid block address
310		 * check for more block on the link list
311		 */
312		valid_addr = next_link_addr;
313		next_link_addr = le16_to_cpu(link_value) * sizeof(u16);
314		IWL_DEBUG_EEPROM(trans->dev, "OTP blocks %d addr 0x%x\n",
315				 usedblocks, next_link_addr);
316		if (iwl_read_otp_word(trans, next_link_addr, &link_value))
317			return -EINVAL;
318		if (!link_value) {
319			/*
320			 * reach the end of link list, return success and
321			 * set address point to the starting address
322			 * of the image
323			 */
324			*validblockaddr = valid_addr;
325			/* skip first 2 bytes (link list pointer) */
326			*validblockaddr += 2;
327			return 0;
328		}
329		/* more in the link list, continue */
330		usedblocks++;
331	} while (usedblocks <= trans->trans_cfg->base_params->max_ll_items);
332
333	/* OTP has no valid blocks */
334	IWL_DEBUG_EEPROM(trans->dev, "OTP has no valid blocks\n");
335	return -EINVAL;
336}
337
338/**
339 * iwl_read_eeprom - read EEPROM contents
340 *
341 * Load the EEPROM contents from adapter and return it
342 * and its size.
343 *
344 * NOTE:  This routine uses the non-debug IO access functions.
345 */
346int iwl_read_eeprom(struct iwl_trans *trans, u8 **eeprom, size_t *eeprom_size)
347{
348	__le16 *e;
349	u32 gp = iwl_read32(trans, CSR_EEPROM_GP);
350	int sz;
351	int ret;
352	u16 addr;
353	u16 validblockaddr = 0;
354	u16 cache_addr = 0;
355	int nvm_is_otp;
356
357	if (!eeprom || !eeprom_size)
358		return -EINVAL;
359
360	nvm_is_otp = iwl_nvm_is_otp(trans);
361	if (nvm_is_otp < 0)
362		return nvm_is_otp;
363
364	sz = trans->trans_cfg->base_params->eeprom_size;
365	IWL_DEBUG_EEPROM(trans->dev, "NVM size = %d\n", sz);
366
367	e = kmalloc(sz, GFP_KERNEL);
368	if (!e)
369		return -ENOMEM;
370
371	ret = iwl_eeprom_verify_signature(trans, nvm_is_otp);
372	if (ret < 0) {
373		IWL_ERR(trans, "EEPROM not found, EEPROM_GP=0x%08x\n", gp);
374		goto err_free;
375	}
376
377	/* Make sure driver (instead of uCode) is allowed to read EEPROM */
378	ret = iwl_eeprom_acquire_semaphore(trans);
379	if (ret < 0) {
380		IWL_ERR(trans, "Failed to acquire EEPROM semaphore.\n");
381		goto err_free;
382	}
383
384	if (nvm_is_otp) {
385		ret = iwl_init_otp_access(trans);
386		if (ret) {
387			IWL_ERR(trans, "Failed to initialize OTP access.\n");
388			goto err_unlock;
389		}
390
391		iwl_write32(trans, CSR_EEPROM_GP,
392			    iwl_read32(trans, CSR_EEPROM_GP) &
393			    ~CSR_EEPROM_GP_IF_OWNER_MSK);
394
395		iwl_set_bit(trans, CSR_OTP_GP_REG,
396			    CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK |
397			    CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK);
398		/* traversing the linked list if no shadow ram supported */
399		if (!trans->trans_cfg->base_params->shadow_ram_support) {
400			ret = iwl_find_otp_image(trans, &validblockaddr);
401			if (ret)
402				goto err_unlock;
403		}
404		for (addr = validblockaddr; addr < validblockaddr + sz;
405		     addr += sizeof(u16)) {
406			__le16 eeprom_data;
407
408			ret = iwl_read_otp_word(trans, addr, &eeprom_data);
409			if (ret)
410				goto err_unlock;
411			e[cache_addr / 2] = eeprom_data;
412			cache_addr += sizeof(u16);
413		}
414	} else {
415		/* eeprom is an array of 16bit values */
416		for (addr = 0; addr < sz; addr += sizeof(u16)) {
417			u32 r;
418
419			iwl_write32(trans, CSR_EEPROM_REG,
420				    CSR_EEPROM_REG_MSK_ADDR & (addr << 1));
421
422			ret = iwl_poll_bit(trans, CSR_EEPROM_REG,
423					   CSR_EEPROM_REG_READ_VALID_MSK,
424					   CSR_EEPROM_REG_READ_VALID_MSK,
425					   IWL_EEPROM_ACCESS_TIMEOUT);
426			if (ret < 0) {
427				IWL_ERR(trans,
428					"Time out reading EEPROM[%d]\n", addr);
429				goto err_unlock;
430			}
431			r = iwl_read32(trans, CSR_EEPROM_REG);
432			e[addr / 2] = cpu_to_le16(r >> 16);
433		}
434	}
435
436	IWL_DEBUG_EEPROM(trans->dev, "NVM Type: %s\n",
437			 nvm_is_otp ? "OTP" : "EEPROM");
438
439	iwl_eeprom_release_semaphore(trans);
440
441	*eeprom_size = sz;
442	*eeprom = (u8 *)e;
443	return 0;
444
445 err_unlock:
446	iwl_eeprom_release_semaphore(trans);
447 err_free:
448	kfree(e);
449
450	return ret;
451}
452IWL_EXPORT_SYMBOL(iwl_read_eeprom);
453