stm32: enable flash bank size override
[fw/openocd] / src / flash / nor / stm32lx.c
1 /***************************************************************************
2  *   Copyright (C) 2005 by Dominic Rath                                    *
3  *   Dominic.Rath@gmx.de                                                   *
4  *                                                                         *
5  *   Copyright (C) 2008 by Spencer Oliver                                  *
6  *   spen@spen-soft.co.uk                                                  *
7  *                                                                         *
8  *   Copyright (C) 2011 by Clement Burin des Roziers                       *
9  *   clement.burin-des-roziers@hikob.com                                   *
10  *                                                                         *
11  *   This program is free software; you can redistribute it and/or modify  *
12  *   it under the terms of the GNU General Public License as published by  *
13  *   the Free Software Foundation; either version 2 of the License, or     *
14  *   (at your option) any later version.                                   *
15  *                                                                         *
16  *   This program is distributed in the hope that it will be useful,       *
17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
19  *   GNU General Public License for more details.                          *
20  *                                                                         *
21  *   You should have received a copy of the GNU General Public License     *
22  *   along with this program; if not, write to the                         *
23  *   Free Software Foundation, Inc.,                                       *
24  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
25  ***************************************************************************/
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include "imp.h"
32 #include <helper/binarybuffer.h>
33 #include <target/algorithm.h>
34 #include <target/armv7m.h>
35 #include <target/cortex_m.h>
36
37 /* stm32lx flash register locations */
38
39 #define FLASH_BASE              0x40023C00
40 #define FLASH_ACR               0x40023C00
41 #define FLASH_PECR              0x40023C04
42 #define FLASH_PDKEYR    0x40023C08
43 #define FLASH_PEKEYR    0x40023C0C
44 #define FLASH_PRGKEYR   0x40023C10
45 #define FLASH_OPTKEYR   0x40023C14
46 #define FLASH_SR                0x40023C18
47 #define FLASH_OBR               0x40023C1C
48 #define FLASH_WRPR              0x40023C20
49
50 /* FLASH_ACR bites */
51 #define FLASH_ACR__LATENCY              (1<<0)
52 #define FLASH_ACR__PRFTEN               (1<<1)
53 #define FLASH_ACR__ACC64                (1<<2)
54 #define FLASH_ACR__SLEEP_PD             (1<<3)
55 #define FLASH_ACR__RUN_PD               (1<<4)
56
57 /* FLASH_PECR bits */
58 #define FLASH_PECR__PELOCK              (1<<0)
59 #define FLASH_PECR__PRGLOCK             (1<<1)
60 #define FLASH_PECR__OPTLOCK             (1<<2)
61 #define FLASH_PECR__PROG                (1<<3)
62 #define FLASH_PECR__DATA                (1<<4)
63 #define FLASH_PECR__FTDW                (1<<8)
64 #define FLASH_PECR__ERASE               (1<<9)
65 #define FLASH_PECR__FPRG                (1<<10)
66 #define FLASH_PECR__EOPIE               (1<<16)
67 #define FLASH_PECR__ERRIE               (1<<17)
68 #define FLASH_PECR__OBL_LAUNCH  (1<<18)
69
70 /* FLASH_SR bits */
71 #define FLASH_SR__BSY           (1<<0)
72 #define FLASH_SR__EOP           (1<<1)
73 #define FLASH_SR__ENDHV         (1<<2)
74 #define FLASH_SR__READY         (1<<3)
75 #define FLASH_SR__WRPERR        (1<<8)
76 #define FLASH_SR__PGAERR        (1<<9)
77 #define FLASH_SR__SIZERR        (1<<10)
78 #define FLASH_SR__OPTVERR       (1<<11)
79
80 /* Unlock keys */
81 #define PEKEY1                  0x89ABCDEF
82 #define PEKEY2                  0x02030405
83 #define PRGKEY1                 0x8C9DAEBF
84 #define PRGKEY2                 0x13141516
85 #define OPTKEY1                 0xFBEAD9C8
86 #define OPTKEY2                 0x24252627
87
88 /* other registers */
89 #define DBGMCU_IDCODE   0xE0042000
90 #define F_SIZE                  0x1FF8004C
91
92 /* Constants */
93 #define FLASH_PAGE_SIZE 256
94 #define FLASH_SECTOR_SIZE 4096
95 #define FLASH_PAGES_PER_SECTOR 16
96 #define FLASH_BANK0_ADDRESS 0x08000000
97
98 /* stm32lx option byte register location */
99 #define OB_RDP                  0x1FF80000
100 #define OB_USER                 0x1FF80004
101 #define OB_WRP0_1               0x1FF80008
102 #define OB_WRP2_3               0x1FF8000C
103
104 /* OB_RDP values */
105 #define OB_RDP__LEVEL0  0xFF5500AA
106 #define OB_RDP__LEVEL1  0xFFFF0000
107
108 /* stm32lx RCC register locations */
109 #define RCC_CR          0x40023800
110 #define RCC_ICSCR       0x40023804
111 #define RCC_CFGR        0x40023808
112
113 /* RCC_ICSCR bits */
114 #define RCC_ICSCR__MSIRANGE_MASK        (7<<13)
115
116 static int stm32lx_unlock_program_memory(struct flash_bank *bank);
117 static int stm32lx_lock_program_memory(struct flash_bank *bank);
118 static int stm32lx_enable_write_half_page(struct flash_bank *bank);
119 static int stm32lx_erase_sector(struct flash_bank *bank, int sector);
120 static int stm32lx_wait_until_bsy_clear(struct flash_bank *bank);
121
122 struct stm32lx_flash_bank {
123         int probed;
124 };
125
126 /* flash bank stm32lx <base> <size> 0 0 <target#>
127  */
128 FLASH_BANK_COMMAND_HANDLER(stm32lx_flash_bank_command)
129 {
130         struct stm32lx_flash_bank *stm32lx_info;
131         if (CMD_ARGC < 6)
132                 return ERROR_COMMAND_SYNTAX_ERROR;
133
134         /* Create the bank structure */
135         stm32lx_info = malloc(sizeof(struct stm32lx_flash_bank));
136
137         /* Check allocation */
138         if (stm32lx_info == NULL) {
139                 LOG_ERROR("failed to allocate bank structure");
140                 return ERROR_FAIL;
141         }
142
143         bank->driver_priv = stm32lx_info;
144
145         stm32lx_info->probed = 0;
146
147         return ERROR_OK;
148 }
149
150 static int stm32lx_protect_check(struct flash_bank *bank)
151 {
152         int retval;
153         struct target *target = bank->target;
154
155         uint32_t wrpr;
156
157         if (target->state != TARGET_HALTED) {
158                 LOG_ERROR("Target not halted");
159                 return ERROR_TARGET_NOT_HALTED;
160         }
161
162         /*
163          * Read the WRPR word, and check each bit (corresponding to each
164          * flash sector
165          */
166         retval = target_read_u32(target, FLASH_WRPR, &wrpr);
167         if (retval != ERROR_OK)
168                 return retval;
169
170         for (int i = 0; i < 32; i++) {
171                 if (wrpr & (1 << i))
172                         bank->sectors[i].is_protected = 1;
173                 else
174                         bank->sectors[i].is_protected = 0;
175         }
176         return ERROR_OK;
177 }
178
179 static int stm32lx_erase(struct flash_bank *bank, int first, int last)
180 {
181         int retval;
182
183         /*
184          * It could be possible to do a mass erase if all sectors must be
185          * erased, but it is not implemented yet.
186          */
187
188         if (bank->target->state != TARGET_HALTED) {
189                 LOG_ERROR("Target not halted");
190                 return ERROR_TARGET_NOT_HALTED;
191         }
192
193         /*
194          * Loop over the selected sectors and erase them
195          */
196         for (int i = first; i <= last; i++) {
197                 retval = stm32lx_erase_sector(bank, i);
198                 if (retval != ERROR_OK)
199                         return retval;
200                 bank->sectors[i].is_erased = 1;
201         }
202         return ERROR_OK;
203 }
204
205 static int stm32lx_protect(struct flash_bank *bank, int set, int first,
206                 int last)
207 {
208         LOG_WARNING("protection of the STM32L flash is not implemented");
209         return ERROR_OK;
210 }
211
212 static int stm32lx_write_half_pages(struct flash_bank *bank, uint8_t *buffer,
213                 uint32_t offset, uint32_t count)
214 {
215         struct target *target = bank->target;
216         uint32_t buffer_size = 16384;
217         struct working_area *write_algorithm;
218         struct working_area *source;
219         uint32_t address = bank->base + offset;
220
221         struct reg_param reg_params[3];
222         struct armv7m_algorithm armv7m_info;
223
224         int retval = ERROR_OK;
225
226         /* see contib/loaders/flash/stm32lx.S for src */
227
228         static const uint8_t stm32lx_flash_write_code[] = {
229                 /* write_word: */
230                 0x00, 0x23,             /* movs r3, #0 */
231                 0x04, 0xe0,             /* b test_done */
232
233                 /* write_word: */
234                 0x51, 0xf8, 0x04, 0xcb, /* ldr ip, [r1], #4 */
235                 0x40, 0xf8, 0x04, 0xcb, /* str ip, [r0], #4 */
236                 0x01, 0x33,             /* adds r3, #1 */
237
238                 /* test_done: */
239                 0x93, 0x42,             /* cmp r3, r2 */
240                 0xf8, 0xd3,             /* bcc write_word */
241                 0x00, 0xbe,             /* bkpt 0 */
242         };
243
244         /* Check if there is an even number of half pages (128bytes) */
245         if (count % 128) {
246                 LOG_ERROR("there should be an even number "
247                                 "of half pages = 128 bytes (count = %" PRIi32 " bytes)", count);
248                 return ERROR_FAIL;
249         }
250
251         /* flash write code */
252         if (target_alloc_working_area(target, sizeof(stm32lx_flash_write_code),
253                         &write_algorithm) != ERROR_OK) {
254                 LOG_DEBUG("no working area for block memory writes");
255                 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
256         };
257
258         /* Write the flashing code */
259         retval = target_write_buffer(target,
260                         write_algorithm->address,
261                         sizeof(stm32lx_flash_write_code),
262                         (uint8_t *)stm32lx_flash_write_code);
263         if (retval != ERROR_OK) {
264                 target_free_working_area(target, write_algorithm);
265                 return retval;
266         }
267
268         /* Allocate half pages memory */
269         while (target_alloc_working_area_try(target, buffer_size, &source) != ERROR_OK) {
270                 if (buffer_size > 1024)
271                         buffer_size -= 1024;
272                 else
273                         buffer_size /= 2;
274
275                 if (buffer_size <= 256) {
276                         /* we already allocated the writing code, but failed to get a
277                          * buffer, free the algorithm */
278                         target_free_working_area(target, write_algorithm);
279
280                         LOG_WARNING("no large enough working area available, can't do block memory writes");
281                         return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
282                 }
283         }
284
285         armv7m_info.common_magic = ARMV7M_COMMON_MAGIC;
286         armv7m_info.core_mode = ARM_MODE_THREAD;
287         init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
288         init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
289         init_reg_param(&reg_params[2], "r2", 32, PARAM_OUT);
290
291         /* Enable half-page write */
292         retval = stm32lx_enable_write_half_page(bank);
293         if (retval != ERROR_OK) {
294                 target_free_working_area(target, source);
295                 target_free_working_area(target, write_algorithm);
296
297                 destroy_reg_param(&reg_params[0]);
298                 destroy_reg_param(&reg_params[1]);
299                 destroy_reg_param(&reg_params[2]);
300                 return retval;
301         }
302
303         struct armv7m_common *armv7m = target_to_armv7m(target);
304         if (armv7m == NULL) {
305
306                 /* something is very wrong if armv7m is NULL */
307                 LOG_ERROR("unable to get armv7m target");
308                 return retval;
309         }
310
311         /* save any DEMCR flags and configure target to catch any Hard Faults */
312         uint32_t demcr_save = armv7m->demcr;
313         armv7m->demcr = VC_HARDERR;
314
315         /* Loop while there are bytes to write */
316         while (count > 0) {
317                 uint32_t this_count;
318                 this_count = (count > buffer_size) ? buffer_size : count;
319
320                 /* Write the next half pages */
321                 retval = target_write_buffer(target, source->address, this_count, buffer);
322                 if (retval != ERROR_OK)
323                         break;
324
325                 /* 4: Store useful information in the registers */
326                 /* the destination address of the copy (R0) */
327                 buf_set_u32(reg_params[0].value, 0, 32, address);
328                 /* The source address of the copy (R1) */
329                 buf_set_u32(reg_params[1].value, 0, 32, source->address);
330                 /* The length of the copy (R2) */
331                 buf_set_u32(reg_params[2].value, 0, 32, this_count / 4);
332
333                 /* 5: Execute the bunch of code */
334                 retval = target_run_algorithm(target, 0, NULL, sizeof(reg_params)
335                                 / sizeof(*reg_params), reg_params,
336                                 write_algorithm->address, 0, 10000, &armv7m_info);
337                 if (retval != ERROR_OK)
338                         break;
339
340                 /* check for Hard Fault */
341                 if (armv7m->exception_number == 3)
342                         break;
343
344                 /* 6: Wait while busy */
345                 retval = stm32lx_wait_until_bsy_clear(bank);
346                 if (retval != ERROR_OK)
347                         break;
348
349                 buffer += this_count;
350                 address += this_count;
351                 count -= this_count;
352         }
353
354         /* restore previous flags */
355         armv7m->demcr = demcr_save;
356
357         if (armv7m->exception_number == 3) {
358
359                 /* the stm32l15x devices seem to have an issue when blank.
360                  * if a ram loader is executed on a blank device it will
361                  * Hard Fault, this issue does not happen for a already programmed device.
362                  * A related issue is described in the stm32l151xx errata (Doc ID 17721 Rev 6 - 2.1.3).
363                  * The workaround of handling the Hard Fault exception does work, but makes the
364                  * loader more complicated, as a compromise we manually write the pages, programming time
365                  * is reduced by 50% using this slower method.
366                  */
367
368                 LOG_WARNING("couldn't use loader, falling back to page memory writes");
369
370                 while (count > 0) {
371                         uint32_t this_count;
372                         this_count = (count > 128) ? 128 : count;
373
374                         /* Write the next half pages */
375                         retval = target_write_buffer(target, address, this_count, buffer);
376                         if (retval != ERROR_OK)
377                                 break;
378
379                         /* Wait while busy */
380                         retval = stm32lx_wait_until_bsy_clear(bank);
381                         if (retval != ERROR_OK)
382                                 break;
383
384                         buffer += this_count;
385                         address += this_count;
386                         count -= this_count;
387                 }
388         }
389
390         if (retval == ERROR_OK)
391                 retval = stm32lx_lock_program_memory(bank);
392
393         target_free_working_area(target, source);
394         target_free_working_area(target, write_algorithm);
395
396         destroy_reg_param(&reg_params[0]);
397         destroy_reg_param(&reg_params[1]);
398         destroy_reg_param(&reg_params[2]);
399
400         return retval;
401 }
402
403 static int stm32lx_write(struct flash_bank *bank, uint8_t *buffer,
404                 uint32_t offset, uint32_t count)
405 {
406         struct target *target = bank->target;
407
408         uint32_t halfpages_number;
409         uint32_t bytes_remaining = 0;
410         uint32_t address = bank->base + offset;
411         uint32_t bytes_written = 0;
412         int retval, retval2;
413
414         if (bank->target->state != TARGET_HALTED) {
415                 LOG_ERROR("Target not halted");
416                 return ERROR_TARGET_NOT_HALTED;
417         }
418
419         if (offset & 0x3) {
420                 LOG_ERROR("offset 0x%" PRIx32 " breaks required 4-byte alignment", offset);
421                 return ERROR_FLASH_DST_BREAKS_ALIGNMENT;
422         }
423
424         retval = stm32lx_unlock_program_memory(bank);
425         if (retval != ERROR_OK)
426                 return retval;
427
428         /* first we need to write any unaligned head bytes upto
429          * the next 128 byte page */
430
431         if (offset % 128)
432                 bytes_remaining = MIN(count, 128 - (offset % 128));
433
434         while (bytes_remaining > 0) {
435                 uint8_t value[4] = {0xff, 0xff, 0xff, 0xff};
436
437                 /* copy remaining bytes into the write buffer */
438                 uint32_t bytes_to_write = MIN(4, bytes_remaining);
439                 memcpy(value, buffer + bytes_written, bytes_to_write);
440
441                 retval = target_write_buffer(target, address, 4, value);
442                 if (retval != ERROR_OK)
443                         goto reset_pg_and_lock;
444
445                 bytes_written += bytes_to_write;
446                 bytes_remaining -= bytes_to_write;
447                 address += 4;
448
449                 retval = stm32lx_wait_until_bsy_clear(bank);
450                 if (retval != ERROR_OK)
451                         goto reset_pg_and_lock;
452         }
453
454         offset += bytes_written;
455         count -= bytes_written;
456
457         /* this should always pass this check here */
458         assert((offset % 128) == 0);
459
460         /* calculate half pages */
461         halfpages_number = count / 128;
462
463         if (halfpages_number) {
464                 retval = stm32lx_write_half_pages(bank, buffer + bytes_written, offset, 128 * halfpages_number);
465                 if (retval == ERROR_TARGET_RESOURCE_NOT_AVAILABLE) {
466                         /* attempt slow memory writes */
467                         LOG_WARNING("couldn't use block writes, falling back to single memory accesses");
468                         halfpages_number = 0;
469                 } else {
470                         if (retval != ERROR_OK)
471                                 return ERROR_FAIL;
472                 }
473         }
474
475         /* write any remaining bytes */
476         uint32_t page_bytes_written = 128 * halfpages_number;
477         bytes_written += page_bytes_written;
478         address += page_bytes_written;
479         bytes_remaining = count - page_bytes_written;
480
481         retval = stm32lx_unlock_program_memory(bank);
482         if (retval != ERROR_OK)
483                 return retval;
484
485         while (bytes_remaining > 0) {
486                 uint8_t value[4] = {0xff, 0xff, 0xff, 0xff};
487
488                 /* copy remaining bytes into the write buffer */
489                 uint32_t bytes_to_write = MIN(4, bytes_remaining);
490                 memcpy(value, buffer + bytes_written, bytes_to_write);
491
492                 retval = target_write_buffer(target, address, 4, value);
493                 if (retval != ERROR_OK)
494                         goto reset_pg_and_lock;
495
496                 bytes_written += bytes_to_write;
497                 bytes_remaining -= bytes_to_write;
498                 address += 4;
499
500                 retval = stm32lx_wait_until_bsy_clear(bank);
501                 if (retval != ERROR_OK)
502                         goto reset_pg_and_lock;
503         }
504
505 reset_pg_and_lock:
506         retval2 = stm32lx_lock_program_memory(bank);
507         if (retval == ERROR_OK)
508                 retval = retval2;
509
510         return retval;
511 }
512
513 static int stm32lx_probe(struct flash_bank *bank)
514 {
515         struct target *target = bank->target;
516         struct stm32lx_flash_bank *stm32lx_info = bank->driver_priv;
517         int i;
518         uint16_t flash_size_in_kb;
519         uint16_t max_flash_size_in_kb;
520         uint32_t device_id;
521
522         stm32lx_info->probed = 0;
523
524         /* read stm32 device id register */
525         int retval = target_read_u32(target, DBGMCU_IDCODE, &device_id);
526         if (retval != ERROR_OK)
527                 return retval;
528
529         LOG_DEBUG("device id = 0x%08" PRIx32 "", device_id);
530
531         /* set max flash size depending on family */
532         switch (device_id & 0xfff) {
533         case 0x416:
534                 max_flash_size_in_kb = 128;
535                 break;
536         case 0x436:
537                 max_flash_size_in_kb = 384;
538                 break;
539         default:
540                 LOG_WARNING("Cannot identify target as a STM32L family.");
541                 return ERROR_FAIL;
542         }
543
544         /* get flash size from target. */
545         retval = target_read_u16(target, F_SIZE, &flash_size_in_kb);
546
547         /* failed reading flash size or flash size invalid (early silicon),
548          * default to max target family */
549         if (retval != ERROR_OK || flash_size_in_kb == 0xffff || flash_size_in_kb == 0) {
550                 LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming %dk flash",
551                         max_flash_size_in_kb);
552                 flash_size_in_kb = max_flash_size_in_kb;
553         }
554
555         /* if the user sets the size manually then ignore the probed value
556          * this allows us to work around devices that have a invalid flash size register value */
557         if (bank->size) {
558                 LOG_INFO("ignoring flash probed value, using configured bank size");
559                 flash_size_in_kb = bank->size / 1024;
560         }
561
562         /* STM32L - we have 32 sectors, 16 pages per sector -> 512 pages
563          * 16 pages for a protection area */
564
565         /* calculate numbers of sectors (4kB per sector) */
566         int num_sectors = (flash_size_in_kb * 1024) / FLASH_SECTOR_SIZE;
567         LOG_INFO("flash size = %dkbytes", flash_size_in_kb);
568
569         if (bank->sectors) {
570                 free(bank->sectors);
571                 bank->sectors = NULL;
572         }
573
574         bank->base = FLASH_BANK0_ADDRESS;
575         bank->size = flash_size_in_kb * 1024;
576         bank->num_sectors = num_sectors;
577         bank->sectors = malloc(sizeof(struct flash_sector) * num_sectors);
578         if (bank->sectors == NULL) {
579                 LOG_ERROR("failed to allocate bank sectors");
580                 return ERROR_FAIL;
581         }
582
583         for (i = 0; i < num_sectors; i++) {
584                 bank->sectors[i].offset = i * FLASH_SECTOR_SIZE;
585                 bank->sectors[i].size = FLASH_SECTOR_SIZE;
586                 bank->sectors[i].is_erased = -1;
587                 bank->sectors[i].is_protected = 1;
588         }
589
590         stm32lx_info->probed = 1;
591
592         return ERROR_OK;
593 }
594
595 static int stm32lx_auto_probe(struct flash_bank *bank)
596 {
597         struct stm32lx_flash_bank *stm32lx_info = bank->driver_priv;
598
599         if (stm32lx_info->probed)
600                 return ERROR_OK;
601
602         return stm32lx_probe(bank);
603 }
604
605 static int stm32lx_erase_check(struct flash_bank *bank)
606 {
607         struct target *target = bank->target;
608         const int buffer_size = 4096;
609         int i;
610         uint32_t nBytes;
611         int retval = ERROR_OK;
612
613         if (bank->target->state != TARGET_HALTED) {
614                 LOG_ERROR("Target not halted");
615                 return ERROR_TARGET_NOT_HALTED;
616         }
617
618         uint8_t *buffer = malloc(buffer_size);
619         if (buffer == NULL) {
620                 LOG_ERROR("failed to allocate read buffer");
621                 return ERROR_FAIL;
622         }
623
624         for (i = 0; i < bank->num_sectors; i++) {
625                 uint32_t j;
626                 bank->sectors[i].is_erased = 1;
627
628                 /* Loop chunk by chunk over the sector */
629                 for (j = 0; j < bank->sectors[i].size; j += buffer_size) {
630                         uint32_t chunk;
631                         chunk = buffer_size;
632                         if (chunk > (j - bank->sectors[i].size))
633                                 chunk = (j - bank->sectors[i].size);
634
635                         retval = target_read_memory(target, bank->base
636                                         + bank->sectors[i].offset + j, 4, chunk / 4, buffer);
637                         if (retval != ERROR_OK)
638                                 break;
639
640                         for (nBytes = 0; nBytes < chunk; nBytes++) {
641                                 if (buffer[nBytes] != 0x00) {
642                                         bank->sectors[i].is_erased = 0;
643                                         break;
644                                 }
645                         }
646                 }
647                 if (retval != ERROR_OK)
648                         break;
649         }
650         free(buffer);
651
652         return retval;
653 }
654
655 static int stm32lx_get_info(struct flash_bank *bank, char *buf, int buf_size)
656 {
657         /* This method must return a string displaying information about the bank */
658
659         struct target *target = bank->target;
660         uint32_t device_id;
661         int printed;
662
663         /* read stm32 device id register */
664         int retval = target_read_u32(target, DBGMCU_IDCODE, &device_id);
665         if (retval != ERROR_OK)
666                 return retval;
667
668         if ((device_id & 0xfff) == 0x416) {
669                 printed = snprintf(buf, buf_size, "stm32lx - Rev: ");
670                 buf += printed;
671                 buf_size -= printed;
672
673                 switch (device_id >> 16) {
674                         case 0x1000:
675                                 snprintf(buf, buf_size, "A");
676                                 break;
677
678                         case 0x1008:
679                                 snprintf(buf, buf_size, "Y");
680                                 break;
681
682                         case 0x1018:
683                                 snprintf(buf, buf_size, "X");
684                                 break;
685
686                         case 0x1038:
687                                 snprintf(buf, buf_size, "W");
688                                 break;
689
690                         case 0x1078:
691                                 snprintf(buf, buf_size, "V");
692                                 break;
693
694                         default:
695                                 snprintf(buf, buf_size, "unknown");
696                                 break;
697                 }
698         } else if ((device_id & 0xfff) == 0x436) {
699                 printed = snprintf(buf, buf_size, "stm32lx (HD) - Rev: ");
700                 buf += printed;
701                 buf_size -= printed;
702
703                 switch (device_id >> 16) {
704                         case 0x1000:
705                                 snprintf(buf, buf_size, "A");
706                                 break;
707
708                         case 0x1008:
709                                 snprintf(buf, buf_size, "Z");
710                                 break;
711
712                         case 0x1018:
713                                 snprintf(buf, buf_size, "Y");
714                                 break;
715
716                         default:
717                                 snprintf(buf, buf_size, "unknown");
718                                 break;
719                 }
720         } else {
721                 snprintf(buf, buf_size, "Cannot identify target as a stm32lx");
722                 return ERROR_FAIL;
723         }
724
725         return ERROR_OK;
726 }
727
728 static const struct command_registration stm32lx_exec_command_handlers[] = {
729         COMMAND_REGISTRATION_DONE
730 };
731
732 static const struct command_registration stm32lx_command_handlers[] = {
733         {
734                 .name = "stm32lx",
735                 .mode = COMMAND_ANY,
736                 .help = "stm32lx flash command group",
737                 .usage = "",
738                 .chain = stm32lx_exec_command_handlers,
739         },
740         COMMAND_REGISTRATION_DONE
741 };
742
743 struct flash_driver stm32lx_flash = {
744                 .name = "stm32lx",
745                 .commands = stm32lx_command_handlers,
746                 .flash_bank_command = stm32lx_flash_bank_command,
747                 .erase = stm32lx_erase,
748                 .protect = stm32lx_protect,
749                 .write = stm32lx_write,
750                 .read = default_flash_read,
751                 .probe = stm32lx_probe,
752                 .auto_probe = stm32lx_auto_probe,
753                 .erase_check = stm32lx_erase_check,
754                 .protect_check = stm32lx_protect_check,
755                 .info = stm32lx_get_info,
756 };
757
758 /* Static methods implementation */
759 static int stm32lx_unlock_program_memory(struct flash_bank *bank)
760 {
761         struct target *target = bank->target;
762         int retval;
763         uint32_t reg32;
764
765         /*
766          * Unlocking the program memory is done by unlocking the PECR,
767          * then by writing the 2 PRGKEY to the PRGKEYR register
768          */
769
770         /* check flash is not already unlocked */
771         retval = target_read_u32(target, FLASH_PECR, &reg32);
772         if (retval != ERROR_OK)
773                 return retval;
774
775         if ((reg32 & FLASH_PECR__PRGLOCK) == 0)
776                 return ERROR_OK;
777
778         /* To unlock the PECR write the 2 PEKEY to the PEKEYR register */
779         retval = target_write_u32(target, FLASH_PEKEYR, PEKEY1);
780         if (retval != ERROR_OK)
781                 return retval;
782
783         retval = target_write_u32(target, FLASH_PEKEYR, PEKEY2);
784         if (retval != ERROR_OK)
785                 return retval;
786
787         /* Make sure it worked */
788         retval = target_read_u32(target, FLASH_PECR, &reg32);
789         if (retval != ERROR_OK)
790                 return retval;
791
792         if (reg32 & FLASH_PECR__PELOCK) {
793                 LOG_ERROR("PELOCK is not cleared :(");
794                 return ERROR_FLASH_OPERATION_FAILED;
795         }
796
797         retval = target_write_u32(target, FLASH_PRGKEYR, PRGKEY1);
798         if (retval != ERROR_OK)
799                 return retval;
800         retval = target_write_u32(target, FLASH_PRGKEYR, PRGKEY2);
801         if (retval != ERROR_OK)
802                 return retval;
803
804         /* Make sure it worked */
805         retval = target_read_u32(target, FLASH_PECR, &reg32);
806         if (retval != ERROR_OK)
807                 return retval;
808
809         if (reg32 & FLASH_PECR__PRGLOCK) {
810                 LOG_ERROR("PRGLOCK is not cleared :(");
811                 return ERROR_FLASH_OPERATION_FAILED;
812         }
813
814         return ERROR_OK;
815 }
816
817 static int stm32lx_enable_write_half_page(struct flash_bank *bank)
818 {
819         struct target *target = bank->target;
820         int retval;
821         uint32_t reg32;
822
823         /**
824          * Unlock the program memory, then set the FPRG bit in the PECR register.
825          */
826         retval = stm32lx_unlock_program_memory(bank);
827         if (retval != ERROR_OK)
828                 return retval;
829
830         retval = target_read_u32(target, FLASH_PECR, &reg32);
831         if (retval != ERROR_OK)
832                 return retval;
833
834         reg32 |= FLASH_PECR__FPRG;
835         retval = target_write_u32(target, FLASH_PECR, reg32);
836         if (retval != ERROR_OK)
837                 return retval;
838
839         retval = target_read_u32(target, FLASH_PECR, &reg32);
840         if (retval != ERROR_OK)
841                 return retval;
842
843         reg32 |= FLASH_PECR__PROG;
844         retval = target_write_u32(target, FLASH_PECR, reg32);
845
846         return retval;
847 }
848
849 static int stm32lx_lock_program_memory(struct flash_bank *bank)
850 {
851         struct target *target = bank->target;
852         int retval;
853         uint32_t reg32;
854
855         /* To lock the program memory, simply set the lock bit and lock PECR */
856
857         retval = target_read_u32(target, FLASH_PECR, &reg32);
858         if (retval != ERROR_OK)
859                 return retval;
860
861         reg32 |= FLASH_PECR__PRGLOCK;
862         retval = target_write_u32(target, FLASH_PECR, reg32);
863         if (retval != ERROR_OK)
864                 return retval;
865
866         retval = target_read_u32(target, FLASH_PECR, &reg32);
867         if (retval != ERROR_OK)
868                 return retval;
869
870         reg32 |= FLASH_PECR__PELOCK;
871         retval = target_write_u32(target, FLASH_PECR, reg32);
872         if (retval != ERROR_OK)
873                 return retval;
874
875         return ERROR_OK;
876 }
877
878 static int stm32lx_erase_sector(struct flash_bank *bank, int sector)
879 {
880         struct target *target = bank->target;
881         int retval;
882         uint32_t reg32;
883
884         /*
885          * To erase a sector (i.e. FLASH_PAGES_PER_SECTOR pages),
886          * first unlock the memory, loop over the pages of this sector
887          * and write 0x0 to its first word.
888          */
889
890         retval = stm32lx_unlock_program_memory(bank);
891         if (retval != ERROR_OK)
892                 return retval;
893
894         for (int page = 0; page < FLASH_PAGES_PER_SECTOR; page++) {
895                 reg32 = FLASH_PECR__PROG | FLASH_PECR__ERASE;
896                 retval = target_write_u32(target, FLASH_PECR, reg32);
897                 if (retval != ERROR_OK)
898                         return retval;
899
900                 retval = stm32lx_wait_until_bsy_clear(bank);
901                 if (retval != ERROR_OK)
902                         return retval;
903
904                 uint32_t addr = bank->base + bank->sectors[sector].offset + (page
905                                 * FLASH_PAGE_SIZE);
906                 retval = target_write_u32(target, addr, 0x0);
907                 if (retval != ERROR_OK)
908                         return retval;
909
910                 retval = stm32lx_wait_until_bsy_clear(bank);
911                 if (retval != ERROR_OK)
912                         return retval;
913         }
914
915         retval = stm32lx_lock_program_memory(bank);
916         if (retval != ERROR_OK)
917                 return retval;
918
919         return ERROR_OK;
920 }
921
922 static int stm32lx_wait_until_bsy_clear(struct flash_bank *bank)
923 {
924         struct target *target = bank->target;
925         uint32_t status;
926         int retval = ERROR_OK;
927         int timeout = 100;
928
929         /* wait for busy to clear */
930         for (;;) {
931                 retval = target_read_u32(target, FLASH_SR, &status);
932                 if (retval != ERROR_OK)
933                         return retval;
934
935                 if ((status & FLASH_SR__BSY) == 0)
936                         break;
937                 if (timeout-- <= 0) {
938                         LOG_ERROR("timed out waiting for flash");
939                         return ERROR_FAIL;
940                 }
941                 alive_sleep(1);
942         }
943
944         if (status & FLASH_SR__WRPERR) {
945                 LOG_ERROR("access denied / write protected");
946                 retval = ERROR_FAIL;
947         }
948
949         if (status & FLASH_SR__PGAERR) {
950                 LOG_ERROR("invalid program address");
951                 retval = ERROR_FAIL;
952         }
953
954         return retval;
955 }