1 /*
2  * Copyright (c) 2017 Linaro Limited
3  * Copyright (c) 2023 Google Inc
4  *
5  * SPDX-License-Identifier: Apache-2.0
6  */
7 
8 #include <string.h>
9 
10 #include <zephyr/device.h>
11 #include <zephyr/drivers/flash.h>
12 #include <zephyr/init.h>
13 #include <zephyr/kernel.h>
14 #include <zephyr/logging/log.h>
15 #include <zephyr/sys/barrier.h>
16 
17 #include <soc.h>
18 
19 #include "flash_stm32.h"
20 
21 LOG_MODULE_REGISTER(flash_stm32f4x, CONFIG_FLASH_LOG_LEVEL);
22 
23 #if FLASH_STM32_WRITE_BLOCK_SIZE == 8
24 typedef uint64_t flash_prg_t;
25 #define FLASH_PROGRAM_SIZE FLASH_PSIZE_DOUBLE_WORD
26 #elif FLASH_STM32_WRITE_BLOCK_SIZE == 4
27 typedef uint32_t flash_prg_t;
28 #define FLASH_PROGRAM_SIZE FLASH_PSIZE_WORD
29 #elif FLASH_STM32_WRITE_BLOCK_SIZE == 2
30 typedef uint16_t flash_prg_t;
31 #define FLASH_PROGRAM_SIZE FLASH_PSIZE_HALF_WORD
32 #elif FLASH_STM32_WRITE_BLOCK_SIZE == 1
33 typedef uint8_t flash_prg_t;
34 #define FLASH_PROGRAM_SIZE FLASH_PSIZE_BYTE
35 #else
36 #error Write block size must be a power of 2, from 1 to 8
37 #endif
38 
flash_stm32_valid_range(const struct device * dev,off_t offset,uint32_t len,bool write)39 bool flash_stm32_valid_range(const struct device *dev, off_t offset,
40 			     uint32_t len,
41 			     bool write)
42 {
43 	ARG_UNUSED(write);
44 
45 #if (FLASH_SECTOR_TOTAL == 12) && defined(FLASH_OPTCR_DB1M)
46 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
47 	/*
48 	 * RM0090, table 7.1: STM32F42xxx, STM32F43xxx
49 	 */
50 	if (regs->OPTCR & FLASH_OPTCR_DB1M) {
51 		/* Device configured in Dual Bank, but not supported for now */
52 		return false;
53 	}
54 #endif
55 
56 	return flash_stm32_range_exists(dev, offset, len);
57 }
58 
flush_cache(FLASH_TypeDef * regs)59 static inline void flush_cache(FLASH_TypeDef *regs)
60 {
61 	if (regs->ACR & FLASH_ACR_DCEN) {
62 		regs->ACR &= ~FLASH_ACR_DCEN;
63 		/* Datasheet: DCRST: Data cache reset
64 		 * This bit can be written only when the data cache is disabled
65 		 */
66 		regs->ACR |= FLASH_ACR_DCRST;
67 		regs->ACR &= ~FLASH_ACR_DCRST;
68 		regs->ACR |= FLASH_ACR_DCEN;
69 	}
70 
71 	if (regs->ACR & FLASH_ACR_ICEN) {
72 		regs->ACR &= ~FLASH_ACR_ICEN;
73 		/* Datasheet: ICRST: Instruction cache reset :
74 		 * This bit can be written only when the instruction cache
75 		 * is disabled
76 		 */
77 		regs->ACR |= FLASH_ACR_ICRST;
78 		regs->ACR &= ~FLASH_ACR_ICRST;
79 		regs->ACR |= FLASH_ACR_ICEN;
80 	}
81 }
82 
write_value(const struct device * dev,off_t offset,flash_prg_t val)83 static int write_value(const struct device *dev, off_t offset, flash_prg_t val)
84 {
85 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
86 #if defined(FLASH_OPTCR_DB1M)
87 	bool dcache_enabled = false;
88 #endif /* FLASH_OPTCR_DB*/
89 	uint32_t tmp;
90 	int rc;
91 
92 	/* if the control register is locked, do not fail silently */
93 	if (regs->CR & FLASH_CR_LOCK) {
94 		return -EIO;
95 	}
96 
97 	rc = flash_stm32_wait_flash_idle(dev);
98 	if (rc < 0) {
99 		return rc;
100 	}
101 
102 #if defined(FLASH_OPTCR_DB1M)
103 	/*
104 	 * Disable the data cache to avoid the silicon errata ES0206 Rev 16 2.2.12:
105 	 * "Data cache might be corrupted during Flash memory read-while-write operation"
106 	 */
107 	if (regs->ACR & FLASH_ACR_DCEN) {
108 		dcache_enabled = true;
109 		regs->ACR &= (~FLASH_ACR_DCEN);
110 	}
111 #endif /* FLASH_OPTCR_DB1M */
112 
113 	regs->CR &= CR_PSIZE_MASK;
114 	regs->CR |= FLASH_PROGRAM_SIZE;
115 	regs->CR |= FLASH_CR_PG;
116 
117 	/* flush the register write */
118 	tmp = regs->CR;
119 
120 	*((flash_prg_t *)(offset + FLASH_STM32_BASE_ADDRESS)) = val;
121 
122 	rc = flash_stm32_wait_flash_idle(dev);
123 	regs->CR &= (~FLASH_CR_PG);
124 
125 #if defined(FLASH_OPTCR_DB1M)
126 	/* Reset/enable the data cache if previously enabled */
127 	if (dcache_enabled) {
128 		regs->ACR |= FLASH_ACR_DCRST;
129 		regs->ACR &= (~FLASH_ACR_DCRST);
130 		regs->ACR |= FLASH_ACR_DCEN;
131 	}
132 #endif /* FLASH_OPTCR_DB1M */
133 
134 	return rc;
135 }
136 
erase_sector(const struct device * dev,uint32_t sector)137 static int erase_sector(const struct device *dev, uint32_t sector)
138 {
139 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
140 	uint32_t tmp;
141 	int rc;
142 
143 	/* if the control register is locked, do not fail silently */
144 	if (regs->CR & FLASH_CR_LOCK) {
145 		return -EIO;
146 	}
147 
148 	rc = flash_stm32_wait_flash_idle(dev);
149 	if (rc < 0) {
150 		return rc;
151 	}
152 
153 	/*
154 	 * If an erase operation in Flash memory also concerns data
155 	 * in the instruction cache, the user has to ensure that these data
156 	 * are rewritten before they are accessed during code execution.
157 	 */
158 	flush_cache(regs);
159 
160 #if FLASH_SECTOR_TOTAL == 24
161 	/*
162 	 * RM0090, §3.9.8: STM32F42xxx, STM32F43xxx
163 	 * RM0386, §3.7.5: STM32F469xx, STM32F479xx
164 	 */
165 	if (sector >= 12) {
166 		/* From sector 12, SNB is offset by 0b10000 */
167 		sector += 4U;
168 	}
169 #endif
170 
171 	regs->CR &= CR_PSIZE_MASK;
172 	regs->CR |= FLASH_PROGRAM_SIZE;
173 
174 	regs->CR &= ~FLASH_CR_SNB;
175 	regs->CR |= FLASH_CR_SER | (sector << 3);
176 	regs->CR |= FLASH_CR_STRT;
177 
178 	/* flush the register write */
179 	tmp = regs->CR;
180 
181 	rc = flash_stm32_wait_flash_idle(dev);
182 	regs->CR &= ~(FLASH_CR_SER | FLASH_CR_SNB);
183 
184 	return rc;
185 }
186 
flash_stm32_block_erase_loop(const struct device * dev,unsigned int offset,unsigned int len)187 int flash_stm32_block_erase_loop(const struct device *dev,
188 				 unsigned int offset,
189 				 unsigned int len)
190 {
191 	struct flash_pages_info info;
192 	uint32_t start_sector, end_sector;
193 	uint32_t i;
194 	int rc = 0;
195 
196 	rc = flash_get_page_info_by_offs(dev, offset, &info);
197 	if (rc) {
198 		return rc;
199 	}
200 	start_sector = info.index;
201 	rc = flash_get_page_info_by_offs(dev, offset + len - 1, &info);
202 	if (rc) {
203 		return rc;
204 	}
205 	end_sector = info.index;
206 
207 	for (i = start_sector; i <= end_sector; i++) {
208 		rc = erase_sector(dev, i);
209 		if (rc < 0) {
210 			break;
211 		}
212 	}
213 
214 	return rc;
215 }
216 
flash_stm32_write_range(const struct device * dev,unsigned int offset,const void * data,unsigned int len)217 int flash_stm32_write_range(const struct device *dev, unsigned int offset,
218 			    const void *data, unsigned int len)
219 {
220 	int i, rc = 0;
221 	flash_prg_t value;
222 
223 	for (i = 0; i < len / sizeof(flash_prg_t); i++) {
224 		value = UNALIGNED_GET((flash_prg_t *)data + i);
225 		rc = write_value(dev, offset + i * sizeof(flash_prg_t), value);
226 		if (rc < 0) {
227 			return rc;
228 		}
229 	}
230 
231 	return rc;
232 }
233 
flash_stm32_option_bytes_write(const struct device * dev,uint32_t mask,uint32_t value)234 int flash_stm32_option_bytes_write(const struct device *dev, uint32_t mask,
235 				   uint32_t value)
236 {
237 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
238 	int rc;
239 
240 	if (regs->OPTCR & FLASH_OPTCR_OPTLOCK) {
241 		return -EIO;
242 	}
243 
244 	if ((regs->OPTCR & mask) == value) {
245 		return 0;
246 	}
247 
248 	rc = flash_stm32_wait_flash_idle(dev);
249 	if (rc < 0) {
250 		return rc;
251 	}
252 
253 	regs->OPTCR = (regs->OPTCR & ~mask) | value;
254 	regs->OPTCR |= FLASH_OPTCR_OPTSTRT;
255 
256 	/* Make sure previous write is completed. */
257 	barrier_dsync_fence_full();
258 
259 	rc = flash_stm32_wait_flash_idle(dev);
260 	if (rc < 0) {
261 		return rc;
262 	}
263 
264 	return 0;
265 }
266 
flash_stm32_option_bytes_read(const struct device * dev)267 uint32_t flash_stm32_option_bytes_read(const struct device *dev)
268 {
269 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
270 
271 	return regs->OPTCR;
272 }
273 
274 #if defined(CONFIG_FLASH_STM32_WRITE_PROTECT)
flash_stm32_update_wp_sectors(const struct device * dev,uint64_t changed_sectors,uint64_t protected_sectors)275 int flash_stm32_update_wp_sectors(const struct device *dev,
276 				  uint64_t changed_sectors,
277 				  uint64_t protected_sectors)
278 {
279 	changed_sectors <<= FLASH_OPTCR_nWRP_Pos;
280 	protected_sectors <<= FLASH_OPTCR_nWRP_Pos;
281 
282 	if ((changed_sectors & FLASH_OPTCR_nWRP_Msk) != changed_sectors) {
283 		return -EINVAL;
284 	}
285 
286 	/* Sector is protected when bit == 0. Flip protected_sectors bits */
287 	protected_sectors = ~protected_sectors & changed_sectors;
288 
289 	return flash_stm32_option_bytes_write(dev, (uint32_t)changed_sectors,
290 					      (uint32_t)protected_sectors);
291 }
292 
flash_stm32_get_wp_sectors(const struct device * dev,uint64_t * protected_sectors)293 int flash_stm32_get_wp_sectors(const struct device *dev,
294 			       uint64_t *protected_sectors)
295 {
296 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
297 
298 	*protected_sectors =
299 		(~regs->OPTCR & FLASH_OPTCR_nWRP_Msk) >> FLASH_OPTCR_nWRP_Pos;
300 
301 	return 0;
302 }
303 #endif /* CONFIG_FLASH_STM32_WRITE_PROTECT */
304 
305 #if defined(CONFIG_FLASH_STM32_READOUT_PROTECTION)
flash_stm32_get_rdp_level(const struct device * dev)306 uint8_t flash_stm32_get_rdp_level(const struct device *dev)
307 {
308 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
309 
310 	return (regs->OPTCR & FLASH_OPTCR_RDP_Msk) >> FLASH_OPTCR_RDP_Pos;
311 }
312 
flash_stm32_set_rdp_level(const struct device * dev,uint8_t level)313 void flash_stm32_set_rdp_level(const struct device *dev, uint8_t level)
314 {
315 	flash_stm32_option_bytes_write(dev, FLASH_OPTCR_RDP_Msk,
316 				       (uint32_t)level << FLASH_OPTCR_RDP_Pos);
317 }
318 #endif /* CONFIG_FLASH_STM32_READOUT_PROTECTION */
319 
320 /*
321  * Different SoC flash layouts are specified in across various
322  * reference manuals, but the flash layout for a given number of
323  * sectors is consistent across these manuals, with one "gotcha". The
324  * number of sectors is given by the HAL as FLASH_SECTOR_TOTAL.
325  *
326  * The only "gotcha" is that when there are 24 sectors, they are split
327  * across 2 "banks" of 12 sectors each, with another set of small
328  * sectors (16 KB) in the second bank occurring after the large ones
329  * (128 KB) in the first. We could consider supporting this as two
330  * devices to make the layout cleaner, but this will do for now.
331  */
332 #ifndef FLASH_SECTOR_TOTAL
333 #error "Unknown flash layout"
334 #else  /* defined(FLASH_SECTOR_TOTAL) */
335 #if FLASH_SECTOR_TOTAL == 5
336 static const struct flash_pages_layout stm32f4_flash_layout[] = {
337 	/* RM0401, table 5: STM32F410Tx, STM32F410Cx, STM32F410Rx */
338 	{.pages_count = 4, .pages_size = KB(16)},
339 	{.pages_count = 1, .pages_size = KB(64)},
340 };
341 #elif FLASH_SECTOR_TOTAL == 6
342 static const struct flash_pages_layout stm32f4_flash_layout[] = {
343 	/* RM0368, table 5: STM32F401xC */
344 	{.pages_count = 4, .pages_size = KB(16)},
345 	{.pages_count = 1, .pages_size = KB(64)},
346 	{.pages_count = 1, .pages_size = KB(128)},
347 };
348 #elif FLASH_SECTOR_TOTAL == 8
349 static const struct flash_pages_layout stm32f4_flash_layout[] = {
350 	/*
351 	 * RM0368, table 5: STM32F401xE
352 	 * RM0383, table 4: STM32F411xE
353 	 * RM0390, table 4: STM32F446xx
354 	 */
355 	{.pages_count = 4, .pages_size = KB(16)},
356 	{.pages_count = 1, .pages_size = KB(64)},
357 	{.pages_count = 3, .pages_size = KB(128)},
358 };
359 #elif FLASH_SECTOR_TOTAL == 12
360 static const struct flash_pages_layout stm32f4_flash_layout[] = {
361 	/*
362 	 * RM0090, table 5: STM32F405xx, STM32F415xx, STM32F407xx, STM32F417xx
363 	 * RM0402, table 5: STM32F412Zx, STM32F412Vx, STM32F412Rx, STM32F412Cx
364 	 */
365 	{.pages_count = 4, .pages_size = KB(16)},
366 	{.pages_count = 1, .pages_size = KB(64)},
367 	{.pages_count = 7, .pages_size = KB(128)},
368 };
369 #elif FLASH_SECTOR_TOTAL == 16
370 static const struct flash_pages_layout stm32f4_flash_layout[] = {
371 	/* RM0430, table 5.: STM32F413xx, STM32F423xx */
372 	{.pages_count = 4, .pages_size = KB(16)},
373 	{.pages_count = 1, .pages_size = KB(64)},
374 	{.pages_count = 11, .pages_size = KB(128)},
375 };
376 #elif FLASH_SECTOR_TOTAL == 24
377 static const struct flash_pages_layout stm32f4_flash_layout[] = {
378 	/*
379 	 * RM0090, table 6: STM32F427xx, STM32F437xx, STM32F429xx, STM32F439xx
380 	 * RM0386, table 4: STM32F469xx, STM32F479xx
381 	 */
382 	{.pages_count = 4, .pages_size = KB(16)},
383 	{.pages_count = 1, .pages_size = KB(64)},
384 	{.pages_count = 7, .pages_size = KB(128)},
385 	{.pages_count = 4, .pages_size = KB(16)},
386 	{.pages_count = 1, .pages_size = KB(64)},
387 	{.pages_count = 7, .pages_size = KB(128)},
388 };
389 #else
390 #error "Unknown flash layout"
391 #endif /* FLASH_SECTOR_TOTAL == 5 */
392 #endif/* !defined(FLASH_SECTOR_TOTAL) */
393 
flash_stm32_page_layout(const struct device * dev,const struct flash_pages_layout ** layout,size_t * layout_size)394 void flash_stm32_page_layout(const struct device *dev,
395 			     const struct flash_pages_layout **layout,
396 			     size_t *layout_size)
397 {
398 	ARG_UNUSED(dev);
399 
400 	*layout = stm32f4_flash_layout;
401 	*layout_size = ARRAY_SIZE(stm32f4_flash_layout);
402 }
403