1 /*
2  * Copyright (c) 2021 STMicroelectronics
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #include <zephyr/kernel.h>
8 #include <zephyr/device.h>
9 #include <string.h>
10 #include <zephyr/drivers/flash.h>
11 #include <zephyr/init.h>
12 #include <soc.h>
13 
14 #include "flash_stm32.h"
15 
flash_stm32_valid_range(const struct device * dev,off_t offset,uint32_t len,bool write)16 bool flash_stm32_valid_range(const struct device *dev, off_t offset,
17 			     uint32_t len,
18 			     bool write)
19 {
20 	ARG_UNUSED(write);
21 
22 	return flash_stm32_range_exists(dev, offset, len);
23 }
24 
flush_cache(FLASH_TypeDef * regs)25 static inline void flush_cache(FLASH_TypeDef *regs)
26 {
27 	/* If Data cache is enabled, disable Data cache, reset Data cache
28 	 * and then re-enable Data cache.
29 	 */
30 	if (regs->ACR & FLASH_ACR_DCEN) {
31 		regs->ACR &= ~FLASH_ACR_DCEN;
32 		/* Datasheet: DCRST: Data cache reset
33 		 * This bit can be written only when the Data cache is disabled
34 		 */
35 		regs->ACR |= FLASH_ACR_DCRST;
36 		regs->ACR &= ~FLASH_ACR_DCRST;
37 		regs->ACR |= FLASH_ACR_DCEN;
38 	}
39 
40 	/* If Instruction cache is enabled, disable Instruction cache, reset
41 	 * Instruction cache and then re-enable Instruction cache.
42 	 */
43 	if (regs->ACR & FLASH_ACR_ICEN) {
44 		regs->ACR &= ~FLASH_ACR_ICEN;
45 		/* Datasheet: ICRST: Instruction cache reset
46 		 * This bit can be written only when the Instruction cache
47 		 * is disabled
48 		 */
49 		regs->ACR |= FLASH_ACR_ICRST;
50 		regs->ACR &= ~FLASH_ACR_ICRST;
51 		regs->ACR |= FLASH_ACR_ICEN;
52 	}
53 }
54 
write_byte(const struct device * dev,off_t offset,uint8_t val)55 static int write_byte(const struct device *dev, off_t offset, uint8_t val)
56 {
57 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
58 	uint32_t tmp;
59 	int rc;
60 
61 	/* if the control register is locked, do not fail silently */
62 	if (regs->CR & FLASH_CR_LOCK) {
63 		return -EIO;
64 	}
65 
66 	/* Check that no Flash main memory operation is ongoing */
67 	rc = flash_stm32_wait_flash_idle(dev);
68 	if (rc < 0) {
69 		return rc;
70 	}
71 
72 	regs->CR &= ~FLASH_CR_PSIZE;
73 	regs->CR |= FLASH_PSIZE_BYTE;
74 	regs->CR |= FLASH_CR_PG;
75 
76 	/* flush the register write */
77 	tmp = regs->CR;
78 
79 	*((uint8_t *) offset + CONFIG_FLASH_BASE_ADDRESS) = val;
80 
81 	/* Wait until the BSY bit is cleared */
82 	rc = flash_stm32_wait_flash_idle(dev);
83 
84 	/* Clear the PG bit */
85 	regs->CR &= (~FLASH_CR_PG);
86 
87 	return rc;
88 }
89 
erase_sector(const struct device * dev,uint32_t sector)90 static int erase_sector(const struct device *dev, uint32_t sector)
91 {
92 	FLASH_TypeDef *regs = FLASH_STM32_REGS(dev);
93 	uint32_t tmp;
94 	int rc;
95 
96 	/* if the control register is locked, do not fail silently */
97 	if (regs->CR & FLASH_CR_LOCK) {
98 		return -EIO;
99 	}
100 
101 	/* Check that no Flash memory operation is ongoing */
102 	rc = flash_stm32_wait_flash_idle(dev);
103 	if (rc < 0) {
104 		return rc;
105 	}
106 
107 	regs->CR &= ~FLASH_CR_SNB;
108 	regs->CR |= FLASH_CR_SER | (sector << 3);
109 	regs->CR |= FLASH_CR_STRT;
110 
111 	/* flush the register write */
112 	tmp = regs->CR;
113 
114 	/* Wait for the BSY bit */
115 	rc = flash_stm32_wait_flash_idle(dev);
116 
117 	flush_cache(regs);
118 
119 	regs->CR &= ~(FLASH_CR_SER | FLASH_CR_SNB);
120 
121 	return rc;
122 }
123 
flash_stm32_block_erase_loop(const struct device * dev,unsigned int offset,unsigned int len)124 int flash_stm32_block_erase_loop(const struct device *dev,
125 				 unsigned int offset,
126 				 unsigned int len)
127 {
128 	struct flash_pages_info info;
129 	uint32_t start_sector, end_sector;
130 	uint32_t i;
131 	int rc = 0;
132 
133 	rc = flash_get_page_info_by_offs(dev, offset, &info);
134 	if (rc) {
135 		return rc;
136 	}
137 	start_sector = info.index;
138 	rc = flash_get_page_info_by_offs(dev, offset + len - 1, &info);
139 	if (rc) {
140 		return rc;
141 	}
142 	end_sector = info.index;
143 
144 	for (i = start_sector; i <= end_sector; i++) {
145 		rc = erase_sector(dev, i);
146 		if (rc < 0) {
147 			break;
148 		}
149 	}
150 
151 	return rc;
152 }
153 
flash_stm32_write_range(const struct device * dev,unsigned int offset,const void * data,unsigned int len)154 int flash_stm32_write_range(const struct device *dev, unsigned int offset,
155 			    const void *data, unsigned int len)
156 {
157 	int i, rc = 0;
158 
159 	for (i = 0; i < len; i++, offset++) {
160 		rc = write_byte(dev, offset, ((const uint8_t *) data)[i]);
161 		if (rc < 0) {
162 			return rc;
163 		}
164 	}
165 
166 	return rc;
167 }
168 
169 /*
170  * The flash memory in stm32f2 series has bank 1 only with 12 sectors,
171  * they are split as 4 sectors of 16 Kbytes, 1 sector of 64 Kbytes,
172  * and 7 sectors of 128 Kbytes.
173  */
174 #ifndef FLASH_SECTOR_TOTAL
175 #error "Unknown flash layout"
176 #else  /* defined(FLASH_SECTOR_TOTAL) */
177 #if FLASH_SECTOR_TOTAL == 12
178 static const struct flash_pages_layout stm32f2_flash_layout[] = {
179 	/*
180 	 * PM0059, table 10: STM32F207xx
181 	 */
182 	{.pages_count = 4, .pages_size = KB(16)},
183 	{.pages_count = 1, .pages_size = KB(64)},
184 	{.pages_count = 7, .pages_size = KB(128)},
185 };
186 #else
187 #error "Unknown flash layout"
188 #endif /* FLASH_SECTOR_TOTAL == 12 */
189 #endif/* !defined(FLASH_SECTOR_TOTAL) */
190 
flash_stm32_page_layout(const struct device * dev,const struct flash_pages_layout ** layout,size_t * layout_size)191 void flash_stm32_page_layout(const struct device *dev,
192 			     const struct flash_pages_layout **layout,
193 			     size_t *layout_size)
194 {
195 	ARG_UNUSED(dev);
196 
197 	*layout = stm32f2_flash_layout;
198 	*layout_size = ARRAY_SIZE(stm32f2_flash_layout);
199 }
200