xref: /openbmc/linux/drivers/mtd/spi-nor/atmel.c (revision 479965a2)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2005, Intec Automation Inc.
4  * Copyright (C) 2014, Freescale Semiconductor, Inc.
5  */
6 
7 #include <linux/mtd/spi-nor.h>
8 
9 #include "core.h"
10 
11 #define ATMEL_SR_GLOBAL_PROTECT_MASK GENMASK(5, 2)
12 
13 /*
14  * The Atmel AT25FS010/AT25FS040 parts have some weird configuration for the
15  * block protection bits. We don't support them. But legacy behavior in linux
16  * is to unlock the whole flash array on startup. Therefore, we have to support
17  * exactly this operation.
18  */
19 static int at25fs_nor_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
20 {
21 	return -EOPNOTSUPP;
22 }
23 
24 static int at25fs_nor_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
25 {
26 	int ret;
27 
28 	/* We only support unlocking the whole flash array */
29 	if (ofs || len != nor->params->size)
30 		return -EINVAL;
31 
32 	/* Write 0x00 to the status register to disable write protection */
33 	ret = spi_nor_write_sr_and_check(nor, 0);
34 	if (ret)
35 		dev_dbg(nor->dev, "unable to clear BP bits, WP# asserted?\n");
36 
37 	return ret;
38 }
39 
40 static int at25fs_nor_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
41 {
42 	return -EOPNOTSUPP;
43 }
44 
45 static const struct spi_nor_locking_ops at25fs_nor_locking_ops = {
46 	.lock = at25fs_nor_lock,
47 	.unlock = at25fs_nor_unlock,
48 	.is_locked = at25fs_nor_is_locked,
49 };
50 
51 static int at25fs_nor_late_init(struct spi_nor *nor)
52 {
53 	nor->params->locking_ops = &at25fs_nor_locking_ops;
54 
55 	return 0;
56 }
57 
58 static const struct spi_nor_fixups at25fs_nor_fixups = {
59 	.late_init = at25fs_nor_late_init,
60 };
61 
62 /**
63  * atmel_nor_set_global_protection - Do a Global Protect or Unprotect command
64  * @nor:	pointer to 'struct spi_nor'
65  * @ofs:	offset in bytes
66  * @len:	len in bytes
67  * @is_protect:	if true do a Global Protect otherwise it is a Global Unprotect
68  *
69  * Return: 0 on success, -error otherwise.
70  */
71 static int atmel_nor_set_global_protection(struct spi_nor *nor, loff_t ofs,
72 					   uint64_t len, bool is_protect)
73 {
74 	int ret;
75 	u8 sr;
76 
77 	/* We only support locking the whole flash array */
78 	if (ofs || len != nor->params->size)
79 		return -EINVAL;
80 
81 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
82 	if (ret)
83 		return ret;
84 
85 	sr = nor->bouncebuf[0];
86 
87 	/* SRWD bit needs to be cleared, otherwise the protection doesn't change */
88 	if (sr & SR_SRWD) {
89 		sr &= ~SR_SRWD;
90 		ret = spi_nor_write_sr_and_check(nor, sr);
91 		if (ret) {
92 			dev_dbg(nor->dev, "unable to clear SRWD bit, WP# asserted?\n");
93 			return ret;
94 		}
95 	}
96 
97 	if (is_protect) {
98 		sr |= ATMEL_SR_GLOBAL_PROTECT_MASK;
99 		/*
100 		 * Set the SRWD bit again as soon as we are protecting
101 		 * anything. This will ensure that the WP# pin is working
102 		 * correctly. By doing this we also behave the same as
103 		 * spi_nor_sr_lock(), which sets SRWD if any block protection
104 		 * is active.
105 		 */
106 		sr |= SR_SRWD;
107 	} else {
108 		sr &= ~ATMEL_SR_GLOBAL_PROTECT_MASK;
109 	}
110 
111 	nor->bouncebuf[0] = sr;
112 
113 	/*
114 	 * We cannot use the spi_nor_write_sr_and_check() because this command
115 	 * isn't really setting any bits, instead it is an pseudo command for
116 	 * "Global Unprotect" or "Global Protect"
117 	 */
118 	return spi_nor_write_sr(nor, nor->bouncebuf, 1);
119 }
120 
121 static int atmel_nor_global_protect(struct spi_nor *nor, loff_t ofs,
122 				    uint64_t len)
123 {
124 	return atmel_nor_set_global_protection(nor, ofs, len, true);
125 }
126 
127 static int atmel_nor_global_unprotect(struct spi_nor *nor, loff_t ofs,
128 				      uint64_t len)
129 {
130 	return atmel_nor_set_global_protection(nor, ofs, len, false);
131 }
132 
133 static int atmel_nor_is_global_protected(struct spi_nor *nor, loff_t ofs,
134 					 uint64_t len)
135 {
136 	int ret;
137 
138 	if (ofs >= nor->params->size || (ofs + len) > nor->params->size)
139 		return -EINVAL;
140 
141 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
142 	if (ret)
143 		return ret;
144 
145 	return ((nor->bouncebuf[0] & ATMEL_SR_GLOBAL_PROTECT_MASK) == ATMEL_SR_GLOBAL_PROTECT_MASK);
146 }
147 
148 static const struct spi_nor_locking_ops atmel_nor_global_protection_ops = {
149 	.lock = atmel_nor_global_protect,
150 	.unlock = atmel_nor_global_unprotect,
151 	.is_locked = atmel_nor_is_global_protected,
152 };
153 
154 static int atmel_nor_global_protection_late_init(struct spi_nor *nor)
155 {
156 	nor->params->locking_ops = &atmel_nor_global_protection_ops;
157 
158 	return 0;
159 }
160 
161 static const struct spi_nor_fixups atmel_nor_global_protection_fixups = {
162 	.late_init = atmel_nor_global_protection_late_init,
163 };
164 
165 static const struct flash_info atmel_nor_parts[] = {
166 	/* Atmel -- some are (confusingly) marketed as "DataFlash" */
167 	{ "at25fs010",  INFO(0x1f6601, 0, 32 * 1024,   4)
168 		FLAGS(SPI_NOR_HAS_LOCK)
169 		NO_SFDP_FLAGS(SECT_4K)
170 		.fixups = &at25fs_nor_fixups },
171 	{ "at25fs040",  INFO(0x1f6604, 0, 64 * 1024,   8)
172 		FLAGS(SPI_NOR_HAS_LOCK)
173 		NO_SFDP_FLAGS(SECT_4K)
174 		.fixups = &at25fs_nor_fixups },
175 	{ "at25df041a", INFO(0x1f4401, 0, 64 * 1024,   8)
176 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
177 		NO_SFDP_FLAGS(SECT_4K)
178 		.fixups = &atmel_nor_global_protection_fixups },
179 	{ "at25df321",  INFO(0x1f4700, 0, 64 * 1024,  64)
180 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
181 		NO_SFDP_FLAGS(SECT_4K)
182 		.fixups = &atmel_nor_global_protection_fixups },
183 	{ "at25df321a", INFO(0x1f4701, 0, 64 * 1024,  64)
184 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
185 		NO_SFDP_FLAGS(SECT_4K)
186 		.fixups = &atmel_nor_global_protection_fixups },
187 	{ "at25df641",  INFO(0x1f4800, 0, 64 * 1024, 128)
188 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
189 		NO_SFDP_FLAGS(SECT_4K)
190 		.fixups = &atmel_nor_global_protection_fixups },
191 	{ "at25sl321",	INFO(0x1f4216, 0, 64 * 1024, 64)
192 		NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
193 	{ "at26f004",   INFO(0x1f0400, 0, 64 * 1024,  8)
194 		NO_SFDP_FLAGS(SECT_4K) },
195 	{ "at26df081a", INFO(0x1f4501, 0, 64 * 1024, 16)
196 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
197 		NO_SFDP_FLAGS(SECT_4K)
198 		.fixups = &atmel_nor_global_protection_fixups },
199 	{ "at26df161a", INFO(0x1f4601, 0, 64 * 1024, 32)
200 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
201 		NO_SFDP_FLAGS(SECT_4K)
202 		.fixups = &atmel_nor_global_protection_fixups },
203 	{ "at26df321",  INFO(0x1f4700, 0, 64 * 1024, 64)
204 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
205 		NO_SFDP_FLAGS(SECT_4K)
206 		.fixups = &atmel_nor_global_protection_fixups },
207 	{ "at45db081d", INFO(0x1f2500, 0, 64 * 1024, 16)
208 		NO_SFDP_FLAGS(SECT_4K) },
209 };
210 
211 const struct spi_nor_manufacturer spi_nor_atmel = {
212 	.name = "atmel",
213 	.parts = atmel_nor_parts,
214 	.nparts = ARRAY_SIZE(atmel_nor_parts),
215 };
216