xref: /openbmc/linux/drivers/mtd/spi-nor/atmel.c (revision 9a29f5fc)
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 void at25fs_nor_late_init(struct spi_nor *nor)
52 {
53 	nor->params->locking_ops = &at25fs_nor_locking_ops;
54 }
55 
56 static const struct spi_nor_fixups at25fs_nor_fixups = {
57 	.late_init = at25fs_nor_late_init,
58 };
59 
60 /**
61  * atmel_nor_set_global_protection - Do a Global Protect or Unprotect command
62  * @nor:	pointer to 'struct spi_nor'
63  * @ofs:	offset in bytes
64  * @len:	len in bytes
65  * @is_protect:	if true do a Global Protect otherwise it is a Global Unprotect
66  *
67  * Return: 0 on success, -error otherwise.
68  */
69 static int atmel_nor_set_global_protection(struct spi_nor *nor, loff_t ofs,
70 					   uint64_t len, bool is_protect)
71 {
72 	int ret;
73 	u8 sr;
74 
75 	/* We only support locking the whole flash array */
76 	if (ofs || len != nor->params->size)
77 		return -EINVAL;
78 
79 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
80 	if (ret)
81 		return ret;
82 
83 	sr = nor->bouncebuf[0];
84 
85 	/* SRWD bit needs to be cleared, otherwise the protection doesn't change */
86 	if (sr & SR_SRWD) {
87 		sr &= ~SR_SRWD;
88 		ret = spi_nor_write_sr_and_check(nor, sr);
89 		if (ret) {
90 			dev_dbg(nor->dev, "unable to clear SRWD bit, WP# asserted?\n");
91 			return ret;
92 		}
93 	}
94 
95 	if (is_protect) {
96 		sr |= ATMEL_SR_GLOBAL_PROTECT_MASK;
97 		/*
98 		 * Set the SRWD bit again as soon as we are protecting
99 		 * anything. This will ensure that the WP# pin is working
100 		 * correctly. By doing this we also behave the same as
101 		 * spi_nor_sr_lock(), which sets SRWD if any block protection
102 		 * is active.
103 		 */
104 		sr |= SR_SRWD;
105 	} else {
106 		sr &= ~ATMEL_SR_GLOBAL_PROTECT_MASK;
107 	}
108 
109 	nor->bouncebuf[0] = sr;
110 
111 	/*
112 	 * We cannot use the spi_nor_write_sr_and_check() because this command
113 	 * isn't really setting any bits, instead it is an pseudo command for
114 	 * "Global Unprotect" or "Global Protect"
115 	 */
116 	return spi_nor_write_sr(nor, nor->bouncebuf, 1);
117 }
118 
119 static int atmel_nor_global_protect(struct spi_nor *nor, loff_t ofs,
120 				    uint64_t len)
121 {
122 	return atmel_nor_set_global_protection(nor, ofs, len, true);
123 }
124 
125 static int atmel_nor_global_unprotect(struct spi_nor *nor, loff_t ofs,
126 				      uint64_t len)
127 {
128 	return atmel_nor_set_global_protection(nor, ofs, len, false);
129 }
130 
131 static int atmel_nor_is_global_protected(struct spi_nor *nor, loff_t ofs,
132 					 uint64_t len)
133 {
134 	int ret;
135 
136 	if (ofs >= nor->params->size || (ofs + len) > nor->params->size)
137 		return -EINVAL;
138 
139 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
140 	if (ret)
141 		return ret;
142 
143 	return ((nor->bouncebuf[0] & ATMEL_SR_GLOBAL_PROTECT_MASK) == ATMEL_SR_GLOBAL_PROTECT_MASK);
144 }
145 
146 static const struct spi_nor_locking_ops atmel_nor_global_protection_ops = {
147 	.lock = atmel_nor_global_protect,
148 	.unlock = atmel_nor_global_unprotect,
149 	.is_locked = atmel_nor_is_global_protected,
150 };
151 
152 static void atmel_nor_global_protection_late_init(struct spi_nor *nor)
153 {
154 	nor->params->locking_ops = &atmel_nor_global_protection_ops;
155 }
156 
157 static const struct spi_nor_fixups atmel_nor_global_protection_fixups = {
158 	.late_init = atmel_nor_global_protection_late_init,
159 };
160 
161 static const struct flash_info atmel_nor_parts[] = {
162 	/* Atmel -- some are (confusingly) marketed as "DataFlash" */
163 	{ "at25fs010",  INFO(0x1f6601, 0, 32 * 1024,   4)
164 		FLAGS(SPI_NOR_HAS_LOCK)
165 		NO_SFDP_FLAGS(SECT_4K)
166 		.fixups = &at25fs_nor_fixups },
167 	{ "at25fs040",  INFO(0x1f6604, 0, 64 * 1024,   8)
168 		FLAGS(SPI_NOR_HAS_LOCK)
169 		NO_SFDP_FLAGS(SECT_4K)
170 		.fixups = &at25fs_nor_fixups },
171 	{ "at25df041a", INFO(0x1f4401, 0, 64 * 1024,   8)
172 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
173 		NO_SFDP_FLAGS(SECT_4K)
174 		.fixups = &atmel_nor_global_protection_fixups },
175 	{ "at25df321",  INFO(0x1f4700, 0, 64 * 1024,  64)
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 	{ "at25df321a", INFO(0x1f4701, 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 	{ "at25df641",  INFO(0x1f4800, 0, 64 * 1024, 128)
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 	{ "at25sl321",	INFO(0x1f4216, 0, 64 * 1024, 64)
188 		NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
189 	{ "at26f004",   INFO(0x1f0400, 0, 64 * 1024,  8)
190 		NO_SFDP_FLAGS(SECT_4K) },
191 	{ "at26df081a", INFO(0x1f4501, 0, 64 * 1024, 16)
192 		FLAGS(SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
193 		NO_SFDP_FLAGS(SECT_4K)
194 		.fixups = &atmel_nor_global_protection_fixups },
195 	{ "at26df161a", INFO(0x1f4601, 0, 64 * 1024, 32)
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 	{ "at26df321",  INFO(0x1f4700, 0, 64 * 1024, 64)
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 	{ "at45db081d", INFO(0x1f2500, 0, 64 * 1024, 16)
204 		NO_SFDP_FLAGS(SECT_4K) },
205 };
206 
207 const struct spi_nor_manufacturer spi_nor_atmel = {
208 	.name = "atmel",
209 	.parts = atmel_nor_parts,
210 	.nparts = ARRAY_SIZE(atmel_nor_parts),
211 };
212