xref: /openbmc/linux/drivers/mtd/spi-nor/atmel.c (revision b4e18b29)
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 atmel_at25fs_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
20 {
21 	return -EOPNOTSUPP;
22 }
23 
24 static int atmel_at25fs_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 atmel_at25fs_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 atmel_at25fs_locking_ops = {
46 	.lock = atmel_at25fs_lock,
47 	.unlock = atmel_at25fs_unlock,
48 	.is_locked = atmel_at25fs_is_locked,
49 };
50 
51 static void atmel_at25fs_default_init(struct spi_nor *nor)
52 {
53 	nor->params->locking_ops = &atmel_at25fs_locking_ops;
54 }
55 
56 static const struct spi_nor_fixups atmel_at25fs_fixups = {
57 	.default_init = atmel_at25fs_default_init,
58 };
59 
60 /**
61  * atmel_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_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_global_protect(struct spi_nor *nor, loff_t ofs, uint64_t len)
120 {
121 	return atmel_set_global_protection(nor, ofs, len, true);
122 }
123 
124 static int atmel_global_unprotect(struct spi_nor *nor, loff_t ofs, uint64_t len)
125 {
126 	return atmel_set_global_protection(nor, ofs, len, false);
127 }
128 
129 static int atmel_is_global_protected(struct spi_nor *nor, loff_t ofs, uint64_t len)
130 {
131 	int ret;
132 
133 	if (ofs >= nor->params->size || (ofs + len) > nor->params->size)
134 		return -EINVAL;
135 
136 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
137 	if (ret)
138 		return ret;
139 
140 	return ((nor->bouncebuf[0] & ATMEL_SR_GLOBAL_PROTECT_MASK) == ATMEL_SR_GLOBAL_PROTECT_MASK);
141 }
142 
143 static const struct spi_nor_locking_ops atmel_global_protection_ops = {
144 	.lock = atmel_global_protect,
145 	.unlock = atmel_global_unprotect,
146 	.is_locked = atmel_is_global_protected,
147 };
148 
149 static void atmel_global_protection_default_init(struct spi_nor *nor)
150 {
151 	nor->params->locking_ops = &atmel_global_protection_ops;
152 }
153 
154 static const struct spi_nor_fixups atmel_global_protection_fixups = {
155 	.default_init = atmel_global_protection_default_init,
156 };
157 
158 static const struct flash_info atmel_parts[] = {
159 	/* Atmel -- some are (confusingly) marketed as "DataFlash" */
160 	{ "at25fs010",  INFO(0x1f6601, 0, 32 * 1024,   4, SECT_4K | SPI_NOR_HAS_LOCK)
161 		.fixups = &atmel_at25fs_fixups },
162 	{ "at25fs040",  INFO(0x1f6604, 0, 64 * 1024,   8, SECT_4K | SPI_NOR_HAS_LOCK)
163 		.fixups = &atmel_at25fs_fixups },
164 
165 	{ "at25df041a", INFO(0x1f4401, 0, 64 * 1024,   8,
166 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
167 			.fixups = &atmel_global_protection_fixups },
168 	{ "at25df321",  INFO(0x1f4700, 0, 64 * 1024,  64,
169 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
170 			.fixups = &atmel_global_protection_fixups },
171 	{ "at25df321a", INFO(0x1f4701, 0, 64 * 1024,  64,
172 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
173 			.fixups = &atmel_global_protection_fixups },
174 	{ "at25df641",  INFO(0x1f4800, 0, 64 * 1024, 128,
175 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
176 			.fixups = &atmel_global_protection_fixups },
177 
178 	{ "at25sl321",	INFO(0x1f4216, 0, 64 * 1024, 64,
179 			     SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
180 
181 	{ "at26f004",   INFO(0x1f0400, 0, 64 * 1024,  8, SECT_4K) },
182 	{ "at26df081a", INFO(0x1f4501, 0, 64 * 1024, 16,
183 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
184 			.fixups = &atmel_global_protection_fixups },
185 	{ "at26df161a", INFO(0x1f4601, 0, 64 * 1024, 32,
186 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
187 			.fixups = &atmel_global_protection_fixups },
188 	{ "at26df321",  INFO(0x1f4700, 0, 64 * 1024, 64,
189 			     SECT_4K | SPI_NOR_HAS_LOCK | SPI_NOR_SWP_IS_VOLATILE)
190 			.fixups = &atmel_global_protection_fixups },
191 
192 	{ "at45db081d", INFO(0x1f2500, 0, 64 * 1024, 16, SECT_4K) },
193 };
194 
195 const struct spi_nor_manufacturer spi_nor_atmel = {
196 	.name = "atmel",
197 	.parts = atmel_parts,
198 	.nparts = ARRAY_SIZE(atmel_parts),
199 };
200