2 * MTD SPI driver for ST M25Pxx (and similar) serial flash chips
4 * Author: Mike Lavender, mike@steroidmicros.com
6 * Copyright (c) 2005, Intec Automation Inc.
8 * Some parts are based on lart.c by Abraham Van Der Merwe
10 * Cleaned up and generalized based on mtd_dataflash.c
12 * This code is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
18 #include <linux/err.h>
19 #include <linux/errno.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/partitions.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/flash.h>
28 #include <linux/mtd/spi-nor.h>
30 #define MAX_CMD_SIZE 6
32 struct spi_device *spi;
33 struct spi_nor spi_nor;
34 u8 command[MAX_CMD_SIZE];
37 static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
39 struct m25p *flash = nor->priv;
40 struct spi_device *spi = flash->spi;
43 ret = spi_write_then_read(spi, &code, 1, val, len);
45 dev_err(&spi->dev, "error %d reading %x\n", ret, code);
50 static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
52 /* opcode is in cmd[0] */
53 cmd[1] = addr >> (nor->addr_width * 8 - 8);
54 cmd[2] = addr >> (nor->addr_width * 8 - 16);
55 cmd[3] = addr >> (nor->addr_width * 8 - 24);
56 cmd[4] = addr >> (nor->addr_width * 8 - 32);
59 static int m25p_cmdsz(struct spi_nor *nor)
61 return 1 + nor->addr_width;
64 static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
66 struct m25p *flash = nor->priv;
67 struct spi_device *spi = flash->spi;
69 flash->command[0] = opcode;
71 memcpy(&flash->command[1], buf, len);
73 return spi_write(spi, flash->command, len + 1);
76 static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
79 struct m25p *flash = nor->priv;
80 struct spi_device *spi = flash->spi;
81 struct spi_transfer t[2] = {};
83 int cmd_sz = m25p_cmdsz(nor);
88 if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
91 flash->command[0] = nor->program_opcode;
92 m25p_addr2cmd(nor, to, flash->command);
94 t[0].tx_buf = flash->command;
96 spi_message_add_tail(&t[0], &m);
100 spi_message_add_tail(&t[1], &m);
102 ret = spi_sync(spi, &m);
106 ret = m.actual_length - cmd_sz;
112 static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
114 return spi_nor_get_protocol_data_nbits(nor->read_proto);
118 * Read an address range from the nor chip. The address range
119 * may be any size provided it is within the physical boundaries.
121 static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
124 struct m25p *flash = nor->priv;
125 struct spi_device *spi = flash->spi;
126 struct spi_transfer t[2];
127 struct spi_message m;
128 unsigned int dummy = nor->read_dummy;
131 /* convert the dummy cycles to the number of bytes */
134 if (spi_flash_read_supported(spi)) {
135 struct spi_flash_read_message msg;
137 memset(&msg, 0, sizeof(msg));
142 msg.read_opcode = nor->read_opcode;
143 msg.addr_width = nor->addr_width;
144 msg.dummy_bytes = dummy;
145 /* TODO: Support other combinations */
146 msg.opcode_nbits = SPI_NBITS_SINGLE;
147 msg.addr_nbits = SPI_NBITS_SINGLE;
148 msg.data_nbits = m25p80_rx_nbits(nor);
150 ret = spi_flash_read(spi, &msg);
156 spi_message_init(&m);
157 memset(t, 0, (sizeof t));
159 flash->command[0] = nor->read_opcode;
160 m25p_addr2cmd(nor, from, flash->command);
162 t[0].tx_buf = flash->command;
163 t[0].len = m25p_cmdsz(nor) + dummy;
164 spi_message_add_tail(&t[0], &m);
167 t[1].rx_nbits = m25p80_rx_nbits(nor);
168 t[1].len = min3(len, spi_max_transfer_size(spi),
169 spi_max_message_size(spi) - t[0].len);
170 spi_message_add_tail(&t[1], &m);
172 ret = spi_sync(spi, &m);
176 ret = m.actual_length - m25p_cmdsz(nor) - dummy;
183 * board specific setup should have ensured the SPI clock used here
184 * matches what the READ command supports, at least until this driver
185 * understands FAST_READ (for clocks over 25 MHz).
187 static int m25p_probe(struct spi_device *spi)
189 struct flash_platform_data *data;
192 struct spi_nor_hwcaps hwcaps = {
193 .mask = SNOR_HWCAPS_READ |
194 SNOR_HWCAPS_READ_FAST |
200 data = dev_get_platdata(&spi->dev);
202 flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
206 nor = &flash->spi_nor;
208 /* install the hooks */
209 nor->read = m25p80_read;
210 nor->write = m25p80_write;
211 nor->write_reg = m25p80_write_reg;
212 nor->read_reg = m25p80_read_reg;
214 nor->dev = &spi->dev;
215 spi_nor_set_flash_node(nor, spi->dev.of_node);
218 spi_set_drvdata(spi, flash);
221 if (spi->mode & SPI_RX_QUAD)
222 hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
223 else if (spi->mode & SPI_RX_DUAL)
224 hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
226 if (data && data->name)
227 nor->mtd.name = data->name;
229 /* For some (historical?) reason many platforms provide two different
230 * names in flash_platform_data: "name" and "type". Quite often name is
231 * set to "m25p80" and then "type" provides a real chip name.
232 * If that's the case, respect "type" and ignore a "name".
234 if (data && data->type)
235 flash_name = data->type;
236 else if (!strcmp(spi->modalias, "spi-nor"))
237 flash_name = NULL; /* auto-detect */
239 flash_name = spi->modalias;
241 ret = spi_nor_scan(nor, flash_name, &hwcaps);
245 return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
246 data ? data->nr_parts : 0);
250 static int m25p_remove(struct spi_device *spi)
252 struct m25p *flash = spi_get_drvdata(spi);
254 /* Clean up MTD stuff. */
255 return mtd_device_unregister(&flash->spi_nor.mtd);
259 * Do NOT add to this array without reading the following:
261 * Historically, many flash devices are bound to this driver by their name. But
262 * since most of these flash are compatible to some extent, and their
263 * differences can often be differentiated by the JEDEC read-ID command, we
264 * encourage new users to add support to the spi-nor library, and simply bind
265 * against a generic string here (e.g., "jedec,spi-nor").
267 * Many flash names are kept here in this list (as well as in spi-nor.c) to
268 * keep them available as module aliases for existing platforms.
270 static const struct spi_device_id m25p_ids[] = {
272 * Allow non-DT platform devices to bind to the "spi-nor" modalias, and
273 * hack around the fact that the SPI core does not provide uevent
274 * matching for .of_match_table
279 * Entries not used in DTs that should be safe to drop after replacing
280 * them with "spi-nor" in platform data.
282 {"s25sl064a"}, {"w25x16"}, {"m25p10"}, {"m25px64"},
285 * Entries that were used in DTs without "jedec,spi-nor" fallback and
286 * should be kept for backward compatibility.
288 {"at25df321a"}, {"at25df641"}, {"at26df081a"},
289 {"mx25l4005a"}, {"mx25l1606e"}, {"mx25l6405d"}, {"mx25l12805d"},
290 {"mx25l25635e"},{"mx66l51235l"},
291 {"n25q064"}, {"n25q128a11"}, {"n25q128a13"}, {"n25q512a"},
292 {"s25fl256s1"}, {"s25fl512s"}, {"s25sl12801"}, {"s25fl008k"},
294 {"sst25vf040b"},{"sst25vf016b"},{"sst25vf032b"},{"sst25wf040"},
295 {"m25p40"}, {"m25p80"}, {"m25p16"}, {"m25p32"},
296 {"m25p64"}, {"m25p128"},
297 {"w25x80"}, {"w25x32"}, {"w25q32"}, {"w25q32dw"},
298 {"w25q80bl"}, {"w25q128"}, {"w25q256"},
300 /* Flashes that can't be detected using JEDEC */
301 {"m25p05-nonjedec"}, {"m25p10-nonjedec"}, {"m25p20-nonjedec"},
302 {"m25p40-nonjedec"}, {"m25p80-nonjedec"}, {"m25p16-nonjedec"},
303 {"m25p32-nonjedec"}, {"m25p64-nonjedec"}, {"m25p128-nonjedec"},
305 /* Everspin MRAMs (non-JEDEC) */
306 { "mr25h256" }, /* 256 Kib, 40 MHz */
307 { "mr25h10" }, /* 1 Mib, 40 MHz */
308 { "mr25h40" }, /* 4 Mib, 40 MHz */
312 MODULE_DEVICE_TABLE(spi, m25p_ids);
314 static const struct of_device_id m25p_of_table[] = {
316 * Generic compatibility for SPI NOR that can be identified by the
317 * JEDEC READ ID opcode (0x9F). Use this, if possible.
319 { .compatible = "jedec,spi-nor" },
322 MODULE_DEVICE_TABLE(of, m25p_of_table);
324 static struct spi_driver m25p80_driver = {
327 .of_match_table = m25p_of_table,
329 .id_table = m25p_ids,
331 .remove = m25p_remove,
333 /* REVISIT: many of these chips have deep power-down modes, which
334 * should clearly be entered on suspend() to minimize power use.
335 * And also when they're otherwise idle...
339 module_spi_driver(m25p80_driver);
341 MODULE_LICENSE("GPL");
342 MODULE_AUTHOR("Mike Lavender");
343 MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");