4 * Driver for SST25L SPI Flash chips
6 * Copyright © 2009 Bluewater Systems Ltd
7 * Author: Andre Renaud <andre@bluewatersys.com>
8 * Author: Ryan Mallon <ryan@bluewatersys.com>
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/init.h>
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/mutex.h>
22 #include <linux/interrupt.h>
23 #include <linux/slab.h>
24 #include <linux/sched.h>
26 #include <linux/mtd/mtd.h>
27 #include <linux/mtd/partitions.h>
29 #include <linux/spi/spi.h>
30 #include <linux/spi/flash.h>
32 /* Erases can take up to 3 seconds! */
33 #define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
35 #define SST25L_CMD_WRSR 0x01 /* Write status register */
36 #define SST25L_CMD_WRDI 0x04 /* Write disable */
37 #define SST25L_CMD_RDSR 0x05 /* Read status register */
38 #define SST25L_CMD_WREN 0x06 /* Write enable */
39 #define SST25L_CMD_READ 0x03 /* High speed read */
41 #define SST25L_CMD_EWSR 0x50 /* Enable write status register */
42 #define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */
43 #define SST25L_CMD_READ_ID 0x90 /* Read device ID */
44 #define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */
46 #define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */
47 #define SST25L_STATUS_WREN (1 << 1) /* Write enabled */
48 #define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */
49 #define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */
52 struct spi_device *spi;
67 #define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
69 static struct flash_info __initdata sst25l_flash_info[] = {
70 {"sst25lf020a", 0xbf43, 256, 1024, 4096},
71 {"sst25lf040a", 0xbf44, 256, 2048, 4096},
74 static int sst25l_status(struct sst25l_flash *flash, int *status)
77 struct spi_transfer t;
78 unsigned char cmd_resp[2];
82 memset(&t, 0, sizeof(struct spi_transfer));
84 cmd_resp[0] = SST25L_CMD_RDSR;
88 t.len = sizeof(cmd_resp);
89 spi_message_add_tail(&t, &m);
90 err = spi_sync(flash->spi, &m);
94 *status = cmd_resp[1];
98 static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
100 unsigned char command[2];
103 command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
104 err = spi_write(flash->spi, command, 1);
108 command[0] = SST25L_CMD_EWSR;
109 err = spi_write(flash->spi, command, 1);
113 command[0] = SST25L_CMD_WRSR;
114 command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1;
115 err = spi_write(flash->spi, command, 2);
120 err = sst25l_status(flash, &status);
123 if (!(status & SST25L_STATUS_WREN))
130 static int sst25l_wait_till_ready(struct sst25l_flash *flash)
132 unsigned long deadline;
135 deadline = jiffies + MAX_READY_WAIT_JIFFIES;
137 err = sst25l_status(flash, &status);
140 if (!(status & SST25L_STATUS_BUSY))
144 } while (!time_after_eq(jiffies, deadline));
149 static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
151 unsigned char command[4];
154 err = sst25l_write_enable(flash, 1);
158 command[0] = SST25L_CMD_SECTOR_ERASE;
159 command[1] = offset >> 16;
160 command[2] = offset >> 8;
162 err = spi_write(flash->spi, command, 4);
166 err = sst25l_wait_till_ready(flash);
170 return sst25l_write_enable(flash, 0);
173 static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
175 struct sst25l_flash *flash = to_sst25l_flash(mtd);
180 if (instr->addr + instr->len > flash->mtd.size)
183 if ((uint32_t)instr->len % mtd->erasesize)
186 if ((uint32_t)instr->addr % mtd->erasesize)
190 end = addr + instr->len;
192 mutex_lock(&flash->lock);
194 err = sst25l_wait_till_ready(flash);
196 mutex_unlock(&flash->lock);
201 err = sst25l_erase_sector(flash, addr);
203 mutex_unlock(&flash->lock);
204 instr->state = MTD_ERASE_FAILED;
205 dev_err(&flash->spi->dev, "Erase failed\n");
209 addr += mtd->erasesize;
212 mutex_unlock(&flash->lock);
214 instr->state = MTD_ERASE_DONE;
215 mtd_erase_callback(instr);
219 static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
220 size_t *retlen, unsigned char *buf)
222 struct sst25l_flash *flash = to_sst25l_flash(mtd);
223 struct spi_transfer transfer[2];
224 struct spi_message message;
225 unsigned char command[4];
228 /* Sanity checking */
232 if (from + len > flash->mtd.size)
238 spi_message_init(&message);
239 memset(&transfer, 0, sizeof(transfer));
241 command[0] = SST25L_CMD_READ;
242 command[1] = from >> 16;
243 command[2] = from >> 8;
246 transfer[0].tx_buf = command;
247 transfer[0].len = sizeof(command);
248 spi_message_add_tail(&transfer[0], &message);
250 transfer[1].rx_buf = buf;
251 transfer[1].len = len;
252 spi_message_add_tail(&transfer[1], &message);
254 mutex_lock(&flash->lock);
256 /* Wait for previous write/erase to complete */
257 ret = sst25l_wait_till_ready(flash);
259 mutex_unlock(&flash->lock);
263 spi_sync(flash->spi, &message);
265 if (retlen && message.actual_length > sizeof(command))
266 *retlen += message.actual_length - sizeof(command);
268 mutex_unlock(&flash->lock);
272 static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
273 size_t *retlen, const unsigned char *buf)
275 struct sst25l_flash *flash = to_sst25l_flash(mtd);
276 int i, j, ret, bytes, copied = 0;
277 unsigned char command[5];
283 if (to + len > flash->mtd.size)
286 if ((uint32_t)to % mtd->writesize)
289 mutex_lock(&flash->lock);
291 ret = sst25l_write_enable(flash, 1);
295 for (i = 0; i < len; i += mtd->writesize) {
296 ret = sst25l_wait_till_ready(flash);
300 /* Write the first byte of the page */
301 command[0] = SST25L_CMD_AAI_PROGRAM;
302 command[1] = (to + i) >> 16;
303 command[2] = (to + i) >> 8;
304 command[3] = (to + i);
306 ret = spi_write(flash->spi, command, 5);
312 * Write the remaining bytes using auto address
315 bytes = min_t(uint32_t, mtd->writesize, len - i);
316 for (j = 1; j < bytes; j++, copied++) {
317 ret = sst25l_wait_till_ready(flash);
321 command[1] = buf[i + j];
322 ret = spi_write(flash->spi, command, 2);
329 ret = sst25l_write_enable(flash, 0);
334 mutex_unlock(&flash->lock);
338 static struct flash_info *__devinit sst25l_match_device(struct spi_device *spi)
340 struct flash_info *flash_info = NULL;
341 struct spi_message m;
342 struct spi_transfer t;
343 unsigned char cmd_resp[6];
347 spi_message_init(&m);
348 memset(&t, 0, sizeof(struct spi_transfer));
350 cmd_resp[0] = SST25L_CMD_READ_ID;
358 t.len = sizeof(cmd_resp);
359 spi_message_add_tail(&t, &m);
360 err = spi_sync(spi, &m);
362 dev_err(&spi->dev, "error reading device id\n");
366 id = (cmd_resp[4] << 8) | cmd_resp[5];
368 for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
369 if (sst25l_flash_info[i].device_id == id)
370 flash_info = &sst25l_flash_info[i];
373 dev_err(&spi->dev, "unknown id %.4x\n", id);
378 static int __devinit sst25l_probe(struct spi_device *spi)
380 struct flash_info *flash_info;
381 struct sst25l_flash *flash;
382 struct flash_platform_data *data;
385 flash_info = sst25l_match_device(spi);
389 flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
394 mutex_init(&flash->lock);
395 dev_set_drvdata(&spi->dev, flash);
397 data = spi->dev.platform_data;
398 if (data && data->name)
399 flash->mtd.name = data->name;
401 flash->mtd.name = dev_name(&spi->dev);
403 flash->mtd.type = MTD_NORFLASH;
404 flash->mtd.flags = MTD_CAP_NORFLASH;
405 flash->mtd.erasesize = flash_info->erase_size;
406 flash->mtd.writesize = flash_info->page_size;
407 flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
408 flash->mtd.erase = sst25l_erase;
409 flash->mtd.read = sst25l_read;
410 flash->mtd.write = sst25l_write;
412 dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
413 (long long)flash->mtd.size >> 10);
415 DEBUG(MTD_DEBUG_LEVEL2,
416 "mtd .name = %s, .size = 0x%llx (%lldMiB) "
417 ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
419 (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
420 flash->mtd.erasesize, flash->mtd.erasesize / 1024,
421 flash->mtd.numeraseregions);
423 if (mtd_has_partitions()) {
424 struct mtd_partition *parts = NULL;
427 if (mtd_has_cmdlinepart()) {
428 static const char *part_probes[] =
429 {"cmdlinepart", NULL};
431 nr_parts = parse_mtd_partitions(&flash->mtd,
436 if (nr_parts <= 0 && data && data->parts) {
438 nr_parts = data->nr_parts;
442 for (i = 0; i < nr_parts; i++) {
443 DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
444 "{.name = %s, .offset = 0x%llx, "
445 ".size = 0x%llx (%lldKiB) }\n",
447 (long long)parts[i].offset,
448 (long long)parts[i].size,
449 (long long)(parts[i].size >> 10));
452 flash->partitioned = 1;
453 return add_mtd_partitions(&flash->mtd,
457 } else if (data && data->nr_parts) {
458 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
459 data->nr_parts, data->name);
462 ret = add_mtd_device(&flash->mtd);
465 dev_set_drvdata(&spi->dev, NULL);
472 static int __exit sst25l_remove(struct spi_device *spi)
474 struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
477 if (mtd_has_partitions() && flash->partitioned)
478 ret = del_mtd_partitions(&flash->mtd);
480 ret = del_mtd_device(&flash->mtd);
486 static struct spi_driver sst25l_driver = {
489 .bus = &spi_bus_type,
490 .owner = THIS_MODULE,
492 .probe = sst25l_probe,
493 .remove = __exit_p(sst25l_remove),
496 static int __init sst25l_init(void)
498 return spi_register_driver(&sst25l_driver);
501 static void __exit sst25l_exit(void)
503 spi_unregister_driver(&sst25l_driver);
506 module_init(sst25l_init);
507 module_exit(sst25l_exit);
509 MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
510 MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
511 "Ryan Mallon <ryan@bluewatersys.com>");
512 MODULE_LICENSE("GPL");