drivers/mtd/devices/m25p80.c

   1 /*
   2  * MTD SPI driver for ST M25Pxx (and similar) serial flash chips
   3  *
   4  * Author: Mike Lavender, mike@steroidmicros.com
   5  *
   6  * Copyright (c) 2005, Intec Automation Inc.
   7  *
   8  * Some parts are based on lart.c by Abraham Van Der Merwe
   9  *
  10  * Cleaned up and generalized based on mtd_dataflash.c
  11  *
  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.
  15  *
  16  */
  17
  18 #include <linux/err.h>
  19 #include <linux/errno.h>
  20 #include <linux/module.h>
  21 #include <linux/device.h>
  22
  23 #include <linux/mtd/mtd.h>
  24 #include <linux/mtd/partitions.h>
  25
  26 #include <linux/spi/spi.h>
  27 #include <linux/spi/flash.h>
  28 #include <linux/mtd/spi-nor.h>
  29
  30 #define MAX_CMD_SIZE            6
  31 struct m25p {
  32         struct spi_device       *spi;
  33         struct spi_nor          spi_nor;
  34         u8                      command[MAX_CMD_SIZE];
  35 };
  36
  37 static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
  38 {
  39         struct m25p *flash = nor->priv;
  40         struct spi_device *spi = flash->spi;
  41         int ret;
  42
  43         ret = spi_write_then_read(spi, &code, 1, val, len);
  44         if (ret < 0)
  45                 dev_err(&spi->dev, "error %d reading %x\n", ret, code);
  46
  47         return ret;
  48 }
  49
  50 static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
  51 {
  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);
  57 }
  58
  59 static int m25p_cmdsz(struct spi_nor *nor)
  60 {
  61         return 1 + nor->addr_width;
  62 }
  63
  64 static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
  65 {
  66         struct m25p *flash = nor->priv;
  67         struct spi_device *spi = flash->spi;
  68
  69         flash->command[0] = opcode;
  70         if (buf)
  71                 memcpy(&flash->command[1], buf, len);
  72
  73         return spi_write(spi, flash->command, len + 1);
  74 }
  75
  76 static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
  77                         size_t *retlen, const u_char *buf)
  78 {
  79         struct m25p *flash = nor->priv;
  80         struct spi_device *spi = flash->spi;
  81         struct spi_transfer t[2] = {};
  82         struct spi_message m;
  83         int cmd_sz = m25p_cmdsz(nor);
  84
  85         spi_message_init(&m);
  86
  87         if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
  88                 cmd_sz = 1;
  89
  90         flash->command[0] = nor->program_opcode;
  91         m25p_addr2cmd(nor, to, flash->command);
  92
  93         t[0].tx_buf = flash->command;
  94         t[0].len = cmd_sz;
  95         spi_message_add_tail(&t[0], &m);
  96
  97         t[1].tx_buf = buf;
  98         t[1].len = len;
  99         spi_message_add_tail(&t[1], &m);
 100
 101         spi_sync(spi, &m);
 102
 103         *retlen += m.actual_length - cmd_sz;
 104 }
 105
 106 static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
 107 {
 108         switch (nor->flash_read) {
 109         case SPI_NOR_DUAL:
 110                 return 2;
 111         case SPI_NOR_QUAD:
 112                 return 4;
 113         default:
 114                 return 0;
 115         }
 116 }
 117
 118 /*
 119  * Read an address range from the nor chip.  The address range
 120  * may be any size provided it is within the physical boundaries.
 121  */
 122 static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 123                         size_t *retlen, u_char *buf)
 124 {
 125         struct m25p *flash = nor->priv;
 126         struct spi_device *spi = flash->spi;
 127         struct spi_transfer t[2];
 128         struct spi_message m;
 129         unsigned int dummy = nor->read_dummy;
 130
 131         /* convert the dummy cycles to the number of bytes */
 132         dummy /= 8;
 133
 134         spi_message_init(&m);
 135         memset(t, 0, (sizeof t));
 136
 137         flash->command[0] = nor->read_opcode;
 138         m25p_addr2cmd(nor, from, flash->command);
 139
 140         t[0].tx_buf = flash->command;
 141         t[0].len = m25p_cmdsz(nor) + dummy;
 142         spi_message_add_tail(&t[0], &m);
 143
 144         t[1].rx_buf = buf;
 145         t[1].rx_nbits = m25p80_rx_nbits(nor);
 146         t[1].len = len;
 147         spi_message_add_tail(&t[1], &m);
 148
 149         spi_sync(spi, &m);
 150
 151         *retlen = m.actual_length - m25p_cmdsz(nor) - dummy;
 152         return 0;
 153 }
 154
 155 /*
 156  * board specific setup should have ensured the SPI clock used here
 157  * matches what the READ command supports, at least until this driver
 158  * understands FAST_READ (for clocks over 25 MHz).
 159  */
 160 static int m25p_probe(struct spi_device *spi)
 161 {
 162         struct flash_platform_data      *data;
 163         struct m25p *flash;
 164         struct spi_nor *nor;
 165         enum read_mode mode = SPI_NOR_NORMAL;
 166         char *flash_name;
 167         int ret;
 168
 169         data = dev_get_platdata(&spi->dev);
 170
 171         flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
 172         if (!flash)
 173                 return -ENOMEM;
 174
 175         nor = &flash->spi_nor;
 176
 177         /* install the hooks */
 178         nor->read = m25p80_read;
 179         nor->write = m25p80_write;
 180         nor->write_reg = m25p80_write_reg;
 181         nor->read_reg = m25p80_read_reg;
 182
 183         nor->dev = &spi->dev;
 184         spi_nor_set_flash_node(nor, spi->dev.of_node);
 185         nor->priv = flash;
 186
 187         spi_set_drvdata(spi, flash);
 188         flash->spi = spi;
 189
 190         if (spi->mode & SPI_RX_QUAD)
 191                 mode = SPI_NOR_QUAD;
 192         else if (spi->mode & SPI_RX_DUAL)
 193                 mode = SPI_NOR_DUAL;
 194
 195         if (data && data->name)
 196                 nor->mtd.name = data->name;
 197
 198         /* For some (historical?) reason many platforms provide two different
 199          * names in flash_platform_data: "name" and "type". Quite often name is
 200          * set to "m25p80" and then "type" provides a real chip name.
 201          * If that's the case, respect "type" and ignore a "name".
 202          */
 203         if (data && data->type)
 204                 flash_name = data->type;
 205         else if (!strcmp(spi->modalias, "spi-nor"))
 206                 flash_name = NULL; /* auto-detect */
 207         else
 208                 flash_name = spi->modalias;
 209
 210         ret = spi_nor_scan(nor, flash_name, mode);
 211         if (ret)
 212                 return ret;
 213
 214         return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
 215                                    data ? data->nr_parts : 0);
 216 }
 217
 218
 219 static int m25p_remove(struct spi_device *spi)
 220 {
 221         struct m25p     *flash = spi_get_drvdata(spi);
 222
 223         /* Clean up MTD stuff. */
 224         return mtd_device_unregister(&flash->spi_nor.mtd);
 225 }
 226
 227 /*
 228  * Do NOT add to this array without reading the following:
 229  *
 230  * Historically, many flash devices are bound to this driver by their name. But
 231  * since most of these flash are compatible to some extent, and their
 232  * differences can often be differentiated by the JEDEC read-ID command, we
 233  * encourage new users to add support to the spi-nor library, and simply bind
 234  * against a generic string here (e.g., "jedec,spi-nor").
 235  *
 236  * Many flash names are kept here in this list (as well as in spi-nor.c) to
 237  * keep them available as module aliases for existing platforms.
 238  */
 239 static const struct spi_device_id m25p_ids[] = {
 240         /*
 241          * Allow non-DT platform devices to bind to the "spi-nor" modalias, and
 242          * hack around the fact that the SPI core does not provide uevent
 243          * matching for .of_match_table
 244          */
 245         {"spi-nor"},
 246
 247         /*
 248          * Entries not used in DTs that should be safe to drop after replacing
 249          * them with "spi-nor" in platform data.
 250          */
 251         {"s25sl064a"},  {"w25x16"},     {"m25p10"},     {"m25px64"},
 252
 253         /*
 254          * Entries that were used in DTs without "jedec,spi-nor" fallback and
 255          * should be kept for backward compatibility.
 256          */
 257         {"at25df321a"}, {"at25df641"},  {"at26df081a"},
 258         {"mr25h256"},
 259         {"mx25l4005a"}, {"mx25l1606e"}, {"mx25l6405d"}, {"mx25l12805d"},
 260         {"mx25l25635e"},{"mx66l51235l"},
 261         {"n25q064"},    {"n25q128a11"}, {"n25q128a13"}, {"n25q512a"},
 262         {"s25fl256s1"}, {"s25fl512s"},  {"s25sl12801"}, {"s25fl008k"},
 263         {"s25fl064k"},
 264         {"sst25vf040b"},{"sst25vf016b"},{"sst25vf032b"},{"sst25wf040"},
 265         {"m25p40"},     {"m25p80"},     {"m25p16"},     {"m25p32"},
 266         {"m25p64"},     {"m25p128"},
 267         {"w25x80"},     {"w25x32"},     {"w25q32"},     {"w25q32dw"},
 268         {"w25q80bl"},   {"w25q128"},    {"w25q256"},
 269
 270         /* Flashes that can't be detected using JEDEC */
 271         {"m25p05-nonjedec"},    {"m25p10-nonjedec"},    {"m25p20-nonjedec"},
 272         {"m25p40-nonjedec"},    {"m25p80-nonjedec"},    {"m25p16-nonjedec"},
 273         {"m25p32-nonjedec"},    {"m25p64-nonjedec"},    {"m25p128-nonjedec"},
 274
 275         { },
 276 };
 277 MODULE_DEVICE_TABLE(spi, m25p_ids);
 278
 279 static const struct of_device_id m25p_of_table[] = {
 280         /*
 281          * Generic compatibility for SPI NOR that can be identified by the
 282          * JEDEC READ ID opcode (0x9F). Use this, if possible.
 283          */
 284         { .compatible = "jedec,spi-nor" },
 285         {}
 286 };
 287 MODULE_DEVICE_TABLE(of, m25p_of_table);
 288
 289 static struct spi_driver m25p80_driver = {
 290         .driver = {
 291                 .name   = "m25p80",
 292                 .of_match_table = m25p_of_table,
 293         },
 294         .id_table       = m25p_ids,
 295         .probe  = m25p_probe,
 296         .remove = m25p_remove,
 297
 298         /* REVISIT: many of these chips have deep power-down modes, which
 299          * should clearly be entered on suspend() to minimize power use.
 300          * And also when they're otherwise idle...
 301          */
 302 };
 303
 304 module_spi_driver(m25p80_driver);
 305
 306 MODULE_LICENSE("GPL");
 307 MODULE_AUTHOR("Mike Lavender");
 308 MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");