drivers/mtd/maps/pismo.c

   1 /*
   2  * PISMO memory driver - http://www.pismoworld.org/
   3  *
   4  * For ARM Realview and Versatile platforms
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License.
   9  */
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/i2c.h>
  13 #include <linux/slab.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/mutex.h>
  17 #include <linux/mtd/physmap.h>
  18 #include <linux/mtd/plat-ram.h>
  19 #include <linux/mtd/pismo.h>
  20
  21 #define PISMO_NUM_CS    5
  22
  23 struct pismo_cs_block {
  24         u8      type;
  25         u8      width;
  26         __le16  access;
  27         __le32  size;
  28         u32     reserved[2];
  29         char    device[32];
  30 } __packed;
  31
  32 struct pismo_eeprom {
  33         struct pismo_cs_block cs[PISMO_NUM_CS];
  34         char    board[15];
  35         u8      sum;
  36 } __packed;
  37
  38 struct pismo_mem {
  39         phys_addr_t base;
  40         u32     size;
  41         u16     access;
  42         u8      width;
  43         u8      type;
  44 };
  45
  46 struct pismo_data {
  47         struct i2c_client       *client;
  48         void                    (*vpp)(void *, int);
  49         void                    *vpp_data;
  50         struct platform_device  *dev[PISMO_NUM_CS];
  51 };
  52
  53 /* FIXME: set_vpp could do with a better calling convention */
  54 static struct pismo_data *vpp_pismo;
  55 static DEFINE_MUTEX(pismo_mutex);
  56
  57 static int pismo_setvpp_probe_fix(struct pismo_data *pismo)
  58 {
  59         mutex_lock(&pismo_mutex);
  60         if (vpp_pismo) {
  61                 mutex_unlock(&pismo_mutex);
  62                 kfree(pismo);
  63                 return -EBUSY;
  64         }
  65         vpp_pismo = pismo;
  66         mutex_unlock(&pismo_mutex);
  67         return 0;
  68 }
  69
  70 static void pismo_setvpp_remove_fix(struct pismo_data *pismo)
  71 {
  72         mutex_lock(&pismo_mutex);
  73         if (vpp_pismo == pismo)
  74                 vpp_pismo = NULL;
  75         mutex_unlock(&pismo_mutex);
  76 }
  77
  78 static void pismo_set_vpp(struct map_info *map, int on)
  79 {
  80         struct pismo_data *pismo = vpp_pismo;
  81
  82         pismo->vpp(pismo->vpp_data, on);
  83 }
  84 /* end of hack */
  85
  86
  87 static unsigned int __devinit pismo_width_to_bytes(unsigned int width)
  88 {
  89         width &= 15;
  90         if (width > 2)
  91                 return 0;
  92         return 1 << width;
  93 }
  94
  95 static int __devinit pismo_eeprom_read(struct i2c_client *client, void *buf,
  96         u8 addr, size_t size)
  97 {
  98         int ret;
  99         struct i2c_msg msg[] = {
 100                 {
 101                         .addr = client->addr,
 102                         .len = sizeof(addr),
 103                         .buf = &addr,
 104                 }, {
 105                         .addr = client->addr,
 106                         .flags = I2C_M_RD,
 107                         .len = size,
 108                         .buf = buf,
 109                 },
 110         };
 111
 112         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 113
 114         return ret == ARRAY_SIZE(msg) ? size : -EIO;
 115 }
 116
 117 static int __devinit pismo_add_device(struct pismo_data *pismo, int i,
 118         struct pismo_mem *region, const char *name, void *pdata, size_t psize)
 119 {
 120         struct platform_device *dev;
 121         struct resource res = { };
 122         phys_addr_t base = region->base;
 123         int ret;
 124
 125         if (base == ~0)
 126                 return -ENXIO;
 127
 128         res.start = base;
 129         res.end = base + region->size - 1;
 130         res.flags = IORESOURCE_MEM;
 131
 132         dev = platform_device_alloc(name, i);
 133         if (!dev)
 134                 return -ENOMEM;
 135         dev->dev.parent = &pismo->client->dev;
 136
 137         do {
 138                 ret = platform_device_add_resources(dev, &res, 1);
 139                 if (ret)
 140                         break;
 141
 142                 ret = platform_device_add_data(dev, pdata, psize);
 143                 if (ret)
 144                         break;
 145
 146                 ret = platform_device_add(dev);
 147                 if (ret)
 148                         break;
 149
 150                 pismo->dev[i] = dev;
 151                 return 0;
 152         } while (0);
 153
 154         platform_device_put(dev);
 155         return ret;
 156 }
 157
 158 static int __devinit pismo_add_nor(struct pismo_data *pismo, int i,
 159         struct pismo_mem *region)
 160 {
 161         struct physmap_flash_data data = {
 162                 .width = region->width,
 163         };
 164
 165         if (pismo->vpp)
 166                 data.set_vpp = pismo_set_vpp;
 167
 168         return pismo_add_device(pismo, i, region, "physmap-flash",
 169                 &data, sizeof(data));
 170 }
 171
 172 static int __devinit pismo_add_sram(struct pismo_data *pismo, int i,
 173         struct pismo_mem *region)
 174 {
 175         struct platdata_mtd_ram data = {
 176                 .bankwidth = region->width,
 177         };
 178
 179         return pismo_add_device(pismo, i, region, "mtd-ram",
 180                 &data, sizeof(data));
 181 }
 182
 183 static void __devinit pismo_add_one(struct pismo_data *pismo, int i,
 184         const struct pismo_cs_block *cs, phys_addr_t base)
 185 {
 186         struct device *dev = &pismo->client->dev;
 187         struct pismo_mem region;
 188
 189         region.base = base;
 190         region.type = cs->type;
 191         region.width = pismo_width_to_bytes(cs->width);
 192         region.access = le16_to_cpu(cs->access);
 193         region.size = le32_to_cpu(cs->size);
 194
 195         if (region.width == 0) {
 196                 dev_err(dev, "cs%u: bad width: %02x, ignoring\n", i, cs->width);
 197                 return;
 198         }
 199
 200         /*
 201          * FIXME: may need to the platforms memory controller here, but at
 202          * the moment we assume that it has already been correctly setup.
 203          * The memory controller can also tell us the base address as well.
 204          */
 205
 206         dev_info(dev, "cs%u: %.32s: type %02x access %u00ps size %uK\n",
 207                 i, cs->device, region.type, region.access, region.size / 1024);
 208
 209         switch (region.type) {
 210         case 0:
 211                 break;
 212         case 1:
 213                 /* static DOC */
 214                 break;
 215         case 2:
 216                 /* static NOR */
 217                 pismo_add_nor(pismo, i, &region);
 218                 break;
 219         case 3:
 220                 /* static RAM */
 221                 pismo_add_sram(pismo, i, &region);
 222                 break;
 223         }
 224 }
 225
 226 static int __devexit pismo_remove(struct i2c_client *client)
 227 {
 228         struct pismo_data *pismo = i2c_get_clientdata(client);
 229         int i;
 230
 231         for (i = 0; i < ARRAY_SIZE(pismo->dev); i++)
 232                 platform_device_unregister(pismo->dev[i]);
 233
 234         /* FIXME: set_vpp needs saner arguments */
 235         pismo_setvpp_remove_fix(pismo);
 236
 237         kfree(pismo);
 238
 239         return 0;
 240 }
 241
 242 static int __devinit pismo_probe(struct i2c_client *client,
 243                                  const struct i2c_device_id *id)
 244 {
 245         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 246         struct pismo_pdata *pdata = client->dev.platform_data;
 247         struct pismo_eeprom eeprom;
 248         struct pismo_data *pismo;
 249         int ret, i;
 250
 251         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
 252                 dev_err(&client->dev, "functionality mismatch\n");
 253                 return -EIO;
 254         }
 255
 256         pismo = kzalloc(sizeof(*pismo), GFP_KERNEL);
 257         if (!pismo)
 258                 return -ENOMEM;
 259
 260         /* FIXME: set_vpp needs saner arguments */
 261         ret = pismo_setvpp_probe_fix(pismo);
 262         if (ret)
 263                 return ret;
 264
 265         pismo->client = client;
 266         if (pdata) {
 267                 pismo->vpp = pdata->set_vpp;
 268                 pismo->vpp_data = pdata->vpp_data;
 269         }
 270         i2c_set_clientdata(client, pismo);
 271
 272         ret = pismo_eeprom_read(client, &eeprom, 0, sizeof(eeprom));
 273         if (ret < 0) {
 274                 dev_err(&client->dev, "error reading EEPROM: %d\n", ret);
 275                 goto exit_free;
 276         }
 277
 278         dev_info(&client->dev, "%.15s board found\n", eeprom.board);
 279
 280         for (i = 0; i < ARRAY_SIZE(eeprom.cs); i++)
 281                 if (eeprom.cs[i].type != 0xff)
 282                         pismo_add_one(pismo, i, &eeprom.cs[i],
 283                                       pdata->cs_addrs[i]);
 284
 285         return 0;
 286
 287  exit_free:
 288         kfree(pismo);
 289         return ret;
 290 }
 291
 292 static const struct i2c_device_id pismo_id[] = {
 293         { "pismo" },
 294         { },
 295 };
 296 MODULE_DEVICE_TABLE(i2c, pismo_id);
 297
 298 static struct i2c_driver pismo_driver = {
 299         .driver = {
 300                 .name   = "pismo",
 301                 .owner  = THIS_MODULE,
 302         },
 303         .probe          = pismo_probe,
 304         .remove         = __devexit_p(pismo_remove),
 305         .id_table       = pismo_id,
 306 };
 307
 308 static int __init pismo_init(void)
 309 {
 310         BUILD_BUG_ON(sizeof(struct pismo_cs_block) != 48);
 311         BUILD_BUG_ON(sizeof(struct pismo_eeprom) != 256);
 312
 313         return i2c_add_driver(&pismo_driver);
 314 }
 315 module_init(pismo_init);
 316
 317 static void __exit pismo_exit(void)
 318 {
 319         i2c_del_driver(&pismo_driver);
 320 }
 321 module_exit(pismo_exit);
 322
 323 MODULE_AUTHOR("Russell King <linux@arm.linux.org.uk>");
 324 MODULE_DESCRIPTION("PISMO memory driver");
 325 MODULE_LICENSE("GPL");