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 static void pismo_set_vpp(struct platform_device *pdev, int on)
  54 {
  55         struct i2c_client *client = to_i2c_client(pdev->dev.parent);
  56         struct pismo_data *pismo = i2c_get_clientdata(client);
  57
  58         pismo->vpp(pismo->vpp_data, on);
  59 }
  60
  61 static unsigned int __devinit pismo_width_to_bytes(unsigned int width)
  62 {
  63         width &= 15;
  64         if (width > 2)
  65                 return 0;
  66         return 1 << width;
  67 }
  68
  69 static int __devinit pismo_eeprom_read(struct i2c_client *client, void *buf,
  70         u8 addr, size_t size)
  71 {
  72         int ret;
  73         struct i2c_msg msg[] = {
  74                 {
  75                         .addr = client->addr,
  76                         .len = sizeof(addr),
  77                         .buf = &addr,
  78                 }, {
  79                         .addr = client->addr,
  80                         .flags = I2C_M_RD,
  81                         .len = size,
  82                         .buf = buf,
  83                 },
  84         };
  85
  86         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  87
  88         return ret == ARRAY_SIZE(msg) ? size : -EIO;
  89 }
  90
  91 static int __devinit pismo_add_device(struct pismo_data *pismo, int i,
  92         struct pismo_mem *region, const char *name, void *pdata, size_t psize)
  93 {
  94         struct platform_device *dev;
  95         struct resource res = { };
  96         phys_addr_t base = region->base;
  97         int ret;
  98
  99         if (base == ~0)
 100                 return -ENXIO;
 101
 102         res.start = base;
 103         res.end = base + region->size - 1;
 104         res.flags = IORESOURCE_MEM;
 105
 106         dev = platform_device_alloc(name, i);
 107         if (!dev)
 108                 return -ENOMEM;
 109         dev->dev.parent = &pismo->client->dev;
 110
 111         do {
 112                 ret = platform_device_add_resources(dev, &res, 1);
 113                 if (ret)
 114                         break;
 115
 116                 ret = platform_device_add_data(dev, pdata, psize);
 117                 if (ret)
 118                         break;
 119
 120                 ret = platform_device_add(dev);
 121                 if (ret)
 122                         break;
 123
 124                 pismo->dev[i] = dev;
 125                 return 0;
 126         } while (0);
 127
 128         platform_device_put(dev);
 129         return ret;
 130 }
 131
 132 static int __devinit pismo_add_nor(struct pismo_data *pismo, int i,
 133         struct pismo_mem *region)
 134 {
 135         struct physmap_flash_data data = {
 136                 .width = region->width,
 137         };
 138
 139         if (pismo->vpp)
 140                 data.set_vpp = pismo_set_vpp;
 141
 142         return pismo_add_device(pismo, i, region, "physmap-flash",
 143                 &data, sizeof(data));
 144 }
 145
 146 static int __devinit pismo_add_sram(struct pismo_data *pismo, int i,
 147         struct pismo_mem *region)
 148 {
 149         struct platdata_mtd_ram data = {
 150                 .bankwidth = region->width,
 151         };
 152
 153         return pismo_add_device(pismo, i, region, "mtd-ram",
 154                 &data, sizeof(data));
 155 }
 156
 157 static void __devinit pismo_add_one(struct pismo_data *pismo, int i,
 158         const struct pismo_cs_block *cs, phys_addr_t base)
 159 {
 160         struct device *dev = &pismo->client->dev;
 161         struct pismo_mem region;
 162
 163         region.base = base;
 164         region.type = cs->type;
 165         region.width = pismo_width_to_bytes(cs->width);
 166         region.access = le16_to_cpu(cs->access);
 167         region.size = le32_to_cpu(cs->size);
 168
 169         if (region.width == 0) {
 170                 dev_err(dev, "cs%u: bad width: %02x, ignoring\n", i, cs->width);
 171                 return;
 172         }
 173
 174         /*
 175          * FIXME: may need to the platforms memory controller here, but at
 176          * the moment we assume that it has already been correctly setup.
 177          * The memory controller can also tell us the base address as well.
 178          */
 179
 180         dev_info(dev, "cs%u: %.32s: type %02x access %u00ps size %uK\n",
 181                 i, cs->device, region.type, region.access, region.size / 1024);
 182
 183         switch (region.type) {
 184         case 0:
 185                 break;
 186         case 1:
 187                 /* static DOC */
 188                 break;
 189         case 2:
 190                 /* static NOR */
 191                 pismo_add_nor(pismo, i, &region);
 192                 break;
 193         case 3:
 194                 /* static RAM */
 195                 pismo_add_sram(pismo, i, &region);
 196                 break;
 197         }
 198 }
 199
 200 static int __devexit pismo_remove(struct i2c_client *client)
 201 {
 202         struct pismo_data *pismo = i2c_get_clientdata(client);
 203         int i;
 204
 205         for (i = 0; i < ARRAY_SIZE(pismo->dev); i++)
 206                 platform_device_unregister(pismo->dev[i]);
 207
 208         kfree(pismo);
 209
 210         return 0;
 211 }
 212
 213 static int __devinit pismo_probe(struct i2c_client *client,
 214                                  const struct i2c_device_id *id)
 215 {
 216         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 217         struct pismo_pdata *pdata = client->dev.platform_data;
 218         struct pismo_eeprom eeprom;
 219         struct pismo_data *pismo;
 220         int ret, i;
 221
 222         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
 223                 dev_err(&client->dev, "functionality mismatch\n");
 224                 return -EIO;
 225         }
 226
 227         pismo = kzalloc(sizeof(*pismo), GFP_KERNEL);
 228         if (!pismo)
 229                 return -ENOMEM;
 230
 231         pismo->client = client;
 232         if (pdata) {
 233                 pismo->vpp = pdata->set_vpp;
 234                 pismo->vpp_data = pdata->vpp_data;
 235         }
 236         i2c_set_clientdata(client, pismo);
 237
 238         ret = pismo_eeprom_read(client, &eeprom, 0, sizeof(eeprom));
 239         if (ret < 0) {
 240                 dev_err(&client->dev, "error reading EEPROM: %d\n", ret);
 241                 goto exit_free;
 242         }
 243
 244         dev_info(&client->dev, "%.15s board found\n", eeprom.board);
 245
 246         for (i = 0; i < ARRAY_SIZE(eeprom.cs); i++)
 247                 if (eeprom.cs[i].type != 0xff)
 248                         pismo_add_one(pismo, i, &eeprom.cs[i],
 249                                       pdata->cs_addrs[i]);
 250
 251         return 0;
 252
 253  exit_free:
 254         kfree(pismo);
 255         return ret;
 256 }
 257
 258 static const struct i2c_device_id pismo_id[] = {
 259         { "pismo" },
 260         { },
 261 };
 262 MODULE_DEVICE_TABLE(i2c, pismo_id);
 263
 264 static struct i2c_driver pismo_driver = {
 265         .driver = {
 266                 .name   = "pismo",
 267                 .owner  = THIS_MODULE,
 268         },
 269         .probe          = pismo_probe,
 270         .remove         = __devexit_p(pismo_remove),
 271         .id_table       = pismo_id,
 272 };
 273
 274 static int __init pismo_init(void)
 275 {
 276         BUILD_BUG_ON(sizeof(struct pismo_cs_block) != 48);
 277         BUILD_BUG_ON(sizeof(struct pismo_eeprom) != 256);
 278
 279         return i2c_add_driver(&pismo_driver);
 280 }
 281 module_init(pismo_init);
 282
 283 static void __exit pismo_exit(void)
 284 {
 285         i2c_del_driver(&pismo_driver);
 286 }
 287 module_exit(pismo_exit);
 288
 289 MODULE_AUTHOR("Russell King <linux@arm.linux.org.uk>");
 290 MODULE_DESCRIPTION("PISMO memory driver");
 291 MODULE_LICENSE("GPL");