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