pismo.c 5.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * PISMO memory driver - http://www.pismoworld.org/
  4. *
  5. * For ARM Realview and Versatile platforms
  6. */
  7. #include <linux/init.h>
  8. #include <linux/module.h>
  9. #include <linux/i2c.h>
  10. #include <linux/slab.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/spinlock.h>
  13. #include <linux/mutex.h>
  14. #include <linux/mtd/physmap.h>
  15. #include <linux/mtd/plat-ram.h>
  16. #include <linux/mtd/pismo.h>
  17. #define PISMO_NUM_CS 5
  18. struct pismo_cs_block {
  19. u8 type;
  20. u8 width;
  21. __le16 access;
  22. __le32 size;
  23. u32 reserved[2];
  24. char device[32];
  25. } __packed;
  26. struct pismo_eeprom {
  27. struct pismo_cs_block cs[PISMO_NUM_CS];
  28. char board[15];
  29. u8 sum;
  30. } __packed;
  31. struct pismo_mem {
  32. phys_addr_t base;
  33. u32 size;
  34. u16 access;
  35. u8 width;
  36. u8 type;
  37. };
  38. struct pismo_data {
  39. struct i2c_client *client;
  40. void (*vpp)(void *, int);
  41. void *vpp_data;
  42. struct platform_device *dev[PISMO_NUM_CS];
  43. };
  44. static void pismo_set_vpp(struct platform_device *pdev, int on)
  45. {
  46. struct i2c_client *client = to_i2c_client(pdev->dev.parent);
  47. struct pismo_data *pismo = i2c_get_clientdata(client);
  48. pismo->vpp(pismo->vpp_data, on);
  49. }
  50. static unsigned int pismo_width_to_bytes(unsigned int width)
  51. {
  52. width &= 15;
  53. if (width > 2)
  54. return 0;
  55. return 1 << width;
  56. }
  57. static int pismo_eeprom_read(struct i2c_client *client, void *buf, u8 addr,
  58. size_t size)
  59. {
  60. int ret;
  61. struct i2c_msg msg[] = {
  62. {
  63. .addr = client->addr,
  64. .len = sizeof(addr),
  65. .buf = &addr,
  66. }, {
  67. .addr = client->addr,
  68. .flags = I2C_M_RD,
  69. .len = size,
  70. .buf = buf,
  71. },
  72. };
  73. ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  74. return ret == ARRAY_SIZE(msg) ? size : -EIO;
  75. }
  76. static int pismo_add_device(struct pismo_data *pismo, int i,
  77. struct pismo_mem *region, const char *name,
  78. void *pdata, size_t psize)
  79. {
  80. struct platform_device *dev;
  81. struct resource res = { };
  82. phys_addr_t base = region->base;
  83. int ret;
  84. if (base == ~0)
  85. return -ENXIO;
  86. res.start = base;
  87. res.end = base + region->size - 1;
  88. res.flags = IORESOURCE_MEM;
  89. dev = platform_device_alloc(name, i);
  90. if (!dev)
  91. return -ENOMEM;
  92. dev->dev.parent = &pismo->client->dev;
  93. do {
  94. ret = platform_device_add_resources(dev, &res, 1);
  95. if (ret)
  96. break;
  97. ret = platform_device_add_data(dev, pdata, psize);
  98. if (ret)
  99. break;
  100. ret = platform_device_add(dev);
  101. if (ret)
  102. break;
  103. pismo->dev[i] = dev;
  104. return 0;
  105. } while (0);
  106. platform_device_put(dev);
  107. return ret;
  108. }
  109. static int pismo_add_nor(struct pismo_data *pismo, int i,
  110. struct pismo_mem *region)
  111. {
  112. struct physmap_flash_data data = {
  113. .width = region->width,
  114. };
  115. if (pismo->vpp)
  116. data.set_vpp = pismo_set_vpp;
  117. return pismo_add_device(pismo, i, region, "physmap-flash",
  118. &data, sizeof(data));
  119. }
  120. static int pismo_add_sram(struct pismo_data *pismo, int i,
  121. struct pismo_mem *region)
  122. {
  123. struct platdata_mtd_ram data = {
  124. .bankwidth = region->width,
  125. };
  126. return pismo_add_device(pismo, i, region, "mtd-ram",
  127. &data, sizeof(data));
  128. }
  129. static void pismo_add_one(struct pismo_data *pismo, int i,
  130. const struct pismo_cs_block *cs, phys_addr_t base)
  131. {
  132. struct device *dev = &pismo->client->dev;
  133. struct pismo_mem region;
  134. region.base = base;
  135. region.type = cs->type;
  136. region.width = pismo_width_to_bytes(cs->width);
  137. region.access = le16_to_cpu(cs->access);
  138. region.size = le32_to_cpu(cs->size);
  139. if (region.width == 0) {
  140. dev_err(dev, "cs%u: bad width: %02x, ignoring\n", i, cs->width);
  141. return;
  142. }
  143. /*
  144. * FIXME: may need to the platforms memory controller here, but at
  145. * the moment we assume that it has already been correctly setup.
  146. * The memory controller can also tell us the base address as well.
  147. */
  148. dev_info(dev, "cs%u: %.32s: type %02x access %u00ps size %uK\n",
  149. i, cs->device, region.type, region.access, region.size / 1024);
  150. switch (region.type) {
  151. case 0:
  152. break;
  153. case 1:
  154. /* static DOC */
  155. break;
  156. case 2:
  157. /* static NOR */
  158. pismo_add_nor(pismo, i, &region);
  159. break;
  160. case 3:
  161. /* static RAM */
  162. pismo_add_sram(pismo, i, &region);
  163. break;
  164. }
  165. }
  166. static int pismo_remove(struct i2c_client *client)
  167. {
  168. struct pismo_data *pismo = i2c_get_clientdata(client);
  169. int i;
  170. for (i = 0; i < ARRAY_SIZE(pismo->dev); i++)
  171. platform_device_unregister(pismo->dev[i]);
  172. kfree(pismo);
  173. return 0;
  174. }
  175. static int pismo_probe(struct i2c_client *client,
  176. const struct i2c_device_id *id)
  177. {
  178. struct pismo_pdata *pdata = client->dev.platform_data;
  179. struct pismo_eeprom eeprom;
  180. struct pismo_data *pismo;
  181. int ret, i;
  182. if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  183. dev_err(&client->dev, "functionality mismatch\n");
  184. return -EIO;
  185. }
  186. pismo = kzalloc(sizeof(*pismo), GFP_KERNEL);
  187. if (!pismo)
  188. return -ENOMEM;
  189. pismo->client = client;
  190. if (pdata) {
  191. pismo->vpp = pdata->set_vpp;
  192. pismo->vpp_data = pdata->vpp_data;
  193. }
  194. i2c_set_clientdata(client, pismo);
  195. ret = pismo_eeprom_read(client, &eeprom, 0, sizeof(eeprom));
  196. if (ret < 0) {
  197. dev_err(&client->dev, "error reading EEPROM: %d\n", ret);
  198. goto exit_free;
  199. }
  200. dev_info(&client->dev, "%.15s board found\n", eeprom.board);
  201. for (i = 0; i < ARRAY_SIZE(eeprom.cs); i++)
  202. if (eeprom.cs[i].type != 0xff)
  203. pismo_add_one(pismo, i, &eeprom.cs[i],
  204. pdata->cs_addrs[i]);
  205. return 0;
  206. exit_free:
  207. kfree(pismo);
  208. return ret;
  209. }
  210. static const struct i2c_device_id pismo_id[] = {
  211. { "pismo" },
  212. { },
  213. };
  214. MODULE_DEVICE_TABLE(i2c, pismo_id);
  215. static struct i2c_driver pismo_driver = {
  216. .driver = {
  217. .name = "pismo",
  218. },
  219. .probe = pismo_probe,
  220. .remove = pismo_remove,
  221. .id_table = pismo_id,
  222. };
  223. static int __init pismo_init(void)
  224. {
  225. BUILD_BUG_ON(sizeof(struct pismo_cs_block) != 48);
  226. BUILD_BUG_ON(sizeof(struct pismo_eeprom) != 256);
  227. return i2c_add_driver(&pismo_driver);
  228. }
  229. module_init(pismo_init);
  230. static void __exit pismo_exit(void)
  231. {
  232. i2c_del_driver(&pismo_driver);
  233. }
  234. module_exit(pismo_exit);
  235. MODULE_AUTHOR("Russell King <linux@arm.linux.org.uk>");
  236. MODULE_DESCRIPTION("PISMO memory driver");
  237. MODULE_LICENSE("GPL");