sprd-efuse.c 11 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. // Copyright (C) 2019 Spreadtrum Communications Inc.
  3. #include <linux/clk.h>
  4. #include <linux/delay.h>
  5. #include <linux/hwspinlock.h>
  6. #include <linux/io.h>
  7. #include <linux/module.h>
  8. #include <linux/nvmem-provider.h>
  9. #include <linux/of_device.h>
  10. #include <linux/platform_device.h>
  11. #define SPRD_EFUSE_ENABLE 0x20
  12. #define SPRD_EFUSE_ERR_FLAG 0x24
  13. #define SPRD_EFUSE_ERR_CLR 0x28
  14. #define SPRD_EFUSE_MAGIC_NUM 0x2c
  15. #define SPRD_EFUSE_FW_CFG 0x50
  16. #define SPRD_EFUSE_PW_SWT 0x54
  17. #define SPRD_EFUSE_MEM(val) (0x1000 + ((val) << 2))
  18. #define SPRD_EFUSE_VDD_EN BIT(0)
  19. #define SPRD_EFUSE_AUTO_CHECK_EN BIT(1)
  20. #define SPRD_EFUSE_DOUBLE_EN BIT(2)
  21. #define SPRD_EFUSE_MARGIN_RD_EN BIT(3)
  22. #define SPRD_EFUSE_LOCK_WR_EN BIT(4)
  23. #define SPRD_EFUSE_ERR_CLR_MASK GENMASK(13, 0)
  24. #define SPRD_EFUSE_ENK1_ON BIT(0)
  25. #define SPRD_EFUSE_ENK2_ON BIT(1)
  26. #define SPRD_EFUSE_PROG_EN BIT(2)
  27. #define SPRD_EFUSE_MAGIC_NUMBER 0x8810
  28. /* Block width (bytes) definitions */
  29. #define SPRD_EFUSE_BLOCK_WIDTH 4
  30. /*
  31. * The Spreadtrum AP efuse contains 2 parts: normal efuse and secure efuse,
  32. * and we can only access the normal efuse in kernel. So define the normal
  33. * block offset index and normal block numbers.
  34. */
  35. #define SPRD_EFUSE_NORMAL_BLOCK_NUMS 24
  36. #define SPRD_EFUSE_NORMAL_BLOCK_OFFSET 72
  37. /* Timeout (ms) for the trylock of hardware spinlocks */
  38. #define SPRD_EFUSE_HWLOCK_TIMEOUT 5000
  39. /*
  40. * Since different Spreadtrum SoC chip can have different normal block numbers
  41. * and offset. And some SoC can support block double feature, which means
  42. * when reading or writing data to efuse memory, the controller can save double
  43. * data in case one data become incorrect after a long period.
  44. *
  45. * Thus we should save them in the device data structure.
  46. */
  47. struct sprd_efuse_variant_data {
  48. u32 blk_nums;
  49. u32 blk_offset;
  50. bool blk_double;
  51. };
  52. struct sprd_efuse {
  53. struct device *dev;
  54. struct clk *clk;
  55. struct hwspinlock *hwlock;
  56. struct mutex mutex;
  57. void __iomem *base;
  58. const struct sprd_efuse_variant_data *data;
  59. };
  60. static const struct sprd_efuse_variant_data ums312_data = {
  61. .blk_nums = SPRD_EFUSE_NORMAL_BLOCK_NUMS,
  62. .blk_offset = SPRD_EFUSE_NORMAL_BLOCK_OFFSET,
  63. .blk_double = false,
  64. };
  65. /*
  66. * On Spreadtrum platform, we have multi-subsystems will access the unique
  67. * efuse controller, so we need one hardware spinlock to synchronize between
  68. * the multiple subsystems.
  69. */
  70. static int sprd_efuse_lock(struct sprd_efuse *efuse)
  71. {
  72. int ret;
  73. mutex_lock(&efuse->mutex);
  74. ret = hwspin_lock_timeout_raw(efuse->hwlock,
  75. SPRD_EFUSE_HWLOCK_TIMEOUT);
  76. if (ret) {
  77. dev_err(efuse->dev, "timeout get the hwspinlock\n");
  78. mutex_unlock(&efuse->mutex);
  79. return ret;
  80. }
  81. return 0;
  82. }
  83. static void sprd_efuse_unlock(struct sprd_efuse *efuse)
  84. {
  85. hwspin_unlock_raw(efuse->hwlock);
  86. mutex_unlock(&efuse->mutex);
  87. }
  88. static void sprd_efuse_set_prog_power(struct sprd_efuse *efuse, bool en)
  89. {
  90. u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);
  91. if (en)
  92. val &= ~SPRD_EFUSE_ENK2_ON;
  93. else
  94. val &= ~SPRD_EFUSE_ENK1_ON;
  95. writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
  96. /* Open or close efuse power need wait 1000us to make power stable. */
  97. usleep_range(1000, 1200);
  98. if (en)
  99. val |= SPRD_EFUSE_ENK1_ON;
  100. else
  101. val |= SPRD_EFUSE_ENK2_ON;
  102. writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
  103. /* Open or close efuse power need wait 1000us to make power stable. */
  104. usleep_range(1000, 1200);
  105. }
  106. static void sprd_efuse_set_read_power(struct sprd_efuse *efuse, bool en)
  107. {
  108. u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
  109. if (en)
  110. val |= SPRD_EFUSE_VDD_EN;
  111. else
  112. val &= ~SPRD_EFUSE_VDD_EN;
  113. writel(val, efuse->base + SPRD_EFUSE_ENABLE);
  114. /* Open or close efuse power need wait 1000us to make power stable. */
  115. usleep_range(1000, 1200);
  116. }
  117. static void sprd_efuse_set_prog_lock(struct sprd_efuse *efuse, bool en)
  118. {
  119. u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
  120. if (en)
  121. val |= SPRD_EFUSE_LOCK_WR_EN;
  122. else
  123. val &= ~SPRD_EFUSE_LOCK_WR_EN;
  124. writel(val, efuse->base + SPRD_EFUSE_ENABLE);
  125. }
  126. static void sprd_efuse_set_auto_check(struct sprd_efuse *efuse, bool en)
  127. {
  128. u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
  129. if (en)
  130. val |= SPRD_EFUSE_AUTO_CHECK_EN;
  131. else
  132. val &= ~SPRD_EFUSE_AUTO_CHECK_EN;
  133. writel(val, efuse->base + SPRD_EFUSE_ENABLE);
  134. }
  135. static void sprd_efuse_set_data_double(struct sprd_efuse *efuse, bool en)
  136. {
  137. u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
  138. if (en)
  139. val |= SPRD_EFUSE_DOUBLE_EN;
  140. else
  141. val &= ~SPRD_EFUSE_DOUBLE_EN;
  142. writel(val, efuse->base + SPRD_EFUSE_ENABLE);
  143. }
  144. static void sprd_efuse_set_prog_en(struct sprd_efuse *efuse, bool en)
  145. {
  146. u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);
  147. if (en)
  148. val |= SPRD_EFUSE_PROG_EN;
  149. else
  150. val &= ~SPRD_EFUSE_PROG_EN;
  151. writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
  152. }
  153. static int sprd_efuse_raw_prog(struct sprd_efuse *efuse, u32 blk, bool doub,
  154. bool lock, u32 *data)
  155. {
  156. u32 status;
  157. int ret = 0;
  158. /*
  159. * We need set the correct magic number before writing the efuse to
  160. * allow programming, and block other programming until we clear the
  161. * magic number.
  162. */
  163. writel(SPRD_EFUSE_MAGIC_NUMBER,
  164. efuse->base + SPRD_EFUSE_MAGIC_NUM);
  165. /*
  166. * Power on the efuse, enable programme and enable double data
  167. * if asked.
  168. */
  169. sprd_efuse_set_prog_power(efuse, true);
  170. sprd_efuse_set_prog_en(efuse, true);
  171. sprd_efuse_set_data_double(efuse, doub);
  172. /*
  173. * Enable the auto-check function to validate if the programming is
  174. * successful.
  175. */
  176. if (lock)
  177. sprd_efuse_set_auto_check(efuse, true);
  178. writel(*data, efuse->base + SPRD_EFUSE_MEM(blk));
  179. /* Disable auto-check and data double after programming */
  180. if (lock)
  181. sprd_efuse_set_auto_check(efuse, false);
  182. sprd_efuse_set_data_double(efuse, false);
  183. /*
  184. * Check the efuse error status, if the programming is successful,
  185. * we should lock this efuse block to avoid programming again.
  186. */
  187. status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
  188. if (status) {
  189. dev_err(efuse->dev,
  190. "write error status %d of block %d\n", ret, blk);
  191. writel(SPRD_EFUSE_ERR_CLR_MASK,
  192. efuse->base + SPRD_EFUSE_ERR_CLR);
  193. ret = -EBUSY;
  194. } else if (lock) {
  195. sprd_efuse_set_prog_lock(efuse, lock);
  196. writel(0, efuse->base + SPRD_EFUSE_MEM(blk));
  197. sprd_efuse_set_prog_lock(efuse, false);
  198. }
  199. sprd_efuse_set_prog_power(efuse, false);
  200. writel(0, efuse->base + SPRD_EFUSE_MAGIC_NUM);
  201. return ret;
  202. }
  203. static int sprd_efuse_raw_read(struct sprd_efuse *efuse, int blk, u32 *val,
  204. bool doub)
  205. {
  206. u32 status;
  207. /*
  208. * Need power on the efuse before reading data from efuse, and will
  209. * power off the efuse after reading process.
  210. */
  211. sprd_efuse_set_read_power(efuse, true);
  212. /* Enable double data if asked */
  213. sprd_efuse_set_data_double(efuse, doub);
  214. /* Start to read data from efuse block */
  215. *val = readl(efuse->base + SPRD_EFUSE_MEM(blk));
  216. /* Disable double data */
  217. sprd_efuse_set_data_double(efuse, false);
  218. /* Power off the efuse */
  219. sprd_efuse_set_read_power(efuse, false);
  220. /*
  221. * Check the efuse error status and clear them if there are some
  222. * errors occurred.
  223. */
  224. status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
  225. if (status) {
  226. dev_err(efuse->dev,
  227. "read error status %d of block %d\n", status, blk);
  228. writel(SPRD_EFUSE_ERR_CLR_MASK,
  229. efuse->base + SPRD_EFUSE_ERR_CLR);
  230. return -EBUSY;
  231. }
  232. return 0;
  233. }
  234. static int sprd_efuse_read(void *context, u32 offset, void *val, size_t bytes)
  235. {
  236. struct sprd_efuse *efuse = context;
  237. bool blk_double = efuse->data->blk_double;
  238. u32 index = offset / SPRD_EFUSE_BLOCK_WIDTH + efuse->data->blk_offset;
  239. u32 blk_offset = (offset % SPRD_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE;
  240. u32 data;
  241. int ret;
  242. ret = sprd_efuse_lock(efuse);
  243. if (ret)
  244. return ret;
  245. ret = clk_prepare_enable(efuse->clk);
  246. if (ret)
  247. goto unlock;
  248. ret = sprd_efuse_raw_read(efuse, index, &data, blk_double);
  249. if (!ret) {
  250. data >>= blk_offset;
  251. memcpy(val, &data, bytes);
  252. }
  253. clk_disable_unprepare(efuse->clk);
  254. unlock:
  255. sprd_efuse_unlock(efuse);
  256. return ret;
  257. }
  258. static int sprd_efuse_write(void *context, u32 offset, void *val, size_t bytes)
  259. {
  260. struct sprd_efuse *efuse = context;
  261. bool blk_double = efuse->data->blk_double;
  262. bool lock;
  263. int ret;
  264. ret = sprd_efuse_lock(efuse);
  265. if (ret)
  266. return ret;
  267. ret = clk_prepare_enable(efuse->clk);
  268. if (ret)
  269. goto unlock;
  270. /*
  271. * If the writing bytes are equal with the block width, which means the
  272. * whole block will be programmed. For this case, we should not allow
  273. * this block to be programmed again by locking this block.
  274. *
  275. * If the block was programmed partially, we should allow this block to
  276. * be programmed again.
  277. */
  278. if (bytes < SPRD_EFUSE_BLOCK_WIDTH)
  279. lock = false;
  280. else
  281. lock = true;
  282. ret = sprd_efuse_raw_prog(efuse, offset, blk_double, lock, val);
  283. clk_disable_unprepare(efuse->clk);
  284. unlock:
  285. sprd_efuse_unlock(efuse);
  286. return ret;
  287. }
  288. static int sprd_efuse_probe(struct platform_device *pdev)
  289. {
  290. struct device_node *np = pdev->dev.of_node;
  291. struct nvmem_device *nvmem;
  292. struct nvmem_config econfig = { };
  293. struct sprd_efuse *efuse;
  294. const struct sprd_efuse_variant_data *pdata;
  295. int ret;
  296. pdata = of_device_get_match_data(&pdev->dev);
  297. if (!pdata) {
  298. dev_err(&pdev->dev, "No matching driver data found\n");
  299. return -EINVAL;
  300. }
  301. efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL);
  302. if (!efuse)
  303. return -ENOMEM;
  304. efuse->base = devm_platform_ioremap_resource(pdev, 0);
  305. if (IS_ERR(efuse->base))
  306. return PTR_ERR(efuse->base);
  307. ret = of_hwspin_lock_get_id(np, 0);
  308. if (ret < 0) {
  309. dev_err(&pdev->dev, "failed to get hwlock id\n");
  310. return ret;
  311. }
  312. efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
  313. if (!efuse->hwlock) {
  314. dev_err(&pdev->dev, "failed to request hwlock\n");
  315. return -ENXIO;
  316. }
  317. efuse->clk = devm_clk_get(&pdev->dev, "enable");
  318. if (IS_ERR(efuse->clk)) {
  319. dev_err(&pdev->dev, "failed to get enable clock\n");
  320. return PTR_ERR(efuse->clk);
  321. }
  322. mutex_init(&efuse->mutex);
  323. efuse->dev = &pdev->dev;
  324. efuse->data = pdata;
  325. econfig.stride = 1;
  326. econfig.word_size = 1;
  327. econfig.read_only = false;
  328. econfig.name = "sprd-efuse";
  329. econfig.size = efuse->data->blk_nums * SPRD_EFUSE_BLOCK_WIDTH;
  330. econfig.reg_read = sprd_efuse_read;
  331. econfig.reg_write = sprd_efuse_write;
  332. econfig.priv = efuse;
  333. econfig.dev = &pdev->dev;
  334. nvmem = devm_nvmem_register(&pdev->dev, &econfig);
  335. if (IS_ERR(nvmem)) {
  336. dev_err(&pdev->dev, "failed to register nvmem\n");
  337. return PTR_ERR(nvmem);
  338. }
  339. return 0;
  340. }
  341. static const struct of_device_id sprd_efuse_of_match[] = {
  342. { .compatible = "sprd,ums312-efuse", .data = &ums312_data },
  343. { }
  344. };
  345. static struct platform_driver sprd_efuse_driver = {
  346. .probe = sprd_efuse_probe,
  347. .driver = {
  348. .name = "sprd-efuse",
  349. .of_match_table = sprd_efuse_of_match,
  350. },
  351. };
  352. module_platform_driver(sprd_efuse_driver);
  353. MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
  354. MODULE_DESCRIPTION("Spreadtrum AP efuse driver");
  355. MODULE_LICENSE("GPL v2");