i2c-imx.c 18 KB

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  1. /*
  2. * Copyright (C) 2002 Motorola GSG-China
  3. *
  4. * This program is free software; you can redistribute it and/or
  5. * modify it under the terms of the GNU General Public License
  6. * as published by the Free Software Foundation; either version 2
  7. * of the License, or (at your option) any later version.
  8. *
  9. * This program is distributed in the hope that it will be useful,
  10. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12. * GNU General Public License for more details.
  13. *
  14. * You should have received a copy of the GNU General Public License
  15. * along with this program; if not, write to the Free Software
  16. * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17. * USA.
  18. *
  19. * Author:
  20. * Darius Augulis, Teltonika Inc.
  21. *
  22. * Desc.:
  23. * Implementation of I2C Adapter/Algorithm Driver
  24. * for I2C Bus integrated in Freescale i.MX/MXC processors
  25. *
  26. * Derived from Motorola GSG China I2C example driver
  27. *
  28. * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
  29. * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
  30. * Copyright (C) 2007 RightHand Technologies, Inc.
  31. * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
  32. *
  33. */
  34. /** Includes *******************************************************************
  35. *******************************************************************************/
  36. #include <linux/init.h>
  37. #include <linux/kernel.h>
  38. #include <linux/module.h>
  39. #include <linux/errno.h>
  40. #include <linux/err.h>
  41. #include <linux/interrupt.h>
  42. #include <linux/delay.h>
  43. #include <linux/i2c.h>
  44. #include <linux/io.h>
  45. #include <linux/sched.h>
  46. #include <linux/platform_device.h>
  47. #include <linux/clk.h>
  48. #include <linux/slab.h>
  49. #include <linux/of.h>
  50. #include <linux/of_device.h>
  51. #include <linux/of_i2c.h>
  52. #include <linux/pinctrl/consumer.h>
  53. #include <linux/platform_data/i2c-imx.h>
  54. /** Defines ********************************************************************
  55. *******************************************************************************/
  56. /* This will be the driver name the kernel reports */
  57. #define DRIVER_NAME "imx-i2c"
  58. /* Default value */
  59. #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
  60. /* IMX I2C registers */
  61. #define IMX_I2C_IADR 0x00 /* i2c slave address */
  62. #define IMX_I2C_IFDR 0x04 /* i2c frequency divider */
  63. #define IMX_I2C_I2CR 0x08 /* i2c control */
  64. #define IMX_I2C_I2SR 0x0C /* i2c status */
  65. #define IMX_I2C_I2DR 0x10 /* i2c transfer data */
  66. /* Bits of IMX I2C registers */
  67. #define I2SR_RXAK 0x01
  68. #define I2SR_IIF 0x02
  69. #define I2SR_SRW 0x04
  70. #define I2SR_IAL 0x10
  71. #define I2SR_IBB 0x20
  72. #define I2SR_IAAS 0x40
  73. #define I2SR_ICF 0x80
  74. #define I2CR_RSTA 0x04
  75. #define I2CR_TXAK 0x08
  76. #define I2CR_MTX 0x10
  77. #define I2CR_MSTA 0x20
  78. #define I2CR_IIEN 0x40
  79. #define I2CR_IEN 0x80
  80. /** Variables ******************************************************************
  81. *******************************************************************************/
  82. /*
  83. * sorted list of clock divider, register value pairs
  84. * taken from table 26-5, p.26-9, Freescale i.MX
  85. * Integrated Portable System Processor Reference Manual
  86. * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  87. *
  88. * Duplicated divider values removed from list
  89. */
  90. static u16 __initdata i2c_clk_div[50][2] = {
  91. { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
  92. { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
  93. { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
  94. { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
  95. { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
  96. { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
  97. { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
  98. { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
  99. { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
  100. { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
  101. { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
  102. { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
  103. { 3072, 0x1E }, { 3840, 0x1F }
  104. };
  105. enum imx_i2c_type {
  106. IMX1_I2C,
  107. IMX21_I2C,
  108. };
  109. struct imx_i2c_struct {
  110. struct i2c_adapter adapter;
  111. struct clk *clk;
  112. void __iomem *base;
  113. wait_queue_head_t queue;
  114. unsigned long i2csr;
  115. unsigned int disable_delay;
  116. int stopped;
  117. unsigned int ifdr; /* IMX_I2C_IFDR */
  118. enum imx_i2c_type devtype;
  119. };
  120. static struct platform_device_id imx_i2c_devtype[] = {
  121. {
  122. .name = "imx1-i2c",
  123. .driver_data = IMX1_I2C,
  124. }, {
  125. .name = "imx21-i2c",
  126. .driver_data = IMX21_I2C,
  127. }, {
  128. /* sentinel */
  129. }
  130. };
  131. MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
  132. static const struct of_device_id i2c_imx_dt_ids[] = {
  133. { .compatible = "fsl,imx1-i2c", .data = &imx_i2c_devtype[IMX1_I2C], },
  134. { .compatible = "fsl,imx21-i2c", .data = &imx_i2c_devtype[IMX21_I2C], },
  135. { /* sentinel */ }
  136. };
  137. static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
  138. {
  139. return i2c_imx->devtype == IMX1_I2C;
  140. }
  141. /** Functions for IMX I2C adapter driver ***************************************
  142. *******************************************************************************/
  143. static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
  144. {
  145. unsigned long orig_jiffies = jiffies;
  146. unsigned int temp;
  147. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  148. while (1) {
  149. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  150. if (for_busy && (temp & I2SR_IBB))
  151. break;
  152. if (!for_busy && !(temp & I2SR_IBB))
  153. break;
  154. if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
  155. dev_dbg(&i2c_imx->adapter.dev,
  156. "<%s> I2C bus is busy\n", __func__);
  157. return -ETIMEDOUT;
  158. }
  159. schedule();
  160. }
  161. return 0;
  162. }
  163. static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
  164. {
  165. wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
  166. if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
  167. dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
  168. return -ETIMEDOUT;
  169. }
  170. dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
  171. i2c_imx->i2csr = 0;
  172. return 0;
  173. }
  174. static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
  175. {
  176. if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
  177. dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
  178. return -EIO; /* No ACK */
  179. }
  180. dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
  181. return 0;
  182. }
  183. static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
  184. {
  185. unsigned int temp = 0;
  186. int result;
  187. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  188. clk_prepare_enable(i2c_imx->clk);
  189. writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
  190. /* Enable I2C controller */
  191. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  192. writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
  193. /* Wait controller to be stable */
  194. udelay(50);
  195. /* Start I2C transaction */
  196. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  197. temp |= I2CR_MSTA;
  198. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  199. result = i2c_imx_bus_busy(i2c_imx, 1);
  200. if (result)
  201. return result;
  202. i2c_imx->stopped = 0;
  203. temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
  204. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  205. return result;
  206. }
  207. static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
  208. {
  209. unsigned int temp = 0;
  210. if (!i2c_imx->stopped) {
  211. /* Stop I2C transaction */
  212. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  213. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  214. temp &= ~(I2CR_MSTA | I2CR_MTX);
  215. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  216. }
  217. if (is_imx1_i2c(i2c_imx)) {
  218. /*
  219. * This delay caused by an i.MXL hardware bug.
  220. * If no (or too short) delay, no "STOP" bit will be generated.
  221. */
  222. udelay(i2c_imx->disable_delay);
  223. }
  224. if (!i2c_imx->stopped) {
  225. i2c_imx_bus_busy(i2c_imx, 0);
  226. i2c_imx->stopped = 1;
  227. }
  228. /* Disable I2C controller */
  229. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  230. clk_disable_unprepare(i2c_imx->clk);
  231. }
  232. static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
  233. unsigned int rate)
  234. {
  235. unsigned int i2c_clk_rate;
  236. unsigned int div;
  237. int i;
  238. /* Divider value calculation */
  239. i2c_clk_rate = clk_get_rate(i2c_imx->clk);
  240. div = (i2c_clk_rate + rate - 1) / rate;
  241. if (div < i2c_clk_div[0][0])
  242. i = 0;
  243. else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
  244. i = ARRAY_SIZE(i2c_clk_div) - 1;
  245. else
  246. for (i = 0; i2c_clk_div[i][0] < div; i++);
  247. /* Store divider value */
  248. i2c_imx->ifdr = i2c_clk_div[i][1];
  249. /*
  250. * There dummy delay is calculated.
  251. * It should be about one I2C clock period long.
  252. * This delay is used in I2C bus disable function
  253. * to fix chip hardware bug.
  254. */
  255. i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
  256. + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
  257. /* dev_dbg() can't be used, because adapter is not yet registered */
  258. #ifdef CONFIG_I2C_DEBUG_BUS
  259. dev_dbg(&i2c_imx->adapter.dev, "<%s> I2C_CLK=%d, REQ DIV=%d\n",
  260. __func__, i2c_clk_rate, div);
  261. dev_dbg(&i2c_imx->adapter.dev, "<%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
  262. __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
  263. #endif
  264. }
  265. static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
  266. {
  267. struct imx_i2c_struct *i2c_imx = dev_id;
  268. unsigned int temp;
  269. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  270. if (temp & I2SR_IIF) {
  271. /* save status register */
  272. i2c_imx->i2csr = temp;
  273. temp &= ~I2SR_IIF;
  274. writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
  275. wake_up(&i2c_imx->queue);
  276. return IRQ_HANDLED;
  277. }
  278. return IRQ_NONE;
  279. }
  280. static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  281. {
  282. int i, result;
  283. dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
  284. __func__, msgs->addr << 1);
  285. /* write slave address */
  286. writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
  287. result = i2c_imx_trx_complete(i2c_imx);
  288. if (result)
  289. return result;
  290. result = i2c_imx_acked(i2c_imx);
  291. if (result)
  292. return result;
  293. dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
  294. /* write data */
  295. for (i = 0; i < msgs->len; i++) {
  296. dev_dbg(&i2c_imx->adapter.dev,
  297. "<%s> write byte: B%d=0x%X\n",
  298. __func__, i, msgs->buf[i]);
  299. writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
  300. result = i2c_imx_trx_complete(i2c_imx);
  301. if (result)
  302. return result;
  303. result = i2c_imx_acked(i2c_imx);
  304. if (result)
  305. return result;
  306. }
  307. return 0;
  308. }
  309. static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  310. {
  311. int i, result;
  312. unsigned int temp;
  313. dev_dbg(&i2c_imx->adapter.dev,
  314. "<%s> write slave address: addr=0x%x\n",
  315. __func__, (msgs->addr << 1) | 0x01);
  316. /* write slave address */
  317. writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
  318. result = i2c_imx_trx_complete(i2c_imx);
  319. if (result)
  320. return result;
  321. result = i2c_imx_acked(i2c_imx);
  322. if (result)
  323. return result;
  324. dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
  325. /* setup bus to read data */
  326. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  327. temp &= ~I2CR_MTX;
  328. if (msgs->len - 1)
  329. temp &= ~I2CR_TXAK;
  330. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  331. readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
  332. dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
  333. /* read data */
  334. for (i = 0; i < msgs->len; i++) {
  335. result = i2c_imx_trx_complete(i2c_imx);
  336. if (result)
  337. return result;
  338. if (i == (msgs->len - 1)) {
  339. /* It must generate STOP before read I2DR to prevent
  340. controller from generating another clock cycle */
  341. dev_dbg(&i2c_imx->adapter.dev,
  342. "<%s> clear MSTA\n", __func__);
  343. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  344. temp &= ~(I2CR_MSTA | I2CR_MTX);
  345. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  346. i2c_imx_bus_busy(i2c_imx, 0);
  347. i2c_imx->stopped = 1;
  348. } else if (i == (msgs->len - 2)) {
  349. dev_dbg(&i2c_imx->adapter.dev,
  350. "<%s> set TXAK\n", __func__);
  351. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  352. temp |= I2CR_TXAK;
  353. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  354. }
  355. msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
  356. dev_dbg(&i2c_imx->adapter.dev,
  357. "<%s> read byte: B%d=0x%X\n",
  358. __func__, i, msgs->buf[i]);
  359. }
  360. return 0;
  361. }
  362. static int i2c_imx_xfer(struct i2c_adapter *adapter,
  363. struct i2c_msg *msgs, int num)
  364. {
  365. unsigned int i, temp;
  366. int result;
  367. struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
  368. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  369. /* Start I2C transfer */
  370. result = i2c_imx_start(i2c_imx);
  371. if (result)
  372. goto fail0;
  373. /* read/write data */
  374. for (i = 0; i < num; i++) {
  375. if (i) {
  376. dev_dbg(&i2c_imx->adapter.dev,
  377. "<%s> repeated start\n", __func__);
  378. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  379. temp |= I2CR_RSTA;
  380. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  381. result = i2c_imx_bus_busy(i2c_imx, 1);
  382. if (result)
  383. goto fail0;
  384. }
  385. dev_dbg(&i2c_imx->adapter.dev,
  386. "<%s> transfer message: %d\n", __func__, i);
  387. /* write/read data */
  388. #ifdef CONFIG_I2C_DEBUG_BUS
  389. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  390. dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
  391. "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
  392. (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
  393. (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
  394. (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
  395. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  396. dev_dbg(&i2c_imx->adapter.dev,
  397. "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
  398. "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
  399. (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
  400. (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
  401. (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
  402. (temp & I2SR_RXAK ? 1 : 0));
  403. #endif
  404. if (msgs[i].flags & I2C_M_RD)
  405. result = i2c_imx_read(i2c_imx, &msgs[i]);
  406. else
  407. result = i2c_imx_write(i2c_imx, &msgs[i]);
  408. if (result)
  409. goto fail0;
  410. }
  411. fail0:
  412. /* Stop I2C transfer */
  413. i2c_imx_stop(i2c_imx);
  414. dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
  415. (result < 0) ? "error" : "success msg",
  416. (result < 0) ? result : num);
  417. return (result < 0) ? result : num;
  418. }
  419. static u32 i2c_imx_func(struct i2c_adapter *adapter)
  420. {
  421. return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  422. }
  423. static struct i2c_algorithm i2c_imx_algo = {
  424. .master_xfer = i2c_imx_xfer,
  425. .functionality = i2c_imx_func,
  426. };
  427. static int __init i2c_imx_probe(struct platform_device *pdev)
  428. {
  429. const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,
  430. &pdev->dev);
  431. struct imx_i2c_struct *i2c_imx;
  432. struct resource *res;
  433. struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
  434. struct pinctrl *pinctrl;
  435. void __iomem *base;
  436. int irq, ret;
  437. u32 bitrate;
  438. dev_dbg(&pdev->dev, "<%s>\n", __func__);
  439. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  440. if (!res) {
  441. dev_err(&pdev->dev, "can't get device resources\n");
  442. return -ENOENT;
  443. }
  444. irq = platform_get_irq(pdev, 0);
  445. if (irq < 0) {
  446. dev_err(&pdev->dev, "can't get irq number\n");
  447. return -ENOENT;
  448. }
  449. base = devm_ioremap_resource(&pdev->dev, res);
  450. if (IS_ERR(base))
  451. return PTR_ERR(base);
  452. i2c_imx = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_struct),
  453. GFP_KERNEL);
  454. if (!i2c_imx) {
  455. dev_err(&pdev->dev, "can't allocate interface\n");
  456. return -ENOMEM;
  457. }
  458. if (of_id)
  459. pdev->id_entry = of_id->data;
  460. i2c_imx->devtype = pdev->id_entry->driver_data;
  461. /* Setup i2c_imx driver structure */
  462. strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
  463. i2c_imx->adapter.owner = THIS_MODULE;
  464. i2c_imx->adapter.algo = &i2c_imx_algo;
  465. i2c_imx->adapter.dev.parent = &pdev->dev;
  466. i2c_imx->adapter.nr = pdev->id;
  467. i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
  468. i2c_imx->base = base;
  469. pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
  470. if (IS_ERR(pinctrl)) {
  471. dev_err(&pdev->dev, "can't get/select pinctrl\n");
  472. return PTR_ERR(pinctrl);
  473. }
  474. /* Get I2C clock */
  475. i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
  476. if (IS_ERR(i2c_imx->clk)) {
  477. dev_err(&pdev->dev, "can't get I2C clock\n");
  478. return PTR_ERR(i2c_imx->clk);
  479. }
  480. /* Request IRQ */
  481. ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
  482. pdev->name, i2c_imx);
  483. if (ret) {
  484. dev_err(&pdev->dev, "can't claim irq %d\n", irq);
  485. return ret;
  486. }
  487. /* Init queue */
  488. init_waitqueue_head(&i2c_imx->queue);
  489. /* Set up adapter data */
  490. i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
  491. /* Set up clock divider */
  492. bitrate = IMX_I2C_BIT_RATE;
  493. ret = of_property_read_u32(pdev->dev.of_node,
  494. "clock-frequency", &bitrate);
  495. if (ret < 0 && pdata && pdata->bitrate)
  496. bitrate = pdata->bitrate;
  497. i2c_imx_set_clk(i2c_imx, bitrate);
  498. /* Set up chip registers to defaults */
  499. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  500. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  501. /* Add I2C adapter */
  502. ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
  503. if (ret < 0) {
  504. dev_err(&pdev->dev, "registration failed\n");
  505. return ret;
  506. }
  507. of_i2c_register_devices(&i2c_imx->adapter);
  508. /* Set up platform driver data */
  509. platform_set_drvdata(pdev, i2c_imx);
  510. dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
  511. dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
  512. res->start, res->end);
  513. dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x\n",
  514. resource_size(res), res->start);
  515. dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
  516. i2c_imx->adapter.name);
  517. dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
  518. return 0; /* Return OK */
  519. }
  520. static int __exit i2c_imx_remove(struct platform_device *pdev)
  521. {
  522. struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
  523. /* remove adapter */
  524. dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
  525. i2c_del_adapter(&i2c_imx->adapter);
  526. /* setup chip registers to defaults */
  527. writeb(0, i2c_imx->base + IMX_I2C_IADR);
  528. writeb(0, i2c_imx->base + IMX_I2C_IFDR);
  529. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  530. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  531. return 0;
  532. }
  533. static struct platform_driver i2c_imx_driver = {
  534. .remove = __exit_p(i2c_imx_remove),
  535. .driver = {
  536. .name = DRIVER_NAME,
  537. .owner = THIS_MODULE,
  538. .of_match_table = i2c_imx_dt_ids,
  539. },
  540. .id_table = imx_i2c_devtype,
  541. };
  542. static int __init i2c_adap_imx_init(void)
  543. {
  544. return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
  545. }
  546. subsys_initcall(i2c_adap_imx_init);
  547. static void __exit i2c_adap_imx_exit(void)
  548. {
  549. platform_driver_unregister(&i2c_imx_driver);
  550. }
  551. module_exit(i2c_adap_imx_exit);
  552. MODULE_LICENSE("GPL");
  553. MODULE_AUTHOR("Darius Augulis");
  554. MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
  555. MODULE_ALIAS("platform:" DRIVER_NAME);