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 <mach/irqs.h>
  49. #include <mach/hardware.h>
  50. #include <mach/i2c.h>
  51. /** Defines ********************************************************************
  52. *******************************************************************************/
  53. /* This will be the driver name the kernel reports */
  54. #define DRIVER_NAME "imx-i2c"
  55. /* Default value */
  56. #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
  57. /* IMX I2C registers */
  58. #define IMX_I2C_IADR 0x00 /* i2c slave address */
  59. #define IMX_I2C_IFDR 0x04 /* i2c frequency divider */
  60. #define IMX_I2C_I2CR 0x08 /* i2c control */
  61. #define IMX_I2C_I2SR 0x0C /* i2c status */
  62. #define IMX_I2C_I2DR 0x10 /* i2c transfer data */
  63. /* Bits of IMX I2C registers */
  64. #define I2SR_RXAK 0x01
  65. #define I2SR_IIF 0x02
  66. #define I2SR_SRW 0x04
  67. #define I2SR_IAL 0x10
  68. #define I2SR_IBB 0x20
  69. #define I2SR_IAAS 0x40
  70. #define I2SR_ICF 0x80
  71. #define I2CR_RSTA 0x04
  72. #define I2CR_TXAK 0x08
  73. #define I2CR_MTX 0x10
  74. #define I2CR_MSTA 0x20
  75. #define I2CR_IIEN 0x40
  76. #define I2CR_IEN 0x80
  77. /** Variables ******************************************************************
  78. *******************************************************************************/
  79. /*
  80. * sorted list of clock divider, register value pairs
  81. * taken from table 26-5, p.26-9, Freescale i.MX
  82. * Integrated Portable System Processor Reference Manual
  83. * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  84. *
  85. * Duplicated divider values removed from list
  86. */
  87. static u16 __initdata i2c_clk_div[50][2] = {
  88. { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
  89. { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
  90. { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
  91. { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
  92. { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
  93. { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
  94. { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
  95. { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
  96. { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
  97. { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
  98. { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
  99. { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
  100. { 3072, 0x1E }, { 3840, 0x1F }
  101. };
  102. struct imx_i2c_struct {
  103. struct i2c_adapter adapter;
  104. struct resource *res;
  105. struct clk *clk;
  106. void __iomem *base;
  107. int irq;
  108. wait_queue_head_t queue;
  109. unsigned long i2csr;
  110. unsigned int disable_delay;
  111. int stopped;
  112. };
  113. /** Functions for IMX I2C adapter driver ***************************************
  114. *******************************************************************************/
  115. static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
  116. {
  117. unsigned long orig_jiffies = jiffies;
  118. unsigned int temp;
  119. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  120. while (1) {
  121. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  122. if (for_busy && (temp & I2SR_IBB))
  123. break;
  124. if (!for_busy && !(temp & I2SR_IBB))
  125. break;
  126. if (signal_pending(current)) {
  127. dev_dbg(&i2c_imx->adapter.dev,
  128. "<%s> I2C Interrupted\n", __func__);
  129. return -EINTR;
  130. }
  131. if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
  132. dev_dbg(&i2c_imx->adapter.dev,
  133. "<%s> I2C bus is busy\n", __func__);
  134. return -EIO;
  135. }
  136. schedule();
  137. }
  138. return 0;
  139. }
  140. static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
  141. {
  142. int result;
  143. result = wait_event_interruptible_timeout(i2c_imx->queue,
  144. i2c_imx->i2csr & I2SR_IIF, HZ / 10);
  145. if (unlikely(result < 0)) {
  146. dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
  147. return result;
  148. } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
  149. dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
  150. return -ETIMEDOUT;
  151. }
  152. dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
  153. i2c_imx->i2csr = 0;
  154. return 0;
  155. }
  156. static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
  157. {
  158. if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
  159. dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
  160. return -EIO; /* No ACK */
  161. }
  162. dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
  163. return 0;
  164. }
  165. static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
  166. {
  167. unsigned int temp = 0;
  168. int result;
  169. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  170. /* Enable I2C controller */
  171. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  172. writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
  173. /* Wait controller to be stable */
  174. udelay(50);
  175. /* Start I2C transaction */
  176. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  177. temp |= I2CR_MSTA;
  178. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  179. result = i2c_imx_bus_busy(i2c_imx, 1);
  180. if (result)
  181. return result;
  182. i2c_imx->stopped = 0;
  183. temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
  184. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  185. return result;
  186. }
  187. static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
  188. {
  189. unsigned int temp = 0;
  190. if (!i2c_imx->stopped) {
  191. /* Stop I2C transaction */
  192. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  193. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  194. temp &= ~(I2CR_MSTA | I2CR_MTX);
  195. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  196. i2c_imx->stopped = 1;
  197. }
  198. if (cpu_is_mx1()) {
  199. /*
  200. * This delay caused by an i.MXL hardware bug.
  201. * If no (or too short) delay, no "STOP" bit will be generated.
  202. */
  203. udelay(i2c_imx->disable_delay);
  204. }
  205. if (!i2c_imx->stopped)
  206. i2c_imx_bus_busy(i2c_imx, 0);
  207. /* Disable I2C controller */
  208. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  209. }
  210. static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
  211. unsigned int rate)
  212. {
  213. unsigned int i2c_clk_rate;
  214. unsigned int div;
  215. int i;
  216. /* Divider value calculation */
  217. i2c_clk_rate = clk_get_rate(i2c_imx->clk);
  218. div = (i2c_clk_rate + rate - 1) / rate;
  219. if (div < i2c_clk_div[0][0])
  220. i = 0;
  221. else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
  222. i = ARRAY_SIZE(i2c_clk_div) - 1;
  223. else
  224. for (i = 0; i2c_clk_div[i][0] < div; i++);
  225. /* Write divider value to register */
  226. writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
  227. /*
  228. * There dummy delay is calculated.
  229. * It should be about one I2C clock period long.
  230. * This delay is used in I2C bus disable function
  231. * to fix chip hardware bug.
  232. */
  233. i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
  234. + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
  235. /* dev_dbg() can't be used, because adapter is not yet registered */
  236. #ifdef CONFIG_I2C_DEBUG_BUS
  237. printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
  238. __func__, i2c_clk_rate, div);
  239. printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
  240. __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
  241. #endif
  242. }
  243. static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
  244. {
  245. struct imx_i2c_struct *i2c_imx = dev_id;
  246. unsigned int temp;
  247. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  248. if (temp & I2SR_IIF) {
  249. /* save status register */
  250. i2c_imx->i2csr = temp;
  251. temp &= ~I2SR_IIF;
  252. writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
  253. wake_up_interruptible(&i2c_imx->queue);
  254. return IRQ_HANDLED;
  255. }
  256. return IRQ_NONE;
  257. }
  258. static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  259. {
  260. int i, result;
  261. dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
  262. __func__, msgs->addr << 1);
  263. /* write slave address */
  264. writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
  265. result = i2c_imx_trx_complete(i2c_imx);
  266. if (result)
  267. return result;
  268. result = i2c_imx_acked(i2c_imx);
  269. if (result)
  270. return result;
  271. dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
  272. /* write data */
  273. for (i = 0; i < msgs->len; i++) {
  274. dev_dbg(&i2c_imx->adapter.dev,
  275. "<%s> write byte: B%d=0x%X\n",
  276. __func__, i, msgs->buf[i]);
  277. writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
  278. result = i2c_imx_trx_complete(i2c_imx);
  279. if (result)
  280. return result;
  281. result = i2c_imx_acked(i2c_imx);
  282. if (result)
  283. return result;
  284. }
  285. return 0;
  286. }
  287. static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  288. {
  289. int i, result;
  290. unsigned int temp;
  291. dev_dbg(&i2c_imx->adapter.dev,
  292. "<%s> write slave address: addr=0x%x\n",
  293. __func__, (msgs->addr << 1) | 0x01);
  294. /* write slave address */
  295. writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
  296. result = i2c_imx_trx_complete(i2c_imx);
  297. if (result)
  298. return result;
  299. result = i2c_imx_acked(i2c_imx);
  300. if (result)
  301. return result;
  302. dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
  303. /* setup bus to read data */
  304. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  305. temp &= ~I2CR_MTX;
  306. if (msgs->len - 1)
  307. temp &= ~I2CR_TXAK;
  308. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  309. readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
  310. dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
  311. /* read data */
  312. for (i = 0; i < msgs->len; i++) {
  313. result = i2c_imx_trx_complete(i2c_imx);
  314. if (result)
  315. return result;
  316. if (i == (msgs->len - 1)) {
  317. /* It must generate STOP before read I2DR to prevent
  318. controller from generating another clock cycle */
  319. dev_dbg(&i2c_imx->adapter.dev,
  320. "<%s> clear MSTA\n", __func__);
  321. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  322. temp &= ~(I2CR_MSTA | I2CR_MTX);
  323. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  324. i2c_imx_bus_busy(i2c_imx, 0);
  325. i2c_imx->stopped = 1;
  326. } else if (i == (msgs->len - 2)) {
  327. dev_dbg(&i2c_imx->adapter.dev,
  328. "<%s> set TXAK\n", __func__);
  329. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  330. temp |= I2CR_TXAK;
  331. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  332. }
  333. msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
  334. dev_dbg(&i2c_imx->adapter.dev,
  335. "<%s> read byte: B%d=0x%X\n",
  336. __func__, i, msgs->buf[i]);
  337. }
  338. return 0;
  339. }
  340. static int i2c_imx_xfer(struct i2c_adapter *adapter,
  341. struct i2c_msg *msgs, int num)
  342. {
  343. unsigned int i, temp;
  344. int result;
  345. struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
  346. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  347. /* Start I2C transfer */
  348. result = i2c_imx_start(i2c_imx);
  349. if (result)
  350. goto fail0;
  351. /* read/write data */
  352. for (i = 0; i < num; i++) {
  353. if (i) {
  354. dev_dbg(&i2c_imx->adapter.dev,
  355. "<%s> repeated start\n", __func__);
  356. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  357. temp |= I2CR_RSTA;
  358. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  359. result = i2c_imx_bus_busy(i2c_imx, 1);
  360. if (result)
  361. goto fail0;
  362. }
  363. dev_dbg(&i2c_imx->adapter.dev,
  364. "<%s> transfer message: %d\n", __func__, i);
  365. /* write/read data */
  366. #ifdef CONFIG_I2C_DEBUG_BUS
  367. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  368. dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
  369. "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
  370. (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
  371. (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
  372. (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
  373. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  374. dev_dbg(&i2c_imx->adapter.dev,
  375. "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
  376. "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
  377. (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
  378. (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
  379. (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
  380. (temp & I2SR_RXAK ? 1 : 0));
  381. #endif
  382. if (msgs[i].flags & I2C_M_RD)
  383. result = i2c_imx_read(i2c_imx, &msgs[i]);
  384. else
  385. result = i2c_imx_write(i2c_imx, &msgs[i]);
  386. }
  387. fail0:
  388. /* Stop I2C transfer */
  389. i2c_imx_stop(i2c_imx);
  390. dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
  391. (result < 0) ? "error" : "success msg",
  392. (result < 0) ? result : num);
  393. return (result < 0) ? result : num;
  394. }
  395. static u32 i2c_imx_func(struct i2c_adapter *adapter)
  396. {
  397. return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  398. }
  399. static struct i2c_algorithm i2c_imx_algo = {
  400. .master_xfer = i2c_imx_xfer,
  401. .functionality = i2c_imx_func,
  402. };
  403. static int __init i2c_imx_probe(struct platform_device *pdev)
  404. {
  405. struct imx_i2c_struct *i2c_imx;
  406. struct resource *res;
  407. struct imxi2c_platform_data *pdata;
  408. void __iomem *base;
  409. resource_size_t res_size;
  410. int irq;
  411. int ret;
  412. dev_dbg(&pdev->dev, "<%s>\n", __func__);
  413. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  414. if (!res) {
  415. dev_err(&pdev->dev, "can't get device resources\n");
  416. return -ENOENT;
  417. }
  418. irq = platform_get_irq(pdev, 0);
  419. if (irq < 0) {
  420. dev_err(&pdev->dev, "can't get irq number\n");
  421. return -ENOENT;
  422. }
  423. pdata = pdev->dev.platform_data;
  424. if (pdata && pdata->init) {
  425. ret = pdata->init(&pdev->dev);
  426. if (ret)
  427. return ret;
  428. }
  429. res_size = resource_size(res);
  430. base = ioremap(res->start, res_size);
  431. if (!base) {
  432. dev_err(&pdev->dev, "ioremap failed\n");
  433. ret = -EIO;
  434. goto fail0;
  435. }
  436. i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
  437. if (!i2c_imx) {
  438. dev_err(&pdev->dev, "can't allocate interface\n");
  439. ret = -ENOMEM;
  440. goto fail1;
  441. }
  442. if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
  443. ret = -EBUSY;
  444. goto fail2;
  445. }
  446. /* Setup i2c_imx driver structure */
  447. strcpy(i2c_imx->adapter.name, pdev->name);
  448. i2c_imx->adapter.owner = THIS_MODULE;
  449. i2c_imx->adapter.algo = &i2c_imx_algo;
  450. i2c_imx->adapter.dev.parent = &pdev->dev;
  451. i2c_imx->adapter.nr = pdev->id;
  452. i2c_imx->irq = irq;
  453. i2c_imx->base = base;
  454. i2c_imx->res = res;
  455. /* Get I2C clock */
  456. i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
  457. if (IS_ERR(i2c_imx->clk)) {
  458. ret = PTR_ERR(i2c_imx->clk);
  459. dev_err(&pdev->dev, "can't get I2C clock\n");
  460. goto fail3;
  461. }
  462. clk_enable(i2c_imx->clk);
  463. /* Request IRQ */
  464. ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
  465. if (ret) {
  466. dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
  467. goto fail4;
  468. }
  469. /* Init queue */
  470. init_waitqueue_head(&i2c_imx->queue);
  471. /* Set up adapter data */
  472. i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
  473. /* Set up clock divider */
  474. if (pdata && pdata->bitrate)
  475. i2c_imx_set_clk(i2c_imx, pdata->bitrate);
  476. else
  477. i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
  478. /* Set up chip registers to defaults */
  479. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  480. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  481. /* Add I2C adapter */
  482. ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
  483. if (ret < 0) {
  484. dev_err(&pdev->dev, "registration failed\n");
  485. goto fail5;
  486. }
  487. /* Set up platform driver data */
  488. platform_set_drvdata(pdev, i2c_imx);
  489. dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
  490. dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
  491. i2c_imx->res->start, i2c_imx->res->end);
  492. dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
  493. res_size, i2c_imx->res->start);
  494. dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
  495. i2c_imx->adapter.name);
  496. dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
  497. return 0; /* Return OK */
  498. fail5:
  499. free_irq(i2c_imx->irq, i2c_imx);
  500. fail4:
  501. clk_disable(i2c_imx->clk);
  502. clk_put(i2c_imx->clk);
  503. fail3:
  504. release_mem_region(i2c_imx->res->start, resource_size(res));
  505. fail2:
  506. kfree(i2c_imx);
  507. fail1:
  508. iounmap(base);
  509. fail0:
  510. if (pdata && pdata->exit)
  511. pdata->exit(&pdev->dev);
  512. return ret; /* Return error number */
  513. }
  514. static int __exit i2c_imx_remove(struct platform_device *pdev)
  515. {
  516. struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
  517. struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
  518. /* remove adapter */
  519. dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
  520. i2c_del_adapter(&i2c_imx->adapter);
  521. platform_set_drvdata(pdev, NULL);
  522. /* free interrupt */
  523. free_irq(i2c_imx->irq, i2c_imx);
  524. /* setup chip registers to defaults */
  525. writeb(0, i2c_imx->base + IMX_I2C_IADR);
  526. writeb(0, i2c_imx->base + IMX_I2C_IFDR);
  527. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  528. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  529. /* Shut down hardware */
  530. if (pdata && pdata->exit)
  531. pdata->exit(&pdev->dev);
  532. /* Disable I2C clock */
  533. clk_disable(i2c_imx->clk);
  534. clk_put(i2c_imx->clk);
  535. release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
  536. iounmap(i2c_imx->base);
  537. kfree(i2c_imx);
  538. return 0;
  539. }
  540. static struct platform_driver i2c_imx_driver = {
  541. .probe = i2c_imx_probe,
  542. .remove = __exit_p(i2c_imx_remove),
  543. .driver = {
  544. .name = DRIVER_NAME,
  545. .owner = THIS_MODULE,
  546. }
  547. };
  548. static int __init i2c_adap_imx_init(void)
  549. {
  550. return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
  551. }
  552. subsys_initcall(i2c_adap_imx_init);
  553. static void __exit i2c_adap_imx_exit(void)
  554. {
  555. platform_driver_unregister(&i2c_imx_driver);
  556. }
  557. module_exit(i2c_adap_imx_exit);
  558. MODULE_LICENSE("GPL");
  559. MODULE_AUTHOR("Darius Augulis");
  560. MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
  561. MODULE_ALIAS("platform:" DRIVER_NAME);