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. /*
  199. * This delay caused by an i.MXL hardware bug.
  200. * If no (or too short) delay, no "STOP" bit will be generated.
  201. */
  202. udelay(i2c_imx->disable_delay);
  203. if (!i2c_imx->stopped)
  204. i2c_imx_bus_busy(i2c_imx, 0);
  205. /* Disable I2C controller */
  206. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  207. }
  208. static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
  209. unsigned int rate)
  210. {
  211. unsigned int i2c_clk_rate;
  212. unsigned int div;
  213. int i;
  214. /* Divider value calculation */
  215. i2c_clk_rate = clk_get_rate(i2c_imx->clk);
  216. div = (i2c_clk_rate + rate - 1) / rate;
  217. if (div < i2c_clk_div[0][0])
  218. i = 0;
  219. else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
  220. i = ARRAY_SIZE(i2c_clk_div) - 1;
  221. else
  222. for (i = 0; i2c_clk_div[i][0] < div; i++);
  223. /* Write divider value to register */
  224. writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
  225. /*
  226. * There dummy delay is calculated.
  227. * It should be about one I2C clock period long.
  228. * This delay is used in I2C bus disable function
  229. * to fix chip hardware bug.
  230. */
  231. i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
  232. + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
  233. /* dev_dbg() can't be used, because adapter is not yet registered */
  234. #ifdef CONFIG_I2C_DEBUG_BUS
  235. printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
  236. __func__, i2c_clk_rate, div);
  237. printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
  238. __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
  239. #endif
  240. }
  241. static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
  242. {
  243. struct imx_i2c_struct *i2c_imx = dev_id;
  244. unsigned int temp;
  245. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  246. if (temp & I2SR_IIF) {
  247. /* save status register */
  248. i2c_imx->i2csr = temp;
  249. temp &= ~I2SR_IIF;
  250. writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
  251. wake_up_interruptible(&i2c_imx->queue);
  252. return IRQ_HANDLED;
  253. }
  254. return IRQ_NONE;
  255. }
  256. static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  257. {
  258. int i, result;
  259. dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
  260. __func__, msgs->addr << 1);
  261. /* write slave address */
  262. writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
  263. result = i2c_imx_trx_complete(i2c_imx);
  264. if (result)
  265. return result;
  266. result = i2c_imx_acked(i2c_imx);
  267. if (result)
  268. return result;
  269. dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
  270. /* write data */
  271. for (i = 0; i < msgs->len; i++) {
  272. dev_dbg(&i2c_imx->adapter.dev,
  273. "<%s> write byte: B%d=0x%X\n",
  274. __func__, i, msgs->buf[i]);
  275. writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
  276. result = i2c_imx_trx_complete(i2c_imx);
  277. if (result)
  278. return result;
  279. result = i2c_imx_acked(i2c_imx);
  280. if (result)
  281. return result;
  282. }
  283. return 0;
  284. }
  285. static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  286. {
  287. int i, result;
  288. unsigned int temp;
  289. dev_dbg(&i2c_imx->adapter.dev,
  290. "<%s> write slave address: addr=0x%x\n",
  291. __func__, (msgs->addr << 1) | 0x01);
  292. /* write slave address */
  293. writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
  294. result = i2c_imx_trx_complete(i2c_imx);
  295. if (result)
  296. return result;
  297. result = i2c_imx_acked(i2c_imx);
  298. if (result)
  299. return result;
  300. dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
  301. /* setup bus to read data */
  302. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  303. temp &= ~I2CR_MTX;
  304. if (msgs->len - 1)
  305. temp &= ~I2CR_TXAK;
  306. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  307. readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
  308. dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
  309. /* read data */
  310. for (i = 0; i < msgs->len; i++) {
  311. result = i2c_imx_trx_complete(i2c_imx);
  312. if (result)
  313. return result;
  314. if (i == (msgs->len - 1)) {
  315. /* It must generate STOP before read I2DR to prevent
  316. controller from generating another clock cycle */
  317. dev_dbg(&i2c_imx->adapter.dev,
  318. "<%s> clear MSTA\n", __func__);
  319. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  320. temp &= ~(I2CR_MSTA | I2CR_MTX);
  321. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  322. i2c_imx_bus_busy(i2c_imx, 0);
  323. i2c_imx->stopped = 1;
  324. } else if (i == (msgs->len - 2)) {
  325. dev_dbg(&i2c_imx->adapter.dev,
  326. "<%s> set TXAK\n", __func__);
  327. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  328. temp |= I2CR_TXAK;
  329. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  330. }
  331. msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
  332. dev_dbg(&i2c_imx->adapter.dev,
  333. "<%s> read byte: B%d=0x%X\n",
  334. __func__, i, msgs->buf[i]);
  335. }
  336. return 0;
  337. }
  338. static int i2c_imx_xfer(struct i2c_adapter *adapter,
  339. struct i2c_msg *msgs, int num)
  340. {
  341. unsigned int i, temp;
  342. int result;
  343. struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
  344. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  345. /* Start I2C transfer */
  346. result = i2c_imx_start(i2c_imx);
  347. if (result)
  348. goto fail0;
  349. /* read/write data */
  350. for (i = 0; i < num; i++) {
  351. if (i) {
  352. dev_dbg(&i2c_imx->adapter.dev,
  353. "<%s> repeated start\n", __func__);
  354. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  355. temp |= I2CR_RSTA;
  356. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  357. result = i2c_imx_bus_busy(i2c_imx, 1);
  358. if (result)
  359. goto fail0;
  360. }
  361. dev_dbg(&i2c_imx->adapter.dev,
  362. "<%s> transfer message: %d\n", __func__, i);
  363. /* write/read data */
  364. #ifdef CONFIG_I2C_DEBUG_BUS
  365. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  366. dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
  367. "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
  368. (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
  369. (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
  370. (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
  371. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  372. dev_dbg(&i2c_imx->adapter.dev,
  373. "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
  374. "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
  375. (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
  376. (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
  377. (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
  378. (temp & I2SR_RXAK ? 1 : 0));
  379. #endif
  380. if (msgs[i].flags & I2C_M_RD)
  381. result = i2c_imx_read(i2c_imx, &msgs[i]);
  382. else
  383. result = i2c_imx_write(i2c_imx, &msgs[i]);
  384. }
  385. fail0:
  386. /* Stop I2C transfer */
  387. i2c_imx_stop(i2c_imx);
  388. dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
  389. (result < 0) ? "error" : "success msg",
  390. (result < 0) ? result : num);
  391. return (result < 0) ? result : num;
  392. }
  393. static u32 i2c_imx_func(struct i2c_adapter *adapter)
  394. {
  395. return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  396. }
  397. static struct i2c_algorithm i2c_imx_algo = {
  398. .master_xfer = i2c_imx_xfer,
  399. .functionality = i2c_imx_func,
  400. };
  401. static int __init i2c_imx_probe(struct platform_device *pdev)
  402. {
  403. struct imx_i2c_struct *i2c_imx;
  404. struct resource *res;
  405. struct imxi2c_platform_data *pdata;
  406. void __iomem *base;
  407. resource_size_t res_size;
  408. int irq;
  409. int ret;
  410. dev_dbg(&pdev->dev, "<%s>\n", __func__);
  411. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  412. if (!res) {
  413. dev_err(&pdev->dev, "can't get device resources\n");
  414. return -ENOENT;
  415. }
  416. irq = platform_get_irq(pdev, 0);
  417. if (irq < 0) {
  418. dev_err(&pdev->dev, "can't get irq number\n");
  419. return -ENOENT;
  420. }
  421. pdata = pdev->dev.platform_data;
  422. if (pdata && pdata->init) {
  423. ret = pdata->init(&pdev->dev);
  424. if (ret)
  425. return ret;
  426. }
  427. res_size = resource_size(res);
  428. base = ioremap(res->start, res_size);
  429. if (!base) {
  430. dev_err(&pdev->dev, "ioremap failed\n");
  431. ret = -EIO;
  432. goto fail0;
  433. }
  434. i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
  435. if (!i2c_imx) {
  436. dev_err(&pdev->dev, "can't allocate interface\n");
  437. ret = -ENOMEM;
  438. goto fail1;
  439. }
  440. if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
  441. ret = -EBUSY;
  442. goto fail2;
  443. }
  444. /* Setup i2c_imx driver structure */
  445. strcpy(i2c_imx->adapter.name, pdev->name);
  446. i2c_imx->adapter.owner = THIS_MODULE;
  447. i2c_imx->adapter.algo = &i2c_imx_algo;
  448. i2c_imx->adapter.dev.parent = &pdev->dev;
  449. i2c_imx->adapter.nr = pdev->id;
  450. i2c_imx->irq = irq;
  451. i2c_imx->base = base;
  452. i2c_imx->res = res;
  453. /* Get I2C clock */
  454. i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
  455. if (IS_ERR(i2c_imx->clk)) {
  456. ret = PTR_ERR(i2c_imx->clk);
  457. dev_err(&pdev->dev, "can't get I2C clock\n");
  458. goto fail3;
  459. }
  460. clk_enable(i2c_imx->clk);
  461. /* Request IRQ */
  462. ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
  463. if (ret) {
  464. dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
  465. goto fail4;
  466. }
  467. /* Init queue */
  468. init_waitqueue_head(&i2c_imx->queue);
  469. /* Set up adapter data */
  470. i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
  471. /* Set up clock divider */
  472. if (pdata && pdata->bitrate)
  473. i2c_imx_set_clk(i2c_imx, pdata->bitrate);
  474. else
  475. i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
  476. /* Set up chip registers to defaults */
  477. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  478. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  479. /* Add I2C adapter */
  480. ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
  481. if (ret < 0) {
  482. dev_err(&pdev->dev, "registration failed\n");
  483. goto fail5;
  484. }
  485. /* Set up platform driver data */
  486. platform_set_drvdata(pdev, i2c_imx);
  487. dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
  488. dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
  489. i2c_imx->res->start, i2c_imx->res->end);
  490. dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
  491. res_size, i2c_imx->res->start);
  492. dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
  493. i2c_imx->adapter.name);
  494. dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
  495. return 0; /* Return OK */
  496. fail5:
  497. free_irq(i2c_imx->irq, i2c_imx);
  498. fail4:
  499. clk_disable(i2c_imx->clk);
  500. clk_put(i2c_imx->clk);
  501. fail3:
  502. release_mem_region(i2c_imx->res->start, resource_size(res));
  503. fail2:
  504. kfree(i2c_imx);
  505. fail1:
  506. iounmap(base);
  507. fail0:
  508. if (pdata && pdata->exit)
  509. pdata->exit(&pdev->dev);
  510. return ret; /* Return error number */
  511. }
  512. static int __exit i2c_imx_remove(struct platform_device *pdev)
  513. {
  514. struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
  515. struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
  516. /* remove adapter */
  517. dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
  518. i2c_del_adapter(&i2c_imx->adapter);
  519. platform_set_drvdata(pdev, NULL);
  520. /* free interrupt */
  521. free_irq(i2c_imx->irq, i2c_imx);
  522. /* setup chip registers to defaults */
  523. writeb(0, i2c_imx->base + IMX_I2C_IADR);
  524. writeb(0, i2c_imx->base + IMX_I2C_IFDR);
  525. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  526. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  527. /* Shut down hardware */
  528. if (pdata && pdata->exit)
  529. pdata->exit(&pdev->dev);
  530. /* Disable I2C clock */
  531. clk_disable(i2c_imx->clk);
  532. clk_put(i2c_imx->clk);
  533. release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
  534. iounmap(i2c_imx->base);
  535. kfree(i2c_imx);
  536. return 0;
  537. }
  538. static struct platform_driver i2c_imx_driver = {
  539. .probe = i2c_imx_probe,
  540. .remove = __exit_p(i2c_imx_remove),
  541. .driver = {
  542. .name = DRIVER_NAME,
  543. .owner = THIS_MODULE,
  544. }
  545. };
  546. static int __init i2c_adap_imx_init(void)
  547. {
  548. return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
  549. }
  550. subsys_initcall(i2c_adap_imx_init);
  551. static void __exit i2c_adap_imx_exit(void)
  552. {
  553. platform_driver_unregister(&i2c_imx_driver);
  554. }
  555. module_exit(i2c_adap_imx_exit);
  556. MODULE_LICENSE("GPL");
  557. MODULE_AUTHOR("Darius Augulis");
  558. MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
  559. MODULE_ALIAS("platform:" DRIVER_NAME);