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. unsigned int ifdr; /* IMX_I2C_IFDR */
  113. };
  114. /** Functions for IMX I2C adapter driver ***************************************
  115. *******************************************************************************/
  116. static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
  117. {
  118. unsigned long orig_jiffies = jiffies;
  119. unsigned int temp;
  120. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  121. while (1) {
  122. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  123. if (for_busy && (temp & I2SR_IBB))
  124. break;
  125. if (!for_busy && !(temp & I2SR_IBB))
  126. break;
  127. if (signal_pending(current)) {
  128. dev_dbg(&i2c_imx->adapter.dev,
  129. "<%s> I2C Interrupted\n", __func__);
  130. return -EINTR;
  131. }
  132. if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
  133. dev_dbg(&i2c_imx->adapter.dev,
  134. "<%s> I2C bus is busy\n", __func__);
  135. return -EIO;
  136. }
  137. schedule();
  138. }
  139. return 0;
  140. }
  141. static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
  142. {
  143. int result;
  144. result = wait_event_interruptible_timeout(i2c_imx->queue,
  145. i2c_imx->i2csr & I2SR_IIF, HZ / 10);
  146. if (unlikely(result < 0)) {
  147. dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
  148. return result;
  149. } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
  150. dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
  151. return -ETIMEDOUT;
  152. }
  153. dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
  154. i2c_imx->i2csr = 0;
  155. return 0;
  156. }
  157. static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
  158. {
  159. if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
  160. dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
  161. return -EIO; /* No ACK */
  162. }
  163. dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
  164. return 0;
  165. }
  166. static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
  167. {
  168. unsigned int temp = 0;
  169. int result;
  170. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  171. clk_enable(i2c_imx->clk);
  172. writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
  173. /* Enable I2C controller */
  174. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  175. writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
  176. /* Wait controller to be stable */
  177. udelay(50);
  178. /* Start I2C transaction */
  179. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  180. temp |= I2CR_MSTA;
  181. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  182. result = i2c_imx_bus_busy(i2c_imx, 1);
  183. if (result)
  184. return result;
  185. i2c_imx->stopped = 0;
  186. temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
  187. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  188. return result;
  189. }
  190. static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
  191. {
  192. unsigned int temp = 0;
  193. if (!i2c_imx->stopped) {
  194. /* Stop I2C transaction */
  195. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  196. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  197. temp &= ~(I2CR_MSTA | I2CR_MTX);
  198. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  199. i2c_imx->stopped = 1;
  200. }
  201. if (cpu_is_mx1()) {
  202. /*
  203. * This delay caused by an i.MXL hardware bug.
  204. * If no (or too short) delay, no "STOP" bit will be generated.
  205. */
  206. udelay(i2c_imx->disable_delay);
  207. }
  208. if (!i2c_imx->stopped)
  209. i2c_imx_bus_busy(i2c_imx, 0);
  210. /* Disable I2C controller */
  211. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  212. clk_disable(i2c_imx->clk);
  213. }
  214. static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
  215. unsigned int rate)
  216. {
  217. unsigned int i2c_clk_rate;
  218. unsigned int div;
  219. int i;
  220. /* Divider value calculation */
  221. i2c_clk_rate = clk_get_rate(i2c_imx->clk);
  222. div = (i2c_clk_rate + rate - 1) / rate;
  223. if (div < i2c_clk_div[0][0])
  224. i = 0;
  225. else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
  226. i = ARRAY_SIZE(i2c_clk_div) - 1;
  227. else
  228. for (i = 0; i2c_clk_div[i][0] < div; i++);
  229. /* Store divider value */
  230. i2c_imx->ifdr = i2c_clk_div[i][1];
  231. /*
  232. * There dummy delay is calculated.
  233. * It should be about one I2C clock period long.
  234. * This delay is used in I2C bus disable function
  235. * to fix chip hardware bug.
  236. */
  237. i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
  238. + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
  239. /* dev_dbg() can't be used, because adapter is not yet registered */
  240. #ifdef CONFIG_I2C_DEBUG_BUS
  241. printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
  242. __func__, i2c_clk_rate, div);
  243. printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
  244. __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
  245. #endif
  246. }
  247. static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
  248. {
  249. struct imx_i2c_struct *i2c_imx = dev_id;
  250. unsigned int temp;
  251. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  252. if (temp & I2SR_IIF) {
  253. /* save status register */
  254. i2c_imx->i2csr = temp;
  255. temp &= ~I2SR_IIF;
  256. writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
  257. wake_up_interruptible(&i2c_imx->queue);
  258. return IRQ_HANDLED;
  259. }
  260. return IRQ_NONE;
  261. }
  262. static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  263. {
  264. int i, result;
  265. dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
  266. __func__, msgs->addr << 1);
  267. /* write slave address */
  268. writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
  269. result = i2c_imx_trx_complete(i2c_imx);
  270. if (result)
  271. return result;
  272. result = i2c_imx_acked(i2c_imx);
  273. if (result)
  274. return result;
  275. dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
  276. /* write data */
  277. for (i = 0; i < msgs->len; i++) {
  278. dev_dbg(&i2c_imx->adapter.dev,
  279. "<%s> write byte: B%d=0x%X\n",
  280. __func__, i, msgs->buf[i]);
  281. writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
  282. result = i2c_imx_trx_complete(i2c_imx);
  283. if (result)
  284. return result;
  285. result = i2c_imx_acked(i2c_imx);
  286. if (result)
  287. return result;
  288. }
  289. return 0;
  290. }
  291. static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  292. {
  293. int i, result;
  294. unsigned int temp;
  295. dev_dbg(&i2c_imx->adapter.dev,
  296. "<%s> write slave address: addr=0x%x\n",
  297. __func__, (msgs->addr << 1) | 0x01);
  298. /* write slave address */
  299. writeb((msgs->addr << 1) | 0x01, 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. dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
  307. /* setup bus to read data */
  308. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  309. temp &= ~I2CR_MTX;
  310. if (msgs->len - 1)
  311. temp &= ~I2CR_TXAK;
  312. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  313. readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
  314. dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
  315. /* read data */
  316. for (i = 0; i < msgs->len; i++) {
  317. result = i2c_imx_trx_complete(i2c_imx);
  318. if (result)
  319. return result;
  320. if (i == (msgs->len - 1)) {
  321. /* It must generate STOP before read I2DR to prevent
  322. controller from generating another clock cycle */
  323. dev_dbg(&i2c_imx->adapter.dev,
  324. "<%s> clear MSTA\n", __func__);
  325. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  326. temp &= ~(I2CR_MSTA | I2CR_MTX);
  327. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  328. i2c_imx_bus_busy(i2c_imx, 0);
  329. i2c_imx->stopped = 1;
  330. } else if (i == (msgs->len - 2)) {
  331. dev_dbg(&i2c_imx->adapter.dev,
  332. "<%s> set TXAK\n", __func__);
  333. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  334. temp |= I2CR_TXAK;
  335. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  336. }
  337. msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
  338. dev_dbg(&i2c_imx->adapter.dev,
  339. "<%s> read byte: B%d=0x%X\n",
  340. __func__, i, msgs->buf[i]);
  341. }
  342. return 0;
  343. }
  344. static int i2c_imx_xfer(struct i2c_adapter *adapter,
  345. struct i2c_msg *msgs, int num)
  346. {
  347. unsigned int i, temp;
  348. int result;
  349. struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
  350. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  351. /* Start I2C transfer */
  352. result = i2c_imx_start(i2c_imx);
  353. if (result)
  354. goto fail0;
  355. /* read/write data */
  356. for (i = 0; i < num; i++) {
  357. if (i) {
  358. dev_dbg(&i2c_imx->adapter.dev,
  359. "<%s> repeated start\n", __func__);
  360. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  361. temp |= I2CR_RSTA;
  362. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  363. result = i2c_imx_bus_busy(i2c_imx, 1);
  364. if (result)
  365. goto fail0;
  366. }
  367. dev_dbg(&i2c_imx->adapter.dev,
  368. "<%s> transfer message: %d\n", __func__, i);
  369. /* write/read data */
  370. #ifdef CONFIG_I2C_DEBUG_BUS
  371. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  372. dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
  373. "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
  374. (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
  375. (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
  376. (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
  377. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  378. dev_dbg(&i2c_imx->adapter.dev,
  379. "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
  380. "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
  381. (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
  382. (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
  383. (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
  384. (temp & I2SR_RXAK ? 1 : 0));
  385. #endif
  386. if (msgs[i].flags & I2C_M_RD)
  387. result = i2c_imx_read(i2c_imx, &msgs[i]);
  388. else
  389. result = i2c_imx_write(i2c_imx, &msgs[i]);
  390. }
  391. fail0:
  392. /* Stop I2C transfer */
  393. i2c_imx_stop(i2c_imx);
  394. dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
  395. (result < 0) ? "error" : "success msg",
  396. (result < 0) ? result : num);
  397. return (result < 0) ? result : num;
  398. }
  399. static u32 i2c_imx_func(struct i2c_adapter *adapter)
  400. {
  401. return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  402. }
  403. static struct i2c_algorithm i2c_imx_algo = {
  404. .master_xfer = i2c_imx_xfer,
  405. .functionality = i2c_imx_func,
  406. };
  407. static int __init i2c_imx_probe(struct platform_device *pdev)
  408. {
  409. struct imx_i2c_struct *i2c_imx;
  410. struct resource *res;
  411. struct imxi2c_platform_data *pdata;
  412. void __iomem *base;
  413. resource_size_t res_size;
  414. int irq;
  415. int ret;
  416. dev_dbg(&pdev->dev, "<%s>\n", __func__);
  417. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  418. if (!res) {
  419. dev_err(&pdev->dev, "can't get device resources\n");
  420. return -ENOENT;
  421. }
  422. irq = platform_get_irq(pdev, 0);
  423. if (irq < 0) {
  424. dev_err(&pdev->dev, "can't get irq number\n");
  425. return -ENOENT;
  426. }
  427. pdata = pdev->dev.platform_data;
  428. if (pdata && pdata->init) {
  429. ret = pdata->init(&pdev->dev);
  430. if (ret)
  431. return ret;
  432. }
  433. res_size = resource_size(res);
  434. base = ioremap(res->start, res_size);
  435. if (!base) {
  436. dev_err(&pdev->dev, "ioremap failed\n");
  437. ret = -EIO;
  438. goto fail0;
  439. }
  440. i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
  441. if (!i2c_imx) {
  442. dev_err(&pdev->dev, "can't allocate interface\n");
  443. ret = -ENOMEM;
  444. goto fail1;
  445. }
  446. if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
  447. ret = -EBUSY;
  448. goto fail2;
  449. }
  450. /* Setup i2c_imx driver structure */
  451. strcpy(i2c_imx->adapter.name, pdev->name);
  452. i2c_imx->adapter.owner = THIS_MODULE;
  453. i2c_imx->adapter.algo = &i2c_imx_algo;
  454. i2c_imx->adapter.dev.parent = &pdev->dev;
  455. i2c_imx->adapter.nr = pdev->id;
  456. i2c_imx->irq = irq;
  457. i2c_imx->base = base;
  458. i2c_imx->res = res;
  459. /* Get I2C clock */
  460. i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
  461. if (IS_ERR(i2c_imx->clk)) {
  462. ret = PTR_ERR(i2c_imx->clk);
  463. dev_err(&pdev->dev, "can't get I2C clock\n");
  464. goto fail3;
  465. }
  466. /* Request IRQ */
  467. ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
  468. if (ret) {
  469. dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
  470. goto fail4;
  471. }
  472. /* Init queue */
  473. init_waitqueue_head(&i2c_imx->queue);
  474. /* Set up adapter data */
  475. i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
  476. /* Set up clock divider */
  477. if (pdata && pdata->bitrate)
  478. i2c_imx_set_clk(i2c_imx, pdata->bitrate);
  479. else
  480. i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
  481. /* Set up chip registers to defaults */
  482. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  483. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  484. /* Add I2C adapter */
  485. ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
  486. if (ret < 0) {
  487. dev_err(&pdev->dev, "registration failed\n");
  488. goto fail5;
  489. }
  490. /* Set up platform driver data */
  491. platform_set_drvdata(pdev, i2c_imx);
  492. dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
  493. dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
  494. i2c_imx->res->start, i2c_imx->res->end);
  495. dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
  496. res_size, i2c_imx->res->start);
  497. dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
  498. i2c_imx->adapter.name);
  499. dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
  500. return 0; /* Return OK */
  501. fail5:
  502. free_irq(i2c_imx->irq, i2c_imx);
  503. fail4:
  504. clk_put(i2c_imx->clk);
  505. fail3:
  506. release_mem_region(i2c_imx->res->start, resource_size(res));
  507. fail2:
  508. kfree(i2c_imx);
  509. fail1:
  510. iounmap(base);
  511. fail0:
  512. if (pdata && pdata->exit)
  513. pdata->exit(&pdev->dev);
  514. return ret; /* Return error number */
  515. }
  516. static int __exit i2c_imx_remove(struct platform_device *pdev)
  517. {
  518. struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
  519. struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
  520. /* remove adapter */
  521. dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
  522. i2c_del_adapter(&i2c_imx->adapter);
  523. platform_set_drvdata(pdev, NULL);
  524. /* free interrupt */
  525. free_irq(i2c_imx->irq, i2c_imx);
  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. /* Shut down hardware */
  532. if (pdata && pdata->exit)
  533. pdata->exit(&pdev->dev);
  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);