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