i2c-imx.c 18 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647
  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 <mach/irqs.h>
  53. #include <mach/hardware.h>
  54. #include <mach/i2c.h>
  55. /** Defines ********************************************************************
  56. *******************************************************************************/
  57. /* This will be the driver name the kernel reports */
  58. #define DRIVER_NAME "imx-i2c"
  59. /* Default value */
  60. #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
  61. /* IMX I2C registers */
  62. #define IMX_I2C_IADR 0x00 /* i2c slave address */
  63. #define IMX_I2C_IFDR 0x04 /* i2c frequency divider */
  64. #define IMX_I2C_I2CR 0x08 /* i2c control */
  65. #define IMX_I2C_I2SR 0x0C /* i2c status */
  66. #define IMX_I2C_I2DR 0x10 /* i2c transfer data */
  67. /* Bits of IMX I2C registers */
  68. #define I2SR_RXAK 0x01
  69. #define I2SR_IIF 0x02
  70. #define I2SR_SRW 0x04
  71. #define I2SR_IAL 0x10
  72. #define I2SR_IBB 0x20
  73. #define I2SR_IAAS 0x40
  74. #define I2SR_ICF 0x80
  75. #define I2CR_RSTA 0x04
  76. #define I2CR_TXAK 0x08
  77. #define I2CR_MTX 0x10
  78. #define I2CR_MSTA 0x20
  79. #define I2CR_IIEN 0x40
  80. #define I2CR_IEN 0x80
  81. /** Variables ******************************************************************
  82. *******************************************************************************/
  83. /*
  84. * sorted list of clock divider, register value pairs
  85. * taken from table 26-5, p.26-9, Freescale i.MX
  86. * Integrated Portable System Processor Reference Manual
  87. * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  88. *
  89. * Duplicated divider values removed from list
  90. */
  91. static u16 __initdata i2c_clk_div[50][2] = {
  92. { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
  93. { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
  94. { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
  95. { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
  96. { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
  97. { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
  98. { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
  99. { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
  100. { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
  101. { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
  102. { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
  103. { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
  104. { 3072, 0x1E }, { 3840, 0x1F }
  105. };
  106. struct imx_i2c_struct {
  107. struct i2c_adapter adapter;
  108. struct resource *res;
  109. struct clk *clk;
  110. void __iomem *base;
  111. int irq;
  112. wait_queue_head_t queue;
  113. unsigned long i2csr;
  114. unsigned int disable_delay;
  115. int stopped;
  116. unsigned int ifdr; /* IMX_I2C_IFDR */
  117. };
  118. static const struct of_device_id i2c_imx_dt_ids[] = {
  119. { .compatible = "fsl,imx1-i2c", },
  120. { /* sentinel */ }
  121. };
  122. /** Functions for IMX I2C adapter driver ***************************************
  123. *******************************************************************************/
  124. static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
  125. {
  126. unsigned long orig_jiffies = jiffies;
  127. unsigned int temp;
  128. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  129. while (1) {
  130. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  131. if (for_busy && (temp & I2SR_IBB))
  132. break;
  133. if (!for_busy && !(temp & I2SR_IBB))
  134. break;
  135. if (signal_pending(current)) {
  136. dev_dbg(&i2c_imx->adapter.dev,
  137. "<%s> I2C Interrupted\n", __func__);
  138. return -EINTR;
  139. }
  140. if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
  141. dev_dbg(&i2c_imx->adapter.dev,
  142. "<%s> I2C bus is busy\n", __func__);
  143. return -ETIMEDOUT;
  144. }
  145. schedule();
  146. }
  147. return 0;
  148. }
  149. static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
  150. {
  151. wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
  152. if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
  153. dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
  154. return -ETIMEDOUT;
  155. }
  156. dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
  157. i2c_imx->i2csr = 0;
  158. return 0;
  159. }
  160. static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
  161. {
  162. if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
  163. dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
  164. return -EIO; /* No ACK */
  165. }
  166. dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
  167. return 0;
  168. }
  169. static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
  170. {
  171. unsigned int temp = 0;
  172. int result;
  173. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  174. clk_enable(i2c_imx->clk);
  175. writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
  176. /* Enable I2C controller */
  177. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  178. writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
  179. /* Wait controller to be stable */
  180. udelay(50);
  181. /* Start I2C transaction */
  182. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  183. temp |= I2CR_MSTA;
  184. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  185. result = i2c_imx_bus_busy(i2c_imx, 1);
  186. if (result)
  187. return result;
  188. i2c_imx->stopped = 0;
  189. temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
  190. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  191. return result;
  192. }
  193. static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
  194. {
  195. unsigned int temp = 0;
  196. if (!i2c_imx->stopped) {
  197. /* Stop I2C transaction */
  198. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  199. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  200. temp &= ~(I2CR_MSTA | I2CR_MTX);
  201. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  202. }
  203. if (cpu_is_mx1()) {
  204. /*
  205. * This delay caused by an i.MXL hardware bug.
  206. * If no (or too short) delay, no "STOP" bit will be generated.
  207. */
  208. udelay(i2c_imx->disable_delay);
  209. }
  210. if (!i2c_imx->stopped) {
  211. i2c_imx_bus_busy(i2c_imx, 0);
  212. i2c_imx->stopped = 1;
  213. }
  214. /* Disable I2C controller */
  215. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  216. clk_disable(i2c_imx->clk);
  217. }
  218. static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
  219. unsigned int rate)
  220. {
  221. unsigned int i2c_clk_rate;
  222. unsigned int div;
  223. int i;
  224. /* Divider value calculation */
  225. i2c_clk_rate = clk_get_rate(i2c_imx->clk);
  226. div = (i2c_clk_rate + rate - 1) / rate;
  227. if (div < i2c_clk_div[0][0])
  228. i = 0;
  229. else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
  230. i = ARRAY_SIZE(i2c_clk_div) - 1;
  231. else
  232. for (i = 0; i2c_clk_div[i][0] < div; i++);
  233. /* Store divider value */
  234. i2c_imx->ifdr = i2c_clk_div[i][1];
  235. /*
  236. * There dummy delay is calculated.
  237. * It should be about one I2C clock period long.
  238. * This delay is used in I2C bus disable function
  239. * to fix chip hardware bug.
  240. */
  241. i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
  242. + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
  243. /* dev_dbg() can't be used, because adapter is not yet registered */
  244. #ifdef CONFIG_I2C_DEBUG_BUS
  245. printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
  246. __func__, i2c_clk_rate, div);
  247. printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
  248. __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
  249. #endif
  250. }
  251. static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
  252. {
  253. struct imx_i2c_struct *i2c_imx = dev_id;
  254. unsigned int temp;
  255. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  256. if (temp & I2SR_IIF) {
  257. /* save status register */
  258. i2c_imx->i2csr = temp;
  259. temp &= ~I2SR_IIF;
  260. writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
  261. wake_up(&i2c_imx->queue);
  262. return IRQ_HANDLED;
  263. }
  264. return IRQ_NONE;
  265. }
  266. static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  267. {
  268. int i, result;
  269. dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
  270. __func__, msgs->addr << 1);
  271. /* write slave address */
  272. writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
  273. result = i2c_imx_trx_complete(i2c_imx);
  274. if (result)
  275. return result;
  276. result = i2c_imx_acked(i2c_imx);
  277. if (result)
  278. return result;
  279. dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
  280. /* write data */
  281. for (i = 0; i < msgs->len; i++) {
  282. dev_dbg(&i2c_imx->adapter.dev,
  283. "<%s> write byte: B%d=0x%X\n",
  284. __func__, i, msgs->buf[i]);
  285. writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
  286. result = i2c_imx_trx_complete(i2c_imx);
  287. if (result)
  288. return result;
  289. result = i2c_imx_acked(i2c_imx);
  290. if (result)
  291. return result;
  292. }
  293. return 0;
  294. }
  295. static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
  296. {
  297. int i, result;
  298. unsigned int temp;
  299. dev_dbg(&i2c_imx->adapter.dev,
  300. "<%s> write slave address: addr=0x%x\n",
  301. __func__, (msgs->addr << 1) | 0x01);
  302. /* write slave address */
  303. writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
  304. result = i2c_imx_trx_complete(i2c_imx);
  305. if (result)
  306. return result;
  307. result = i2c_imx_acked(i2c_imx);
  308. if (result)
  309. return result;
  310. dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
  311. /* setup bus to read data */
  312. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  313. temp &= ~I2CR_MTX;
  314. if (msgs->len - 1)
  315. temp &= ~I2CR_TXAK;
  316. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  317. readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
  318. dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
  319. /* read data */
  320. for (i = 0; i < msgs->len; i++) {
  321. result = i2c_imx_trx_complete(i2c_imx);
  322. if (result)
  323. return result;
  324. if (i == (msgs->len - 1)) {
  325. /* It must generate STOP before read I2DR to prevent
  326. controller from generating another clock cycle */
  327. dev_dbg(&i2c_imx->adapter.dev,
  328. "<%s> clear MSTA\n", __func__);
  329. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  330. temp &= ~(I2CR_MSTA | I2CR_MTX);
  331. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  332. i2c_imx_bus_busy(i2c_imx, 0);
  333. i2c_imx->stopped = 1;
  334. } else if (i == (msgs->len - 2)) {
  335. dev_dbg(&i2c_imx->adapter.dev,
  336. "<%s> set TXAK\n", __func__);
  337. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  338. temp |= I2CR_TXAK;
  339. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  340. }
  341. msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
  342. dev_dbg(&i2c_imx->adapter.dev,
  343. "<%s> read byte: B%d=0x%X\n",
  344. __func__, i, msgs->buf[i]);
  345. }
  346. return 0;
  347. }
  348. static int i2c_imx_xfer(struct i2c_adapter *adapter,
  349. struct i2c_msg *msgs, int num)
  350. {
  351. unsigned int i, temp;
  352. int result;
  353. struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
  354. dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
  355. /* Start I2C transfer */
  356. result = i2c_imx_start(i2c_imx);
  357. if (result)
  358. goto fail0;
  359. /* read/write data */
  360. for (i = 0; i < num; i++) {
  361. if (i) {
  362. dev_dbg(&i2c_imx->adapter.dev,
  363. "<%s> repeated start\n", __func__);
  364. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  365. temp |= I2CR_RSTA;
  366. writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
  367. result = i2c_imx_bus_busy(i2c_imx, 1);
  368. if (result)
  369. goto fail0;
  370. }
  371. dev_dbg(&i2c_imx->adapter.dev,
  372. "<%s> transfer message: %d\n", __func__, i);
  373. /* write/read data */
  374. #ifdef CONFIG_I2C_DEBUG_BUS
  375. temp = readb(i2c_imx->base + IMX_I2C_I2CR);
  376. dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
  377. "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
  378. (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
  379. (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
  380. (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
  381. temp = readb(i2c_imx->base + IMX_I2C_I2SR);
  382. dev_dbg(&i2c_imx->adapter.dev,
  383. "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
  384. "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
  385. (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
  386. (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
  387. (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
  388. (temp & I2SR_RXAK ? 1 : 0));
  389. #endif
  390. if (msgs[i].flags & I2C_M_RD)
  391. result = i2c_imx_read(i2c_imx, &msgs[i]);
  392. else
  393. result = i2c_imx_write(i2c_imx, &msgs[i]);
  394. if (result)
  395. goto fail0;
  396. }
  397. fail0:
  398. /* Stop I2C transfer */
  399. i2c_imx_stop(i2c_imx);
  400. dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
  401. (result < 0) ? "error" : "success msg",
  402. (result < 0) ? result : num);
  403. return (result < 0) ? result : num;
  404. }
  405. static u32 i2c_imx_func(struct i2c_adapter *adapter)
  406. {
  407. return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  408. }
  409. static struct i2c_algorithm i2c_imx_algo = {
  410. .master_xfer = i2c_imx_xfer,
  411. .functionality = i2c_imx_func,
  412. };
  413. static int __init i2c_imx_probe(struct platform_device *pdev)
  414. {
  415. struct imx_i2c_struct *i2c_imx;
  416. struct resource *res;
  417. struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
  418. void __iomem *base;
  419. resource_size_t res_size;
  420. int irq, bitrate;
  421. int ret;
  422. dev_dbg(&pdev->dev, "<%s>\n", __func__);
  423. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  424. if (!res) {
  425. dev_err(&pdev->dev, "can't get device resources\n");
  426. return -ENOENT;
  427. }
  428. irq = platform_get_irq(pdev, 0);
  429. if (irq < 0) {
  430. dev_err(&pdev->dev, "can't get irq number\n");
  431. return -ENOENT;
  432. }
  433. res_size = resource_size(res);
  434. if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
  435. dev_err(&pdev->dev, "request_mem_region failed\n");
  436. return -EBUSY;
  437. }
  438. base = ioremap(res->start, res_size);
  439. if (!base) {
  440. dev_err(&pdev->dev, "ioremap failed\n");
  441. ret = -EIO;
  442. goto fail1;
  443. }
  444. i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
  445. if (!i2c_imx) {
  446. dev_err(&pdev->dev, "can't allocate interface\n");
  447. ret = -ENOMEM;
  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->adapter.dev.of_node = pdev->dev.of_node;
  457. i2c_imx->irq = irq;
  458. i2c_imx->base = base;
  459. i2c_imx->res = res;
  460. /* Get I2C clock */
  461. i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
  462. if (IS_ERR(i2c_imx->clk)) {
  463. ret = PTR_ERR(i2c_imx->clk);
  464. dev_err(&pdev->dev, "can't get I2C clock\n");
  465. goto fail3;
  466. }
  467. /* Request IRQ */
  468. ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
  469. if (ret) {
  470. dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
  471. goto fail4;
  472. }
  473. /* Init queue */
  474. init_waitqueue_head(&i2c_imx->queue);
  475. /* Set up adapter data */
  476. i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
  477. /* Set up clock divider */
  478. bitrate = IMX_I2C_BIT_RATE;
  479. ret = of_property_read_u32(pdev->dev.of_node,
  480. "clock-frequency", &bitrate);
  481. if (ret < 0 && pdata && pdata->bitrate)
  482. bitrate = pdata->bitrate;
  483. i2c_imx_set_clk(i2c_imx, bitrate);
  484. /* Set up chip registers to defaults */
  485. writeb(0, i2c_imx->base + IMX_I2C_I2CR);
  486. writeb(0, i2c_imx->base + IMX_I2C_I2SR);
  487. /* Add I2C adapter */
  488. ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
  489. if (ret < 0) {
  490. dev_err(&pdev->dev, "registration failed\n");
  491. goto fail5;
  492. }
  493. of_i2c_register_devices(&i2c_imx->adapter);
  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. return ret; /* Return error number */
  516. }
  517. static int __exit i2c_imx_remove(struct platform_device *pdev)
  518. {
  519. struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
  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. clk_put(i2c_imx->clk);
  532. iounmap(i2c_imx->base);
  533. release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
  534. kfree(i2c_imx);
  535. return 0;
  536. }
  537. static struct platform_driver i2c_imx_driver = {
  538. .remove = __exit_p(i2c_imx_remove),
  539. .driver = {
  540. .name = DRIVER_NAME,
  541. .owner = THIS_MODULE,
  542. .of_match_table = i2c_imx_dt_ids,
  543. }
  544. };
  545. static int __init i2c_adap_imx_init(void)
  546. {
  547. return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
  548. }
  549. subsys_initcall(i2c_adap_imx_init);
  550. static void __exit i2c_adap_imx_exit(void)
  551. {
  552. platform_driver_unregister(&i2c_imx_driver);
  553. }
  554. module_exit(i2c_adap_imx_exit);
  555. MODULE_LICENSE("GPL");
  556. MODULE_AUTHOR("Darius Augulis");
  557. MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
  558. MODULE_ALIAS("platform:" DRIVER_NAME);