spi_bfin5xx.c 39 KB

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  1. /*
  2. * Blackfin On-Chip SPI Driver
  3. *
  4. * Copyright 2004-2007 Analog Devices Inc.
  5. *
  6. * Enter bugs at http://blackfin.uclinux.org/
  7. *
  8. * Licensed under the GPL-2 or later.
  9. */
  10. #include <linux/init.h>
  11. #include <linux/module.h>
  12. #include <linux/delay.h>
  13. #include <linux/device.h>
  14. #include <linux/slab.h>
  15. #include <linux/io.h>
  16. #include <linux/ioport.h>
  17. #include <linux/irq.h>
  18. #include <linux/errno.h>
  19. #include <linux/interrupt.h>
  20. #include <linux/platform_device.h>
  21. #include <linux/dma-mapping.h>
  22. #include <linux/spi/spi.h>
  23. #include <linux/workqueue.h>
  24. #include <asm/dma.h>
  25. #include <asm/portmux.h>
  26. #include <asm/bfin5xx_spi.h>
  27. #include <asm/cacheflush.h>
  28. #define DRV_NAME "bfin-spi"
  29. #define DRV_AUTHOR "Bryan Wu, Luke Yang"
  30. #define DRV_DESC "Blackfin on-chip SPI Controller Driver"
  31. #define DRV_VERSION "1.0"
  32. MODULE_AUTHOR(DRV_AUTHOR);
  33. MODULE_DESCRIPTION(DRV_DESC);
  34. MODULE_LICENSE("GPL");
  35. #define START_STATE ((void *)0)
  36. #define RUNNING_STATE ((void *)1)
  37. #define DONE_STATE ((void *)2)
  38. #define ERROR_STATE ((void *)-1)
  39. #define QUEUE_RUNNING 0
  40. #define QUEUE_STOPPED 1
  41. /* Value to send if no TX value is supplied */
  42. #define SPI_IDLE_TXVAL 0x0000
  43. struct driver_data {
  44. /* Driver model hookup */
  45. struct platform_device *pdev;
  46. /* SPI framework hookup */
  47. struct spi_master *master;
  48. /* Regs base of SPI controller */
  49. void __iomem *regs_base;
  50. /* Pin request list */
  51. u16 *pin_req;
  52. /* BFIN hookup */
  53. struct bfin5xx_spi_master *master_info;
  54. /* Driver message queue */
  55. struct workqueue_struct *workqueue;
  56. struct work_struct pump_messages;
  57. spinlock_t lock;
  58. struct list_head queue;
  59. int busy;
  60. int run;
  61. /* Message Transfer pump */
  62. struct tasklet_struct pump_transfers;
  63. /* Current message transfer state info */
  64. struct spi_message *cur_msg;
  65. struct spi_transfer *cur_transfer;
  66. struct chip_data *cur_chip;
  67. size_t len_in_bytes;
  68. size_t len;
  69. void *tx;
  70. void *tx_end;
  71. void *rx;
  72. void *rx_end;
  73. /* DMA stuffs */
  74. int dma_channel;
  75. int dma_mapped;
  76. int dma_requested;
  77. dma_addr_t rx_dma;
  78. dma_addr_t tx_dma;
  79. size_t rx_map_len;
  80. size_t tx_map_len;
  81. u8 n_bytes;
  82. int cs_change;
  83. void (*write) (struct driver_data *);
  84. void (*read) (struct driver_data *);
  85. void (*duplex) (struct driver_data *);
  86. };
  87. struct chip_data {
  88. u16 ctl_reg;
  89. u16 baud;
  90. u16 flag;
  91. u8 chip_select_num;
  92. u8 n_bytes;
  93. u8 width; /* 0 or 1 */
  94. u8 enable_dma;
  95. u8 bits_per_word; /* 8 or 16 */
  96. u8 cs_change_per_word;
  97. u16 cs_chg_udelay; /* Some devices require > 255usec delay */
  98. u32 cs_gpio;
  99. u16 idle_tx_val;
  100. void (*write) (struct driver_data *);
  101. void (*read) (struct driver_data *);
  102. void (*duplex) (struct driver_data *);
  103. };
  104. #define DEFINE_SPI_REG(reg, off) \
  105. static inline u16 read_##reg(struct driver_data *drv_data) \
  106. { return bfin_read16(drv_data->regs_base + off); } \
  107. static inline void write_##reg(struct driver_data *drv_data, u16 v) \
  108. { bfin_write16(drv_data->regs_base + off, v); }
  109. DEFINE_SPI_REG(CTRL, 0x00)
  110. DEFINE_SPI_REG(FLAG, 0x04)
  111. DEFINE_SPI_REG(STAT, 0x08)
  112. DEFINE_SPI_REG(TDBR, 0x0C)
  113. DEFINE_SPI_REG(RDBR, 0x10)
  114. DEFINE_SPI_REG(BAUD, 0x14)
  115. DEFINE_SPI_REG(SHAW, 0x18)
  116. static void bfin_spi_enable(struct driver_data *drv_data)
  117. {
  118. u16 cr;
  119. cr = read_CTRL(drv_data);
  120. write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
  121. }
  122. static void bfin_spi_disable(struct driver_data *drv_data)
  123. {
  124. u16 cr;
  125. cr = read_CTRL(drv_data);
  126. write_CTRL(drv_data, (cr & (~BIT_CTL_ENABLE)));
  127. }
  128. /* Caculate the SPI_BAUD register value based on input HZ */
  129. static u16 hz_to_spi_baud(u32 speed_hz)
  130. {
  131. u_long sclk = get_sclk();
  132. u16 spi_baud = (sclk / (2 * speed_hz));
  133. if ((sclk % (2 * speed_hz)) > 0)
  134. spi_baud++;
  135. if (spi_baud < MIN_SPI_BAUD_VAL)
  136. spi_baud = MIN_SPI_BAUD_VAL;
  137. return spi_baud;
  138. }
  139. static int bfin_spi_flush(struct driver_data *drv_data)
  140. {
  141. unsigned long limit = loops_per_jiffy << 1;
  142. /* wait for stop and clear stat */
  143. while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && --limit)
  144. cpu_relax();
  145. write_STAT(drv_data, BIT_STAT_CLR);
  146. return limit;
  147. }
  148. /* Chip select operation functions for cs_change flag */
  149. static void bfin_spi_cs_active(struct driver_data *drv_data, struct chip_data *chip)
  150. {
  151. if (likely(chip->chip_select_num)) {
  152. u16 flag = read_FLAG(drv_data);
  153. flag |= chip->flag;
  154. flag &= ~(chip->flag << 8);
  155. write_FLAG(drv_data, flag);
  156. } else {
  157. gpio_set_value(chip->cs_gpio, 0);
  158. }
  159. }
  160. static void bfin_spi_cs_deactive(struct driver_data *drv_data, struct chip_data *chip)
  161. {
  162. if (likely(chip->chip_select_num)) {
  163. u16 flag = read_FLAG(drv_data);
  164. flag &= ~chip->flag;
  165. flag |= (chip->flag << 8);
  166. write_FLAG(drv_data, flag);
  167. } else {
  168. gpio_set_value(chip->cs_gpio, 1);
  169. }
  170. /* Move delay here for consistency */
  171. if (chip->cs_chg_udelay)
  172. udelay(chip->cs_chg_udelay);
  173. }
  174. /* stop controller and re-config current chip*/
  175. static void bfin_spi_restore_state(struct driver_data *drv_data)
  176. {
  177. struct chip_data *chip = drv_data->cur_chip;
  178. /* Clear status and disable clock */
  179. write_STAT(drv_data, BIT_STAT_CLR);
  180. bfin_spi_disable(drv_data);
  181. dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
  182. /* Load the registers */
  183. write_CTRL(drv_data, chip->ctl_reg);
  184. write_BAUD(drv_data, chip->baud);
  185. bfin_spi_enable(drv_data);
  186. bfin_spi_cs_active(drv_data, chip);
  187. }
  188. /* used to kick off transfer in rx mode and read unwanted RX data */
  189. static inline void bfin_spi_dummy_read(struct driver_data *drv_data)
  190. {
  191. (void) read_RDBR(drv_data);
  192. }
  193. static void bfin_spi_null_writer(struct driver_data *drv_data)
  194. {
  195. u8 n_bytes = drv_data->n_bytes;
  196. u16 tx_val = drv_data->cur_chip->idle_tx_val;
  197. /* clear RXS (we check for RXS inside the loop) */
  198. bfin_spi_dummy_read(drv_data);
  199. while (drv_data->tx < drv_data->tx_end) {
  200. write_TDBR(drv_data, tx_val);
  201. drv_data->tx += n_bytes;
  202. /* wait until transfer finished.
  203. checking SPIF or TXS may not guarantee transfer completion */
  204. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  205. cpu_relax();
  206. /* discard RX data and clear RXS */
  207. bfin_spi_dummy_read(drv_data);
  208. }
  209. }
  210. static void bfin_spi_null_reader(struct driver_data *drv_data)
  211. {
  212. u8 n_bytes = drv_data->n_bytes;
  213. u16 tx_val = drv_data->cur_chip->idle_tx_val;
  214. /* discard old RX data and clear RXS */
  215. bfin_spi_dummy_read(drv_data);
  216. while (drv_data->rx < drv_data->rx_end) {
  217. write_TDBR(drv_data, tx_val);
  218. drv_data->rx += n_bytes;
  219. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  220. cpu_relax();
  221. bfin_spi_dummy_read(drv_data);
  222. }
  223. }
  224. static void bfin_spi_u8_writer(struct driver_data *drv_data)
  225. {
  226. /* clear RXS (we check for RXS inside the loop) */
  227. bfin_spi_dummy_read(drv_data);
  228. while (drv_data->tx < drv_data->tx_end) {
  229. write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
  230. /* wait until transfer finished.
  231. checking SPIF or TXS may not guarantee transfer completion */
  232. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  233. cpu_relax();
  234. /* discard RX data and clear RXS */
  235. bfin_spi_dummy_read(drv_data);
  236. }
  237. }
  238. static void bfin_spi_u8_cs_chg_writer(struct driver_data *drv_data)
  239. {
  240. struct chip_data *chip = drv_data->cur_chip;
  241. /* clear RXS (we check for RXS inside the loop) */
  242. bfin_spi_dummy_read(drv_data);
  243. while (drv_data->tx < drv_data->tx_end) {
  244. bfin_spi_cs_active(drv_data, chip);
  245. write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
  246. /* make sure transfer finished before deactiving CS */
  247. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  248. cpu_relax();
  249. bfin_spi_dummy_read(drv_data);
  250. bfin_spi_cs_deactive(drv_data, chip);
  251. }
  252. }
  253. static void bfin_spi_u8_reader(struct driver_data *drv_data)
  254. {
  255. u16 tx_val = drv_data->cur_chip->idle_tx_val;
  256. /* discard old RX data and clear RXS */
  257. bfin_spi_dummy_read(drv_data);
  258. while (drv_data->rx < drv_data->rx_end) {
  259. write_TDBR(drv_data, tx_val);
  260. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  261. cpu_relax();
  262. *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
  263. }
  264. }
  265. static void bfin_spi_u8_cs_chg_reader(struct driver_data *drv_data)
  266. {
  267. struct chip_data *chip = drv_data->cur_chip;
  268. u16 tx_val = chip->idle_tx_val;
  269. /* discard old RX data and clear RXS */
  270. bfin_spi_dummy_read(drv_data);
  271. while (drv_data->rx < drv_data->rx_end) {
  272. bfin_spi_cs_active(drv_data, chip);
  273. write_TDBR(drv_data, tx_val);
  274. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  275. cpu_relax();
  276. *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
  277. bfin_spi_cs_deactive(drv_data, chip);
  278. }
  279. }
  280. static void bfin_spi_u8_duplex(struct driver_data *drv_data)
  281. {
  282. /* discard old RX data and clear RXS */
  283. bfin_spi_dummy_read(drv_data);
  284. while (drv_data->rx < drv_data->rx_end) {
  285. write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
  286. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  287. cpu_relax();
  288. *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
  289. }
  290. }
  291. static void bfin_spi_u8_cs_chg_duplex(struct driver_data *drv_data)
  292. {
  293. struct chip_data *chip = drv_data->cur_chip;
  294. /* discard old RX data and clear RXS */
  295. bfin_spi_dummy_read(drv_data);
  296. while (drv_data->rx < drv_data->rx_end) {
  297. bfin_spi_cs_active(drv_data, chip);
  298. write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
  299. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  300. cpu_relax();
  301. *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
  302. bfin_spi_cs_deactive(drv_data, chip);
  303. }
  304. }
  305. static void bfin_spi_u16_writer(struct driver_data *drv_data)
  306. {
  307. /* clear RXS (we check for RXS inside the loop) */
  308. bfin_spi_dummy_read(drv_data);
  309. while (drv_data->tx < drv_data->tx_end) {
  310. write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
  311. drv_data->tx += 2;
  312. /* wait until transfer finished.
  313. checking SPIF or TXS may not guarantee transfer completion */
  314. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  315. cpu_relax();
  316. /* discard RX data and clear RXS */
  317. bfin_spi_dummy_read(drv_data);
  318. }
  319. }
  320. static void bfin_spi_u16_cs_chg_writer(struct driver_data *drv_data)
  321. {
  322. struct chip_data *chip = drv_data->cur_chip;
  323. /* clear RXS (we check for RXS inside the loop) */
  324. bfin_spi_dummy_read(drv_data);
  325. while (drv_data->tx < drv_data->tx_end) {
  326. bfin_spi_cs_active(drv_data, chip);
  327. write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
  328. drv_data->tx += 2;
  329. /* make sure transfer finished before deactiving CS */
  330. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  331. cpu_relax();
  332. bfin_spi_dummy_read(drv_data);
  333. bfin_spi_cs_deactive(drv_data, chip);
  334. }
  335. }
  336. static void bfin_spi_u16_reader(struct driver_data *drv_data)
  337. {
  338. u16 tx_val = drv_data->cur_chip->idle_tx_val;
  339. /* discard old RX data and clear RXS */
  340. bfin_spi_dummy_read(drv_data);
  341. while (drv_data->rx < drv_data->rx_end) {
  342. write_TDBR(drv_data, tx_val);
  343. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  344. cpu_relax();
  345. *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
  346. drv_data->rx += 2;
  347. }
  348. }
  349. static void bfin_spi_u16_cs_chg_reader(struct driver_data *drv_data)
  350. {
  351. struct chip_data *chip = drv_data->cur_chip;
  352. u16 tx_val = chip->idle_tx_val;
  353. /* discard old RX data and clear RXS */
  354. bfin_spi_dummy_read(drv_data);
  355. while (drv_data->rx < drv_data->rx_end) {
  356. bfin_spi_cs_active(drv_data, chip);
  357. write_TDBR(drv_data, tx_val);
  358. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  359. cpu_relax();
  360. *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
  361. drv_data->rx += 2;
  362. bfin_spi_cs_deactive(drv_data, chip);
  363. }
  364. }
  365. static void bfin_spi_u16_duplex(struct driver_data *drv_data)
  366. {
  367. /* discard old RX data and clear RXS */
  368. bfin_spi_dummy_read(drv_data);
  369. while (drv_data->rx < drv_data->rx_end) {
  370. write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
  371. drv_data->tx += 2;
  372. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  373. cpu_relax();
  374. *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
  375. drv_data->rx += 2;
  376. }
  377. }
  378. static void bfin_spi_u16_cs_chg_duplex(struct driver_data *drv_data)
  379. {
  380. struct chip_data *chip = drv_data->cur_chip;
  381. /* discard old RX data and clear RXS */
  382. bfin_spi_dummy_read(drv_data);
  383. while (drv_data->rx < drv_data->rx_end) {
  384. bfin_spi_cs_active(drv_data, chip);
  385. write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
  386. drv_data->tx += 2;
  387. while (!(read_STAT(drv_data) & BIT_STAT_RXS))
  388. cpu_relax();
  389. *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
  390. drv_data->rx += 2;
  391. bfin_spi_cs_deactive(drv_data, chip);
  392. }
  393. }
  394. /* test if ther is more transfer to be done */
  395. static void *bfin_spi_next_transfer(struct driver_data *drv_data)
  396. {
  397. struct spi_message *msg = drv_data->cur_msg;
  398. struct spi_transfer *trans = drv_data->cur_transfer;
  399. /* Move to next transfer */
  400. if (trans->transfer_list.next != &msg->transfers) {
  401. drv_data->cur_transfer =
  402. list_entry(trans->transfer_list.next,
  403. struct spi_transfer, transfer_list);
  404. return RUNNING_STATE;
  405. } else
  406. return DONE_STATE;
  407. }
  408. /*
  409. * caller already set message->status;
  410. * dma and pio irqs are blocked give finished message back
  411. */
  412. static void bfin_spi_giveback(struct driver_data *drv_data)
  413. {
  414. struct chip_data *chip = drv_data->cur_chip;
  415. struct spi_transfer *last_transfer;
  416. unsigned long flags;
  417. struct spi_message *msg;
  418. spin_lock_irqsave(&drv_data->lock, flags);
  419. msg = drv_data->cur_msg;
  420. drv_data->cur_msg = NULL;
  421. drv_data->cur_transfer = NULL;
  422. drv_data->cur_chip = NULL;
  423. queue_work(drv_data->workqueue, &drv_data->pump_messages);
  424. spin_unlock_irqrestore(&drv_data->lock, flags);
  425. last_transfer = list_entry(msg->transfers.prev,
  426. struct spi_transfer, transfer_list);
  427. msg->state = NULL;
  428. if (!drv_data->cs_change)
  429. bfin_spi_cs_deactive(drv_data, chip);
  430. /* Not stop spi in autobuffer mode */
  431. if (drv_data->tx_dma != 0xFFFF)
  432. bfin_spi_disable(drv_data);
  433. if (msg->complete)
  434. msg->complete(msg->context);
  435. }
  436. static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
  437. {
  438. struct driver_data *drv_data = dev_id;
  439. struct chip_data *chip = drv_data->cur_chip;
  440. struct spi_message *msg = drv_data->cur_msg;
  441. unsigned long timeout;
  442. unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
  443. u16 spistat = read_STAT(drv_data);
  444. dev_dbg(&drv_data->pdev->dev,
  445. "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
  446. dmastat, spistat);
  447. clear_dma_irqstat(drv_data->dma_channel);
  448. /*
  449. * wait for the last transaction shifted out. HRM states:
  450. * at this point there may still be data in the SPI DMA FIFO waiting
  451. * to be transmitted ... software needs to poll TXS in the SPI_STAT
  452. * register until it goes low for 2 successive reads
  453. */
  454. if (drv_data->tx != NULL) {
  455. while ((read_STAT(drv_data) & TXS) ||
  456. (read_STAT(drv_data) & TXS))
  457. cpu_relax();
  458. }
  459. dev_dbg(&drv_data->pdev->dev,
  460. "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
  461. dmastat, read_STAT(drv_data));
  462. timeout = jiffies + HZ;
  463. while (!(read_STAT(drv_data) & SPIF))
  464. if (!time_before(jiffies, timeout)) {
  465. dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF");
  466. break;
  467. } else
  468. cpu_relax();
  469. if ((dmastat & DMA_ERR) && (spistat & RBSY)) {
  470. msg->state = ERROR_STATE;
  471. dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
  472. } else {
  473. msg->actual_length += drv_data->len_in_bytes;
  474. if (drv_data->cs_change)
  475. bfin_spi_cs_deactive(drv_data, chip);
  476. /* Move to next transfer */
  477. msg->state = bfin_spi_next_transfer(drv_data);
  478. }
  479. /* Schedule transfer tasklet */
  480. tasklet_schedule(&drv_data->pump_transfers);
  481. /* free the irq handler before next transfer */
  482. dev_dbg(&drv_data->pdev->dev,
  483. "disable dma channel irq%d\n",
  484. drv_data->dma_channel);
  485. dma_disable_irq(drv_data->dma_channel);
  486. return IRQ_HANDLED;
  487. }
  488. static void bfin_spi_pump_transfers(unsigned long data)
  489. {
  490. struct driver_data *drv_data = (struct driver_data *)data;
  491. struct spi_message *message = NULL;
  492. struct spi_transfer *transfer = NULL;
  493. struct spi_transfer *previous = NULL;
  494. struct chip_data *chip = NULL;
  495. u8 width;
  496. u16 cr, dma_width, dma_config;
  497. u32 tranf_success = 1;
  498. u8 full_duplex = 0;
  499. /* Get current state information */
  500. message = drv_data->cur_msg;
  501. transfer = drv_data->cur_transfer;
  502. chip = drv_data->cur_chip;
  503. /*
  504. * if msg is error or done, report it back using complete() callback
  505. */
  506. /* Handle for abort */
  507. if (message->state == ERROR_STATE) {
  508. dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
  509. message->status = -EIO;
  510. bfin_spi_giveback(drv_data);
  511. return;
  512. }
  513. /* Handle end of message */
  514. if (message->state == DONE_STATE) {
  515. dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
  516. message->status = 0;
  517. bfin_spi_giveback(drv_data);
  518. return;
  519. }
  520. /* Delay if requested at end of transfer */
  521. if (message->state == RUNNING_STATE) {
  522. dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
  523. previous = list_entry(transfer->transfer_list.prev,
  524. struct spi_transfer, transfer_list);
  525. if (previous->delay_usecs)
  526. udelay(previous->delay_usecs);
  527. }
  528. /* Setup the transfer state based on the type of transfer */
  529. if (bfin_spi_flush(drv_data) == 0) {
  530. dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
  531. message->status = -EIO;
  532. bfin_spi_giveback(drv_data);
  533. return;
  534. }
  535. if (transfer->len == 0) {
  536. /* Move to next transfer of this msg */
  537. message->state = bfin_spi_next_transfer(drv_data);
  538. /* Schedule next transfer tasklet */
  539. tasklet_schedule(&drv_data->pump_transfers);
  540. }
  541. if (transfer->tx_buf != NULL) {
  542. drv_data->tx = (void *)transfer->tx_buf;
  543. drv_data->tx_end = drv_data->tx + transfer->len;
  544. dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
  545. transfer->tx_buf, drv_data->tx_end);
  546. } else {
  547. drv_data->tx = NULL;
  548. }
  549. if (transfer->rx_buf != NULL) {
  550. full_duplex = transfer->tx_buf != NULL;
  551. drv_data->rx = transfer->rx_buf;
  552. drv_data->rx_end = drv_data->rx + transfer->len;
  553. dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
  554. transfer->rx_buf, drv_data->rx_end);
  555. } else {
  556. drv_data->rx = NULL;
  557. }
  558. drv_data->rx_dma = transfer->rx_dma;
  559. drv_data->tx_dma = transfer->tx_dma;
  560. drv_data->len_in_bytes = transfer->len;
  561. drv_data->cs_change = transfer->cs_change;
  562. /* Bits per word setup */
  563. switch (transfer->bits_per_word) {
  564. case 8:
  565. drv_data->n_bytes = 1;
  566. width = CFG_SPI_WORDSIZE8;
  567. drv_data->read = chip->cs_change_per_word ?
  568. bfin_spi_u8_cs_chg_reader : bfin_spi_u8_reader;
  569. drv_data->write = chip->cs_change_per_word ?
  570. bfin_spi_u8_cs_chg_writer : bfin_spi_u8_writer;
  571. drv_data->duplex = chip->cs_change_per_word ?
  572. bfin_spi_u8_cs_chg_duplex : bfin_spi_u8_duplex;
  573. break;
  574. case 16:
  575. drv_data->n_bytes = 2;
  576. width = CFG_SPI_WORDSIZE16;
  577. drv_data->read = chip->cs_change_per_word ?
  578. bfin_spi_u16_cs_chg_reader : bfin_spi_u16_reader;
  579. drv_data->write = chip->cs_change_per_word ?
  580. bfin_spi_u16_cs_chg_writer : bfin_spi_u16_writer;
  581. drv_data->duplex = chip->cs_change_per_word ?
  582. bfin_spi_u16_cs_chg_duplex : bfin_spi_u16_duplex;
  583. break;
  584. default:
  585. /* No change, the same as default setting */
  586. drv_data->n_bytes = chip->n_bytes;
  587. width = chip->width;
  588. drv_data->write = drv_data->tx ? chip->write : bfin_spi_null_writer;
  589. drv_data->read = drv_data->rx ? chip->read : bfin_spi_null_reader;
  590. drv_data->duplex = chip->duplex ? chip->duplex : bfin_spi_null_writer;
  591. break;
  592. }
  593. cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
  594. cr |= (width << 8);
  595. write_CTRL(drv_data, cr);
  596. if (width == CFG_SPI_WORDSIZE16) {
  597. drv_data->len = (transfer->len) >> 1;
  598. } else {
  599. drv_data->len = transfer->len;
  600. }
  601. dev_dbg(&drv_data->pdev->dev,
  602. "transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
  603. drv_data->write, chip->write, bfin_spi_null_writer);
  604. /* speed and width has been set on per message */
  605. message->state = RUNNING_STATE;
  606. dma_config = 0;
  607. /* Speed setup (surely valid because already checked) */
  608. if (transfer->speed_hz)
  609. write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
  610. else
  611. write_BAUD(drv_data, chip->baud);
  612. write_STAT(drv_data, BIT_STAT_CLR);
  613. cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
  614. if (drv_data->cs_change)
  615. bfin_spi_cs_active(drv_data, chip);
  616. dev_dbg(&drv_data->pdev->dev,
  617. "now pumping a transfer: width is %d, len is %d\n",
  618. width, transfer->len);
  619. /*
  620. * Try to map dma buffer and do a dma transfer. If successful use,
  621. * different way to r/w according to the enable_dma settings and if
  622. * we are not doing a full duplex transfer (since the hardware does
  623. * not support full duplex DMA transfers).
  624. */
  625. if (!full_duplex && drv_data->cur_chip->enable_dma
  626. && drv_data->len > 6) {
  627. unsigned long dma_start_addr, flags;
  628. disable_dma(drv_data->dma_channel);
  629. clear_dma_irqstat(drv_data->dma_channel);
  630. /* config dma channel */
  631. dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
  632. set_dma_x_count(drv_data->dma_channel, drv_data->len);
  633. if (width == CFG_SPI_WORDSIZE16) {
  634. set_dma_x_modify(drv_data->dma_channel, 2);
  635. dma_width = WDSIZE_16;
  636. } else {
  637. set_dma_x_modify(drv_data->dma_channel, 1);
  638. dma_width = WDSIZE_8;
  639. }
  640. /* poll for SPI completion before start */
  641. while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
  642. cpu_relax();
  643. /* dirty hack for autobuffer DMA mode */
  644. if (drv_data->tx_dma == 0xFFFF) {
  645. dev_dbg(&drv_data->pdev->dev,
  646. "doing autobuffer DMA out.\n");
  647. /* no irq in autobuffer mode */
  648. dma_config =
  649. (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
  650. set_dma_config(drv_data->dma_channel, dma_config);
  651. set_dma_start_addr(drv_data->dma_channel,
  652. (unsigned long)drv_data->tx);
  653. enable_dma(drv_data->dma_channel);
  654. /* start SPI transfer */
  655. write_CTRL(drv_data, cr | BIT_CTL_TIMOD_DMA_TX);
  656. /* just return here, there can only be one transfer
  657. * in this mode
  658. */
  659. message->status = 0;
  660. bfin_spi_giveback(drv_data);
  661. return;
  662. }
  663. /* In dma mode, rx or tx must be NULL in one transfer */
  664. dma_config = (RESTART | dma_width | DI_EN);
  665. if (drv_data->rx != NULL) {
  666. /* set transfer mode, and enable SPI */
  667. dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
  668. drv_data->rx, drv_data->len_in_bytes);
  669. /* invalidate caches, if needed */
  670. if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
  671. invalidate_dcache_range((unsigned long) drv_data->rx,
  672. (unsigned long) (drv_data->rx +
  673. drv_data->len_in_bytes));
  674. dma_config |= WNR;
  675. dma_start_addr = (unsigned long)drv_data->rx;
  676. cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;
  677. } else if (drv_data->tx != NULL) {
  678. dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
  679. /* flush caches, if needed */
  680. if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
  681. flush_dcache_range((unsigned long) drv_data->tx,
  682. (unsigned long) (drv_data->tx +
  683. drv_data->len_in_bytes));
  684. dma_start_addr = (unsigned long)drv_data->tx;
  685. cr |= BIT_CTL_TIMOD_DMA_TX;
  686. } else
  687. BUG();
  688. /* oh man, here there be monsters ... and i dont mean the
  689. * fluffy cute ones from pixar, i mean the kind that'll eat
  690. * your data, kick your dog, and love it all. do *not* try
  691. * and change these lines unless you (1) heavily test DMA
  692. * with SPI flashes on a loaded system (e.g. ping floods),
  693. * (2) know just how broken the DMA engine interaction with
  694. * the SPI peripheral is, and (3) have someone else to blame
  695. * when you screw it all up anyways.
  696. */
  697. set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
  698. set_dma_config(drv_data->dma_channel, dma_config);
  699. local_irq_save(flags);
  700. SSYNC();
  701. write_CTRL(drv_data, cr);
  702. enable_dma(drv_data->dma_channel);
  703. dma_enable_irq(drv_data->dma_channel);
  704. local_irq_restore(flags);
  705. } else {
  706. /* IO mode write then read */
  707. dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
  708. /* we always use SPI_WRITE mode. SPI_READ mode
  709. seems to have problems with setting up the
  710. output value in TDBR prior to the transfer. */
  711. write_CTRL(drv_data, (cr | CFG_SPI_WRITE));
  712. if (full_duplex) {
  713. /* full duplex mode */
  714. BUG_ON((drv_data->tx_end - drv_data->tx) !=
  715. (drv_data->rx_end - drv_data->rx));
  716. dev_dbg(&drv_data->pdev->dev,
  717. "IO duplex: cr is 0x%x\n", cr);
  718. drv_data->duplex(drv_data);
  719. if (drv_data->tx != drv_data->tx_end)
  720. tranf_success = 0;
  721. } else if (drv_data->tx != NULL) {
  722. /* write only half duplex */
  723. dev_dbg(&drv_data->pdev->dev,
  724. "IO write: cr is 0x%x\n", cr);
  725. drv_data->write(drv_data);
  726. if (drv_data->tx != drv_data->tx_end)
  727. tranf_success = 0;
  728. } else if (drv_data->rx != NULL) {
  729. /* read only half duplex */
  730. dev_dbg(&drv_data->pdev->dev,
  731. "IO read: cr is 0x%x\n", cr);
  732. drv_data->read(drv_data);
  733. if (drv_data->rx != drv_data->rx_end)
  734. tranf_success = 0;
  735. }
  736. if (!tranf_success) {
  737. dev_dbg(&drv_data->pdev->dev,
  738. "IO write error!\n");
  739. message->state = ERROR_STATE;
  740. } else {
  741. /* Update total byte transfered */
  742. message->actual_length += drv_data->len_in_bytes;
  743. /* Move to next transfer of this msg */
  744. message->state = bfin_spi_next_transfer(drv_data);
  745. if (drv_data->cs_change)
  746. bfin_spi_cs_deactive(drv_data, chip);
  747. }
  748. /* Schedule next transfer tasklet */
  749. tasklet_schedule(&drv_data->pump_transfers);
  750. }
  751. }
  752. /* pop a msg from queue and kick off real transfer */
  753. static void bfin_spi_pump_messages(struct work_struct *work)
  754. {
  755. struct driver_data *drv_data;
  756. unsigned long flags;
  757. drv_data = container_of(work, struct driver_data, pump_messages);
  758. /* Lock queue and check for queue work */
  759. spin_lock_irqsave(&drv_data->lock, flags);
  760. if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
  761. /* pumper kicked off but no work to do */
  762. drv_data->busy = 0;
  763. spin_unlock_irqrestore(&drv_data->lock, flags);
  764. return;
  765. }
  766. /* Make sure we are not already running a message */
  767. if (drv_data->cur_msg) {
  768. spin_unlock_irqrestore(&drv_data->lock, flags);
  769. return;
  770. }
  771. /* Extract head of queue */
  772. drv_data->cur_msg = list_entry(drv_data->queue.next,
  773. struct spi_message, queue);
  774. /* Setup the SSP using the per chip configuration */
  775. drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
  776. bfin_spi_restore_state(drv_data);
  777. list_del_init(&drv_data->cur_msg->queue);
  778. /* Initial message state */
  779. drv_data->cur_msg->state = START_STATE;
  780. drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
  781. struct spi_transfer, transfer_list);
  782. dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
  783. "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
  784. drv_data->cur_chip->baud, drv_data->cur_chip->flag,
  785. drv_data->cur_chip->ctl_reg);
  786. dev_dbg(&drv_data->pdev->dev,
  787. "the first transfer len is %d\n",
  788. drv_data->cur_transfer->len);
  789. /* Mark as busy and launch transfers */
  790. tasklet_schedule(&drv_data->pump_transfers);
  791. drv_data->busy = 1;
  792. spin_unlock_irqrestore(&drv_data->lock, flags);
  793. }
  794. /*
  795. * got a msg to transfer, queue it in drv_data->queue.
  796. * And kick off message pumper
  797. */
  798. static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
  799. {
  800. struct driver_data *drv_data = spi_master_get_devdata(spi->master);
  801. unsigned long flags;
  802. spin_lock_irqsave(&drv_data->lock, flags);
  803. if (drv_data->run == QUEUE_STOPPED) {
  804. spin_unlock_irqrestore(&drv_data->lock, flags);
  805. return -ESHUTDOWN;
  806. }
  807. msg->actual_length = 0;
  808. msg->status = -EINPROGRESS;
  809. msg->state = START_STATE;
  810. dev_dbg(&spi->dev, "adding an msg in transfer() \n");
  811. list_add_tail(&msg->queue, &drv_data->queue);
  812. if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
  813. queue_work(drv_data->workqueue, &drv_data->pump_messages);
  814. spin_unlock_irqrestore(&drv_data->lock, flags);
  815. return 0;
  816. }
  817. #define MAX_SPI_SSEL 7
  818. static u16 ssel[][MAX_SPI_SSEL] = {
  819. {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
  820. P_SPI0_SSEL4, P_SPI0_SSEL5,
  821. P_SPI0_SSEL6, P_SPI0_SSEL7},
  822. {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
  823. P_SPI1_SSEL4, P_SPI1_SSEL5,
  824. P_SPI1_SSEL6, P_SPI1_SSEL7},
  825. {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
  826. P_SPI2_SSEL4, P_SPI2_SSEL5,
  827. P_SPI2_SSEL6, P_SPI2_SSEL7},
  828. };
  829. /* first setup for new devices */
  830. static int bfin_spi_setup(struct spi_device *spi)
  831. {
  832. struct bfin5xx_spi_chip *chip_info;
  833. struct chip_data *chip = NULL;
  834. struct driver_data *drv_data = spi_master_get_devdata(spi->master);
  835. int ret = -EINVAL;
  836. if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
  837. goto error;
  838. /* Only alloc (or use chip_info) on first setup */
  839. chip_info = NULL;
  840. chip = spi_get_ctldata(spi);
  841. if (chip == NULL) {
  842. chip = kzalloc(sizeof(*chip), GFP_KERNEL);
  843. if (!chip) {
  844. dev_err(&spi->dev, "cannot allocate chip data\n");
  845. ret = -ENOMEM;
  846. goto error;
  847. }
  848. chip->enable_dma = 0;
  849. chip_info = spi->controller_data;
  850. }
  851. /* chip_info isn't always needed */
  852. if (chip_info) {
  853. /* Make sure people stop trying to set fields via ctl_reg
  854. * when they should actually be using common SPI framework.
  855. * Currently we let through: WOM EMISO PSSE GM SZ TIMOD.
  856. * Not sure if a user actually needs/uses any of these,
  857. * but let's assume (for now) they do.
  858. */
  859. if (chip_info->ctl_reg & (SPE|MSTR|CPOL|CPHA|LSBF|SIZE)) {
  860. dev_err(&spi->dev, "do not set bits in ctl_reg "
  861. "that the SPI framework manages\n");
  862. goto error;
  863. }
  864. chip->enable_dma = chip_info->enable_dma != 0
  865. && drv_data->master_info->enable_dma;
  866. chip->ctl_reg = chip_info->ctl_reg;
  867. chip->bits_per_word = chip_info->bits_per_word;
  868. chip->cs_change_per_word = chip_info->cs_change_per_word;
  869. chip->cs_chg_udelay = chip_info->cs_chg_udelay;
  870. chip->cs_gpio = chip_info->cs_gpio;
  871. chip->idle_tx_val = chip_info->idle_tx_val;
  872. }
  873. /* translate common spi framework into our register */
  874. if (spi->mode & SPI_CPOL)
  875. chip->ctl_reg |= CPOL;
  876. if (spi->mode & SPI_CPHA)
  877. chip->ctl_reg |= CPHA;
  878. if (spi->mode & SPI_LSB_FIRST)
  879. chip->ctl_reg |= LSBF;
  880. /* we dont support running in slave mode (yet?) */
  881. chip->ctl_reg |= MSTR;
  882. /*
  883. * Notice: for blackfin, the speed_hz is the value of register
  884. * SPI_BAUD, not the real baudrate
  885. */
  886. chip->baud = hz_to_spi_baud(spi->max_speed_hz);
  887. chip->flag = 1 << (spi->chip_select);
  888. chip->chip_select_num = spi->chip_select;
  889. switch (chip->bits_per_word) {
  890. case 8:
  891. chip->n_bytes = 1;
  892. chip->width = CFG_SPI_WORDSIZE8;
  893. chip->read = chip->cs_change_per_word ?
  894. bfin_spi_u8_cs_chg_reader : bfin_spi_u8_reader;
  895. chip->write = chip->cs_change_per_word ?
  896. bfin_spi_u8_cs_chg_writer : bfin_spi_u8_writer;
  897. chip->duplex = chip->cs_change_per_word ?
  898. bfin_spi_u8_cs_chg_duplex : bfin_spi_u8_duplex;
  899. break;
  900. case 16:
  901. chip->n_bytes = 2;
  902. chip->width = CFG_SPI_WORDSIZE16;
  903. chip->read = chip->cs_change_per_word ?
  904. bfin_spi_u16_cs_chg_reader : bfin_spi_u16_reader;
  905. chip->write = chip->cs_change_per_word ?
  906. bfin_spi_u16_cs_chg_writer : bfin_spi_u16_writer;
  907. chip->duplex = chip->cs_change_per_word ?
  908. bfin_spi_u16_cs_chg_duplex : bfin_spi_u16_duplex;
  909. break;
  910. default:
  911. dev_err(&spi->dev, "%d bits_per_word is not supported\n",
  912. chip->bits_per_word);
  913. goto error;
  914. }
  915. /*
  916. * if any one SPI chip is registered and wants DMA, request the
  917. * DMA channel for it
  918. */
  919. if (chip->enable_dma && !drv_data->dma_requested) {
  920. /* register dma irq handler */
  921. ret = request_dma(drv_data->dma_channel, "BFIN_SPI_DMA");
  922. if (ret) {
  923. dev_err(&spi->dev,
  924. "Unable to request BlackFin SPI DMA channel\n");
  925. goto error;
  926. }
  927. drv_data->dma_requested = 1;
  928. ret = set_dma_callback(drv_data->dma_channel,
  929. bfin_spi_dma_irq_handler, drv_data);
  930. if (ret) {
  931. dev_err(&spi->dev, "Unable to set dma callback\n");
  932. goto error;
  933. }
  934. dma_disable_irq(drv_data->dma_channel);
  935. }
  936. if (chip->chip_select_num == 0) {
  937. ret = gpio_request(chip->cs_gpio, spi->modalias);
  938. if (ret) {
  939. dev_err(&spi->dev, "gpio_request() error\n");
  940. goto pin_error;
  941. }
  942. gpio_direction_output(chip->cs_gpio, 1);
  943. }
  944. dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
  945. spi->modalias, chip->width, chip->enable_dma);
  946. dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
  947. chip->ctl_reg, chip->flag);
  948. spi_set_ctldata(spi, chip);
  949. dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
  950. if (chip->chip_select_num > 0 &&
  951. chip->chip_select_num <= spi->master->num_chipselect) {
  952. ret = peripheral_request(ssel[spi->master->bus_num]
  953. [chip->chip_select_num-1], spi->modalias);
  954. if (ret) {
  955. dev_err(&spi->dev, "peripheral_request() error\n");
  956. goto pin_error;
  957. }
  958. }
  959. bfin_spi_cs_deactive(drv_data, chip);
  960. return 0;
  961. pin_error:
  962. if (chip->chip_select_num == 0)
  963. gpio_free(chip->cs_gpio);
  964. else
  965. peripheral_free(ssel[spi->master->bus_num]
  966. [chip->chip_select_num - 1]);
  967. error:
  968. if (chip) {
  969. if (drv_data->dma_requested)
  970. free_dma(drv_data->dma_channel);
  971. drv_data->dma_requested = 0;
  972. kfree(chip);
  973. /* prevent free 'chip' twice */
  974. spi_set_ctldata(spi, NULL);
  975. }
  976. return ret;
  977. }
  978. /*
  979. * callback for spi framework.
  980. * clean driver specific data
  981. */
  982. static void bfin_spi_cleanup(struct spi_device *spi)
  983. {
  984. struct chip_data *chip = spi_get_ctldata(spi);
  985. if (!chip)
  986. return;
  987. if ((chip->chip_select_num > 0)
  988. && (chip->chip_select_num <= spi->master->num_chipselect))
  989. peripheral_free(ssel[spi->master->bus_num]
  990. [chip->chip_select_num-1]);
  991. if (chip->chip_select_num == 0)
  992. gpio_free(chip->cs_gpio);
  993. kfree(chip);
  994. /* prevent free 'chip' twice */
  995. spi_set_ctldata(spi, NULL);
  996. }
  997. static inline int bfin_spi_init_queue(struct driver_data *drv_data)
  998. {
  999. INIT_LIST_HEAD(&drv_data->queue);
  1000. spin_lock_init(&drv_data->lock);
  1001. drv_data->run = QUEUE_STOPPED;
  1002. drv_data->busy = 0;
  1003. /* init transfer tasklet */
  1004. tasklet_init(&drv_data->pump_transfers,
  1005. bfin_spi_pump_transfers, (unsigned long)drv_data);
  1006. /* init messages workqueue */
  1007. INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
  1008. drv_data->workqueue = create_singlethread_workqueue(
  1009. dev_name(drv_data->master->dev.parent));
  1010. if (drv_data->workqueue == NULL)
  1011. return -EBUSY;
  1012. return 0;
  1013. }
  1014. static inline int bfin_spi_start_queue(struct driver_data *drv_data)
  1015. {
  1016. unsigned long flags;
  1017. spin_lock_irqsave(&drv_data->lock, flags);
  1018. if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
  1019. spin_unlock_irqrestore(&drv_data->lock, flags);
  1020. return -EBUSY;
  1021. }
  1022. drv_data->run = QUEUE_RUNNING;
  1023. drv_data->cur_msg = NULL;
  1024. drv_data->cur_transfer = NULL;
  1025. drv_data->cur_chip = NULL;
  1026. spin_unlock_irqrestore(&drv_data->lock, flags);
  1027. queue_work(drv_data->workqueue, &drv_data->pump_messages);
  1028. return 0;
  1029. }
  1030. static inline int bfin_spi_stop_queue(struct driver_data *drv_data)
  1031. {
  1032. unsigned long flags;
  1033. unsigned limit = 500;
  1034. int status = 0;
  1035. spin_lock_irqsave(&drv_data->lock, flags);
  1036. /*
  1037. * This is a bit lame, but is optimized for the common execution path.
  1038. * A wait_queue on the drv_data->busy could be used, but then the common
  1039. * execution path (pump_messages) would be required to call wake_up or
  1040. * friends on every SPI message. Do this instead
  1041. */
  1042. drv_data->run = QUEUE_STOPPED;
  1043. while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
  1044. spin_unlock_irqrestore(&drv_data->lock, flags);
  1045. msleep(10);
  1046. spin_lock_irqsave(&drv_data->lock, flags);
  1047. }
  1048. if (!list_empty(&drv_data->queue) || drv_data->busy)
  1049. status = -EBUSY;
  1050. spin_unlock_irqrestore(&drv_data->lock, flags);
  1051. return status;
  1052. }
  1053. static inline int bfin_spi_destroy_queue(struct driver_data *drv_data)
  1054. {
  1055. int status;
  1056. status = bfin_spi_stop_queue(drv_data);
  1057. if (status != 0)
  1058. return status;
  1059. destroy_workqueue(drv_data->workqueue);
  1060. return 0;
  1061. }
  1062. static int __init bfin_spi_probe(struct platform_device *pdev)
  1063. {
  1064. struct device *dev = &pdev->dev;
  1065. struct bfin5xx_spi_master *platform_info;
  1066. struct spi_master *master;
  1067. struct driver_data *drv_data = 0;
  1068. struct resource *res;
  1069. int status = 0;
  1070. platform_info = dev->platform_data;
  1071. /* Allocate master with space for drv_data */
  1072. master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
  1073. if (!master) {
  1074. dev_err(&pdev->dev, "can not alloc spi_master\n");
  1075. return -ENOMEM;
  1076. }
  1077. drv_data = spi_master_get_devdata(master);
  1078. drv_data->master = master;
  1079. drv_data->master_info = platform_info;
  1080. drv_data->pdev = pdev;
  1081. drv_data->pin_req = platform_info->pin_req;
  1082. /* the spi->mode bits supported by this driver: */
  1083. master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
  1084. master->bus_num = pdev->id;
  1085. master->num_chipselect = platform_info->num_chipselect;
  1086. master->cleanup = bfin_spi_cleanup;
  1087. master->setup = bfin_spi_setup;
  1088. master->transfer = bfin_spi_transfer;
  1089. /* Find and map our resources */
  1090. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  1091. if (res == NULL) {
  1092. dev_err(dev, "Cannot get IORESOURCE_MEM\n");
  1093. status = -ENOENT;
  1094. goto out_error_get_res;
  1095. }
  1096. drv_data->regs_base = ioremap(res->start, resource_size(res));
  1097. if (drv_data->regs_base == NULL) {
  1098. dev_err(dev, "Cannot map IO\n");
  1099. status = -ENXIO;
  1100. goto out_error_ioremap;
  1101. }
  1102. drv_data->dma_channel = platform_get_irq(pdev, 0);
  1103. if (drv_data->dma_channel < 0) {
  1104. dev_err(dev, "No DMA channel specified\n");
  1105. status = -ENOENT;
  1106. goto out_error_no_dma_ch;
  1107. }
  1108. /* Initial and start queue */
  1109. status = bfin_spi_init_queue(drv_data);
  1110. if (status != 0) {
  1111. dev_err(dev, "problem initializing queue\n");
  1112. goto out_error_queue_alloc;
  1113. }
  1114. status = bfin_spi_start_queue(drv_data);
  1115. if (status != 0) {
  1116. dev_err(dev, "problem starting queue\n");
  1117. goto out_error_queue_alloc;
  1118. }
  1119. status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
  1120. if (status != 0) {
  1121. dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
  1122. goto out_error_queue_alloc;
  1123. }
  1124. /* Reset SPI registers. If these registers were used by the boot loader,
  1125. * the sky may fall on your head if you enable the dma controller.
  1126. */
  1127. write_CTRL(drv_data, BIT_CTL_CPHA | BIT_CTL_MASTER);
  1128. write_FLAG(drv_data, 0xFF00);
  1129. /* Register with the SPI framework */
  1130. platform_set_drvdata(pdev, drv_data);
  1131. status = spi_register_master(master);
  1132. if (status != 0) {
  1133. dev_err(dev, "problem registering spi master\n");
  1134. goto out_error_queue_alloc;
  1135. }
  1136. dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
  1137. DRV_DESC, DRV_VERSION, drv_data->regs_base,
  1138. drv_data->dma_channel);
  1139. return status;
  1140. out_error_queue_alloc:
  1141. bfin_spi_destroy_queue(drv_data);
  1142. out_error_no_dma_ch:
  1143. iounmap((void *) drv_data->regs_base);
  1144. out_error_ioremap:
  1145. out_error_get_res:
  1146. spi_master_put(master);
  1147. return status;
  1148. }
  1149. /* stop hardware and remove the driver */
  1150. static int __devexit bfin_spi_remove(struct platform_device *pdev)
  1151. {
  1152. struct driver_data *drv_data = platform_get_drvdata(pdev);
  1153. int status = 0;
  1154. if (!drv_data)
  1155. return 0;
  1156. /* Remove the queue */
  1157. status = bfin_spi_destroy_queue(drv_data);
  1158. if (status != 0)
  1159. return status;
  1160. /* Disable the SSP at the peripheral and SOC level */
  1161. bfin_spi_disable(drv_data);
  1162. /* Release DMA */
  1163. if (drv_data->master_info->enable_dma) {
  1164. if (dma_channel_active(drv_data->dma_channel))
  1165. free_dma(drv_data->dma_channel);
  1166. }
  1167. /* Disconnect from the SPI framework */
  1168. spi_unregister_master(drv_data->master);
  1169. peripheral_free_list(drv_data->pin_req);
  1170. /* Prevent double remove */
  1171. platform_set_drvdata(pdev, NULL);
  1172. return 0;
  1173. }
  1174. #ifdef CONFIG_PM
  1175. static int bfin_spi_suspend(struct platform_device *pdev, pm_message_t state)
  1176. {
  1177. struct driver_data *drv_data = platform_get_drvdata(pdev);
  1178. int status = 0;
  1179. status = bfin_spi_stop_queue(drv_data);
  1180. if (status != 0)
  1181. return status;
  1182. /* stop hardware */
  1183. bfin_spi_disable(drv_data);
  1184. return 0;
  1185. }
  1186. static int bfin_spi_resume(struct platform_device *pdev)
  1187. {
  1188. struct driver_data *drv_data = platform_get_drvdata(pdev);
  1189. int status = 0;
  1190. /* Enable the SPI interface */
  1191. bfin_spi_enable(drv_data);
  1192. /* Start the queue running */
  1193. status = bfin_spi_start_queue(drv_data);
  1194. if (status != 0) {
  1195. dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
  1196. return status;
  1197. }
  1198. return 0;
  1199. }
  1200. #else
  1201. #define bfin_spi_suspend NULL
  1202. #define bfin_spi_resume NULL
  1203. #endif /* CONFIG_PM */
  1204. MODULE_ALIAS("platform:bfin-spi");
  1205. static struct platform_driver bfin_spi_driver = {
  1206. .driver = {
  1207. .name = DRV_NAME,
  1208. .owner = THIS_MODULE,
  1209. },
  1210. .suspend = bfin_spi_suspend,
  1211. .resume = bfin_spi_resume,
  1212. .remove = __devexit_p(bfin_spi_remove),
  1213. };
  1214. static int __init bfin_spi_init(void)
  1215. {
  1216. return platform_driver_probe(&bfin_spi_driver, bfin_spi_probe);
  1217. }
  1218. module_init(bfin_spi_init);
  1219. static void __exit bfin_spi_exit(void)
  1220. {
  1221. platform_driver_unregister(&bfin_spi_driver);
  1222. }
  1223. module_exit(bfin_spi_exit);