serial.c 16 KB

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  1. /*
  2. * (C) Copyright 2004
  3. * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  4. *
  5. * SPDX-License-Identifier: GPL-2.0+
  6. */
  7. #include <common.h>
  8. #include <environment.h>
  9. #include <serial.h>
  10. #include <stdio_dev.h>
  11. #include <post.h>
  12. #include <linux/compiler.h>
  13. #include <errno.h>
  14. DECLARE_GLOBAL_DATA_PTR;
  15. static struct serial_device *serial_devices;
  16. static struct serial_device *serial_current;
  17. /*
  18. * Table with supported baudrates (defined in config_xyz.h)
  19. */
  20. static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
  21. /**
  22. * serial_null() - Void registration routine of a serial driver
  23. *
  24. * This routine implements a void registration routine of a serial
  25. * driver. The registration routine of a particular driver is aliased
  26. * to this empty function in case the driver is not compiled into
  27. * U-Boot.
  28. */
  29. static void serial_null(void)
  30. {
  31. }
  32. /**
  33. * on_baudrate() - Update the actual baudrate when the env var changes
  34. *
  35. * This will check for a valid baudrate and only apply it if valid.
  36. */
  37. static int on_baudrate(const char *name, const char *value, enum env_op op,
  38. int flags)
  39. {
  40. int i;
  41. int baudrate;
  42. switch (op) {
  43. case env_op_create:
  44. case env_op_overwrite:
  45. /*
  46. * Switch to new baudrate if new baudrate is supported
  47. */
  48. baudrate = simple_strtoul(value, NULL, 10);
  49. /* Not actually changing */
  50. if (gd->baudrate == baudrate)
  51. return 0;
  52. for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
  53. if (baudrate == baudrate_table[i])
  54. break;
  55. }
  56. if (i == ARRAY_SIZE(baudrate_table)) {
  57. if ((flags & H_FORCE) == 0)
  58. printf("## Baudrate %d bps not supported\n",
  59. baudrate);
  60. return 1;
  61. }
  62. if ((flags & H_INTERACTIVE) != 0) {
  63. printf("## Switch baudrate to %d"
  64. " bps and press ENTER ...\n", baudrate);
  65. udelay(50000);
  66. }
  67. gd->baudrate = baudrate;
  68. serial_setbrg();
  69. udelay(50000);
  70. if ((flags & H_INTERACTIVE) != 0)
  71. while (1) {
  72. if (getc() == '\r')
  73. break;
  74. }
  75. return 0;
  76. case env_op_delete:
  77. printf("## Baudrate may not be deleted\n");
  78. return 1;
  79. default:
  80. return 0;
  81. }
  82. }
  83. U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
  84. /**
  85. * serial_initfunc() - Forward declare of driver registration routine
  86. * @name: Name of the real driver registration routine.
  87. *
  88. * This macro expands onto forward declaration of a driver registration
  89. * routine, which is then used below in serial_initialize() function.
  90. * The declaration is made weak and aliases to serial_null() so in case
  91. * the driver is not compiled in, the function is still declared and can
  92. * be used, but aliases to serial_null() and thus is optimized away.
  93. */
  94. #define serial_initfunc(name) \
  95. void name(void) \
  96. __attribute__((weak, alias("serial_null")));
  97. serial_initfunc(amirix_serial_initialize);
  98. serial_initfunc(arc_serial_initialize);
  99. serial_initfunc(arm_dcc_initialize);
  100. serial_initfunc(asc_serial_initialize);
  101. serial_initfunc(atmel_serial_initialize);
  102. serial_initfunc(au1x00_serial_initialize);
  103. serial_initfunc(bfin_jtag_initialize);
  104. serial_initfunc(bfin_serial_initialize);
  105. serial_initfunc(bmw_serial_initialize);
  106. serial_initfunc(clps7111_serial_initialize);
  107. serial_initfunc(cogent_serial_initialize);
  108. serial_initfunc(cpci750_serial_initialize);
  109. serial_initfunc(evb64260_serial_initialize);
  110. serial_initfunc(imx_serial_initialize);
  111. serial_initfunc(iop480_serial_initialize);
  112. serial_initfunc(jz_serial_initialize);
  113. serial_initfunc(leon2_serial_initialize);
  114. serial_initfunc(leon3_serial_initialize);
  115. serial_initfunc(lh7a40x_serial_initialize);
  116. serial_initfunc(lpc32xx_serial_initialize);
  117. serial_initfunc(marvell_serial_initialize);
  118. serial_initfunc(max3100_serial_initialize);
  119. serial_initfunc(mcf_serial_initialize);
  120. serial_initfunc(ml2_serial_initialize);
  121. serial_initfunc(mpc85xx_serial_initialize);
  122. serial_initfunc(mpc8xx_serial_initialize);
  123. serial_initfunc(mxc_serial_initialize);
  124. serial_initfunc(mxs_auart_initialize);
  125. serial_initfunc(ns16550_serial_initialize);
  126. serial_initfunc(oc_serial_initialize);
  127. serial_initfunc(p3mx_serial_initialize);
  128. serial_initfunc(pl01x_serial_initialize);
  129. serial_initfunc(pxa_serial_initialize);
  130. serial_initfunc(s3c24xx_serial_initialize);
  131. serial_initfunc(s5p_serial_initialize);
  132. serial_initfunc(sa1100_serial_initialize);
  133. serial_initfunc(sandbox_serial_initialize);
  134. serial_initfunc(sconsole_serial_initialize);
  135. serial_initfunc(sh_serial_initialize);
  136. serial_initfunc(stm32_serial_initialize);
  137. serial_initfunc(uartlite_serial_initialize);
  138. serial_initfunc(zynq_serial_initialize);
  139. /**
  140. * serial_register() - Register serial driver with serial driver core
  141. * @dev: Pointer to the serial driver structure
  142. *
  143. * This function registers the serial driver supplied via @dev with
  144. * serial driver core, thus making U-Boot aware of it and making it
  145. * available for U-Boot to use. On platforms that still require manual
  146. * relocation of constant variables, relocation of the supplied structure
  147. * is performed.
  148. */
  149. void serial_register(struct serial_device *dev)
  150. {
  151. #ifdef CONFIG_NEEDS_MANUAL_RELOC
  152. if (dev->start)
  153. dev->start += gd->reloc_off;
  154. if (dev->stop)
  155. dev->stop += gd->reloc_off;
  156. if (dev->setbrg)
  157. dev->setbrg += gd->reloc_off;
  158. if (dev->getc)
  159. dev->getc += gd->reloc_off;
  160. if (dev->tstc)
  161. dev->tstc += gd->reloc_off;
  162. if (dev->putc)
  163. dev->putc += gd->reloc_off;
  164. if (dev->puts)
  165. dev->puts += gd->reloc_off;
  166. #endif
  167. dev->next = serial_devices;
  168. serial_devices = dev;
  169. }
  170. /**
  171. * serial_initialize() - Register all compiled-in serial port drivers
  172. *
  173. * This function registers all serial port drivers that are compiled
  174. * into the U-Boot binary with the serial core, thus making them
  175. * available to U-Boot to use. Lastly, this function assigns a default
  176. * serial port to the serial core. That serial port is then used as a
  177. * default output.
  178. */
  179. void serial_initialize(void)
  180. {
  181. amirix_serial_initialize();
  182. arc_serial_initialize();
  183. arm_dcc_initialize();
  184. asc_serial_initialize();
  185. atmel_serial_initialize();
  186. au1x00_serial_initialize();
  187. bfin_jtag_initialize();
  188. bfin_serial_initialize();
  189. bmw_serial_initialize();
  190. clps7111_serial_initialize();
  191. cogent_serial_initialize();
  192. cpci750_serial_initialize();
  193. evb64260_serial_initialize();
  194. imx_serial_initialize();
  195. iop480_serial_initialize();
  196. jz_serial_initialize();
  197. leon2_serial_initialize();
  198. leon3_serial_initialize();
  199. lh7a40x_serial_initialize();
  200. lpc32xx_serial_initialize();
  201. marvell_serial_initialize();
  202. max3100_serial_initialize();
  203. mcf_serial_initialize();
  204. ml2_serial_initialize();
  205. mpc85xx_serial_initialize();
  206. mpc8xx_serial_initialize();
  207. mxc_serial_initialize();
  208. mxs_auart_initialize();
  209. ns16550_serial_initialize();
  210. oc_serial_initialize();
  211. p3mx_serial_initialize();
  212. pl01x_serial_initialize();
  213. pxa_serial_initialize();
  214. s3c24xx_serial_initialize();
  215. s5p_serial_initialize();
  216. sa1100_serial_initialize();
  217. sandbox_serial_initialize();
  218. sconsole_serial_initialize();
  219. sh_serial_initialize();
  220. stm32_serial_initialize();
  221. uartlite_serial_initialize();
  222. zynq_serial_initialize();
  223. serial_assign(default_serial_console()->name);
  224. }
  225. static int serial_stub_start(struct stdio_dev *sdev)
  226. {
  227. struct serial_device *dev = sdev->priv;
  228. return dev->start();
  229. }
  230. static int serial_stub_stop(struct stdio_dev *sdev)
  231. {
  232. struct serial_device *dev = sdev->priv;
  233. return dev->stop();
  234. }
  235. static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
  236. {
  237. struct serial_device *dev = sdev->priv;
  238. dev->putc(ch);
  239. }
  240. static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
  241. {
  242. struct serial_device *dev = sdev->priv;
  243. dev->puts(str);
  244. }
  245. static int serial_stub_getc(struct stdio_dev *sdev)
  246. {
  247. struct serial_device *dev = sdev->priv;
  248. return dev->getc();
  249. }
  250. static int serial_stub_tstc(struct stdio_dev *sdev)
  251. {
  252. struct serial_device *dev = sdev->priv;
  253. return dev->tstc();
  254. }
  255. /**
  256. * serial_stdio_init() - Register serial ports with STDIO core
  257. *
  258. * This function generates a proxy driver for each serial port driver.
  259. * These proxy drivers then register with the STDIO core, making the
  260. * serial drivers available as STDIO devices.
  261. */
  262. void serial_stdio_init(void)
  263. {
  264. struct stdio_dev dev;
  265. struct serial_device *s = serial_devices;
  266. while (s) {
  267. memset(&dev, 0, sizeof(dev));
  268. strcpy(dev.name, s->name);
  269. dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
  270. dev.start = serial_stub_start;
  271. dev.stop = serial_stub_stop;
  272. dev.putc = serial_stub_putc;
  273. dev.puts = serial_stub_puts;
  274. dev.getc = serial_stub_getc;
  275. dev.tstc = serial_stub_tstc;
  276. dev.priv = s;
  277. stdio_register(&dev);
  278. s = s->next;
  279. }
  280. }
  281. /**
  282. * serial_assign() - Select the serial output device by name
  283. * @name: Name of the serial driver to be used as default output
  284. *
  285. * This function configures the serial output multiplexing by
  286. * selecting which serial device will be used as default. In case
  287. * the STDIO "serial" device is selected as stdin/stdout/stderr,
  288. * the serial device previously configured by this function will be
  289. * used for the particular operation.
  290. *
  291. * Returns 0 on success, negative on error.
  292. */
  293. int serial_assign(const char *name)
  294. {
  295. struct serial_device *s;
  296. for (s = serial_devices; s; s = s->next) {
  297. if (strcmp(s->name, name))
  298. continue;
  299. serial_current = s;
  300. return 0;
  301. }
  302. return -EINVAL;
  303. }
  304. /**
  305. * serial_reinit_all() - Reinitialize all compiled-in serial ports
  306. *
  307. * This function reinitializes all serial ports that are compiled
  308. * into U-Boot by calling their serial_start() functions.
  309. */
  310. void serial_reinit_all(void)
  311. {
  312. struct serial_device *s;
  313. for (s = serial_devices; s; s = s->next)
  314. s->start();
  315. }
  316. /**
  317. * get_current() - Return pointer to currently selected serial port
  318. *
  319. * This function returns a pointer to currently selected serial port.
  320. * The currently selected serial port is altered by serial_assign()
  321. * function.
  322. *
  323. * In case this function is called before relocation or before any serial
  324. * port is configured, this function calls default_serial_console() to
  325. * determine the serial port. Otherwise, the configured serial port is
  326. * returned.
  327. *
  328. * Returns pointer to the currently selected serial port on success,
  329. * NULL on error.
  330. */
  331. static struct serial_device *get_current(void)
  332. {
  333. struct serial_device *dev;
  334. if (!(gd->flags & GD_FLG_RELOC))
  335. dev = default_serial_console();
  336. else if (!serial_current)
  337. dev = default_serial_console();
  338. else
  339. dev = serial_current;
  340. /* We must have a console device */
  341. if (!dev) {
  342. #ifdef CONFIG_SPL_BUILD
  343. puts("Cannot find console\n");
  344. hang();
  345. #else
  346. panic("Cannot find console\n");
  347. #endif
  348. }
  349. return dev;
  350. }
  351. /**
  352. * serial_init() - Initialize currently selected serial port
  353. *
  354. * This function initializes the currently selected serial port. This
  355. * usually involves setting up the registers of that particular port,
  356. * enabling clock and such. This function uses the get_current() call
  357. * to determine which port is selected.
  358. *
  359. * Returns 0 on success, negative on error.
  360. */
  361. int serial_init(void)
  362. {
  363. gd->flags |= GD_FLG_SERIAL_READY;
  364. return get_current()->start();
  365. }
  366. /**
  367. * serial_setbrg() - Configure baud-rate of currently selected serial port
  368. *
  369. * This function configures the baud-rate of the currently selected
  370. * serial port. The baud-rate is retrieved from global data within
  371. * the serial port driver. This function uses the get_current() call
  372. * to determine which port is selected.
  373. *
  374. * Returns 0 on success, negative on error.
  375. */
  376. void serial_setbrg(void)
  377. {
  378. get_current()->setbrg();
  379. }
  380. /**
  381. * serial_getc() - Read character from currently selected serial port
  382. *
  383. * This function retrieves a character from currently selected serial
  384. * port. In case there is no character waiting on the serial port,
  385. * this function will block and wait for the character to appear. This
  386. * function uses the get_current() call to determine which port is
  387. * selected.
  388. *
  389. * Returns the character on success, negative on error.
  390. */
  391. int serial_getc(void)
  392. {
  393. return get_current()->getc();
  394. }
  395. /**
  396. * serial_tstc() - Test if data is available on currently selected serial port
  397. *
  398. * This function tests if one or more characters are available on
  399. * currently selected serial port. This function never blocks. This
  400. * function uses the get_current() call to determine which port is
  401. * selected.
  402. *
  403. * Returns positive if character is available, zero otherwise.
  404. */
  405. int serial_tstc(void)
  406. {
  407. return get_current()->tstc();
  408. }
  409. /**
  410. * serial_putc() - Output character via currently selected serial port
  411. * @c: Single character to be output from the serial port.
  412. *
  413. * This function outputs a character via currently selected serial
  414. * port. This character is passed to the serial port driver responsible
  415. * for controlling the hardware. The hardware may still be in process
  416. * of transmitting another character, therefore this function may block
  417. * for a short amount of time. This function uses the get_current()
  418. * call to determine which port is selected.
  419. */
  420. void serial_putc(const char c)
  421. {
  422. get_current()->putc(c);
  423. }
  424. /**
  425. * serial_puts() - Output string via currently selected serial port
  426. * @s: Zero-terminated string to be output from the serial port.
  427. *
  428. * This function outputs a zero-terminated string via currently
  429. * selected serial port. This function behaves as an accelerator
  430. * in case the hardware can queue multiple characters for transfer.
  431. * The whole string that is to be output is available to the function
  432. * implementing the hardware manipulation. Transmitting the whole
  433. * string may take some time, thus this function may block for some
  434. * amount of time. This function uses the get_current() call to
  435. * determine which port is selected.
  436. */
  437. void serial_puts(const char *s)
  438. {
  439. get_current()->puts(s);
  440. }
  441. /**
  442. * default_serial_puts() - Output string by calling serial_putc() in loop
  443. * @s: Zero-terminated string to be output from the serial port.
  444. *
  445. * This function outputs a zero-terminated string by calling serial_putc()
  446. * in a loop. Most drivers do not support queueing more than one byte for
  447. * transfer, thus this function precisely implements their serial_puts().
  448. *
  449. * To optimize the number of get_current() calls, this function only
  450. * calls get_current() once and then directly accesses the putc() call
  451. * of the &struct serial_device .
  452. */
  453. void default_serial_puts(const char *s)
  454. {
  455. struct serial_device *dev = get_current();
  456. while (*s)
  457. dev->putc(*s++);
  458. }
  459. #if CONFIG_POST & CONFIG_SYS_POST_UART
  460. static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
  461. /**
  462. * uart_post_test() - Test the currently selected serial port using POST
  463. * @flags: POST framework flags
  464. *
  465. * Do a loopback test of the currently selected serial port. This
  466. * function is only useful in the context of the POST testing framwork.
  467. * The serial port is first configured into loopback mode and then
  468. * characters are sent through it.
  469. *
  470. * Returns 0 on success, value otherwise.
  471. */
  472. /* Mark weak until post/cpu/.../uart.c migrate over */
  473. __weak
  474. int uart_post_test(int flags)
  475. {
  476. unsigned char c;
  477. int ret, saved_baud, b;
  478. struct serial_device *saved_dev, *s;
  479. /* Save current serial state */
  480. ret = 0;
  481. saved_dev = serial_current;
  482. saved_baud = gd->baudrate;
  483. for (s = serial_devices; s; s = s->next) {
  484. /* If this driver doesn't support loop back, skip it */
  485. if (!s->loop)
  486. continue;
  487. /* Test the next device */
  488. serial_current = s;
  489. ret = serial_init();
  490. if (ret)
  491. goto done;
  492. /* Consume anything that happens to be queued */
  493. while (serial_tstc())
  494. serial_getc();
  495. /* Enable loop back */
  496. s->loop(1);
  497. /* Test every available baud rate */
  498. for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
  499. gd->baudrate = bauds[b];
  500. serial_setbrg();
  501. /*
  502. * Stick to printable chars to avoid issues:
  503. * - terminal corruption
  504. * - serial program reacting to sequences and sending
  505. * back random extra data
  506. * - most serial drivers add in extra chars (like \r\n)
  507. */
  508. for (c = 0x20; c < 0x7f; ++c) {
  509. /* Send it out */
  510. serial_putc(c);
  511. /* Make sure it's the same one */
  512. ret = (c != serial_getc());
  513. if (ret) {
  514. s->loop(0);
  515. goto done;
  516. }
  517. /* Clean up the output in case it was sent */
  518. serial_putc('\b');
  519. ret = ('\b' != serial_getc());
  520. if (ret) {
  521. s->loop(0);
  522. goto done;
  523. }
  524. }
  525. }
  526. /* Disable loop back */
  527. s->loop(0);
  528. /* XXX: There is no serial_stop() !? */
  529. if (s->stop)
  530. s->stop();
  531. }
  532. done:
  533. /* Restore previous serial state */
  534. serial_current = saved_dev;
  535. gd->baudrate = saved_baud;
  536. serial_reinit_all();
  537. serial_setbrg();
  538. return ret;
  539. }
  540. #endif