serial_pxa.c 7.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
  4. *
  5. * (C) Copyright 2002
  6. * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
  7. *
  8. * (C) Copyright 2002
  9. * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  10. * Marius Groeger <mgroeger@sysgo.de>
  11. *
  12. * (C) Copyright 2002
  13. * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  14. * Alex Zuepke <azu@sysgo.de>
  15. *
  16. * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
  17. *
  18. * Modified to add driver model (DM) support
  19. * (C) Copyright 2016 Marcel Ziswiler <marcel.ziswiler@toradex.com>
  20. */
  21. #include <common.h>
  22. #include <hang.h>
  23. #include <asm/arch/pxa-regs.h>
  24. #include <asm/arch/regs-uart.h>
  25. #include <asm/io.h>
  26. #include <dm.h>
  27. #include <dm/platform_data/serial_pxa.h>
  28. #include <linux/compiler.h>
  29. #include <serial.h>
  30. #include <watchdog.h>
  31. DECLARE_GLOBAL_DATA_PTR;
  32. static uint32_t pxa_uart_get_baud_divider(int baudrate)
  33. {
  34. return 921600 / baudrate;
  35. }
  36. static void pxa_uart_toggle_clock(uint32_t uart_index, int enable)
  37. {
  38. uint32_t clk_reg, clk_offset, reg;
  39. clk_reg = UART_CLK_REG;
  40. clk_offset = UART_CLK_BASE << uart_index;
  41. reg = readl(clk_reg);
  42. if (enable)
  43. reg |= clk_offset;
  44. else
  45. reg &= ~clk_offset;
  46. writel(reg, clk_reg);
  47. }
  48. /*
  49. * Enable clock and set baud rate, parity etc.
  50. */
  51. void pxa_setbrg_common(struct pxa_uart_regs *uart_regs, int port, int baudrate)
  52. {
  53. uint32_t divider = pxa_uart_get_baud_divider(baudrate);
  54. if (!divider)
  55. hang();
  56. pxa_uart_toggle_clock(port, 1);
  57. /* Disable interrupts and FIFOs */
  58. writel(0, &uart_regs->ier);
  59. writel(0, &uart_regs->fcr);
  60. /* Set baud rate */
  61. writel(LCR_WLS0 | LCR_WLS1 | LCR_DLAB, &uart_regs->lcr);
  62. writel(divider & 0xff, &uart_regs->dll);
  63. writel(divider >> 8, &uart_regs->dlh);
  64. writel(LCR_WLS0 | LCR_WLS1, &uart_regs->lcr);
  65. /* Enable UART */
  66. writel(IER_UUE, &uart_regs->ier);
  67. }
  68. #ifndef CONFIG_DM_SERIAL
  69. static struct pxa_uart_regs *pxa_uart_index_to_regs(uint32_t uart_index)
  70. {
  71. switch (uart_index) {
  72. case FFUART_INDEX: return (struct pxa_uart_regs *)FFUART_BASE;
  73. case BTUART_INDEX: return (struct pxa_uart_regs *)BTUART_BASE;
  74. case STUART_INDEX: return (struct pxa_uart_regs *)STUART_BASE;
  75. case HWUART_INDEX: return (struct pxa_uart_regs *)HWUART_BASE;
  76. default:
  77. return NULL;
  78. }
  79. }
  80. /*
  81. * Enable clock and set baud rate, parity etc.
  82. */
  83. void pxa_setbrg_dev(uint32_t uart_index)
  84. {
  85. struct pxa_uart_regs *uart_regs = pxa_uart_index_to_regs(uart_index);
  86. if (!uart_regs)
  87. panic("Failed getting UART registers\n");
  88. pxa_setbrg_common(uart_regs, uart_index, gd->baudrate);
  89. }
  90. /*
  91. * Initialise the serial port with the given baudrate. The settings
  92. * are always 8 data bits, no parity, 1 stop bit, no start bits.
  93. */
  94. int pxa_init_dev(unsigned int uart_index)
  95. {
  96. pxa_setbrg_dev(uart_index);
  97. return 0;
  98. }
  99. /*
  100. * Output a single byte to the serial port.
  101. */
  102. void pxa_putc_dev(unsigned int uart_index, const char c)
  103. {
  104. struct pxa_uart_regs *uart_regs;
  105. /* If \n, also do \r */
  106. if (c == '\n')
  107. pxa_putc_dev(uart_index, '\r');
  108. uart_regs = pxa_uart_index_to_regs(uart_index);
  109. if (!uart_regs)
  110. hang();
  111. while (!(readl(&uart_regs->lsr) & LSR_TEMT))
  112. WATCHDOG_RESET();
  113. writel(c, &uart_regs->thr);
  114. }
  115. /*
  116. * Read a single byte from the serial port. Returns 1 on success, 0
  117. * otherwise. When the function is succesfull, the character read is
  118. * written into its argument c.
  119. */
  120. int pxa_tstc_dev(unsigned int uart_index)
  121. {
  122. struct pxa_uart_regs *uart_regs;
  123. uart_regs = pxa_uart_index_to_regs(uart_index);
  124. if (!uart_regs)
  125. return -1;
  126. return readl(&uart_regs->lsr) & LSR_DR;
  127. }
  128. /*
  129. * Read a single byte from the serial port. Returns 1 on success, 0
  130. * otherwise. When the function is succesfull, the character read is
  131. * written into its argument c.
  132. */
  133. int pxa_getc_dev(unsigned int uart_index)
  134. {
  135. struct pxa_uart_regs *uart_regs;
  136. uart_regs = pxa_uart_index_to_regs(uart_index);
  137. if (!uart_regs)
  138. return -1;
  139. while (!(readl(&uart_regs->lsr) & LSR_DR))
  140. WATCHDOG_RESET();
  141. return readl(&uart_regs->rbr) & 0xff;
  142. }
  143. void pxa_puts_dev(unsigned int uart_index, const char *s)
  144. {
  145. while (*s)
  146. pxa_putc_dev(uart_index, *s++);
  147. }
  148. #define pxa_uart(uart, UART) \
  149. int uart##_init(void) \
  150. { \
  151. return pxa_init_dev(UART##_INDEX); \
  152. } \
  153. \
  154. void uart##_setbrg(void) \
  155. { \
  156. return pxa_setbrg_dev(UART##_INDEX); \
  157. } \
  158. \
  159. void uart##_putc(const char c) \
  160. { \
  161. return pxa_putc_dev(UART##_INDEX, c); \
  162. } \
  163. \
  164. void uart##_puts(const char *s) \
  165. { \
  166. return pxa_puts_dev(UART##_INDEX, s); \
  167. } \
  168. \
  169. int uart##_getc(void) \
  170. { \
  171. return pxa_getc_dev(UART##_INDEX); \
  172. } \
  173. \
  174. int uart##_tstc(void) \
  175. { \
  176. return pxa_tstc_dev(UART##_INDEX); \
  177. } \
  178. #define pxa_uart_desc(uart) \
  179. struct serial_device serial_##uart##_device = \
  180. { \
  181. .name = "serial_"#uart, \
  182. .start = uart##_init, \
  183. .stop = NULL, \
  184. .setbrg = uart##_setbrg, \
  185. .getc = uart##_getc, \
  186. .tstc = uart##_tstc, \
  187. .putc = uart##_putc, \
  188. .puts = uart##_puts, \
  189. };
  190. #define pxa_uart_multi(uart, UART) \
  191. pxa_uart(uart, UART) \
  192. pxa_uart_desc(uart)
  193. #if defined(CONFIG_HWUART)
  194. pxa_uart_multi(hwuart, HWUART)
  195. #endif
  196. #if defined(CONFIG_STUART)
  197. pxa_uart_multi(stuart, STUART)
  198. #endif
  199. #if defined(CONFIG_FFUART)
  200. pxa_uart_multi(ffuart, FFUART)
  201. #endif
  202. #if defined(CONFIG_BTUART)
  203. pxa_uart_multi(btuart, BTUART)
  204. #endif
  205. __weak struct serial_device *default_serial_console(void)
  206. {
  207. #if CONFIG_CONS_INDEX == 1
  208. return &serial_hwuart_device;
  209. #elif CONFIG_CONS_INDEX == 2
  210. return &serial_stuart_device;
  211. #elif CONFIG_CONS_INDEX == 3
  212. return &serial_ffuart_device;
  213. #elif CONFIG_CONS_INDEX == 4
  214. return &serial_btuart_device;
  215. #else
  216. #error "Bad CONFIG_CONS_INDEX."
  217. #endif
  218. }
  219. void pxa_serial_initialize(void)
  220. {
  221. #if defined(CONFIG_FFUART)
  222. serial_register(&serial_ffuart_device);
  223. #endif
  224. #if defined(CONFIG_BTUART)
  225. serial_register(&serial_btuart_device);
  226. #endif
  227. #if defined(CONFIG_STUART)
  228. serial_register(&serial_stuart_device);
  229. #endif
  230. }
  231. #endif /* CONFIG_DM_SERIAL */
  232. #ifdef CONFIG_DM_SERIAL
  233. static int pxa_serial_probe(struct udevice *dev)
  234. {
  235. struct pxa_serial_platdata *plat = dev->platdata;
  236. pxa_setbrg_common((struct pxa_uart_regs *)plat->base, plat->port,
  237. plat->baudrate);
  238. return 0;
  239. }
  240. static int pxa_serial_putc(struct udevice *dev, const char ch)
  241. {
  242. struct pxa_serial_platdata *plat = dev->platdata;
  243. struct pxa_uart_regs *uart_regs = (struct pxa_uart_regs *)plat->base;
  244. /* Wait for last character to go. */
  245. if (!(readl(&uart_regs->lsr) & LSR_TEMT))
  246. return -EAGAIN;
  247. writel(ch, &uart_regs->thr);
  248. return 0;
  249. }
  250. static int pxa_serial_getc(struct udevice *dev)
  251. {
  252. struct pxa_serial_platdata *plat = dev->platdata;
  253. struct pxa_uart_regs *uart_regs = (struct pxa_uart_regs *)plat->base;
  254. /* Wait for a character to arrive. */
  255. if (!(readl(&uart_regs->lsr) & LSR_DR))
  256. return -EAGAIN;
  257. return readl(&uart_regs->rbr) & 0xff;
  258. }
  259. int pxa_serial_setbrg(struct udevice *dev, int baudrate)
  260. {
  261. struct pxa_serial_platdata *plat = dev->platdata;
  262. struct pxa_uart_regs *uart_regs = (struct pxa_uart_regs *)plat->base;
  263. int port = plat->port;
  264. pxa_setbrg_common(uart_regs, port, baudrate);
  265. return 0;
  266. }
  267. static int pxa_serial_pending(struct udevice *dev, bool input)
  268. {
  269. struct pxa_serial_platdata *plat = dev->platdata;
  270. struct pxa_uart_regs *uart_regs = (struct pxa_uart_regs *)plat->base;
  271. if (input)
  272. return readl(&uart_regs->lsr) & LSR_DR ? 1 : 0;
  273. else
  274. return readl(&uart_regs->lsr) & LSR_TEMT ? 0 : 1;
  275. return 0;
  276. }
  277. static const struct dm_serial_ops pxa_serial_ops = {
  278. .putc = pxa_serial_putc,
  279. .pending = pxa_serial_pending,
  280. .getc = pxa_serial_getc,
  281. .setbrg = pxa_serial_setbrg,
  282. };
  283. U_BOOT_DRIVER(serial_pxa) = {
  284. .name = "serial_pxa",
  285. .id = UCLASS_SERIAL,
  286. .probe = pxa_serial_probe,
  287. .ops = &pxa_serial_ops,
  288. .flags = DM_FLAG_PRE_RELOC,
  289. };
  290. #endif /* CONFIG_DM_SERIAL */