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