altera_jtag_uart.c 3.4 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150
  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
  4. * Scott McNutt <smcnutt@psyent.com>
  5. */
  6. #include <common.h>
  7. #include <dm.h>
  8. #include <errno.h>
  9. #include <serial.h>
  10. #include <asm/io.h>
  11. /* data register */
  12. #define ALTERA_JTAG_RVALID BIT(15) /* Read valid */
  13. /* control register */
  14. #define ALTERA_JTAG_AC BIT(10) /* activity indicator */
  15. #define ALTERA_JTAG_RRDY BIT(12) /* read available */
  16. #define ALTERA_JTAG_WSPACE(d) ((d) >> 16) /* Write space avail */
  17. /* Write fifo size. FIXME: this should be extracted with sopc2dts */
  18. #define ALTERA_JTAG_WRITE_DEPTH 64
  19. struct altera_jtaguart_regs {
  20. u32 data; /* Data register */
  21. u32 control; /* Control register */
  22. };
  23. struct altera_jtaguart_platdata {
  24. struct altera_jtaguart_regs *regs;
  25. };
  26. static int altera_jtaguart_setbrg(struct udevice *dev, int baudrate)
  27. {
  28. return 0;
  29. }
  30. static int altera_jtaguart_putc(struct udevice *dev, const char ch)
  31. {
  32. struct altera_jtaguart_platdata *plat = dev->platdata;
  33. struct altera_jtaguart_regs *const regs = plat->regs;
  34. u32 st = readl(&regs->control);
  35. #ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
  36. if (!(st & ALTERA_JTAG_AC)) /* no connection yet */
  37. return -ENETUNREACH;
  38. #endif
  39. if (ALTERA_JTAG_WSPACE(st) == 0)
  40. return -EAGAIN;
  41. writel(ch, &regs->data);
  42. return 0;
  43. }
  44. static int altera_jtaguart_pending(struct udevice *dev, bool input)
  45. {
  46. struct altera_jtaguart_platdata *plat = dev->platdata;
  47. struct altera_jtaguart_regs *const regs = plat->regs;
  48. u32 st = readl(&regs->control);
  49. if (input)
  50. return st & ALTERA_JTAG_RRDY ? 1 : 0;
  51. else
  52. return !(ALTERA_JTAG_WSPACE(st) == ALTERA_JTAG_WRITE_DEPTH);
  53. }
  54. static int altera_jtaguart_getc(struct udevice *dev)
  55. {
  56. struct altera_jtaguart_platdata *plat = dev->platdata;
  57. struct altera_jtaguart_regs *const regs = plat->regs;
  58. u32 val;
  59. val = readl(&regs->data);
  60. if (!(val & ALTERA_JTAG_RVALID))
  61. return -EAGAIN;
  62. return val & 0xff;
  63. }
  64. static int altera_jtaguart_probe(struct udevice *dev)
  65. {
  66. #ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
  67. struct altera_jtaguart_platdata *plat = dev->platdata;
  68. struct altera_jtaguart_regs *const regs = plat->regs;
  69. writel(ALTERA_JTAG_AC, &regs->control); /* clear AC flag */
  70. #endif
  71. return 0;
  72. }
  73. static int altera_jtaguart_ofdata_to_platdata(struct udevice *dev)
  74. {
  75. struct altera_jtaguart_platdata *plat = dev_get_platdata(dev);
  76. plat->regs = map_physmem(devfdt_get_addr(dev),
  77. sizeof(struct altera_jtaguart_regs),
  78. MAP_NOCACHE);
  79. return 0;
  80. }
  81. static const struct dm_serial_ops altera_jtaguart_ops = {
  82. .putc = altera_jtaguart_putc,
  83. .pending = altera_jtaguart_pending,
  84. .getc = altera_jtaguart_getc,
  85. .setbrg = altera_jtaguart_setbrg,
  86. };
  87. static const struct udevice_id altera_jtaguart_ids[] = {
  88. { .compatible = "altr,juart-1.0" },
  89. {}
  90. };
  91. U_BOOT_DRIVER(altera_jtaguart) = {
  92. .name = "altera_jtaguart",
  93. .id = UCLASS_SERIAL,
  94. .of_match = altera_jtaguart_ids,
  95. .ofdata_to_platdata = altera_jtaguart_ofdata_to_platdata,
  96. .platdata_auto_alloc_size = sizeof(struct altera_jtaguart_platdata),
  97. .probe = altera_jtaguart_probe,
  98. .ops = &altera_jtaguart_ops,
  99. };
  100. #ifdef CONFIG_DEBUG_UART_ALTERA_JTAGUART
  101. #include <debug_uart.h>
  102. static inline void _debug_uart_init(void)
  103. {
  104. }
  105. static inline void _debug_uart_putc(int ch)
  106. {
  107. struct altera_jtaguart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
  108. while (1) {
  109. u32 st = readl(&regs->control);
  110. if (ALTERA_JTAG_WSPACE(st))
  111. break;
  112. }
  113. writel(ch, &regs->data);
  114. }
  115. DEBUG_UART_FUNCS
  116. #endif