altera_jtag_uart.c 3.4 KB

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