devtree.c 1.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
  4. *
  5. * Based on reduced version of METAG
  6. */
  7. #include <linux/init.h>
  8. #include <linux/reboot.h>
  9. #include <linux/memblock.h>
  10. #include <linux/of.h>
  11. #include <linux/of_fdt.h>
  12. #include <asm/mach_desc.h>
  13. #ifdef CONFIG_SERIAL_EARLYCON
  14. static unsigned int __initdata arc_base_baud;
  15. unsigned int __init arc_early_base_baud(void)
  16. {
  17. return arc_base_baud/16;
  18. }
  19. static void __init arc_set_early_base_baud(unsigned long dt_root)
  20. {
  21. if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
  22. arc_base_baud = 166666666; /* Fixed 166.6MHz clk (TB10x) */
  23. else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp") ||
  24. of_flat_dt_is_compatible(dt_root, "snps,hsdk"))
  25. arc_base_baud = 33333333; /* Fixed 33MHz clk (AXS10x & HSDK) */
  26. else
  27. arc_base_baud = 50000000; /* Fixed default 50MHz */
  28. }
  29. #else
  30. #define arc_set_early_base_baud(dt_root)
  31. #endif
  32. static const void * __init arch_get_next_mach(const char *const **match)
  33. {
  34. static const struct machine_desc *mdesc = __arch_info_begin;
  35. const struct machine_desc *m = mdesc;
  36. if (m >= __arch_info_end)
  37. return NULL;
  38. mdesc++;
  39. *match = m->dt_compat;
  40. return m;
  41. }
  42. /**
  43. * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
  44. * @dt: virtual address pointer to dt blob
  45. *
  46. * If a dtb was passed to the kernel, then use it to choose the correct
  47. * machine_desc and to setup the system.
  48. */
  49. const struct machine_desc * __init setup_machine_fdt(void *dt)
  50. {
  51. const struct machine_desc *mdesc;
  52. unsigned long dt_root;
  53. if (!early_init_dt_scan(dt))
  54. return NULL;
  55. mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
  56. if (!mdesc)
  57. machine_halt();
  58. dt_root = of_get_flat_dt_root();
  59. arc_set_early_base_baud(dt_root);
  60. return mdesc;
  61. }