LXR linux/arch/mips/generic/board-ocelot.c

   1// SPDX-License-Identifier: (GPL-2.0 OR MIT)
   2/*
   3 * Microsemi MIPS SoC support
   4 *
   5 * Copyright (c) 2017 Microsemi Corporation
   6 */
   7#include <asm/machine.h>
   8#include <asm/prom.h>
   9
  10#define DEVCPU_GCB_CHIP_REGS_CHIP_ID    0x71070000
  11#define CHIP_ID_PART_ID                 GENMASK(27, 12)
  12
  13#define OCELOT_PART_ID                  (0x7514 << 12)
  14
  15#define UART_UART                       0x70100000
  16
  17static __init bool ocelot_detect(void)
  18{
  19        u32 rev;
  20        int idx;
  21
  22        /* Look for the TLB entry set up by redboot before trying to use it */
  23        write_c0_entryhi(DEVCPU_GCB_CHIP_REGS_CHIP_ID);
  24        mtc0_tlbw_hazard();
  25        tlb_probe();
  26        tlb_probe_hazard();
  27        idx = read_c0_index();
  28        if (idx < 0)
  29                return 0;
  30
  31        /* A TLB entry exists, lets assume its usable and check the CHIP ID */
  32        rev = __raw_readl((void __iomem *)DEVCPU_GCB_CHIP_REGS_CHIP_ID);
  33
  34        if ((rev & CHIP_ID_PART_ID) != OCELOT_PART_ID)
  35                return 0;
  36
  37        /* Copy command line from bootloader early for Initrd detection */
  38        if (fw_arg0 < 10 && (fw_arg1 & 0xFFF00000) == 0x80000000) {
  39                unsigned int prom_argc = fw_arg0;
  40                const char **prom_argv = (const char **)fw_arg1;
  41
  42                if (prom_argc > 1 && strlen(prom_argv[1]) > 0)
  43                        /* ignore all built-in args if any f/w args given */
  44                        strcpy(arcs_cmdline, prom_argv[1]);
  45        }
  46
  47        return 1;
  48}
  49
  50static void __init ocelot_earlyprintk_init(void)
  51{
  52        void __iomem *uart_base;
  53
  54        uart_base = ioremap_nocache(UART_UART, 0x20);
  55        setup_8250_early_printk_port((unsigned long)uart_base, 2, 50000);
  56}
  57
  58static void __init ocelot_late_init(void)
  59{
  60        ocelot_earlyprintk_init();
  61}
  62
  63static __init const void *ocelot_fixup_fdt(const void *fdt,
  64                                           const void *match_data)
  65{
  66        /* This has to be done so late because ioremap needs to work */
  67        late_time_init = ocelot_late_init;
  68
  69        return fdt;
  70}
  71
  72extern char __dtb_ocelot_pcb123_begin[];
  73
  74MIPS_MACHINE(ocelot) = {
  75        .fdt = __dtb_ocelot_pcb123_begin,
  76        .fixup_fdt = ocelot_fixup_fdt,
  77        .detect = ocelot_detect,
  78};
  79