arch/mips/generic/init.c

   1 /*
   2  * Copyright (C) 2016 Imagination Technologies
   3  * Author: Paul Burton <paul.burton@imgtec.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation;  either version 2 of the  License, or (at your
   8  * option) any later version.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/clk-provider.h>
  13 #include <linux/clocksource.h>
  14 #include <linux/init.h>
  15 #include <linux/irqchip.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_platform.h>
  18
  19 #include <asm/fw/fw.h>
  20 #include <asm/irq_cpu.h>
  21 #include <asm/machine.h>
  22 #include <asm/mips-cpc.h>
  23 #include <asm/prom.h>
  24 #include <asm/smp-ops.h>
  25 #include <asm/time.h>
  26
  27 static __initdata const void *fdt;
  28 static __initdata const struct mips_machine *mach;
  29 static __initdata const void *mach_match_data;
  30
  31 void __init prom_init(void)
  32 {
  33         plat_get_fdt();
  34         BUG_ON(!fdt);
  35 }
  36
  37 void __init *plat_get_fdt(void)
  38 {
  39         const struct mips_machine *check_mach;
  40         const struct of_device_id *match;
  41
  42         if (fdt)
  43                 /* Already set up */
  44                 return (void *)fdt;
  45
  46         if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
  47                 /*
  48                  * We booted using the UHI boot protocol, so we have been
  49                  * provided with the appropriate device tree for the board.
  50                  * Make use of it & search for any machine struct based upon
  51                  * the root compatible string.
  52                  */
  53                 fdt = (void *)fw_arg1;
  54
  55                 for_each_mips_machine(check_mach) {
  56                         match = mips_machine_is_compatible(check_mach, fdt);
  57                         if (match) {
  58                                 mach = check_mach;
  59                                 mach_match_data = match->data;
  60                                 break;
  61                         }
  62                 }
  63         } else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
  64                 /*
  65                  * We weren't booted using the UHI boot protocol, but do
  66                  * support some number of boards with legacy boot protocols.
  67                  * Attempt to find the right one.
  68                  */
  69                 for_each_mips_machine(check_mach) {
  70                         if (!check_mach->detect)
  71                                 continue;
  72
  73                         if (!check_mach->detect())
  74                                 continue;
  75
  76                         mach = check_mach;
  77                 }
  78
  79                 /*
  80                  * If we don't recognise the machine then we can't continue, so
  81                  * die here.
  82                  */
  83                 BUG_ON(!mach);
  84
  85                 /* Retrieve the machine's FDT */
  86                 fdt = mach->fdt;
  87         }
  88         return (void *)fdt;
  89 }
  90
  91 void __init plat_fdt_relocated(void *new_location)
  92 {
  93         /*
  94          * reset fdt as the cached value would point to the location
  95          * before relocations happened and update the location argument
  96          * if it was passed using UHI
  97          */
  98         fdt = NULL;
  99
 100         if (fw_arg0 == -2)
 101                 fw_arg1 = (unsigned long)new_location;
 102 }
 103
 104 void __init plat_mem_setup(void)
 105 {
 106         if (mach && mach->fixup_fdt)
 107                 fdt = mach->fixup_fdt(fdt, mach_match_data);
 108
 109         strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 110         __dt_setup_arch((void *)fdt);
 111 }
 112
 113 void __init device_tree_init(void)
 114 {
 115         int err;
 116
 117         unflatten_and_copy_device_tree();
 118         mips_cpc_probe();
 119
 120         err = register_cps_smp_ops();
 121         if (err)
 122                 err = register_up_smp_ops();
 123 }
 124
 125 void __init plat_time_init(void)
 126 {
 127         struct device_node *np;
 128         struct clk *clk;
 129
 130         of_clk_init(NULL);
 131
 132         if (!cpu_has_counter) {
 133                 mips_hpt_frequency = 0;
 134         } else if (mach && mach->measure_hpt_freq) {
 135                 mips_hpt_frequency = mach->measure_hpt_freq();
 136         } else {
 137                 np = of_get_cpu_node(0, NULL);
 138                 if (!np) {
 139                         pr_err("Failed to get CPU node\n");
 140                         return;
 141                 }
 142
 143                 clk = of_clk_get(np, 0);
 144                 if (IS_ERR(clk)) {
 145                         pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
 146                         return;
 147                 }
 148
 149                 mips_hpt_frequency = clk_get_rate(clk);
 150                 clk_put(clk);
 151
 152                 switch (boot_cpu_type()) {
 153                 case CPU_20KC:
 154                 case CPU_25KF:
 155                         /* The counter runs at the CPU clock rate */
 156                         break;
 157                 default:
 158                         /* The counter runs at half the CPU clock rate */
 159                         mips_hpt_frequency /= 2;
 160                         break;
 161                 }
 162         }
 163
 164         clocksource_probe();
 165 }
 166
 167 void __init arch_init_irq(void)
 168 {
 169         struct device_node *intc_node;
 170
 171         intc_node = of_find_compatible_node(NULL, NULL,
 172                                             "mti,cpu-interrupt-controller");
 173         if (!cpu_has_veic && !intc_node)
 174                 mips_cpu_irq_init();
 175
 176         irqchip_init();
 177 }
 178
 179 static int __init publish_devices(void)
 180 {
 181         if (!of_have_populated_dt())
 182                 panic("Device-tree not present");
 183
 184         if (of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL))
 185                 panic("Failed to populate DT");
 186
 187         return 0;
 188 }
 189 arch_initcall(publish_devices);
 190
 191 void __init prom_free_prom_memory(void)
 192 {
 193 }