target/linux/realtek/files-5.15/arch/mips/rtl838x/setup.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Setup for the Realtek RTL838X SoC:
   4  *      Memory, Timer and Serial
   5  *
   6  * Copyright (C) 2020 B. Koblitz
   7  * based on the original BSP by
   8  * Copyright (C) 2006-2012 Tony Wu (tonywu@realtek.com)
   9  *
  10  */
  11
  12 #include <linux/console.h>
  13 #include <linux/init.h>
  14 #include <linux/clkdev.h>
  15 #include <linux/clk-provider.h>
  16 #include <linux/clk.h>
  17 #include <linux/delay.h>
  18 #include <linux/of_fdt.h>
  19 #include <linux/irqchip.h>
  20
  21 #include <asm/addrspace.h>
  22 #include <asm/io.h>
  23 #include <asm/bootinfo.h>
  24 #include <asm/time.h>
  25 #include <asm/prom.h>
  26 #include <asm/smp-ops.h>
  27
  28 #include "mach-rtl83xx.h"
  29
  30 extern struct rtl83xx_soc_info soc_info;
  31
  32 void __init plat_mem_setup(void)
  33 {
  34         void *dtb;
  35
  36         set_io_port_base(KSEG1);
  37
  38         dtb = get_fdt();
  39         if (!dtb)
  40                 panic("no dtb found");
  41
  42         /*
  43          * Load the devicetree. This causes the chosen node to be
  44          * parsed resulting in our memory appearing
  45          */
  46         __dt_setup_arch(dtb);
  47 }
  48
  49 void plat_time_init_fallback(void)
  50 {
  51         struct device_node *np;
  52         u32 freq = 500000000;
  53
  54         np = of_find_node_by_name(NULL, "cpus");
  55         if (!np) {
  56                 pr_err("Missing 'cpus' DT node, using default frequency.");
  57         } else {
  58                 if (of_property_read_u32(np, "frequency", &freq) < 0)
  59                         pr_err("No 'frequency' property in DT, using default.");
  60                 else
  61                         pr_info("CPU frequency from device tree: %dMHz", freq / 1000000);
  62                 of_node_put(np);
  63         }
  64         mips_hpt_frequency = freq / 2;
  65 }
  66
  67 void __init plat_time_init(void)
  68 {
  69 /*
  70  * Initialization routine resembles generic MIPS plat_time_init() with
  71  * lazy error handling. The final fallback is only needed until we have
  72  * converted all device trees to new clock syntax.
  73  */
  74         struct device_node *np;
  75         struct clk *clk;
  76
  77         of_clk_init(NULL);
  78
  79         mips_hpt_frequency = 0;
  80         np = of_get_cpu_node(0, NULL);
  81         if (!np) {
  82                 pr_err("Failed to get CPU node\n");
  83         } else {
  84                 clk = of_clk_get(np, 0);
  85                 if (IS_ERR(clk)) {
  86                         pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
  87                 } else {
  88                         mips_hpt_frequency = clk_get_rate(clk) / 2;
  89                         clk_put(clk);
  90                 }
  91         }
  92
  93         if (!mips_hpt_frequency)
  94                 plat_time_init_fallback();
  95
  96         timer_probe();
  97 }
  98
  99 void __init arch_init_irq(void)
 100 {
 101         irqchip_init();
 102 }