arch/mips/lantiq/xway/reset.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/io.h>
  11 #include <linux/ioport.h>
  12 #include <linux/pm.h>
  13 #include <linux/export.h>
  14 #include <linux/delay.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of_platform.h>
  17
  18 #include <asm/reboot.h>
  19
  20 #include <lantiq_soc.h>
  21
  22 #include "../prom.h"
  23
  24 #define ltq_rcu_w32(x, y)       ltq_w32((x), ltq_rcu_membase + (y))
  25 #define ltq_rcu_r32(x)          ltq_r32(ltq_rcu_membase + (x))
  26
  27 /* reset request register */
  28 #define RCU_RST_REQ             0x0010
  29 /* reset status register */
  30 #define RCU_RST_STAT            0x0014
  31 /* vr9 gphy registers */
  32 #define RCU_GFS_ADD0_XRX200     0x0020
  33 #define RCU_GFS_ADD1_XRX200     0x0068
  34
  35 /* reboot bit */
  36 #define RCU_RD_GPHY0_XRX200     BIT(31)
  37 #define RCU_RD_SRST             BIT(30)
  38 #define RCU_RD_GPHY1_XRX200     BIT(29)
  39
  40 /* reset cause */
  41 #define RCU_STAT_SHIFT          26
  42 /* boot selection */
  43 #define RCU_BOOT_SEL(x)         ((x >> 18) & 0x7)
  44 #define RCU_BOOT_SEL_XRX200(x)  (((x >> 17) & 0xf) | ((x >> 8) & 0x10))
  45
  46 /* remapped base addr of the reset control unit */
  47 static void __iomem *ltq_rcu_membase;
  48 static struct device_node *ltq_rcu_np;
  49
  50 /* This function is used by the watchdog driver */
  51 int ltq_reset_cause(void)
  52 {
  53         u32 val = ltq_rcu_r32(RCU_RST_STAT);
  54         return val >> RCU_STAT_SHIFT;
  55 }
  56 EXPORT_SYMBOL_GPL(ltq_reset_cause);
  57
  58 /* allow platform code to find out what source we booted from */
  59 unsigned char ltq_boot_select(void)
  60 {
  61         u32 val = ltq_rcu_r32(RCU_RST_STAT);
  62
  63         if (of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200"))
  64                 return RCU_BOOT_SEL_XRX200(val);
  65
  66         return RCU_BOOT_SEL(val);
  67 }
  68
  69 /* reset / boot a gphy */
  70 static struct ltq_xrx200_gphy_reset {
  71         u32 rd;
  72         u32 addr;
  73 } xrx200_gphy[] = {
  74         {RCU_RD_GPHY0_XRX200, RCU_GFS_ADD0_XRX200},
  75         {RCU_RD_GPHY1_XRX200, RCU_GFS_ADD1_XRX200},
  76 };
  77
  78 /* reset and boot a gphy. these phys only exist on xrx200 SoC */
  79 int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr)
  80 {
  81         struct clk *clk;
  82
  83         if (!of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200")) {
  84                 dev_err(dev, "this SoC has no GPHY\n");
  85                 return -EINVAL;
  86         }
  87
  88         clk = clk_get_sys("1f203000.rcu", "gphy");
  89         if (IS_ERR(clk))
  90                 return PTR_ERR(clk);
  91
  92         clk_enable(clk);
  93
  94         if (id > 1) {
  95                 dev_err(dev, "%u is an invalid gphy id\n", id);
  96                 return -EINVAL;
  97         }
  98         dev_info(dev, "booting GPHY%u firmware at %X\n", id, dev_addr);
  99
 100         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | xrx200_gphy[id].rd,
 101                         RCU_RST_REQ);
 102         ltq_rcu_w32(dev_addr, xrx200_gphy[id].addr);
 103         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~xrx200_gphy[id].rd,
 104                         RCU_RST_REQ);
 105         return 0;
 106 }
 107
 108 /* reset a io domain for u micro seconds */
 109 void ltq_reset_once(unsigned int module, ulong u)
 110 {
 111         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | module, RCU_RST_REQ);
 112         udelay(u);
 113         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~module, RCU_RST_REQ);
 114 }
 115
 116 static void ltq_machine_restart(char *command)
 117 {
 118         local_irq_disable();
 119         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | RCU_RD_SRST, RCU_RST_REQ);
 120         unreachable();
 121 }
 122
 123 static void ltq_machine_halt(void)
 124 {
 125         local_irq_disable();
 126         unreachable();
 127 }
 128
 129 static void ltq_machine_power_off(void)
 130 {
 131         local_irq_disable();
 132         unreachable();
 133 }
 134
 135 static int __init mips_reboot_setup(void)
 136 {
 137         struct resource res;
 138
 139         ltq_rcu_np = of_find_compatible_node(NULL, NULL, "lantiq,rcu-xway");
 140         if (!ltq_rcu_np)
 141                 ltq_rcu_np = of_find_compatible_node(NULL, NULL,
 142                                                         "lantiq,rcu-xrx200");
 143
 144         /* check if all the reset register range is available */
 145         if (!ltq_rcu_np)
 146                 panic("Failed to load reset resources from devicetree");
 147
 148         if (of_address_to_resource(ltq_rcu_np, 0, &res))
 149                 panic("Failed to get rcu memory range");
 150
 151         if (request_mem_region(res.start, resource_size(&res), res.name) < 0)
 152                 pr_err("Failed to request rcu memory");
 153
 154         ltq_rcu_membase = ioremap_nocache(res.start, resource_size(&res));
 155         if (!ltq_rcu_membase)
 156                 panic("Failed to remap core memory");
 157
 158         _machine_restart = ltq_machine_restart;
 159         _machine_halt = ltq_machine_halt;
 160         pm_power_off = ltq_machine_power_off;
 161
 162         return 0;
 163 }
 164
 165 arch_initcall(mips_reboot_setup);