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 #include <linux/reset-controller.h>
  18
  19 #include <asm/reboot.h>
  20
  21 #include <lantiq_soc.h>
  22
  23 #include "../prom.h"
  24
  25 #define ltq_rcu_w32(x, y)       ltq_w32((x), ltq_rcu_membase + (y))
  26 #define ltq_rcu_r32(x)          ltq_r32(ltq_rcu_membase + (x))
  27
  28 /* reset request register */
  29 #define RCU_RST_REQ             0x0010
  30 /* reset status register */
  31 #define RCU_RST_STAT            0x0014
  32 /* vr9 gphy registers */
  33 #define RCU_GFS_ADD0_XRX200     0x0020
  34 #define RCU_GFS_ADD1_XRX200     0x0068
  35
  36 /* reboot bit */
  37 #define RCU_RD_GPHY0_XRX200     BIT(31)
  38 #define RCU_RD_SRST             BIT(30)
  39 #define RCU_RD_GPHY1_XRX200     BIT(29)
  40
  41 /* reset cause */
  42 #define RCU_STAT_SHIFT          26
  43 /* boot selection */
  44 #define RCU_BOOT_SEL(x)         ((x >> 18) & 0x7)
  45 #define RCU_BOOT_SEL_XRX200(x)  (((x >> 17) & 0xf) | ((x >> 8) & 0x10))
  46
  47 /* remapped base addr of the reset control unit */
  48 static void __iomem *ltq_rcu_membase;
  49 static struct device_node *ltq_rcu_np;
  50
  51 /* This function is used by the watchdog driver */
  52 int ltq_reset_cause(void)
  53 {
  54         u32 val = ltq_rcu_r32(RCU_RST_STAT);
  55         return val >> RCU_STAT_SHIFT;
  56 }
  57 EXPORT_SYMBOL_GPL(ltq_reset_cause);
  58
  59 /* allow platform code to find out what source we booted from */
  60 unsigned char ltq_boot_select(void)
  61 {
  62         u32 val = ltq_rcu_r32(RCU_RST_STAT);
  63
  64         if (of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200"))
  65                 return RCU_BOOT_SEL_XRX200(val);
  66
  67         return RCU_BOOT_SEL(val);
  68 }
  69
  70 /* reset / boot a gphy */
  71 static struct ltq_xrx200_gphy_reset {
  72         u32 rd;
  73         u32 addr;
  74 } xrx200_gphy[] = {
  75         {RCU_RD_GPHY0_XRX200, RCU_GFS_ADD0_XRX200},
  76         {RCU_RD_GPHY1_XRX200, RCU_GFS_ADD1_XRX200},
  77 };
  78
  79 /* reset and boot a gphy. these phys only exist on xrx200 SoC */
  80 int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr)
  81 {
  82         struct clk *clk;
  83
  84         if (!of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200")) {
  85                 dev_err(dev, "this SoC has no GPHY\n");
  86                 return -EINVAL;
  87         }
  88
  89         clk = clk_get_sys("1f203000.rcu", "gphy");
  90         if (IS_ERR(clk))
  91                 return PTR_ERR(clk);
  92
  93         clk_enable(clk);
  94
  95         if (id > 1) {
  96                 dev_err(dev, "%u is an invalid gphy id\n", id);
  97                 return -EINVAL;
  98         }
  99         dev_info(dev, "booting GPHY%u firmware at %X\n", id, dev_addr);
 100
 101         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | xrx200_gphy[id].rd,
 102                         RCU_RST_REQ);
 103         ltq_rcu_w32(dev_addr, xrx200_gphy[id].addr);
 104         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~xrx200_gphy[id].rd,
 105                         RCU_RST_REQ);
 106         return 0;
 107 }
 108
 109 /* reset a io domain for u micro seconds */
 110 void ltq_reset_once(unsigned int module, ulong u)
 111 {
 112         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | module, RCU_RST_REQ);
 113         udelay(u);
 114         ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~module, RCU_RST_REQ);
 115 }
 116
 117 static int ltq_assert_device(struct reset_controller_dev *rcdev,
 118                                 unsigned long id)
 119 {
 120         u32 val;
 121
 122         if (id < 8)
 123                 return -1;
 124
 125         val = ltq_rcu_r32(RCU_RST_REQ);
 126         val |= BIT(id);
 127         ltq_rcu_w32(val, RCU_RST_REQ);
 128
 129         return 0;
 130 }
 131
 132 static int ltq_deassert_device(struct reset_controller_dev *rcdev,
 133                                   unsigned long id)
 134 {
 135         u32 val;
 136
 137         if (id < 8)
 138                 return -1;
 139
 140         val = ltq_rcu_r32(RCU_RST_REQ);
 141         val &= ~BIT(id);
 142         ltq_rcu_w32(val, RCU_RST_REQ);
 143
 144         return 0;
 145 }
 146
 147 static int ltq_reset_device(struct reset_controller_dev *rcdev,
 148                                unsigned long id)
 149 {
 150         ltq_assert_device(rcdev, id);
 151         return ltq_deassert_device(rcdev, id);
 152 }
 153
 154 static struct reset_control_ops reset_ops = {
 155         .reset = ltq_reset_device,
 156         .assert = ltq_assert_device,
 157         .deassert = ltq_deassert_device,
 158 };
 159
 160 static struct reset_controller_dev reset_dev = {
 161         .ops                    = &reset_ops,
 162         .owner                  = THIS_MODULE,
 163         .nr_resets              = 32,
 164         .of_reset_n_cells       = 1,
 165 };
 166
 167 void ltq_rst_init(void)
 168 {
 169         reset_dev.of_node = of_find_compatible_node(NULL, NULL,
 170                                                 "lantiq,xway-reset");
 171         if (!reset_dev.of_node)
 172                 pr_err("Failed to find reset controller node");
 173         else
 174                 reset_controller_register(&reset_dev);
 175 }
 176
 177 static void ltq_machine_restart(char *command)
 178 {
 179         u32 val = ltq_rcu_r32(RCU_RST_REQ);
 180
 181         if (of_device_is_compatible(ltq_rcu_np, "lantiq,rcu-xrx200"))
 182                 val |= RCU_RD_GPHY1_XRX200 | RCU_RD_GPHY0_XRX200;
 183
 184         val |= RCU_RD_SRST;
 185
 186         local_irq_disable();
 187         ltq_rcu_w32(val, RCU_RST_REQ);
 188         unreachable();
 189 }
 190
 191 static void ltq_machine_halt(void)
 192 {
 193         local_irq_disable();
 194         unreachable();
 195 }
 196
 197 static void ltq_machine_power_off(void)
 198 {
 199         local_irq_disable();
 200         unreachable();
 201 }
 202
 203 static int __init mips_reboot_setup(void)
 204 {
 205         struct resource res;
 206
 207         ltq_rcu_np = of_find_compatible_node(NULL, NULL, "lantiq,rcu-xway");
 208         if (!ltq_rcu_np)
 209                 ltq_rcu_np = of_find_compatible_node(NULL, NULL,
 210                                                         "lantiq,rcu-xrx200");
 211
 212         /* check if all the reset register range is available */
 213         if (!ltq_rcu_np)
 214                 panic("Failed to load reset resources from devicetree");
 215
 216         if (of_address_to_resource(ltq_rcu_np, 0, &res))
 217                 panic("Failed to get rcu memory range");
 218
 219         if (request_mem_region(res.start, resource_size(&res), res.name) < 0)
 220                 pr_err("Failed to request rcu memory");
 221
 222         ltq_rcu_membase = ioremap_nocache(res.start, resource_size(&res));
 223         if (!ltq_rcu_membase)
 224                 panic("Failed to remap core memory");
 225
 226         _machine_restart = ltq_machine_restart;
 227         _machine_halt = ltq_machine_halt;
 228         pm_power_off = ltq_machine_power_off;
 229
 230         return 0;
 231 }
 232
 233 arch_initcall(mips_reboot_setup);