arch/arm/mach-integrator/core.c

   1 /*
   2  *  linux/arch/arm/mach-integrator/core.c
   3  *
   4  *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2, as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/device.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/sched.h>
  17
  18 #include <asm/hardware.h>
  19 #include <asm/irq.h>
  20 #include <asm/io.h>
  21 #include <asm/hardware/amba.h>
  22 #include <asm/arch/cm.h>
  23 #include <asm/system.h>
  24 #include <asm/leds.h>
  25 #include <asm/mach/time.h>
  26
  27 #include "common.h"
  28
  29 static struct amba_device rtc_device = {
  30         .dev            = {
  31                 .bus_id = "mb:15",
  32         },
  33         .res            = {
  34                 .start  = INTEGRATOR_RTC_BASE,
  35                 .end    = INTEGRATOR_RTC_BASE + SZ_4K - 1,
  36                 .flags  = IORESOURCE_MEM,
  37         },
  38         .irq            = { IRQ_RTCINT, NO_IRQ },
  39         .periphid       = 0x00041030,
  40 };
  41
  42 static struct amba_device uart0_device = {
  43         .dev            = {
  44                 .bus_id = "mb:16",
  45         },
  46         .res            = {
  47                 .start  = INTEGRATOR_UART0_BASE,
  48                 .end    = INTEGRATOR_UART0_BASE + SZ_4K - 1,
  49                 .flags  = IORESOURCE_MEM,
  50         },
  51         .irq            = { IRQ_UARTINT0, NO_IRQ },
  52         .periphid       = 0x0041010,
  53 };
  54
  55 static struct amba_device uart1_device = {
  56         .dev            = {
  57                 .bus_id = "mb:17",
  58         },
  59         .res            = {
  60                 .start  = INTEGRATOR_UART1_BASE,
  61                 .end    = INTEGRATOR_UART1_BASE + SZ_4K - 1,
  62                 .flags  = IORESOURCE_MEM,
  63         },
  64         .irq            = { IRQ_UARTINT1, NO_IRQ },
  65         .periphid       = 0x0041010,
  66 };
  67
  68 static struct amba_device kmi0_device = {
  69         .dev            = {
  70                 .bus_id = "mb:18",
  71         },
  72         .res            = {
  73                 .start  = KMI0_BASE,
  74                 .end    = KMI0_BASE + SZ_4K - 1,
  75                 .flags  = IORESOURCE_MEM,
  76         },
  77         .irq            = { IRQ_KMIINT0, NO_IRQ },
  78         .periphid       = 0x00041050,
  79 };
  80
  81 static struct amba_device kmi1_device = {
  82         .dev            = {
  83                 .bus_id = "mb:19",
  84         },
  85         .res            = {
  86                 .start  = KMI1_BASE,
  87                 .end    = KMI1_BASE + SZ_4K - 1,
  88                 .flags  = IORESOURCE_MEM,
  89         },
  90         .irq            = { IRQ_KMIINT1, NO_IRQ },
  91         .periphid       = 0x00041050,
  92 };
  93
  94 static struct amba_device *amba_devs[] __initdata = {
  95         &rtc_device,
  96         &uart0_device,
  97         &uart1_device,
  98         &kmi0_device,
  99         &kmi1_device,
 100 };
 101
 102 static int __init integrator_init(void)
 103 {
 104         int i;
 105
 106         for (i = 0; i < ARRAY_SIZE(amba_devs); i++) {
 107                 struct amba_device *d = amba_devs[i];
 108                 amba_device_register(d, &iomem_resource);
 109         }
 110
 111         return 0;
 112 }
 113
 114 arch_initcall(integrator_init);
 115
 116 #define CM_CTRL IO_ADDRESS(INTEGRATOR_HDR_BASE) + INTEGRATOR_HDR_CTRL_OFFSET
 117
 118 static DEFINE_SPINLOCK(cm_lock);
 119
 120 /**
 121  * cm_control - update the CM_CTRL register.
 122  * @mask: bits to change
 123  * @set: bits to set
 124  */
 125 void cm_control(u32 mask, u32 set)
 126 {
 127         unsigned long flags;
 128         u32 val;
 129
 130         spin_lock_irqsave(&cm_lock, flags);
 131         val = readl(CM_CTRL) & ~mask;
 132         writel(val | set, CM_CTRL);
 133         spin_unlock_irqrestore(&cm_lock, flags);
 134 }
 135
 136 EXPORT_SYMBOL(cm_control);
 137
 138 /*
 139  * Where is the timer (VA)?
 140  */
 141 #define TIMER0_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000000)
 142 #define TIMER1_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000100)
 143 #define TIMER2_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000200)
 144 #define VA_IC_BASE     IO_ADDRESS(INTEGRATOR_IC_BASE)
 145
 146 /*
 147  * How long is the timer interval?
 148  */
 149 #define TIMER_INTERVAL  (TICKS_PER_uSEC * mSEC_10)
 150 #if TIMER_INTERVAL >= 0x100000
 151 #define TICKS2USECS(x)  (256 * (x) / TICKS_PER_uSEC)
 152 #elif TIMER_INTERVAL >= 0x10000
 153 #define TICKS2USECS(x)  (16 * (x) / TICKS_PER_uSEC)
 154 #else
 155 #define TICKS2USECS(x)  ((x) / TICKS_PER_uSEC)
 156 #endif
 157
 158 /*
 159  * What does it look like?
 160  */
 161 typedef struct TimerStruct {
 162         unsigned long TimerLoad;
 163         unsigned long TimerValue;
 164         unsigned long TimerControl;
 165         unsigned long TimerClear;
 166 } TimerStruct_t;
 167
 168 static unsigned long timer_reload;
 169
 170 /*
 171  * Returns number of ms since last clock interrupt.  Note that interrupts
 172  * will have been disabled by do_gettimeoffset()
 173  */
 174 unsigned long integrator_gettimeoffset(void)
 175 {
 176         volatile TimerStruct_t *timer1 = (TimerStruct_t *)TIMER1_VA_BASE;
 177         unsigned long ticks1, ticks2, status;
 178
 179         /*
 180          * Get the current number of ticks.  Note that there is a race
 181          * condition between us reading the timer and checking for
 182          * an interrupt.  We get around this by ensuring that the
 183          * counter has not reloaded between our two reads.
 184          */
 185         ticks2 = timer1->TimerValue & 0xffff;
 186         do {
 187                 ticks1 = ticks2;
 188                 status = __raw_readl(VA_IC_BASE + IRQ_RAW_STATUS);
 189                 ticks2 = timer1->TimerValue & 0xffff;
 190         } while (ticks2 > ticks1);
 191
 192         /*
 193          * Number of ticks since last interrupt.
 194          */
 195         ticks1 = timer_reload - ticks2;
 196
 197         /*
 198          * Interrupt pending?  If so, we've reloaded once already.
 199          */
 200         if (status & (1 << IRQ_TIMERINT1))
 201                 ticks1 += timer_reload;
 202
 203         /*
 204          * Convert the ticks to usecs
 205          */
 206         return TICKS2USECS(ticks1);
 207 }
 208
 209 /*
 210  * IRQ handler for the timer
 211  */
 212 static irqreturn_t
 213 integrator_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 214 {
 215         volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE;
 216
 217         write_seqlock(&xtime_lock);
 218
 219         // ...clear the interrupt
 220         timer1->TimerClear = 1;
 221
 222         timer_tick(regs);
 223
 224         write_sequnlock(&xtime_lock);
 225
 226         return IRQ_HANDLED;
 227 }
 228
 229 static struct irqaction integrator_timer_irq = {
 230         .name           = "Integrator Timer Tick",
 231         .flags          = SA_INTERRUPT,
 232         .handler        = integrator_timer_interrupt
 233 };
 234
 235 /*
 236  * Set up timer interrupt, and return the current time in seconds.
 237  */
 238 void __init integrator_time_init(unsigned long reload, unsigned int ctrl)
 239 {
 240         volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *)TIMER0_VA_BASE;
 241         volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE;
 242         volatile TimerStruct_t *timer2 = (volatile TimerStruct_t *)TIMER2_VA_BASE;
 243         unsigned int timer_ctrl = 0x80 | 0x40;  /* periodic */
 244
 245         timer_reload = reload;
 246         timer_ctrl |= ctrl;
 247
 248         if (timer_reload > 0x100000) {
 249                 timer_reload >>= 8;
 250                 timer_ctrl |= 0x08; /* /256 */
 251         } else if (timer_reload > 0x010000) {
 252                 timer_reload >>= 4;
 253                 timer_ctrl |= 0x04; /* /16 */
 254         }
 255
 256         /*
 257          * Initialise to a known state (all timers off)
 258          */
 259         timer0->TimerControl = 0;
 260         timer1->TimerControl = 0;
 261         timer2->TimerControl = 0;
 262
 263         timer1->TimerLoad    = timer_reload;
 264         timer1->TimerValue   = timer_reload;
 265         timer1->TimerControl = timer_ctrl;
 266
 267         /*
 268          * Make irqs happen for the system timer
 269          */
 270         setup_irq(IRQ_TIMERINT1, &integrator_timer_irq);
 271 }