arch/arm/mach-ebsa110/core.c

   1 /*
   2  *  linux/arch/arm/mach-ebsa110/core.c
   3  *
   4  *  Copyright (C) 1998-2001 Russell King
   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  *  Extra MM routines for the EBSA-110 architecture
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/mm.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/serial_8250.h>
  16 #include <linux/init.h>
  17
  18 #include <asm/hardware.h>
  19 #include <asm/irq.h>
  20 #include <asm/io.h>
  21 #include <asm/setup.h>
  22 #include <asm/mach-types.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/page.h>
  25 #include <asm/system.h>
  26
  27 #include <asm/mach/arch.h>
  28 #include <asm/mach/irq.h>
  29 #include <asm/mach/map.h>
  30
  31 #include <asm/mach/time.h>
  32
  33 #define IRQ_MASK                0xfe000000      /* read */
  34 #define IRQ_MSET                0xfe000000      /* write */
  35 #define IRQ_STAT                0xff000000      /* read */
  36 #define IRQ_MCLR                0xff000000      /* write */
  37
  38 static void ebsa110_mask_irq(unsigned int irq)
  39 {
  40         __raw_writeb(1 << irq, IRQ_MCLR);
  41 }
  42
  43 static void ebsa110_unmask_irq(unsigned int irq)
  44 {
  45         __raw_writeb(1 << irq, IRQ_MSET);
  46 }
  47
  48 static struct irqchip ebsa110_irq_chip = {
  49         .ack    = ebsa110_mask_irq,
  50         .mask   = ebsa110_mask_irq,
  51         .unmask = ebsa110_unmask_irq,
  52 };
  53
  54 static void __init ebsa110_init_irq(void)
  55 {
  56         unsigned long flags;
  57         unsigned int irq;
  58
  59         local_irq_save(flags);
  60         __raw_writeb(0xff, IRQ_MCLR);
  61         __raw_writeb(0x55, IRQ_MSET);
  62         __raw_writeb(0x00, IRQ_MSET);
  63         if (__raw_readb(IRQ_MASK) != 0x55)
  64                 while (1);
  65         __raw_writeb(0xff, IRQ_MCLR);   /* clear all interrupt enables */
  66         local_irq_restore(flags);
  67
  68         for (irq = 0; irq < NR_IRQS; irq++) {
  69                 set_irq_chip(irq, &ebsa110_irq_chip);
  70                 set_irq_handler(irq, do_level_IRQ);
  71                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  72         }
  73 }
  74
  75 static struct map_desc ebsa110_io_desc[] __initdata = {
  76         /*
  77          * sparse external-decode ISAIO space
  78          */
  79         { IRQ_STAT,    TRICK4_PHYS, PGDIR_SIZE,  MT_DEVICE }, /* IRQ_STAT/IRQ_MCLR */
  80         { IRQ_MASK,    TRICK3_PHYS, PGDIR_SIZE,  MT_DEVICE }, /* IRQ_MASK/IRQ_MSET */
  81         { SOFT_BASE,   TRICK1_PHYS, PGDIR_SIZE,  MT_DEVICE }, /* SOFT_BASE */
  82         { PIT_BASE,    TRICK0_PHYS, PGDIR_SIZE,  MT_DEVICE }, /* PIT_BASE */
  83
  84         /*
  85          * self-decode ISAIO space
  86          */
  87         { ISAIO_BASE,  ISAIO_PHYS,  ISAIO_SIZE,  MT_DEVICE },
  88         { ISAMEM_BASE, ISAMEM_PHYS, ISAMEM_SIZE, MT_DEVICE }
  89 };
  90
  91 static void __init ebsa110_map_io(void)
  92 {
  93         iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
  94 }
  95
  96
  97 #define PIT_CTRL                (PIT_BASE + 0x0d)
  98 #define PIT_T2                  (PIT_BASE + 0x09)
  99 #define PIT_T1                  (PIT_BASE + 0x05)
 100 #define PIT_T0                  (PIT_BASE + 0x01)
 101
 102 /*
 103  * This is the rate at which your MCLK signal toggles (in Hz)
 104  * This was measured on a 10 digit frequency counter sampling
 105  * over 1 second.
 106  */
 107 #define MCLK    47894000
 108
 109 /*
 110  * This is the rate at which the PIT timers get clocked
 111  */
 112 #define CLKBY7  (MCLK / 7)
 113
 114 /*
 115  * This is the counter value.  We tick at 200Hz on this platform.
 116  */
 117 #define COUNT   ((CLKBY7 + (HZ / 2)) / HZ)
 118
 119 /*
 120  * Get the time offset from the system PIT.  Note that if we have missed an
 121  * interrupt, then the PIT counter will roll over (ie, be negative).
 122  * This actually works out to be convenient.
 123  */
 124 static unsigned long ebsa110_gettimeoffset(void)
 125 {
 126         unsigned long offset, count;
 127
 128         __raw_writeb(0x40, PIT_CTRL);
 129         count = __raw_readb(PIT_T1);
 130         count |= __raw_readb(PIT_T1) << 8;
 131
 132         /*
 133          * If count > COUNT, make the number negative.
 134          */
 135         if (count > COUNT)
 136                 count |= 0xffff0000;
 137
 138         offset = COUNT;
 139         offset -= count;
 140
 141         /*
 142          * `offset' is in units of timer counts.  Convert
 143          * offset to units of microseconds.
 144          */
 145         offset = offset * (1000000 / HZ) / COUNT;
 146
 147         return offset;
 148 }
 149
 150 static irqreturn_t
 151 ebsa110_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 152 {
 153         u32 count;
 154
 155         write_seqlock(&xtime_lock);
 156
 157         /* latch and read timer 1 */
 158         __raw_writeb(0x40, PIT_CTRL);
 159         count = __raw_readb(PIT_T1);
 160         count |= __raw_readb(PIT_T1) << 8;
 161
 162         count += COUNT;
 163
 164         __raw_writeb(count & 0xff, PIT_T1);
 165         __raw_writeb(count >> 8, PIT_T1);
 166
 167         timer_tick(regs);
 168
 169         write_sequnlock(&xtime_lock);
 170
 171         return IRQ_HANDLED;
 172 }
 173
 174 static struct irqaction ebsa110_timer_irq = {
 175         .name           = "EBSA110 Timer Tick",
 176         .flags          = SA_INTERRUPT | SA_TIMER,
 177         .handler        = ebsa110_timer_interrupt,
 178 };
 179
 180 /*
 181  * Set up timer interrupt.
 182  */
 183 static void __init ebsa110_timer_init(void)
 184 {
 185         /*
 186          * Timer 1, mode 2, LSB/MSB
 187          */
 188         __raw_writeb(0x70, PIT_CTRL);
 189         __raw_writeb(COUNT & 0xff, PIT_T1);
 190         __raw_writeb(COUNT >> 8, PIT_T1);
 191
 192         setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
 193 }
 194
 195 static struct sys_timer ebsa110_timer = {
 196         .init           = ebsa110_timer_init,
 197         .offset         = ebsa110_gettimeoffset,
 198 };
 199
 200 static struct plat_serial8250_port serial_platform_data[] = {
 201         {
 202                 .iobase         = 0x3f8,
 203                 .irq            = 1,
 204                 .uartclk        = 1843200,
 205                 .regshift       = 0,
 206                 .iotype         = UPIO_PORT,
 207                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
 208         },
 209         {
 210                 .iobase         = 0x2f8,
 211                 .irq            = 2,
 212                 .uartclk        = 1843200,
 213                 .regshift       = 0,
 214                 .iotype         = UPIO_PORT,
 215                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
 216         },
 217         { },
 218 };
 219
 220 static struct platform_device serial_device = {
 221         .name                   = "serial8250",
 222         .id                     = PLAT8250_DEV_PLATFORM,
 223         .dev                    = {
 224                 .platform_data  = serial_platform_data,
 225         },
 226 };
 227
 228 static int __init ebsa110_init(void)
 229 {
 230         return platform_device_register(&serial_device);
 231 }
 232
 233 arch_initcall(ebsa110_init);
 234
 235 MACHINE_START(EBSA110, "EBSA110")
 236         /* Maintainer: Russell King */
 237         .phys_ram       = 0x00000000,
 238         .phys_io        = 0xe0000000,
 239         .io_pg_offst    = ((0xe0000000) >> 18) & 0xfffc,
 240         .boot_params    = 0x00000400,
 241         .reserve_lp0    = 1,
 242         .reserve_lp2    = 1,
 243         .soft_reboot    = 1,
 244         .map_io         = ebsa110_map_io,
 245         .init_irq       = ebsa110_init_irq,
 246         .timer          = &ebsa110_timer,
 247 MACHINE_END