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 #include <linux/io.h>
  18
  19 #include <mach/hardware.h>
  20 #include <asm/irq.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(struct irq_data *d)
  39 {
  40         __raw_writeb(1 << d->irq, IRQ_MCLR);
  41 }
  42
  43 static void ebsa110_unmask_irq(struct irq_data *d)
  44 {
  45         __raw_writeb(1 << d->irq, IRQ_MSET);
  46 }
  47
  48 static struct irq_chip ebsa110_irq_chip = {
  49         .irq_ack        = ebsa110_mask_irq,
  50         .irq_mask       = ebsa110_mask_irq,
  51         .irq_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                 irq_set_chip_and_handler(irq, &ebsa110_irq_chip,
  70                                          handle_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/IRQ_MCLR */
  80                 .virtual        = IRQ_STAT,
  81                 .pfn            = __phys_to_pfn(TRICK4_PHYS),
  82                 .length         = PGDIR_SIZE,
  83                 .type           = MT_DEVICE
  84         }, {    /* IRQ_MASK/IRQ_MSET */
  85                 .virtual        = IRQ_MASK,
  86                 .pfn            = __phys_to_pfn(TRICK3_PHYS),
  87                 .length         = PGDIR_SIZE,
  88                 .type           = MT_DEVICE
  89         }, {    /* SOFT_BASE */
  90                 .virtual        = SOFT_BASE,
  91                 .pfn            = __phys_to_pfn(TRICK1_PHYS),
  92                 .length         = PGDIR_SIZE,
  93                 .type           = MT_DEVICE
  94         }, {    /* PIT_BASE */
  95                 .virtual        = PIT_BASE,
  96                 .pfn            = __phys_to_pfn(TRICK0_PHYS),
  97                 .length         = PGDIR_SIZE,
  98                 .type           = MT_DEVICE
  99         },
 100
 101         /*
 102          * self-decode ISAIO space
 103          */
 104         {
 105                 .virtual        = ISAIO_BASE,
 106                 .pfn            = __phys_to_pfn(ISAIO_PHYS),
 107                 .length         = ISAIO_SIZE,
 108                 .type           = MT_DEVICE
 109         }, {
 110                 .virtual        = ISAMEM_BASE,
 111                 .pfn            = __phys_to_pfn(ISAMEM_PHYS),
 112                 .length         = ISAMEM_SIZE,
 113                 .type           = MT_DEVICE
 114         }
 115 };
 116
 117 static void __init ebsa110_map_io(void)
 118 {
 119         iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
 120 }
 121
 122
 123 #define PIT_CTRL                (PIT_BASE + 0x0d)
 124 #define PIT_T2                  (PIT_BASE + 0x09)
 125 #define PIT_T1                  (PIT_BASE + 0x05)
 126 #define PIT_T0                  (PIT_BASE + 0x01)
 127
 128 /*
 129  * This is the rate at which your MCLK signal toggles (in Hz)
 130  * This was measured on a 10 digit frequency counter sampling
 131  * over 1 second.
 132  */
 133 #define MCLK    47894000
 134
 135 /*
 136  * This is the rate at which the PIT timers get clocked
 137  */
 138 #define CLKBY7  (MCLK / 7)
 139
 140 /*
 141  * This is the counter value.  We tick at 200Hz on this platform.
 142  */
 143 #define COUNT   ((CLKBY7 + (HZ / 2)) / HZ)
 144
 145 /*
 146  * Get the time offset from the system PIT.  Note that if we have missed an
 147  * interrupt, then the PIT counter will roll over (ie, be negative).
 148  * This actually works out to be convenient.
 149  */
 150 static unsigned long ebsa110_gettimeoffset(void)
 151 {
 152         unsigned long offset, count;
 153
 154         __raw_writeb(0x40, PIT_CTRL);
 155         count = __raw_readb(PIT_T1);
 156         count |= __raw_readb(PIT_T1) << 8;
 157
 158         /*
 159          * If count > COUNT, make the number negative.
 160          */
 161         if (count > COUNT)
 162                 count |= 0xffff0000;
 163
 164         offset = COUNT;
 165         offset -= count;
 166
 167         /*
 168          * `offset' is in units of timer counts.  Convert
 169          * offset to units of microseconds.
 170          */
 171         offset = offset * (1000000 / HZ) / COUNT;
 172
 173         return offset;
 174 }
 175
 176 static irqreturn_t
 177 ebsa110_timer_interrupt(int irq, void *dev_id)
 178 {
 179         u32 count;
 180
 181         /* latch and read timer 1 */
 182         __raw_writeb(0x40, PIT_CTRL);
 183         count = __raw_readb(PIT_T1);
 184         count |= __raw_readb(PIT_T1) << 8;
 185
 186         count += COUNT;
 187
 188         __raw_writeb(count & 0xff, PIT_T1);
 189         __raw_writeb(count >> 8, PIT_T1);
 190
 191         timer_tick();
 192
 193         return IRQ_HANDLED;
 194 }
 195
 196 static struct irqaction ebsa110_timer_irq = {
 197         .name           = "EBSA110 Timer Tick",
 198         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
 199         .handler        = ebsa110_timer_interrupt,
 200 };
 201
 202 /*
 203  * Set up timer interrupt.
 204  */
 205 static void __init ebsa110_timer_init(void)
 206 {
 207         /*
 208          * Timer 1, mode 2, LSB/MSB
 209          */
 210         __raw_writeb(0x70, PIT_CTRL);
 211         __raw_writeb(COUNT & 0xff, PIT_T1);
 212         __raw_writeb(COUNT >> 8, PIT_T1);
 213
 214         setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
 215 }
 216
 217 static struct sys_timer ebsa110_timer = {
 218         .init           = ebsa110_timer_init,
 219         .offset         = ebsa110_gettimeoffset,
 220 };
 221
 222 static struct plat_serial8250_port serial_platform_data[] = {
 223         {
 224                 .iobase         = 0x3f8,
 225                 .irq            = 1,
 226                 .uartclk        = 1843200,
 227                 .regshift       = 0,
 228                 .iotype         = UPIO_PORT,
 229                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
 230         },
 231         {
 232                 .iobase         = 0x2f8,
 233                 .irq            = 2,
 234                 .uartclk        = 1843200,
 235                 .regshift       = 0,
 236                 .iotype         = UPIO_PORT,
 237                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
 238         },
 239         { },
 240 };
 241
 242 static struct platform_device serial_device = {
 243         .name                   = "serial8250",
 244         .id                     = PLAT8250_DEV_PLATFORM,
 245         .dev                    = {
 246                 .platform_data  = serial_platform_data,
 247         },
 248 };
 249
 250 static struct resource am79c961_resources[] = {
 251         {
 252                 .start          = 0x220,
 253                 .end            = 0x238,
 254                 .flags          = IORESOURCE_IO,
 255         }, {
 256                 .start          = IRQ_EBSA110_ETHERNET,
 257                 .end            = IRQ_EBSA110_ETHERNET,
 258                 .flags          = IORESOURCE_IRQ,
 259         },
 260 };
 261
 262 static struct platform_device am79c961_device = {
 263         .name                   = "am79c961",
 264         .id                     = -1,
 265         .num_resources          = ARRAY_SIZE(am79c961_resources),
 266         .resource               = am79c961_resources,
 267 };
 268
 269 static struct platform_device *ebsa110_devices[] = {
 270         &serial_device,
 271         &am79c961_device,
 272 };
 273
 274 static int __init ebsa110_init(void)
 275 {
 276         return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices));
 277 }
 278
 279 arch_initcall(ebsa110_init);
 280
 281 static void ebsa110_restart(char mode, const char *cmd)
 282 {
 283         soft_restart(0x80000000);
 284 }
 285
 286 MACHINE_START(EBSA110, "EBSA110")
 287         /* Maintainer: Russell King */
 288         .atag_offset    = 0x400,
 289         .reserve_lp0    = 1,
 290         .reserve_lp2    = 1,
 291         .restart_mode   = 's',
 292         .map_io         = ebsa110_map_io,
 293         .init_irq       = ebsa110_init_irq,
 294         .timer          = &ebsa110_timer,
 295         .restart        = ebsa110_restart,
 296 MACHINE_END