Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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, |
| 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 = 0, |
| 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 | BOOT_MEM(0x00000000, 0xe0000000, 0xe0000000) |
| 238 | BOOT_PARAMS(0x00000400) |
| 239 | DISABLE_PARPORT(0) |
| 240 | DISABLE_PARPORT(2) |
| 241 | SOFT_REBOOT |
| 242 | MAPIO(ebsa110_map_io) |
| 243 | INITIRQ(ebsa110_init_irq) |
| 244 | .timer = &ebsa110_timer, |
| 245 | MACHINE_END |