Root/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
38static void ebsa110_mask_irq(unsigned int irq)
39{
40    __raw_writeb(1 << irq, IRQ_MCLR);
41}
42
43static void ebsa110_unmask_irq(unsigned int irq)
44{
45    __raw_writeb(1 << irq, IRQ_MSET);
46}
47
48static struct irq_chip ebsa110_irq_chip = {
49    .ack = ebsa110_mask_irq,
50    .mask = ebsa110_mask_irq,
51    .unmask = ebsa110_unmask_irq,
52};
53 
54static 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, handle_level_irq);
71        set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
72    }
73}
74
75static 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
117static 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 */
150static 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
176static irqreturn_t
177ebsa110_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
196static 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 */
205static 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
217static struct sys_timer ebsa110_timer = {
218    .init = ebsa110_timer_init,
219    .offset = ebsa110_gettimeoffset,
220};
221
222static 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
242static struct platform_device serial_device = {
243    .name = "serial8250",
244    .id = PLAT8250_DEV_PLATFORM,
245    .dev = {
246        .platform_data = serial_platform_data,
247    },
248};
249
250static 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
262static struct platform_device am79c961_device = {
263    .name = "am79c961",
264    .id = -1,
265    .num_resources = ARRAY_SIZE(am79c961_resources),
266    .resource = am79c961_resources,
267};
268
269static struct platform_device *ebsa110_devices[] = {
270    &serial_device,
271    &am79c961_device,
272};
273
274static int __init ebsa110_init(void)
275{
276    return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices));
277}
278
279arch_initcall(ebsa110_init);
280
281MACHINE_START(EBSA110, "EBSA110")
282    /* Maintainer: Russell King */
283    .boot_params = 0x00000400,
284    .reserve_lp0 = 1,
285    .reserve_lp2 = 1,
286    .soft_reboot = 1,
287    .map_io = ebsa110_map_io,
288    .init_irq = ebsa110_init_irq,
289    .timer = &ebsa110_timer,
290MACHINE_END
291

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