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
ebsa110_mask_irq(struct irq_data * d)38 static void ebsa110_mask_irq(struct irq_data *d)
39 {
40 __raw_writeb(1 << d->irq, IRQ_MCLR);
41 }
42
ebsa110_unmask_irq(struct irq_data * d)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
ebsa110_init_irq(void)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
ebsa110_map_io(void)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 */
ebsa110_gettimeoffset(void)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
ebsa110_timer_interrupt(int irq,void * dev_id)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 */
ebsa110_timer_init(void)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
ebsa110_init(void)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
ebsa110_restart(char mode,const char * cmd)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
297