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_misc.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 #include "core.h"
34
35 static void ebsa110_mask_irq(struct irq_data *d)
36 {
37 __raw_writeb(1 << d->irq, IRQ_MCLR);
38 }
39
40 static void ebsa110_unmask_irq(struct irq_data *d)
41 {
42 __raw_writeb(1 << d->irq, IRQ_MSET);
43 }
44
45 static struct irq_chip ebsa110_irq_chip = {
46 .irq_ack = ebsa110_mask_irq,
47 .irq_mask = ebsa110_mask_irq,
48 .irq_unmask = ebsa110_unmask_irq,
49 };
50
51 static void __init ebsa110_init_irq(void)
52 {
53 unsigned long flags;
54 unsigned int irq;
55
56 local_irq_save(flags);
57 __raw_writeb(0xff, IRQ_MCLR);
58 __raw_writeb(0x55, IRQ_MSET);
59 __raw_writeb(0x00, IRQ_MSET);
60 if (__raw_readb(IRQ_MASK) != 0x55)
61 while (1);
62 __raw_writeb(0xff, IRQ_MCLR); /* clear all interrupt enables */
63 local_irq_restore(flags);
64
65 for (irq = 0; irq < NR_IRQS; irq++) {
66 irq_set_chip_and_handler(irq, &ebsa110_irq_chip,
67 handle_level_irq);
68 irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
69 }
70 }
71
72 static struct map_desc ebsa110_io_desc[] __initdata = {
73 /*
74 * sparse external-decode ISAIO space
75 */
76 { /* IRQ_STAT/IRQ_MCLR */
77 .virtual = (unsigned long)IRQ_STAT,
78 .pfn = __phys_to_pfn(TRICK4_PHYS),
79 .length = TRICK4_SIZE,
80 .type = MT_DEVICE
81 }, { /* IRQ_MASK/IRQ_MSET */
82 .virtual = (unsigned long)IRQ_MASK,
83 .pfn = __phys_to_pfn(TRICK3_PHYS),
84 .length = TRICK3_SIZE,
85 .type = MT_DEVICE
86 }, { /* SOFT_BASE */
87 .virtual = (unsigned long)SOFT_BASE,
88 .pfn = __phys_to_pfn(TRICK1_PHYS),
89 .length = TRICK1_SIZE,
90 .type = MT_DEVICE
91 }, { /* PIT_BASE */
92 .virtual = (unsigned long)PIT_BASE,
93 .pfn = __phys_to_pfn(TRICK0_PHYS),
94 .length = TRICK0_SIZE,
95 .type = MT_DEVICE
96 },
97
98 /*
99 * self-decode ISAIO space
100 */
101 {
102 .virtual = ISAIO_BASE,
103 .pfn = __phys_to_pfn(ISAIO_PHYS),
104 .length = ISAIO_SIZE,
105 .type = MT_DEVICE
106 }, {
107 .virtual = ISAMEM_BASE,
108 .pfn = __phys_to_pfn(ISAMEM_PHYS),
109 .length = ISAMEM_SIZE,
110 .type = MT_DEVICE
111 }
112 };
113
114 static void __init ebsa110_map_io(void)
115 {
116 iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
117 }
118
119 static void __iomem *ebsa110_ioremap_caller(phys_addr_t cookie, size_t size,
120 unsigned int flags, void *caller)
121 {
122 return (void __iomem *)cookie;
123 }
124
125 static void ebsa110_iounmap(volatile void __iomem *io_addr)
126 {}
127
128 static void __init ebsa110_init_early(void)
129 {
130 arch_ioremap_caller = ebsa110_ioremap_caller;
131 arch_iounmap = ebsa110_iounmap;
132 }
133
134 #define PIT_CTRL (PIT_BASE + 0x0d)
135 #define PIT_T2 (PIT_BASE + 0x09)
136 #define PIT_T1 (PIT_BASE + 0x05)
137 #define PIT_T0 (PIT_BASE + 0x01)
138
139 /*
140 * This is the rate at which your MCLK signal toggles (in Hz)
141 * This was measured on a 10 digit frequency counter sampling
142 * over 1 second.
143 */
144 #define MCLK 47894000
145
146 /*
147 * This is the rate at which the PIT timers get clocked
148 */
149 #define CLKBY7 (MCLK / 7)
150
151 /*
152 * This is the counter value. We tick at 200Hz on this platform.
153 */
154 #define COUNT ((CLKBY7 + (HZ / 2)) / HZ)
155
156 /*
157 * Get the time offset from the system PIT. Note that if we have missed an
158 * interrupt, then the PIT counter will roll over (ie, be negative).
159 * This actually works out to be convenient.
160 */
161 static u32 ebsa110_gettimeoffset(void)
162 {
163 unsigned long offset, count;
164
165 __raw_writeb(0x40, PIT_CTRL);
166 count = __raw_readb(PIT_T1);
167 count |= __raw_readb(PIT_T1) << 8;
168
169 /*
170 * If count > COUNT, make the number negative.
171 */
172 if (count > COUNT)
173 count |= 0xffff0000;
174
175 offset = COUNT;
176 offset -= count;
177
178 /*
179 * `offset' is in units of timer counts. Convert
180 * offset to units of microseconds.
181 */
182 offset = offset * (1000000 / HZ) / COUNT;
183
184 return offset * 1000;
185 }
186
187 static irqreturn_t
188 ebsa110_timer_interrupt(int irq, void *dev_id)
189 {
190 u32 count;
191
192 /* latch and read timer 1 */
193 __raw_writeb(0x40, PIT_CTRL);
194 count = __raw_readb(PIT_T1);
195 count |= __raw_readb(PIT_T1) << 8;
196
197 count += COUNT;
198
199 __raw_writeb(count & 0xff, PIT_T1);
200 __raw_writeb(count >> 8, PIT_T1);
201
202 timer_tick();
203
204 return IRQ_HANDLED;
205 }
206
207 static struct irqaction ebsa110_timer_irq = {
208 .name = "EBSA110 Timer Tick",
209 .flags = IRQF_TIMER | IRQF_IRQPOLL,
210 .handler = ebsa110_timer_interrupt,
211 };
212
213 /*
214 * Set up timer interrupt.
215 */
216 void __init ebsa110_timer_init(void)
217 {
218 arch_gettimeoffset = ebsa110_gettimeoffset;
219
220 /*
221 * Timer 1, mode 2, LSB/MSB
222 */
223 __raw_writeb(0x70, PIT_CTRL);
224 __raw_writeb(COUNT & 0xff, PIT_T1);
225 __raw_writeb(COUNT >> 8, PIT_T1);
226
227 setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
228 }
229
230 static struct plat_serial8250_port serial_platform_data[] = {
231 {
232 .iobase = 0x3f8,
233 .irq = 1,
234 .uartclk = 1843200,
235 .regshift = 0,
236 .iotype = UPIO_PORT,
237 .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
238 },
239 {
240 .iobase = 0x2f8,
241 .irq = 2,
242 .uartclk = 1843200,
243 .regshift = 0,
244 .iotype = UPIO_PORT,
245 .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
246 },
247 { },
248 };
249
250 static struct platform_device serial_device = {
251 .name = "serial8250",
252 .id = PLAT8250_DEV_PLATFORM,
253 .dev = {
254 .platform_data = serial_platform_data,
255 },
256 };
257
258 static struct resource am79c961_resources[] = {
259 {
260 .start = 0x220,
261 .end = 0x238,
262 .flags = IORESOURCE_IO,
263 }, {
264 .start = IRQ_EBSA110_ETHERNET,
265 .end = IRQ_EBSA110_ETHERNET,
266 .flags = IORESOURCE_IRQ,
267 },
268 };
269
270 static struct platform_device am79c961_device = {
271 .name = "am79c961",
272 .id = -1,
273 .num_resources = ARRAY_SIZE(am79c961_resources),
274 .resource = am79c961_resources,
275 };
276
277 static struct platform_device *ebsa110_devices[] = {
278 &serial_device,
279 &am79c961_device,
280 };
281
282 /*
283 * EBSA110 idling methodology:
284 *
285 * We can not execute the "wait for interrupt" instruction since that
286 * will stop our MCLK signal (which provides the clock for the glue
287 * logic, and therefore the timer interrupt).
288 *
289 * Instead, we spin, polling the IRQ_STAT register for the occurrence
290 * of any interrupt with core clock down to the memory clock.
291 */
292 static void ebsa110_idle(void)
293 {
294 const char *irq_stat = (char *)0xff000000;
295
296 /* disable clock switching */
297 asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc");
298
299 /* wait for an interrupt to occur */
300 while (!*irq_stat);
301
302 /* enable clock switching */
303 asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc");
304 }
305
306 static int __init ebsa110_init(void)
307 {
308 arm_pm_idle = ebsa110_idle;
309 return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices));
310 }
311
312 arch_initcall(ebsa110_init);
313
314 static void ebsa110_restart(enum reboot_mode mode, const char *cmd)
315 {
316 soft_restart(0x80000000);
317 }
318
319 MACHINE_START(EBSA110, "EBSA110")
320 /* Maintainer: Russell King */
321 .atag_offset = 0x400,
322 .reserve_lp0 = 1,
323 .reserve_lp2 = 1,
324 .map_io = ebsa110_map_io,
325 .init_early = ebsa110_init_early,
326 .init_irq = ebsa110_init_irq,
327 .init_time = ebsa110_timer_init,
328 .restart = ebsa110_restart,
329 MACHINE_END
330
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