2 * linux/arch/arm/mach-ebsa110/core.c
4 * Copyright (C) 1998-2001 Russell King
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.
10 * Extra MM routines for the EBSA-110 architecture
12 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/serial_8250.h>
16 #include <linux/init.h>
19 #include <mach/hardware.h>
21 #include <asm/setup.h>
22 #include <asm/mach-types.h>
23 #include <asm/pgtable.h>
25 #include <asm/system_misc.h>
27 #include <asm/mach/arch.h>
28 #include <asm/mach/irq.h>
29 #include <asm/mach/map.h>
31 #include <asm/mach/time.h>
35 static void ebsa110_mask_irq(struct irq_data
*d
)
37 __raw_writeb(1 << d
->irq
, IRQ_MCLR
);
40 static void ebsa110_unmask_irq(struct irq_data
*d
)
42 __raw_writeb(1 << d
->irq
, IRQ_MSET
);
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
,
51 static void __init
ebsa110_init_irq(void)
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)
62 __raw_writeb(0xff, IRQ_MCLR
); /* clear all interrupt enables */
63 local_irq_restore(flags
);
65 for (irq
= 0; irq
< NR_IRQS
; irq
++) {
66 irq_set_chip_and_handler(irq
, &ebsa110_irq_chip
,
68 set_irq_flags(irq
, IRQF_VALID
| IRQF_PROBE
);
72 static struct map_desc ebsa110_io_desc
[] __initdata
= {
74 * sparse external-decode ISAIO space
76 { /* IRQ_STAT/IRQ_MCLR */
77 .virtual = (unsigned long)IRQ_STAT
,
78 .pfn
= __phys_to_pfn(TRICK4_PHYS
),
79 .length
= TRICK4_SIZE
,
81 }, { /* IRQ_MASK/IRQ_MSET */
82 .virtual = (unsigned long)IRQ_MASK
,
83 .pfn
= __phys_to_pfn(TRICK3_PHYS
),
84 .length
= TRICK3_SIZE
,
87 .virtual = (unsigned long)SOFT_BASE
,
88 .pfn
= __phys_to_pfn(TRICK1_PHYS
),
89 .length
= TRICK1_SIZE
,
92 .virtual = (unsigned long)PIT_BASE
,
93 .pfn
= __phys_to_pfn(TRICK0_PHYS
),
94 .length
= TRICK0_SIZE
,
99 * self-decode ISAIO space
102 .virtual = ISAIO_BASE
,
103 .pfn
= __phys_to_pfn(ISAIO_PHYS
),
104 .length
= ISAIO_SIZE
,
107 .virtual = ISAMEM_BASE
,
108 .pfn
= __phys_to_pfn(ISAMEM_PHYS
),
109 .length
= ISAMEM_SIZE
,
114 static void __init
ebsa110_map_io(void)
116 iotable_init(ebsa110_io_desc
, ARRAY_SIZE(ebsa110_io_desc
));
119 static void __iomem
*ebsa110_ioremap_caller(phys_addr_t cookie
, size_t size
,
120 unsigned int flags
, void *caller
)
122 return (void __iomem
*)cookie
;
125 static void ebsa110_iounmap(volatile void __iomem
*io_addr
)
128 static void __init
ebsa110_init_early(void)
130 arch_ioremap_caller
= ebsa110_ioremap_caller
;
131 arch_iounmap
= ebsa110_iounmap
;
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)
140 * This is the rate at which your MCLK signal toggles (in Hz)
141 * This was measured on a 10 digit frequency counter sampling
144 #define MCLK 47894000
147 * This is the rate at which the PIT timers get clocked
149 #define CLKBY7 (MCLK / 7)
152 * This is the counter value. We tick at 200Hz on this platform.
154 #define COUNT ((CLKBY7 + (HZ / 2)) / HZ)
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.
161 static u32
ebsa110_gettimeoffset(void)
163 unsigned long offset
, count
;
165 __raw_writeb(0x40, PIT_CTRL
);
166 count
= __raw_readb(PIT_T1
);
167 count
|= __raw_readb(PIT_T1
) << 8;
170 * If count > COUNT, make the number negative.
179 * `offset' is in units of timer counts. Convert
180 * offset to units of microseconds.
182 offset
= offset
* (1000000 / HZ
) / COUNT
;
184 return offset
* 1000;
188 ebsa110_timer_interrupt(int irq
, void *dev_id
)
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;
199 __raw_writeb(count
& 0xff, PIT_T1
);
200 __raw_writeb(count
>> 8, PIT_T1
);
207 static struct irqaction ebsa110_timer_irq
= {
208 .name
= "EBSA110 Timer Tick",
209 .flags
= IRQF_DISABLED
| IRQF_TIMER
| IRQF_IRQPOLL
,
210 .handler
= ebsa110_timer_interrupt
,
214 * Set up timer interrupt.
216 void __init
ebsa110_timer_init(void)
218 arch_gettimeoffset
= ebsa110_gettimeoffset
;
221 * Timer 1, mode 2, LSB/MSB
223 __raw_writeb(0x70, PIT_CTRL
);
224 __raw_writeb(COUNT
& 0xff, PIT_T1
);
225 __raw_writeb(COUNT
>> 8, PIT_T1
);
227 setup_irq(IRQ_EBSA110_TIMER0
, &ebsa110_timer_irq
);
230 static struct plat_serial8250_port serial_platform_data
[] = {
237 .flags
= UPF_BOOT_AUTOCONF
| UPF_SKIP_TEST
,
245 .flags
= UPF_BOOT_AUTOCONF
| UPF_SKIP_TEST
,
250 static struct platform_device serial_device
= {
251 .name
= "serial8250",
252 .id
= PLAT8250_DEV_PLATFORM
,
254 .platform_data
= serial_platform_data
,
258 static struct resource am79c961_resources
[] = {
262 .flags
= IORESOURCE_IO
,
264 .start
= IRQ_EBSA110_ETHERNET
,
265 .end
= IRQ_EBSA110_ETHERNET
,
266 .flags
= IORESOURCE_IRQ
,
270 static struct platform_device am79c961_device
= {
273 .num_resources
= ARRAY_SIZE(am79c961_resources
),
274 .resource
= am79c961_resources
,
277 static struct platform_device
*ebsa110_devices
[] = {
283 * EBSA110 idling methodology:
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).
289 * Instead, we spin, polling the IRQ_STAT register for the occurrence
290 * of any interrupt with core clock down to the memory clock.
292 static void ebsa110_idle(void)
294 const char *irq_stat
= (char *)0xff000000;
296 /* disable clock switching */
297 asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc");
299 /* wait for an interrupt to occur */
302 /* enable clock switching */
303 asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc");
306 static int __init
ebsa110_init(void)
308 arm_pm_idle
= ebsa110_idle
;
309 return platform_add_devices(ebsa110_devices
, ARRAY_SIZE(ebsa110_devices
));
312 arch_initcall(ebsa110_init
);
314 static void ebsa110_restart(enum reboot_mode mode
, const char *cmd
)
316 soft_restart(0x80000000);
319 MACHINE_START(EBSA110
, "EBSA110")
320 /* Maintainer: Russell King */
321 .atag_offset
= 0x400,
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
,