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323 lines
7.0 KiB
323 lines
7.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/arch/arm/mach-ebsa110/core.c |
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* |
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* Copyright (C) 1998-2001 Russell King |
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* |
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* Extra MM routines for the EBSA-110 architecture |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <linux/serial_8250.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <mach/hardware.h> |
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#include <asm/irq.h> |
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#include <asm/setup.h> |
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#include <asm/mach-types.h> |
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#include <asm/page.h> |
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#include <asm/system_misc.h> |
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#include <asm/mach/arch.h> |
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#include <asm/mach/irq.h> |
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#include <asm/mach/map.h> |
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#include <asm/mach/time.h> |
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#include "core.h" |
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static void ebsa110_mask_irq(struct irq_data *d) |
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{ |
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__raw_writeb(1 << d->irq, IRQ_MCLR); |
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} |
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static void ebsa110_unmask_irq(struct irq_data *d) |
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{ |
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__raw_writeb(1 << d->irq, IRQ_MSET); |
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} |
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static struct irq_chip ebsa110_irq_chip = { |
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.irq_ack = ebsa110_mask_irq, |
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.irq_mask = ebsa110_mask_irq, |
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.irq_unmask = ebsa110_unmask_irq, |
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}; |
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static void __init ebsa110_init_irq(void) |
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{ |
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unsigned long flags; |
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unsigned int irq; |
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local_irq_save(flags); |
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__raw_writeb(0xff, IRQ_MCLR); |
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__raw_writeb(0x55, IRQ_MSET); |
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__raw_writeb(0x00, IRQ_MSET); |
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if (__raw_readb(IRQ_MASK) != 0x55) |
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while (1); |
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__raw_writeb(0xff, IRQ_MCLR); /* clear all interrupt enables */ |
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local_irq_restore(flags); |
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for (irq = 0; irq < NR_IRQS; irq++) { |
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irq_set_chip_and_handler(irq, &ebsa110_irq_chip, |
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handle_level_irq); |
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irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE); |
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} |
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} |
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static struct map_desc ebsa110_io_desc[] __initdata = { |
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/* |
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* sparse external-decode ISAIO space |
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*/ |
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{ /* IRQ_STAT/IRQ_MCLR */ |
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.virtual = (unsigned long)IRQ_STAT, |
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.pfn = __phys_to_pfn(TRICK4_PHYS), |
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.length = TRICK4_SIZE, |
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.type = MT_DEVICE |
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}, { /* IRQ_MASK/IRQ_MSET */ |
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.virtual = (unsigned long)IRQ_MASK, |
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.pfn = __phys_to_pfn(TRICK3_PHYS), |
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.length = TRICK3_SIZE, |
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.type = MT_DEVICE |
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}, { /* SOFT_BASE */ |
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.virtual = (unsigned long)SOFT_BASE, |
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.pfn = __phys_to_pfn(TRICK1_PHYS), |
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.length = TRICK1_SIZE, |
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.type = MT_DEVICE |
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}, { /* PIT_BASE */ |
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.virtual = (unsigned long)PIT_BASE, |
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.pfn = __phys_to_pfn(TRICK0_PHYS), |
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.length = TRICK0_SIZE, |
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.type = MT_DEVICE |
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}, |
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/* |
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* self-decode ISAIO space |
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*/ |
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{ |
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.virtual = ISAIO_BASE, |
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.pfn = __phys_to_pfn(ISAIO_PHYS), |
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.length = ISAIO_SIZE, |
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.type = MT_DEVICE |
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}, { |
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.virtual = ISAMEM_BASE, |
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.pfn = __phys_to_pfn(ISAMEM_PHYS), |
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.length = ISAMEM_SIZE, |
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.type = MT_DEVICE |
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} |
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}; |
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static void __init ebsa110_map_io(void) |
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{ |
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iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc)); |
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} |
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static void __iomem *ebsa110_ioremap_caller(phys_addr_t cookie, size_t size, |
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unsigned int flags, void *caller) |
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{ |
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return (void __iomem *)cookie; |
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} |
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static void ebsa110_iounmap(volatile void __iomem *io_addr) |
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{} |
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static void __init ebsa110_init_early(void) |
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{ |
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arch_ioremap_caller = ebsa110_ioremap_caller; |
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arch_iounmap = ebsa110_iounmap; |
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} |
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#define PIT_CTRL (PIT_BASE + 0x0d) |
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#define PIT_T2 (PIT_BASE + 0x09) |
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#define PIT_T1 (PIT_BASE + 0x05) |
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#define PIT_T0 (PIT_BASE + 0x01) |
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/* |
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* This is the rate at which your MCLK signal toggles (in Hz) |
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* This was measured on a 10 digit frequency counter sampling |
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* over 1 second. |
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*/ |
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#define MCLK 47894000 |
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/* |
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* This is the rate at which the PIT timers get clocked |
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*/ |
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#define CLKBY7 (MCLK / 7) |
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/* |
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* This is the counter value. We tick at 200Hz on this platform. |
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*/ |
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#define COUNT ((CLKBY7 + (HZ / 2)) / HZ) |
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/* |
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* Get the time offset from the system PIT. Note that if we have missed an |
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* interrupt, then the PIT counter will roll over (ie, be negative). |
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* This actually works out to be convenient. |
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*/ |
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static u32 ebsa110_gettimeoffset(void) |
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{ |
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unsigned long offset, count; |
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__raw_writeb(0x40, PIT_CTRL); |
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count = __raw_readb(PIT_T1); |
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count |= __raw_readb(PIT_T1) << 8; |
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/* |
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* If count > COUNT, make the number negative. |
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*/ |
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if (count > COUNT) |
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count |= 0xffff0000; |
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offset = COUNT; |
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offset -= count; |
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/* |
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* `offset' is in units of timer counts. Convert |
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* offset to units of microseconds. |
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*/ |
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offset = offset * (1000000 / HZ) / COUNT; |
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return offset * 1000; |
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} |
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static irqreturn_t |
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ebsa110_timer_interrupt(int irq, void *dev_id) |
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{ |
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u32 count; |
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/* latch and read timer 1 */ |
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__raw_writeb(0x40, PIT_CTRL); |
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count = __raw_readb(PIT_T1); |
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count |= __raw_readb(PIT_T1) << 8; |
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count += COUNT; |
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__raw_writeb(count & 0xff, PIT_T1); |
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__raw_writeb(count >> 8, PIT_T1); |
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timer_tick(); |
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return IRQ_HANDLED; |
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} |
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/* |
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* Set up timer interrupt. |
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*/ |
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void __init ebsa110_timer_init(void) |
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{ |
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int irq = IRQ_EBSA110_TIMER0; |
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arch_gettimeoffset = ebsa110_gettimeoffset; |
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/* |
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* Timer 1, mode 2, LSB/MSB |
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*/ |
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__raw_writeb(0x70, PIT_CTRL); |
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__raw_writeb(COUNT & 0xff, PIT_T1); |
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__raw_writeb(COUNT >> 8, PIT_T1); |
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if (request_irq(irq, ebsa110_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, |
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"EBSA110 Timer Tick", NULL)) |
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pr_err("Failed to request irq %d (EBSA110 Timer Tick)\n", irq); |
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} |
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static struct plat_serial8250_port serial_platform_data[] = { |
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{ |
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.iobase = 0x3f8, |
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.irq = 1, |
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.uartclk = 1843200, |
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.regshift = 0, |
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.iotype = UPIO_PORT, |
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.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST, |
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}, |
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{ |
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.iobase = 0x2f8, |
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.irq = 2, |
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.uartclk = 1843200, |
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.regshift = 0, |
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.iotype = UPIO_PORT, |
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.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST, |
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}, |
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{ }, |
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}; |
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static struct platform_device serial_device = { |
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.name = "serial8250", |
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.id = PLAT8250_DEV_PLATFORM, |
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.dev = { |
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.platform_data = serial_platform_data, |
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}, |
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}; |
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static struct resource am79c961_resources[] = { |
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{ |
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.start = 0x220, |
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.end = 0x238, |
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.flags = IORESOURCE_IO, |
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}, { |
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.start = IRQ_EBSA110_ETHERNET, |
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.end = IRQ_EBSA110_ETHERNET, |
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.flags = IORESOURCE_IRQ, |
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}, |
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}; |
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static struct platform_device am79c961_device = { |
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.name = "am79c961", |
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.id = -1, |
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.num_resources = ARRAY_SIZE(am79c961_resources), |
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.resource = am79c961_resources, |
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}; |
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static struct platform_device *ebsa110_devices[] = { |
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&serial_device, |
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&am79c961_device, |
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}; |
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/* |
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* EBSA110 idling methodology: |
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* |
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* We can not execute the "wait for interrupt" instruction since that |
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* will stop our MCLK signal (which provides the clock for the glue |
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* logic, and therefore the timer interrupt). |
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* |
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* Instead, we spin, polling the IRQ_STAT register for the occurrence |
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* of any interrupt with core clock down to the memory clock. |
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*/ |
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static void ebsa110_idle(void) |
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{ |
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const char *irq_stat = (char *)0xff000000; |
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/* disable clock switching */ |
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asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc"); |
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/* wait for an interrupt to occur */ |
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while (!*irq_stat); |
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/* enable clock switching */ |
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asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc"); |
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} |
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static int __init ebsa110_init(void) |
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{ |
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arm_pm_idle = ebsa110_idle; |
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return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices)); |
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} |
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arch_initcall(ebsa110_init); |
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static void ebsa110_restart(enum reboot_mode mode, const char *cmd) |
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{ |
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soft_restart(0x80000000); |
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} |
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MACHINE_START(EBSA110, "EBSA110") |
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/* Maintainer: Russell King */ |
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.atag_offset = 0x400, |
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.reserve_lp0 = 1, |
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.reserve_lp2 = 1, |
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.map_io = ebsa110_map_io, |
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.init_early = ebsa110_init_early, |
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.init_irq = ebsa110_init_irq, |
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.init_time = ebsa110_timer_init, |
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.restart = ebsa110_restart, |
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MACHINE_END
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