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02a00cf672
Implement Standby support. In this mode, we'll suspend all drivers, put the SDRAM in self-refresh mode and switch off the HSB bus ("frozen" mode.) Implement Suspend-to-mem support. In this mode, we suspend all drivers, put the SDRAM into self-refresh mode and switch off all internal clocks except the 32 kHz oscillator ("stop" mode.) The lowest-level suspend code runs from a small portion of SRAM allocated at startup time. This gets rid of a small potential race with the SDRAM where we might try to enter self-refresh mode in the middle of an icache burst. We also relocate all interrupt and exception handlers to SRAM during the small window when we enter and exit the low-power modes. We don't need to do any special tricks to start and stop the PLL. The main clock is automatically gated by hardware until the PLL is stable. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
218 lines
4.5 KiB
C
218 lines
4.5 KiB
C
/*
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* Copyright (C) 2006, 2008 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/platform_device.h>
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#include <linux/sysdev.h>
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#include <asm/io.h>
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#include "intc.h"
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struct intc {
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void __iomem *regs;
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struct irq_chip chip;
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struct sys_device sysdev;
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#ifdef CONFIG_PM
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unsigned long suspend_ipr;
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unsigned long saved_ipr[64];
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#endif
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};
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extern struct platform_device at32_intc0_device;
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/*
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* TODO: We may be able to implement mask/unmask by setting IxM flags
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* in the status register.
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*/
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static void intc_mask_irq(unsigned int irq)
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{
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}
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static void intc_unmask_irq(unsigned int irq)
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{
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}
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static struct intc intc0 = {
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.chip = {
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.name = "intc",
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.mask = intc_mask_irq,
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.unmask = intc_unmask_irq,
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},
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};
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/*
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* All interrupts go via intc at some point.
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*/
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asmlinkage void do_IRQ(int level, struct pt_regs *regs)
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{
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struct irq_desc *desc;
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struct pt_regs *old_regs;
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unsigned int irq;
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unsigned long status_reg;
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local_irq_disable();
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old_regs = set_irq_regs(regs);
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irq_enter();
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irq = intc_readl(&intc0, INTCAUSE0 - 4 * level);
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desc = irq_desc + irq;
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desc->handle_irq(irq, desc);
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/*
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* Clear all interrupt level masks so that we may handle
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* interrupts during softirq processing. If this is a nested
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* interrupt, interrupts must stay globally disabled until we
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* return.
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*/
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status_reg = sysreg_read(SR);
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status_reg &= ~(SYSREG_BIT(I0M) | SYSREG_BIT(I1M)
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| SYSREG_BIT(I2M) | SYSREG_BIT(I3M));
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sysreg_write(SR, status_reg);
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irq_exit();
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set_irq_regs(old_regs);
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}
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void __init init_IRQ(void)
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{
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extern void _evba(void);
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extern void irq_level0(void);
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struct resource *regs;
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struct clk *pclk;
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unsigned int i;
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u32 offset, readback;
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regs = platform_get_resource(&at32_intc0_device, IORESOURCE_MEM, 0);
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if (!regs) {
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printk(KERN_EMERG "intc: no mmio resource defined\n");
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goto fail;
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}
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pclk = clk_get(&at32_intc0_device.dev, "pclk");
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if (IS_ERR(pclk)) {
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printk(KERN_EMERG "intc: no clock defined\n");
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goto fail;
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}
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clk_enable(pclk);
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intc0.regs = ioremap(regs->start, regs->end - regs->start + 1);
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if (!intc0.regs) {
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printk(KERN_EMERG "intc: failed to map registers (0x%08lx)\n",
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(unsigned long)regs->start);
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goto fail;
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}
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/*
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* Initialize all interrupts to level 0 (lowest priority). The
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* priority level may be changed by calling
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* irq_set_priority().
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*
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*/
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offset = (unsigned long)&irq_level0 - (unsigned long)&_evba;
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for (i = 0; i < NR_INTERNAL_IRQS; i++) {
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intc_writel(&intc0, INTPR0 + 4 * i, offset);
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readback = intc_readl(&intc0, INTPR0 + 4 * i);
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if (readback == offset)
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set_irq_chip_and_handler(i, &intc0.chip,
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handle_simple_irq);
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}
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/* Unmask all interrupt levels */
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sysreg_write(SR, (sysreg_read(SR)
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& ~(SR_I3M | SR_I2M | SR_I1M | SR_I0M)));
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return;
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fail:
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panic("Interrupt controller initialization failed!\n");
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}
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#ifdef CONFIG_PM
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void intc_set_suspend_handler(unsigned long offset)
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{
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intc0.suspend_ipr = offset;
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}
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static int intc_suspend(struct sys_device *sdev, pm_message_t state)
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{
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struct intc *intc = container_of(sdev, struct intc, sysdev);
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int i;
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if (unlikely(!irqs_disabled())) {
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pr_err("intc_suspend: called with interrupts enabled\n");
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return -EINVAL;
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}
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if (unlikely(!intc->suspend_ipr)) {
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pr_err("intc_suspend: suspend_ipr not initialized\n");
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return -EINVAL;
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}
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for (i = 0; i < 64; i++) {
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intc->saved_ipr[i] = intc_readl(intc, INTPR0 + 4 * i);
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intc_writel(intc, INTPR0 + 4 * i, intc->suspend_ipr);
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}
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return 0;
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}
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static int intc_resume(struct sys_device *sdev)
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{
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struct intc *intc = container_of(sdev, struct intc, sysdev);
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int i;
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WARN_ON(!irqs_disabled());
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for (i = 0; i < 64; i++)
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intc_writel(intc, INTPR0 + 4 * i, intc->saved_ipr[i]);
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return 0;
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}
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#else
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#define intc_suspend NULL
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#define intc_resume NULL
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#endif
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static struct sysdev_class intc_class = {
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.name = "intc",
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.suspend = intc_suspend,
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.resume = intc_resume,
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};
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static int __init intc_init_sysdev(void)
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{
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int ret;
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ret = sysdev_class_register(&intc_class);
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if (ret)
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return ret;
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intc0.sysdev.id = 0;
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intc0.sysdev.cls = &intc_class;
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ret = sysdev_register(&intc0.sysdev);
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return ret;
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}
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device_initcall(intc_init_sysdev);
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unsigned long intc_get_pending(unsigned int group)
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{
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return intc_readl(&intc0, INTREQ0 + 4 * group);
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}
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EXPORT_SYMBOL_GPL(intc_get_pending);
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