204 lines
4.3 KiB
C
204 lines
4.3 KiB
C
/*
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* Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
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*
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* Author: John Rigby, <jrigby@freescale.com>
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*
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* Description:
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* MPC5121ADS CPLD irq handling
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*
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* This is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/io.h>
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#include <asm/prom.h>
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static struct device_node *cpld_pic_node;
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static struct irq_host *cpld_pic_host;
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/*
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* Bits to ignore in the misc_status register
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* 0x10 touch screen pendown is hard routed to irq1
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* 0x02 pci status is read from pci status register
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*/
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#define MISC_IGNORE 0x12
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/*
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* Nothing to ignore in pci status register
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*/
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#define PCI_IGNORE 0x00
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struct cpld_pic {
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u8 pci_mask;
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u8 pci_status;
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u8 route;
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u8 misc_mask;
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u8 misc_status;
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u8 misc_control;
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};
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static struct cpld_pic __iomem *cpld_regs;
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static void __iomem *
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irq_to_pic_mask(unsigned int irq)
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{
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return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask;
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}
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static unsigned int
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irq_to_pic_bit(unsigned int irq)
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{
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return 1 << (irq & 0x7);
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}
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static void
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cpld_mask_irq(struct irq_data *d)
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{
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unsigned int cpld_irq = (unsigned int)irq_map[d->irq].hwirq;
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void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
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out_8(pic_mask,
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in_8(pic_mask) | irq_to_pic_bit(cpld_irq));
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}
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static void
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cpld_unmask_irq(struct irq_data *d)
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{
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unsigned int cpld_irq = (unsigned int)irq_map[d->irq].hwirq;
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void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
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out_8(pic_mask,
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in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq));
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}
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static struct irq_chip cpld_pic = {
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.name = "CPLD PIC",
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.irq_mask = cpld_mask_irq,
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.irq_ack = cpld_mask_irq,
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.irq_unmask = cpld_unmask_irq,
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};
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static int
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cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp,
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u8 __iomem *maskp)
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{
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int cpld_irq;
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u8 status = in_8(statusp);
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u8 mask = in_8(maskp);
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/* ignore don't cares and masked irqs */
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status |= (ignore | mask);
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if (status == 0xff)
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return NO_IRQ_IGNORE;
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cpld_irq = ffz(status) + offset;
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return irq_linear_revmap(cpld_pic_host, cpld_irq);
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}
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static void
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cpld_pic_cascade(unsigned int irq, struct irq_desc *desc)
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{
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irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status,
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&cpld_regs->pci_mask);
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if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
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generic_handle_irq(irq);
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return;
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}
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irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status,
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&cpld_regs->misc_mask);
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if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
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generic_handle_irq(irq);
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return;
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}
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}
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static int
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cpld_pic_host_match(struct irq_host *h, struct device_node *node)
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{
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return cpld_pic_node == node;
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}
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static int
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cpld_pic_host_map(struct irq_host *h, unsigned int virq,
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irq_hw_number_t hw)
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{
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irq_set_status_flags(virq, IRQ_LEVEL);
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irq_set_chip_and_handler(virq, &cpld_pic, handle_level_irq);
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return 0;
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}
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static struct
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irq_host_ops cpld_pic_host_ops = {
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.match = cpld_pic_host_match,
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.map = cpld_pic_host_map,
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};
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void __init
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mpc5121_ads_cpld_map(void)
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{
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struct device_node *np = NULL;
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np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
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if (!np) {
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printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
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return;
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}
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cpld_regs = of_iomap(np, 0);
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of_node_put(np);
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}
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void __init
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mpc5121_ads_cpld_pic_init(void)
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{
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unsigned int cascade_irq;
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struct device_node *np = NULL;
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pr_debug("cpld_ic_init\n");
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np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
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if (!np) {
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printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
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return;
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}
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if (!cpld_regs)
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goto end;
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cascade_irq = irq_of_parse_and_map(np, 0);
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if (cascade_irq == NO_IRQ)
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goto end;
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/*
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* statically route touch screen pendown through 1
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* and ignore it here
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* route all others through our cascade irq
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*/
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out_8(&cpld_regs->route, 0xfd);
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out_8(&cpld_regs->pci_mask, 0xff);
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/* unmask pci ints in misc mask */
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out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE));
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cpld_pic_node = of_node_get(np);
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cpld_pic_host =
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irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 16, &cpld_pic_host_ops, 16);
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if (!cpld_pic_host) {
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printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
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goto end;
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}
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irq_set_chained_handler(cascade_irq, cpld_pic_cascade);
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end:
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of_node_put(np);
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}
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