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