| /* |
| * 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 NO_IRQ; |
| |
| 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 != NO_IRQ) { |
| generic_handle_irq(irq); |
| return; |
| } |
| |
| irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status, |
| &cpld_regs->misc_mask); |
| if (irq != NO_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 == NO_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); |
| } |