1/* 2 * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved. 3 * 4 * Author: John Rigby, <jrigby@freescale.com> 5 * 6 * Description: 7 * MPC5121ADS CPLD irq handling 8 * 9 * This is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 */ 14 15#undef DEBUG 16 17#include <linux/kernel.h> 18#include <linux/interrupt.h> 19#include <linux/irq.h> 20#include <linux/io.h> 21#include <asm/prom.h> 22 23static struct device_node *cpld_pic_node; 24static struct irq_host *cpld_pic_host; 25 26/* 27 * Bits to ignore in the misc_status register 28 * 0x10 touch screen pendown is hard routed to irq1 29 * 0x02 pci status is read from pci status register 30 */ 31#define MISC_IGNORE 0x12 32 33/* 34 * Nothing to ignore in pci status register 35 */ 36#define PCI_IGNORE 0x00 37 38struct cpld_pic { 39 u8 pci_mask; 40 u8 pci_status; 41 u8 route; 42 u8 misc_mask; 43 u8 misc_status; 44 u8 misc_control; 45}; 46 47static struct cpld_pic __iomem *cpld_regs; 48 49static void __iomem * 50irq_to_pic_mask(unsigned int irq) 51{ 52 return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask; 53} 54 55static unsigned int 56irq_to_pic_bit(unsigned int irq) 57{ 58 return 1 << (irq & 0x7); 59} 60 61static void 62cpld_mask_irq(unsigned int irq) 63{ 64 unsigned int cpld_irq = (unsigned int)irq_map[irq].hwirq; 65 void __iomem *pic_mask = irq_to_pic_mask(cpld_irq); 66 67 out_8(pic_mask, 68 in_8(pic_mask) | irq_to_pic_bit(cpld_irq)); 69} 70 71static void 72cpld_unmask_irq(unsigned int irq) 73{ 74 unsigned int cpld_irq = (unsigned int)irq_map[irq].hwirq; 75 void __iomem *pic_mask = irq_to_pic_mask(cpld_irq); 76 77 out_8(pic_mask, 78 in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq)); 79} 80 81static struct irq_chip cpld_pic = { 82 .name = "CPLD PIC", 83 .mask = cpld_mask_irq, 84 .ack = cpld_mask_irq, 85 .unmask = cpld_unmask_irq, 86}; 87 88static int 89cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp, 90 u8 __iomem *maskp) 91{ 92 int cpld_irq; 93 u8 status = in_8(statusp); 94 u8 mask = in_8(maskp); 95 96 /* ignore don't cares and masked irqs */ 97 status |= (ignore | mask); 98 99 if (status == 0xff) 100 return NO_IRQ_IGNORE; 101 102 cpld_irq = ffz(status) + offset; 103 104 return irq_linear_revmap(cpld_pic_host, cpld_irq); 105} 106 107static void 108cpld_pic_cascade(unsigned int irq, struct irq_desc *desc) 109{ 110 irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status, 111 &cpld_regs->pci_mask); 112 if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) { 113 generic_handle_irq(irq); 114 return; 115 } 116 117 irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status, 118 &cpld_regs->misc_mask); 119 if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) { 120 generic_handle_irq(irq); 121 return; 122 } 123} 124 125static int 126cpld_pic_host_match(struct irq_host *h, struct device_node *node) 127{ 128 return cpld_pic_node == node; 129} 130 131static int 132cpld_pic_host_map(struct irq_host *h, unsigned int virq, 133 irq_hw_number_t hw) 134{ 135 irq_to_desc(virq)->status |= IRQ_LEVEL; 136 set_irq_chip_and_handler(virq, &cpld_pic, handle_level_irq); 137 return 0; 138} 139 140static struct 141irq_host_ops cpld_pic_host_ops = { 142 .match = cpld_pic_host_match, 143 .map = cpld_pic_host_map, 144}; 145 146void __init 147mpc5121_ads_cpld_map(void) 148{ 149 struct device_node *np = NULL; 150 151 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic"); 152 if (!np) { 153 printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n"); 154 return; 155 } 156 157 cpld_regs = of_iomap(np, 0); 158 of_node_put(np); 159} 160 161void __init 162mpc5121_ads_cpld_pic_init(void) 163{ 164 unsigned int cascade_irq; 165 struct device_node *np = NULL; 166 167 pr_debug("cpld_ic_init\n"); 168 169 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic"); 170 if (!np) { 171 printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n"); 172 return; 173 } 174 175 if (!cpld_regs) 176 goto end; 177 178 cascade_irq = irq_of_parse_and_map(np, 0); 179 if (cascade_irq == NO_IRQ) 180 goto end; 181 182 /* 183 * statically route touch screen pendown through 1 184 * and ignore it here 185 * route all others through our cascade irq 186 */ 187 out_8(&cpld_regs->route, 0xfd); 188 out_8(&cpld_regs->pci_mask, 0xff); 189 /* unmask pci ints in misc mask */ 190 out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE)); 191 192 cpld_pic_node = of_node_get(np); 193 194 cpld_pic_host = 195 irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 16, &cpld_pic_host_ops, 16); 196 if (!cpld_pic_host) { 197 printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n"); 198 goto end; 199 } 200 201 set_irq_chained_handler(cascade_irq, cpld_pic_cascade); 202end: 203 of_node_put(np); 204} 205