1 /* 2 * Broadcom BCM7120 style Level 2 interrupt controller driver 3 * 4 * Copyright (C) 2014 Broadcom Corporation 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/init.h> 14 #include <linux/slab.h> 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/of.h> 18 #include <linux/of_irq.h> 19 #include <linux/of_address.h> 20 #include <linux/of_platform.h> 21 #include <linux/interrupt.h> 22 #include <linux/irq.h> 23 #include <linux/io.h> 24 #include <linux/irqdomain.h> 25 #include <linux/reboot.h> 26 #include <linux/irqchip/chained_irq.h> 27 28 #include "irqchip.h" 29 30 #include <asm/mach/irq.h> 31 32 /* Register offset in the L2 interrupt controller */ 33 #define IRQEN 0x00 34 #define IRQSTAT 0x04 35 36 struct bcm7120_l2_intc_data { 37 void __iomem *base; 38 struct irq_domain *domain; 39 bool can_wake; 40 u32 irq_fwd_mask; 41 u32 irq_map_mask; 42 u32 saved_mask; 43 }; 44 45 static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc) 46 { 47 struct bcm7120_l2_intc_data *b = irq_desc_get_handler_data(desc); 48 struct irq_chip *chip = irq_desc_get_chip(desc); 49 u32 status; 50 51 chained_irq_enter(chip, desc); 52 53 status = __raw_readl(b->base + IRQSTAT); 54 55 if (status == 0) { 56 do_bad_IRQ(irq, desc); 57 goto out; 58 } 59 60 do { 61 irq = ffs(status) - 1; 62 status &= ~(1 << irq); 63 generic_handle_irq(irq_find_mapping(b->domain, irq)); 64 } while (status); 65 66 out: 67 chained_irq_exit(chip, desc); 68 } 69 70 static void bcm7120_l2_intc_suspend(struct irq_data *d) 71 { 72 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 73 struct bcm7120_l2_intc_data *b = gc->private; 74 u32 reg; 75 76 irq_gc_lock(gc); 77 /* Save the current mask and the interrupt forward mask */ 78 b->saved_mask = __raw_readl(b->base) | b->irq_fwd_mask; 79 if (b->can_wake) { 80 reg = b->saved_mask | gc->wake_active; 81 __raw_writel(reg, b->base); 82 } 83 irq_gc_unlock(gc); 84 } 85 86 static void bcm7120_l2_intc_resume(struct irq_data *d) 87 { 88 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 89 struct bcm7120_l2_intc_data *b = gc->private; 90 91 /* Restore the saved mask */ 92 irq_gc_lock(gc); 93 __raw_writel(b->saved_mask, b->base); 94 irq_gc_unlock(gc); 95 } 96 97 static int bcm7120_l2_intc_init_one(struct device_node *dn, 98 struct bcm7120_l2_intc_data *data, 99 int irq, const __be32 *map_mask) 100 { 101 int parent_irq; 102 103 parent_irq = irq_of_parse_and_map(dn, irq); 104 if (parent_irq < 0) { 105 pr_err("failed to map interrupt %d\n", irq); 106 return parent_irq; 107 } 108 109 data->irq_map_mask |= be32_to_cpup(map_mask + irq); 110 111 irq_set_handler_data(parent_irq, data); 112 irq_set_chained_handler(parent_irq, bcm7120_l2_intc_irq_handle); 113 114 return 0; 115 } 116 117 int __init bcm7120_l2_intc_of_init(struct device_node *dn, 118 struct device_node *parent) 119 { 120 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; 121 struct bcm7120_l2_intc_data *data; 122 struct irq_chip_generic *gc; 123 struct irq_chip_type *ct; 124 const __be32 *map_mask; 125 int num_parent_irqs; 126 int ret = 0, len, irq; 127 128 data = kzalloc(sizeof(*data), GFP_KERNEL); 129 if (!data) 130 return -ENOMEM; 131 132 data->base = of_iomap(dn, 0); 133 if (!data->base) { 134 pr_err("failed to remap intc L2 registers\n"); 135 ret = -ENOMEM; 136 goto out_free; 137 } 138 139 if (of_property_read_u32(dn, "brcm,int-fwd-mask", &data->irq_fwd_mask)) 140 data->irq_fwd_mask = 0; 141 142 /* Enable all interrupt specified in the interrupt forward mask and have 143 * the other disabled 144 */ 145 __raw_writel(data->irq_fwd_mask, data->base + IRQEN); 146 147 num_parent_irqs = of_irq_count(dn); 148 if (num_parent_irqs <= 0) { 149 pr_err("invalid number of parent interrupts\n"); 150 ret = -ENOMEM; 151 goto out_unmap; 152 } 153 154 map_mask = of_get_property(dn, "brcm,int-map-mask", &len); 155 if (!map_mask || (len != (sizeof(*map_mask) * num_parent_irqs))) { 156 pr_err("invalid brcm,int-map-mask property\n"); 157 ret = -EINVAL; 158 goto out_unmap; 159 } 160 161 for (irq = 0; irq < num_parent_irqs; irq++) { 162 ret = bcm7120_l2_intc_init_one(dn, data, irq, map_mask); 163 if (ret) 164 goto out_unmap; 165 } 166 167 data->domain = irq_domain_add_linear(dn, 32, 168 &irq_generic_chip_ops, NULL); 169 if (!data->domain) { 170 ret = -ENOMEM; 171 goto out_unmap; 172 } 173 174 ret = irq_alloc_domain_generic_chips(data->domain, 32, 1, 175 dn->full_name, handle_level_irq, clr, 0, 176 IRQ_GC_INIT_MASK_CACHE); 177 if (ret) { 178 pr_err("failed to allocate generic irq chip\n"); 179 goto out_free_domain; 180 } 181 182 gc = irq_get_domain_generic_chip(data->domain, 0); 183 gc->unused = 0xfffffff & ~data->irq_map_mask; 184 gc->reg_base = data->base; 185 gc->private = data; 186 ct = gc->chip_types; 187 188 ct->regs.mask = IRQEN; 189 ct->chip.irq_mask = irq_gc_mask_clr_bit; 190 ct->chip.irq_unmask = irq_gc_mask_set_bit; 191 ct->chip.irq_ack = irq_gc_noop; 192 ct->chip.irq_suspend = bcm7120_l2_intc_suspend; 193 ct->chip.irq_resume = bcm7120_l2_intc_resume; 194 195 if (of_property_read_bool(dn, "brcm,irq-can-wake")) { 196 data->can_wake = true; 197 /* This IRQ chip can wake the system, set all relevant child 198 * interupts in wake_enabled mask 199 */ 200 gc->wake_enabled = 0xffffffff; 201 gc->wake_enabled &= ~gc->unused; 202 ct->chip.irq_set_wake = irq_gc_set_wake; 203 } 204 205 pr_info("registered BCM7120 L2 intc (mem: 0x%p, parent IRQ(s): %d)\n", 206 data->base, num_parent_irqs); 207 208 return 0; 209 210 out_free_domain: 211 irq_domain_remove(data->domain); 212 out_unmap: 213 iounmap(data->base); 214 out_free: 215 kfree(data); 216 return ret; 217 } 218 IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,bcm7120-l2-intc", 219 bcm7120_l2_intc_of_init); 220