1 /* 2 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver 3 * 4 * Copyright (C) 2014-2017 Broadcom 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 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/init.h> 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 #include <linux/platform_device.h> 22 #include <linux/spinlock.h> 23 #include <linux/of.h> 24 #include <linux/of_irq.h> 25 #include <linux/of_address.h> 26 #include <linux/of_platform.h> 27 #include <linux/interrupt.h> 28 #include <linux/irq.h> 29 #include <linux/io.h> 30 #include <linux/irqdomain.h> 31 #include <linux/irqchip.h> 32 #include <linux/irqchip/chained_irq.h> 33 34 struct brcmstb_intc_init_params { 35 irq_flow_handler_t handler; 36 int cpu_status; 37 int cpu_clear; 38 int cpu_mask_status; 39 int cpu_mask_set; 40 int cpu_mask_clear; 41 }; 42 43 /* Register offsets in the L2 latched interrupt controller */ 44 static const struct brcmstb_intc_init_params l2_edge_intc_init = { 45 .handler = handle_edge_irq, 46 .cpu_status = 0x00, 47 .cpu_clear = 0x08, 48 .cpu_mask_status = 0x0c, 49 .cpu_mask_set = 0x10, 50 .cpu_mask_clear = 0x14 51 }; 52 53 /* Register offsets in the L2 level interrupt controller */ 54 static const struct brcmstb_intc_init_params l2_lvl_intc_init = { 55 .handler = handle_level_irq, 56 .cpu_status = 0x00, 57 .cpu_clear = -1, /* Register not present */ 58 .cpu_mask_status = 0x04, 59 .cpu_mask_set = 0x08, 60 .cpu_mask_clear = 0x0C 61 }; 62 63 /* L2 intc private data structure */ 64 struct brcmstb_l2_intc_data { 65 struct irq_domain *domain; 66 struct irq_chip_generic *gc; 67 int status_offset; 68 int mask_offset; 69 bool can_wake; 70 u32 saved_mask; /* for suspend/resume */ 71 }; 72 73 /** 74 * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt 75 * @d: irq_data 76 * 77 * Chip has separate enable/disable registers instead of a single mask 78 * register and pending interrupt is acknowledged by setting a bit. 79 * 80 * Note: This function is generic and could easily be added to the 81 * generic irqchip implementation if there ever becomes a will to do so. 82 * Perhaps with a name like irq_gc_mask_disable_and_ack_set(). 83 * 84 * e.g.: https://patchwork.kernel.org/patch/9831047/ 85 */ 86 static void brcmstb_l2_mask_and_ack(struct irq_data *d) 87 { 88 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 89 struct irq_chip_type *ct = irq_data_get_chip_type(d); 90 u32 mask = d->mask; 91 92 irq_gc_lock(gc); 93 irq_reg_writel(gc, mask, ct->regs.disable); 94 *ct->mask_cache &= ~mask; 95 irq_reg_writel(gc, mask, ct->regs.ack); 96 irq_gc_unlock(gc); 97 } 98 99 static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc) 100 { 101 struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc); 102 struct irq_chip *chip = irq_desc_get_chip(desc); 103 unsigned int irq; 104 u32 status; 105 106 chained_irq_enter(chip, desc); 107 108 status = irq_reg_readl(b->gc, b->status_offset) & 109 ~(irq_reg_readl(b->gc, b->mask_offset)); 110 111 if (status == 0) { 112 raw_spin_lock(&desc->lock); 113 handle_bad_irq(desc); 114 raw_spin_unlock(&desc->lock); 115 goto out; 116 } 117 118 do { 119 irq = ffs(status) - 1; 120 status &= ~(1 << irq); 121 generic_handle_irq(irq_linear_revmap(b->domain, irq)); 122 } while (status); 123 out: 124 chained_irq_exit(chip, desc); 125 } 126 127 static void brcmstb_l2_intc_suspend(struct irq_data *d) 128 { 129 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 130 struct irq_chip_type *ct = irq_data_get_chip_type(d); 131 struct brcmstb_l2_intc_data *b = gc->private; 132 unsigned long flags; 133 134 irq_gc_lock_irqsave(gc, flags); 135 /* Save the current mask */ 136 b->saved_mask = irq_reg_readl(gc, ct->regs.mask); 137 138 if (b->can_wake) { 139 /* Program the wakeup mask */ 140 irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable); 141 irq_reg_writel(gc, gc->wake_active, ct->regs.enable); 142 } 143 irq_gc_unlock_irqrestore(gc, flags); 144 } 145 146 static void brcmstb_l2_intc_resume(struct irq_data *d) 147 { 148 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 149 struct irq_chip_type *ct = irq_data_get_chip_type(d); 150 struct brcmstb_l2_intc_data *b = gc->private; 151 unsigned long flags; 152 153 irq_gc_lock_irqsave(gc, flags); 154 if (ct->chip.irq_ack) { 155 /* Clear unmasked non-wakeup interrupts */ 156 irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, 157 ct->regs.ack); 158 } 159 160 /* Restore the saved mask */ 161 irq_reg_writel(gc, b->saved_mask, ct->regs.disable); 162 irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable); 163 irq_gc_unlock_irqrestore(gc, flags); 164 } 165 166 static int __init brcmstb_l2_intc_of_init(struct device_node *np, 167 struct device_node *parent, 168 const struct brcmstb_intc_init_params 169 *init_params) 170 { 171 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; 172 struct brcmstb_l2_intc_data *data; 173 struct irq_chip_type *ct; 174 int ret; 175 unsigned int flags; 176 int parent_irq; 177 void __iomem *base; 178 179 data = kzalloc(sizeof(*data), GFP_KERNEL); 180 if (!data) 181 return -ENOMEM; 182 183 base = of_iomap(np, 0); 184 if (!base) { 185 pr_err("failed to remap intc L2 registers\n"); 186 ret = -ENOMEM; 187 goto out_free; 188 } 189 190 /* Disable all interrupts by default */ 191 writel(0xffffffff, base + init_params->cpu_mask_set); 192 193 /* Wakeup interrupts may be retained from S5 (cold boot) */ 194 data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake"); 195 if (!data->can_wake && (init_params->cpu_clear >= 0)) 196 writel(0xffffffff, base + init_params->cpu_clear); 197 198 parent_irq = irq_of_parse_and_map(np, 0); 199 if (!parent_irq) { 200 pr_err("failed to find parent interrupt\n"); 201 ret = -EINVAL; 202 goto out_unmap; 203 } 204 205 data->domain = irq_domain_add_linear(np, 32, 206 &irq_generic_chip_ops, NULL); 207 if (!data->domain) { 208 ret = -ENOMEM; 209 goto out_unmap; 210 } 211 212 /* MIPS chips strapped for BE will automagically configure the 213 * peripheral registers for CPU-native byte order. 214 */ 215 flags = 0; 216 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) 217 flags |= IRQ_GC_BE_IO; 218 219 /* Allocate a single Generic IRQ chip for this node */ 220 ret = irq_alloc_domain_generic_chips(data->domain, 32, 1, 221 np->full_name, init_params->handler, clr, 0, flags); 222 if (ret) { 223 pr_err("failed to allocate generic irq chip\n"); 224 goto out_free_domain; 225 } 226 227 /* Set the IRQ chaining logic */ 228 irq_set_chained_handler_and_data(parent_irq, 229 brcmstb_l2_intc_irq_handle, data); 230 231 data->gc = irq_get_domain_generic_chip(data->domain, 0); 232 data->gc->reg_base = base; 233 data->gc->private = data; 234 data->status_offset = init_params->cpu_status; 235 data->mask_offset = init_params->cpu_mask_status; 236 237 ct = data->gc->chip_types; 238 239 if (init_params->cpu_clear >= 0) { 240 ct->regs.ack = init_params->cpu_clear; 241 ct->chip.irq_ack = irq_gc_ack_set_bit; 242 ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack; 243 } else { 244 /* No Ack - but still slightly more efficient to define this */ 245 ct->chip.irq_mask_ack = irq_gc_mask_disable_reg; 246 } 247 248 ct->chip.irq_mask = irq_gc_mask_disable_reg; 249 ct->regs.disable = init_params->cpu_mask_set; 250 ct->regs.mask = init_params->cpu_mask_status; 251 252 ct->chip.irq_unmask = irq_gc_unmask_enable_reg; 253 ct->regs.enable = init_params->cpu_mask_clear; 254 255 ct->chip.irq_suspend = brcmstb_l2_intc_suspend; 256 ct->chip.irq_resume = brcmstb_l2_intc_resume; 257 ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend; 258 259 if (data->can_wake) { 260 /* This IRQ chip can wake the system, set all child interrupts 261 * in wake_enabled mask 262 */ 263 data->gc->wake_enabled = 0xffffffff; 264 ct->chip.irq_set_wake = irq_gc_set_wake; 265 } 266 267 return 0; 268 269 out_free_domain: 270 irq_domain_remove(data->domain); 271 out_unmap: 272 iounmap(base); 273 out_free: 274 kfree(data); 275 return ret; 276 } 277 278 static int __init brcmstb_l2_edge_intc_of_init(struct device_node *np, 279 struct device_node *parent) 280 { 281 return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init); 282 } 283 IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init); 284 285 static int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np, 286 struct device_node *parent) 287 { 288 return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init); 289 } 290 IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc", 291 brcmstb_l2_lvl_intc_of_init); 292