1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver 4 * 5 * Copyright (C) 2014-2017 Broadcom 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/init.h> 11 #include <linux/slab.h> 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/spinlock.h> 15 #include <linux/of.h> 16 #include <linux/of_irq.h> 17 #include <linux/of_address.h> 18 #include <linux/of_platform.h> 19 #include <linux/interrupt.h> 20 #include <linux/irq.h> 21 #include <linux/io.h> 22 #include <linux/irqdomain.h> 23 #include <linux/irqchip.h> 24 #include <linux/irqchip/chained_irq.h> 25 26 struct brcmstb_intc_init_params { 27 irq_flow_handler_t handler; 28 int cpu_status; 29 int cpu_clear; 30 int cpu_mask_status; 31 int cpu_mask_set; 32 int cpu_mask_clear; 33 }; 34 35 /* Register offsets in the L2 latched interrupt controller */ 36 static const struct brcmstb_intc_init_params l2_edge_intc_init = { 37 .handler = handle_edge_irq, 38 .cpu_status = 0x00, 39 .cpu_clear = 0x08, 40 .cpu_mask_status = 0x0c, 41 .cpu_mask_set = 0x10, 42 .cpu_mask_clear = 0x14 43 }; 44 45 /* Register offsets in the L2 level interrupt controller */ 46 static const struct brcmstb_intc_init_params l2_lvl_intc_init = { 47 .handler = handle_level_irq, 48 .cpu_status = 0x00, 49 .cpu_clear = -1, /* Register not present */ 50 .cpu_mask_status = 0x04, 51 .cpu_mask_set = 0x08, 52 .cpu_mask_clear = 0x0C 53 }; 54 55 /* L2 intc private data structure */ 56 struct brcmstb_l2_intc_data { 57 struct irq_domain *domain; 58 struct irq_chip_generic *gc; 59 int status_offset; 60 int mask_offset; 61 bool can_wake; 62 u32 saved_mask; /* for suspend/resume */ 63 }; 64 65 /** 66 * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt 67 * @d: irq_data 68 * 69 * Chip has separate enable/disable registers instead of a single mask 70 * register and pending interrupt is acknowledged by setting a bit. 71 * 72 * Note: This function is generic and could easily be added to the 73 * generic irqchip implementation if there ever becomes a will to do so. 74 * Perhaps with a name like irq_gc_mask_disable_and_ack_set(). 75 * 76 * e.g.: https://patchwork.kernel.org/patch/9831047/ 77 */ 78 static void brcmstb_l2_mask_and_ack(struct irq_data *d) 79 { 80 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 81 struct irq_chip_type *ct = irq_data_get_chip_type(d); 82 u32 mask = d->mask; 83 84 irq_gc_lock(gc); 85 irq_reg_writel(gc, mask, ct->regs.disable); 86 *ct->mask_cache &= ~mask; 87 irq_reg_writel(gc, mask, ct->regs.ack); 88 irq_gc_unlock(gc); 89 } 90 91 static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc) 92 { 93 struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc); 94 struct irq_chip *chip = irq_desc_get_chip(desc); 95 unsigned int irq; 96 u32 status; 97 98 chained_irq_enter(chip, desc); 99 100 status = irq_reg_readl(b->gc, b->status_offset) & 101 ~(irq_reg_readl(b->gc, b->mask_offset)); 102 103 if (status == 0) { 104 raw_spin_lock(&desc->lock); 105 handle_bad_irq(desc); 106 raw_spin_unlock(&desc->lock); 107 goto out; 108 } 109 110 do { 111 irq = ffs(status) - 1; 112 status &= ~(1 << irq); 113 generic_handle_irq(irq_linear_revmap(b->domain, irq)); 114 } while (status); 115 out: 116 chained_irq_exit(chip, desc); 117 } 118 119 static void brcmstb_l2_intc_suspend(struct irq_data *d) 120 { 121 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 122 struct irq_chip_type *ct = irq_data_get_chip_type(d); 123 struct brcmstb_l2_intc_data *b = gc->private; 124 unsigned long flags; 125 126 irq_gc_lock_irqsave(gc, flags); 127 /* Save the current mask */ 128 b->saved_mask = irq_reg_readl(gc, ct->regs.mask); 129 130 if (b->can_wake) { 131 /* Program the wakeup mask */ 132 irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable); 133 irq_reg_writel(gc, gc->wake_active, ct->regs.enable); 134 } 135 irq_gc_unlock_irqrestore(gc, flags); 136 } 137 138 static void brcmstb_l2_intc_resume(struct irq_data *d) 139 { 140 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); 141 struct irq_chip_type *ct = irq_data_get_chip_type(d); 142 struct brcmstb_l2_intc_data *b = gc->private; 143 unsigned long flags; 144 145 irq_gc_lock_irqsave(gc, flags); 146 if (ct->chip.irq_ack) { 147 /* Clear unmasked non-wakeup interrupts */ 148 irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, 149 ct->regs.ack); 150 } 151 152 /* Restore the saved mask */ 153 irq_reg_writel(gc, b->saved_mask, ct->regs.disable); 154 irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable); 155 irq_gc_unlock_irqrestore(gc, flags); 156 } 157 158 static int __init brcmstb_l2_intc_of_init(struct device_node *np, 159 struct device_node *parent, 160 const struct brcmstb_intc_init_params 161 *init_params) 162 { 163 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; 164 struct brcmstb_l2_intc_data *data; 165 struct irq_chip_type *ct; 166 int ret; 167 unsigned int flags; 168 int parent_irq; 169 void __iomem *base; 170 171 data = kzalloc(sizeof(*data), GFP_KERNEL); 172 if (!data) 173 return -ENOMEM; 174 175 base = of_iomap(np, 0); 176 if (!base) { 177 pr_err("failed to remap intc L2 registers\n"); 178 ret = -ENOMEM; 179 goto out_free; 180 } 181 182 /* Disable all interrupts by default */ 183 writel(0xffffffff, base + init_params->cpu_mask_set); 184 185 /* Wakeup interrupts may be retained from S5 (cold boot) */ 186 data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake"); 187 if (!data->can_wake && (init_params->cpu_clear >= 0)) 188 writel(0xffffffff, base + init_params->cpu_clear); 189 190 parent_irq = irq_of_parse_and_map(np, 0); 191 if (!parent_irq) { 192 pr_err("failed to find parent interrupt\n"); 193 ret = -EINVAL; 194 goto out_unmap; 195 } 196 197 data->domain = irq_domain_add_linear(np, 32, 198 &irq_generic_chip_ops, NULL); 199 if (!data->domain) { 200 ret = -ENOMEM; 201 goto out_unmap; 202 } 203 204 /* MIPS chips strapped for BE will automagically configure the 205 * peripheral registers for CPU-native byte order. 206 */ 207 flags = 0; 208 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) 209 flags |= IRQ_GC_BE_IO; 210 211 /* Allocate a single Generic IRQ chip for this node */ 212 ret = irq_alloc_domain_generic_chips(data->domain, 32, 1, 213 np->full_name, init_params->handler, clr, 0, flags); 214 if (ret) { 215 pr_err("failed to allocate generic irq chip\n"); 216 goto out_free_domain; 217 } 218 219 /* Set the IRQ chaining logic */ 220 irq_set_chained_handler_and_data(parent_irq, 221 brcmstb_l2_intc_irq_handle, data); 222 223 data->gc = irq_get_domain_generic_chip(data->domain, 0); 224 data->gc->reg_base = base; 225 data->gc->private = data; 226 data->status_offset = init_params->cpu_status; 227 data->mask_offset = init_params->cpu_mask_status; 228 229 ct = data->gc->chip_types; 230 231 if (init_params->cpu_clear >= 0) { 232 ct->regs.ack = init_params->cpu_clear; 233 ct->chip.irq_ack = irq_gc_ack_set_bit; 234 ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack; 235 } else { 236 /* No Ack - but still slightly more efficient to define this */ 237 ct->chip.irq_mask_ack = irq_gc_mask_disable_reg; 238 } 239 240 ct->chip.irq_mask = irq_gc_mask_disable_reg; 241 ct->regs.disable = init_params->cpu_mask_set; 242 ct->regs.mask = init_params->cpu_mask_status; 243 244 ct->chip.irq_unmask = irq_gc_unmask_enable_reg; 245 ct->regs.enable = init_params->cpu_mask_clear; 246 247 ct->chip.irq_suspend = brcmstb_l2_intc_suspend; 248 ct->chip.irq_resume = brcmstb_l2_intc_resume; 249 ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend; 250 251 if (data->can_wake) { 252 /* This IRQ chip can wake the system, set all child interrupts 253 * in wake_enabled mask 254 */ 255 data->gc->wake_enabled = 0xffffffff; 256 ct->chip.irq_set_wake = irq_gc_set_wake; 257 } 258 259 pr_info("registered L2 intc (%pOF, parent irq: %d)\n", np, parent_irq); 260 261 return 0; 262 263 out_free_domain: 264 irq_domain_remove(data->domain); 265 out_unmap: 266 iounmap(base); 267 out_free: 268 kfree(data); 269 return ret; 270 } 271 272 static int __init brcmstb_l2_edge_intc_of_init(struct device_node *np, 273 struct device_node *parent) 274 { 275 return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init); 276 } 277 IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init); 278 279 static int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np, 280 struct device_node *parent) 281 { 282 return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init); 283 } 284 IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc", 285 brcmstb_l2_lvl_intc_of_init); 286