1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com> 4 * Loongson HyperTransport Interrupt Vector support 5 */ 6 7 #define pr_fmt(fmt) "htvec: " fmt 8 9 #include <linux/interrupt.h> 10 #include <linux/irq.h> 11 #include <linux/irqchip.h> 12 #include <linux/irqdomain.h> 13 #include <linux/irqchip/chained_irq.h> 14 #include <linux/kernel.h> 15 #include <linux/platform_device.h> 16 #include <linux/of_address.h> 17 #include <linux/of_irq.h> 18 #include <linux/of_platform.h> 19 20 /* Registers */ 21 #define HTVEC_EN_OFF 0x20 22 #define HTVEC_MAX_PARENT_IRQ 8 23 24 #define VEC_COUNT_PER_REG 32 25 #define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG) 26 #define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG) 27 28 struct htvec { 29 int num_parents; 30 void __iomem *base; 31 struct irq_domain *htvec_domain; 32 raw_spinlock_t htvec_lock; 33 }; 34 35 static void htvec_irq_dispatch(struct irq_desc *desc) 36 { 37 int i; 38 u32 pending; 39 bool handled = false; 40 struct irq_chip *chip = irq_desc_get_chip(desc); 41 struct htvec *priv = irq_desc_get_handler_data(desc); 42 43 chained_irq_enter(chip, desc); 44 45 for (i = 0; i < priv->num_parents; i++) { 46 pending = readl(priv->base + 4 * i); 47 while (pending) { 48 int bit = __ffs(pending); 49 50 generic_handle_domain_irq(priv->htvec_domain, 51 bit + VEC_COUNT_PER_REG * i); 52 pending &= ~BIT(bit); 53 handled = true; 54 } 55 } 56 57 if (!handled) 58 spurious_interrupt(); 59 60 chained_irq_exit(chip, desc); 61 } 62 63 static void htvec_ack_irq(struct irq_data *d) 64 { 65 struct htvec *priv = irq_data_get_irq_chip_data(d); 66 67 writel(BIT(VEC_REG_BIT(d->hwirq)), 68 priv->base + VEC_REG_IDX(d->hwirq) * 4); 69 } 70 71 static void htvec_mask_irq(struct irq_data *d) 72 { 73 u32 reg; 74 void __iomem *addr; 75 struct htvec *priv = irq_data_get_irq_chip_data(d); 76 77 raw_spin_lock(&priv->htvec_lock); 78 addr = priv->base + HTVEC_EN_OFF; 79 addr += VEC_REG_IDX(d->hwirq) * 4; 80 reg = readl(addr); 81 reg &= ~BIT(VEC_REG_BIT(d->hwirq)); 82 writel(reg, addr); 83 raw_spin_unlock(&priv->htvec_lock); 84 } 85 86 static void htvec_unmask_irq(struct irq_data *d) 87 { 88 u32 reg; 89 void __iomem *addr; 90 struct htvec *priv = irq_data_get_irq_chip_data(d); 91 92 raw_spin_lock(&priv->htvec_lock); 93 addr = priv->base + HTVEC_EN_OFF; 94 addr += VEC_REG_IDX(d->hwirq) * 4; 95 reg = readl(addr); 96 reg |= BIT(VEC_REG_BIT(d->hwirq)); 97 writel(reg, addr); 98 raw_spin_unlock(&priv->htvec_lock); 99 } 100 101 static struct irq_chip htvec_irq_chip = { 102 .name = "LOONGSON_HTVEC", 103 .irq_mask = htvec_mask_irq, 104 .irq_unmask = htvec_unmask_irq, 105 .irq_ack = htvec_ack_irq, 106 }; 107 108 static int htvec_domain_alloc(struct irq_domain *domain, unsigned int virq, 109 unsigned int nr_irqs, void *arg) 110 { 111 int ret; 112 unsigned long hwirq; 113 unsigned int type, i; 114 struct htvec *priv = domain->host_data; 115 116 ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type); 117 if (ret) 118 return ret; 119 120 for (i = 0; i < nr_irqs; i++) { 121 irq_domain_set_info(domain, virq + i, hwirq + i, &htvec_irq_chip, 122 priv, handle_edge_irq, NULL, NULL); 123 } 124 125 return 0; 126 } 127 128 static void htvec_domain_free(struct irq_domain *domain, unsigned int virq, 129 unsigned int nr_irqs) 130 { 131 int i; 132 133 for (i = 0; i < nr_irqs; i++) { 134 struct irq_data *d = irq_domain_get_irq_data(domain, virq + i); 135 136 irq_set_handler(virq + i, NULL); 137 irq_domain_reset_irq_data(d); 138 } 139 } 140 141 static const struct irq_domain_ops htvec_domain_ops = { 142 .translate = irq_domain_translate_onecell, 143 .alloc = htvec_domain_alloc, 144 .free = htvec_domain_free, 145 }; 146 147 static void htvec_reset(struct htvec *priv) 148 { 149 u32 idx; 150 151 /* Clear IRQ cause registers, mask all interrupts */ 152 for (idx = 0; idx < priv->num_parents; idx++) { 153 writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx); 154 writel_relaxed(0xFFFFFFFF, priv->base + 4 * idx); 155 } 156 } 157 158 static int htvec_of_init(struct device_node *node, 159 struct device_node *parent) 160 { 161 struct htvec *priv; 162 int err, parent_irq[8], i; 163 164 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 165 if (!priv) 166 return -ENOMEM; 167 168 raw_spin_lock_init(&priv->htvec_lock); 169 priv->base = of_iomap(node, 0); 170 if (!priv->base) { 171 err = -ENOMEM; 172 goto free_priv; 173 } 174 175 /* Interrupt may come from any of the 8 interrupt lines */ 176 for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) { 177 parent_irq[i] = irq_of_parse_and_map(node, i); 178 if (parent_irq[i] <= 0) 179 break; 180 181 priv->num_parents++; 182 } 183 184 if (!priv->num_parents) { 185 pr_err("Failed to get parent irqs\n"); 186 err = -ENODEV; 187 goto iounmap_base; 188 } 189 190 priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node), 191 (VEC_COUNT_PER_REG * priv->num_parents), 192 &htvec_domain_ops, priv); 193 if (!priv->htvec_domain) { 194 pr_err("Failed to create IRQ domain\n"); 195 err = -ENOMEM; 196 goto irq_dispose; 197 } 198 199 htvec_reset(priv); 200 201 for (i = 0; i < priv->num_parents; i++) 202 irq_set_chained_handler_and_data(parent_irq[i], 203 htvec_irq_dispatch, priv); 204 205 return 0; 206 207 irq_dispose: 208 for (; i > 0; i--) 209 irq_dispose_mapping(parent_irq[i - 1]); 210 iounmap_base: 211 iounmap(priv->base); 212 free_priv: 213 kfree(priv); 214 215 return err; 216 } 217 218 IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init); 219