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| 1 | +// SPDX-License-Identifier: GPL-2.0 |
| 2 | +/* |
| 3 | + * Copyright (C) 2020, Jiaxun Yang <[email protected]> |
| 4 | + * Loongson PCH PIC support |
| 5 | + */ |
| 6 | + |
| 7 | +#define pr_fmt(fmt) "pch-pic: " 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/kernel.h> |
| 14 | +#include <linux/platform_device.h> |
| 15 | +#include <linux/of_address.h> |
| 16 | +#include <linux/of_irq.h> |
| 17 | +#include <linux/of_platform.h> |
| 18 | + |
| 19 | +/* Registers */ |
| 20 | +#define PCH_PIC_MASK 0x20 |
| 21 | +#define PCH_PIC_HTMSI_EN 0x40 |
| 22 | +#define PCH_PIC_EDGE 0x60 |
| 23 | +#define PCH_PIC_CLR 0x80 |
| 24 | +#define PCH_PIC_AUTO0 0xc0 |
| 25 | +#define PCH_PIC_AUTO1 0xe0 |
| 26 | +#define PCH_INT_ROUTE(irq) (0x100 + irq) |
| 27 | +#define PCH_INT_HTVEC(irq) (0x200 + irq) |
| 28 | +#define PCH_PIC_POL 0x3e0 |
| 29 | + |
| 30 | +#define PIC_COUNT_PER_REG 32 |
| 31 | +#define PIC_REG_COUNT 2 |
| 32 | +#define PIC_COUNT (PIC_COUNT_PER_REG * PIC_REG_COUNT) |
| 33 | +#define PIC_REG_IDX(irq_id) ((irq_id) / PIC_COUNT_PER_REG) |
| 34 | +#define PIC_REG_BIT(irq_id) ((irq_id) % PIC_COUNT_PER_REG) |
| 35 | + |
| 36 | +struct pch_pic { |
| 37 | + void __iomem *base; |
| 38 | + struct irq_domain *pic_domain; |
| 39 | + u32 ht_vec_base; |
| 40 | + raw_spinlock_t pic_lock; |
| 41 | +}; |
| 42 | + |
| 43 | +static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit) |
| 44 | +{ |
| 45 | + u32 reg; |
| 46 | + void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4; |
| 47 | + |
| 48 | + raw_spin_lock(&priv->pic_lock); |
| 49 | + reg = readl(addr); |
| 50 | + reg |= BIT(PIC_REG_BIT(bit)); |
| 51 | + writel(reg, addr); |
| 52 | + raw_spin_unlock(&priv->pic_lock); |
| 53 | +} |
| 54 | + |
| 55 | +static void pch_pic_bitclr(struct pch_pic *priv, int offset, int bit) |
| 56 | +{ |
| 57 | + u32 reg; |
| 58 | + void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4; |
| 59 | + |
| 60 | + raw_spin_lock(&priv->pic_lock); |
| 61 | + reg = readl(addr); |
| 62 | + reg &= ~BIT(PIC_REG_BIT(bit)); |
| 63 | + writel(reg, addr); |
| 64 | + raw_spin_unlock(&priv->pic_lock); |
| 65 | +} |
| 66 | + |
| 67 | +static void pch_pic_eoi_irq(struct irq_data *d) |
| 68 | +{ |
| 69 | + u32 idx = PIC_REG_IDX(d->hwirq); |
| 70 | + struct pch_pic *priv = irq_data_get_irq_chip_data(d); |
| 71 | + |
| 72 | + writel(BIT(PIC_REG_BIT(d->hwirq)), |
| 73 | + priv->base + PCH_PIC_CLR + idx * 4); |
| 74 | +} |
| 75 | + |
| 76 | +static void pch_pic_mask_irq(struct irq_data *d) |
| 77 | +{ |
| 78 | + struct pch_pic *priv = irq_data_get_irq_chip_data(d); |
| 79 | + |
| 80 | + pch_pic_bitset(priv, PCH_PIC_MASK, d->hwirq); |
| 81 | + irq_chip_mask_parent(d); |
| 82 | +} |
| 83 | + |
| 84 | +static void pch_pic_unmask_irq(struct irq_data *d) |
| 85 | +{ |
| 86 | + struct pch_pic *priv = irq_data_get_irq_chip_data(d); |
| 87 | + |
| 88 | + irq_chip_unmask_parent(d); |
| 89 | + pch_pic_bitclr(priv, PCH_PIC_MASK, d->hwirq); |
| 90 | +} |
| 91 | + |
| 92 | +static int pch_pic_set_type(struct irq_data *d, unsigned int type) |
| 93 | +{ |
| 94 | + struct pch_pic *priv = irq_data_get_irq_chip_data(d); |
| 95 | + int ret = 0; |
| 96 | + |
| 97 | + switch (type) { |
| 98 | + case IRQ_TYPE_EDGE_RISING: |
| 99 | + pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq); |
| 100 | + pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq); |
| 101 | + break; |
| 102 | + case IRQ_TYPE_EDGE_FALLING: |
| 103 | + pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq); |
| 104 | + pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq); |
| 105 | + break; |
| 106 | + case IRQ_TYPE_LEVEL_HIGH: |
| 107 | + pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq); |
| 108 | + pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq); |
| 109 | + break; |
| 110 | + case IRQ_TYPE_LEVEL_LOW: |
| 111 | + pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq); |
| 112 | + pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq); |
| 113 | + break; |
| 114 | + default: |
| 115 | + ret = -EINVAL; |
| 116 | + break; |
| 117 | + } |
| 118 | + |
| 119 | + return ret; |
| 120 | +} |
| 121 | + |
| 122 | +static struct irq_chip pch_pic_irq_chip = { |
| 123 | + .name = "PCH PIC", |
| 124 | + .irq_mask = pch_pic_mask_irq, |
| 125 | + .irq_unmask = pch_pic_unmask_irq, |
| 126 | + .irq_ack = irq_chip_ack_parent, |
| 127 | + .irq_eoi = pch_pic_eoi_irq, |
| 128 | + .irq_set_affinity = irq_chip_set_affinity_parent, |
| 129 | + .irq_set_type = pch_pic_set_type, |
| 130 | +}; |
| 131 | + |
| 132 | +static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq, |
| 133 | + unsigned int nr_irqs, void *arg) |
| 134 | +{ |
| 135 | + int err; |
| 136 | + unsigned int type; |
| 137 | + unsigned long hwirq; |
| 138 | + struct irq_fwspec fwspec; |
| 139 | + struct pch_pic *priv = domain->host_data; |
| 140 | + |
| 141 | + irq_domain_translate_twocell(domain, arg, &hwirq, &type); |
| 142 | + |
| 143 | + fwspec.fwnode = domain->parent->fwnode; |
| 144 | + fwspec.param_count = 1; |
| 145 | + fwspec.param[0] = hwirq + priv->ht_vec_base; |
| 146 | + |
| 147 | + err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); |
| 148 | + if (err) |
| 149 | + return err; |
| 150 | + |
| 151 | + irq_domain_set_info(domain, virq, hwirq, |
| 152 | + &pch_pic_irq_chip, priv, |
| 153 | + handle_fasteoi_ack_irq, NULL, NULL); |
| 154 | + irq_set_probe(virq); |
| 155 | + |
| 156 | + return 0; |
| 157 | +} |
| 158 | + |
| 159 | +static const struct irq_domain_ops pch_pic_domain_ops = { |
| 160 | + .translate = irq_domain_translate_twocell, |
| 161 | + .alloc = pch_pic_alloc, |
| 162 | + .free = irq_domain_free_irqs_parent, |
| 163 | +}; |
| 164 | + |
| 165 | +static void pch_pic_reset(struct pch_pic *priv) |
| 166 | +{ |
| 167 | + int i; |
| 168 | + |
| 169 | + for (i = 0; i < PIC_COUNT; i++) { |
| 170 | + /* Write vectore ID */ |
| 171 | + writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(i)); |
| 172 | + /* Hardcode route to HT0 Lo */ |
| 173 | + writeb(1, priv->base + PCH_INT_ROUTE(i)); |
| 174 | + } |
| 175 | + |
| 176 | + for (i = 0; i < PIC_REG_COUNT; i++) { |
| 177 | + /* Clear IRQ cause registers, mask all interrupts */ |
| 178 | + writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_MASK + 4 * i); |
| 179 | + writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_CLR + 4 * i); |
| 180 | + /* Clear auto bounce, we don't need that */ |
| 181 | + writel_relaxed(0, priv->base + PCH_PIC_AUTO0 + 4 * i); |
| 182 | + writel_relaxed(0, priv->base + PCH_PIC_AUTO1 + 4 * i); |
| 183 | + /* Enable HTMSI transformer */ |
| 184 | + writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_HTMSI_EN + 4 * i); |
| 185 | + } |
| 186 | +} |
| 187 | + |
| 188 | +static int pch_pic_of_init(struct device_node *node, |
| 189 | + struct device_node *parent) |
| 190 | +{ |
| 191 | + struct pch_pic *priv; |
| 192 | + struct irq_domain *parent_domain; |
| 193 | + int err; |
| 194 | + |
| 195 | + priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
| 196 | + if (!priv) |
| 197 | + return -ENOMEM; |
| 198 | + |
| 199 | + raw_spin_lock_init(&priv->pic_lock); |
| 200 | + priv->base = of_iomap(node, 0); |
| 201 | + if (!priv->base) { |
| 202 | + err = -ENOMEM; |
| 203 | + goto free_priv; |
| 204 | + } |
| 205 | + |
| 206 | + parent_domain = irq_find_host(parent); |
| 207 | + if (!parent_domain) { |
| 208 | + pr_err("Failed to find the parent domain\n"); |
| 209 | + err = -ENXIO; |
| 210 | + goto iounmap_base; |
| 211 | + } |
| 212 | + |
| 213 | + if (of_property_read_u32(node, "loongson,pic-base-vec", |
| 214 | + &priv->ht_vec_base)) { |
| 215 | + pr_err("Failed to determine pic-base-vec\n"); |
| 216 | + err = -EINVAL; |
| 217 | + goto iounmap_base; |
| 218 | + } |
| 219 | + |
| 220 | + priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0, |
| 221 | + PIC_COUNT, |
| 222 | + of_node_to_fwnode(node), |
| 223 | + &pch_pic_domain_ops, |
| 224 | + priv); |
| 225 | + if (!priv->pic_domain) { |
| 226 | + pr_err("Failed to create IRQ domain\n"); |
| 227 | + err = -ENOMEM; |
| 228 | + goto iounmap_base; |
| 229 | + } |
| 230 | + |
| 231 | + pch_pic_reset(priv); |
| 232 | + |
| 233 | + return 0; |
| 234 | + |
| 235 | +iounmap_base: |
| 236 | + iounmap(priv->base); |
| 237 | +free_priv: |
| 238 | + kfree(priv); |
| 239 | + |
| 240 | + return err; |
| 241 | +} |
| 242 | + |
| 243 | +IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init); |
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