drivers/irqchip/irq-loongson-pch-pic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
   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_mask_irq(struct irq_data *d)
  68 {
  69         struct pch_pic *priv = irq_data_get_irq_chip_data(d);
  70
  71         pch_pic_bitset(priv, PCH_PIC_MASK, d->hwirq);
  72         irq_chip_mask_parent(d);
  73 }
  74
  75 static void pch_pic_unmask_irq(struct irq_data *d)
  76 {
  77         struct pch_pic *priv = irq_data_get_irq_chip_data(d);
  78
  79         writel(BIT(PIC_REG_BIT(d->hwirq)),
  80                         priv->base + PCH_PIC_CLR + PIC_REG_IDX(d->hwirq) * 4);
  81
  82         irq_chip_unmask_parent(d);
  83         pch_pic_bitclr(priv, PCH_PIC_MASK, d->hwirq);
  84 }
  85
  86 static int pch_pic_set_type(struct irq_data *d, unsigned int type)
  87 {
  88         struct pch_pic *priv = irq_data_get_irq_chip_data(d);
  89         int ret = 0;
  90
  91         switch (type) {
  92         case IRQ_TYPE_EDGE_RISING:
  93                 pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq);
  94                 pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq);
  95                 irq_set_handler_locked(d, handle_edge_irq);
  96                 break;
  97         case IRQ_TYPE_EDGE_FALLING:
  98                 pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq);
  99                 pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq);
 100                 irq_set_handler_locked(d, handle_edge_irq);
 101                 break;
 102         case IRQ_TYPE_LEVEL_HIGH:
 103                 pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq);
 104                 pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq);
 105                 irq_set_handler_locked(d, handle_level_irq);
 106                 break;
 107         case IRQ_TYPE_LEVEL_LOW:
 108                 pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq);
 109                 pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq);
 110                 irq_set_handler_locked(d, handle_level_irq);
 111                 break;
 112         default:
 113                 ret = -EINVAL;
 114                 break;
 115         }
 116
 117         return ret;
 118 }
 119
 120 static void pch_pic_ack_irq(struct irq_data *d)
 121 {
 122         unsigned int reg;
 123         struct pch_pic *priv = irq_data_get_irq_chip_data(d);
 124
 125         reg = readl(priv->base + PCH_PIC_EDGE + PIC_REG_IDX(d->hwirq) * 4);
 126         if (reg & BIT(PIC_REG_BIT(d->hwirq))) {
 127                 writel(BIT(PIC_REG_BIT(d->hwirq)),
 128                         priv->base + PCH_PIC_CLR + PIC_REG_IDX(d->hwirq) * 4);
 129         }
 130         irq_chip_ack_parent(d);
 131 }
 132
 133 static struct irq_chip pch_pic_irq_chip = {
 134         .name                   = "PCH PIC",
 135         .irq_mask               = pch_pic_mask_irq,
 136         .irq_unmask             = pch_pic_unmask_irq,
 137         .irq_ack                = pch_pic_ack_irq,
 138         .irq_set_affinity       = irq_chip_set_affinity_parent,
 139         .irq_set_type           = pch_pic_set_type,
 140 };
 141
 142 static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
 143                               unsigned int nr_irqs, void *arg)
 144 {
 145         int err;
 146         unsigned int type;
 147         unsigned long hwirq;
 148         struct irq_fwspec *fwspec = arg;
 149         struct irq_fwspec parent_fwspec;
 150         struct pch_pic *priv = domain->host_data;
 151
 152         err = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type);
 153         if (err)
 154                 return err;
 155
 156         parent_fwspec.fwnode = domain->parent->fwnode;
 157         parent_fwspec.param_count = 1;
 158         parent_fwspec.param[0] = hwirq + priv->ht_vec_base;
 159
 160         err = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
 161         if (err)
 162                 return err;
 163
 164         irq_domain_set_info(domain, virq, hwirq,
 165                             &pch_pic_irq_chip, priv,
 166                             handle_level_irq, NULL, NULL);
 167         irq_set_probe(virq);
 168
 169         return 0;
 170 }
 171
 172 static const struct irq_domain_ops pch_pic_domain_ops = {
 173         .translate      = irq_domain_translate_twocell,
 174         .alloc          = pch_pic_alloc,
 175         .free           = irq_domain_free_irqs_parent,
 176 };
 177
 178 static void pch_pic_reset(struct pch_pic *priv)
 179 {
 180         int i;
 181
 182         for (i = 0; i < PIC_COUNT; i++) {
 183                 /* Write vectored ID */
 184                 writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(i));
 185                 /* Hardcode route to HT0 Lo */
 186                 writeb(1, priv->base + PCH_INT_ROUTE(i));
 187         }
 188
 189         for (i = 0; i < PIC_REG_COUNT; i++) {
 190                 /* Clear IRQ cause registers, mask all interrupts */
 191                 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_MASK + 4 * i);
 192                 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_CLR + 4 * i);
 193                 /* Clear auto bounce, we don't need that */
 194                 writel_relaxed(0, priv->base + PCH_PIC_AUTO0 + 4 * i);
 195                 writel_relaxed(0, priv->base + PCH_PIC_AUTO1 + 4 * i);
 196                 /* Enable HTMSI transformer */
 197                 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_HTMSI_EN + 4 * i);
 198         }
 199 }
 200
 201 static int pch_pic_of_init(struct device_node *node,
 202                                 struct device_node *parent)
 203 {
 204         struct pch_pic *priv;
 205         struct irq_domain *parent_domain;
 206         int err;
 207
 208         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 209         if (!priv)
 210                 return -ENOMEM;
 211
 212         raw_spin_lock_init(&priv->pic_lock);
 213         priv->base = of_iomap(node, 0);
 214         if (!priv->base) {
 215                 err = -ENOMEM;
 216                 goto free_priv;
 217         }
 218
 219         parent_domain = irq_find_host(parent);
 220         if (!parent_domain) {
 221                 pr_err("Failed to find the parent domain\n");
 222                 err = -ENXIO;
 223                 goto iounmap_base;
 224         }
 225
 226         if (of_property_read_u32(node, "loongson,pic-base-vec",
 227                                 &priv->ht_vec_base)) {
 228                 pr_err("Failed to determine pic-base-vec\n");
 229                 err = -EINVAL;
 230                 goto iounmap_base;
 231         }
 232
 233         priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
 234                                                        PIC_COUNT,
 235                                                        of_node_to_fwnode(node),
 236                                                        &pch_pic_domain_ops,
 237                                                        priv);
 238         if (!priv->pic_domain) {
 239                 pr_err("Failed to create IRQ domain\n");
 240                 err = -ENOMEM;
 241                 goto iounmap_base;
 242         }
 243
 244         pch_pic_reset(priv);
 245
 246         return 0;
 247
 248 iounmap_base:
 249         iounmap(priv->base);
 250 free_priv:
 251         kfree(priv);
 252
 253         return err;
 254 }
 255
 256 IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);