drivers/irqchip/irq-mtk-cirq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2016 MediaTek Inc.
   4  * Author: Youlin.Pei <youlin.pei@mediatek.com>
   5  */
   6
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqchip.h>
  11 #include <linux/irqdomain.h>
  12 #include <linux/of.h>
  13 #include <linux/of_irq.h>
  14 #include <linux/of_address.h>
  15 #include <linux/slab.h>
  16 #include <linux/syscore_ops.h>
  17
  18 #define CIRQ_ACK        0x40
  19 #define CIRQ_MASK_SET   0xc0
  20 #define CIRQ_MASK_CLR   0x100
  21 #define CIRQ_SENS_SET   0x180
  22 #define CIRQ_SENS_CLR   0x1c0
  23 #define CIRQ_POL_SET    0x240
  24 #define CIRQ_POL_CLR    0x280
  25 #define CIRQ_CONTROL    0x300
  26
  27 #define CIRQ_EN 0x1
  28 #define CIRQ_EDGE       0x2
  29 #define CIRQ_FLUSH      0x4
  30
  31 struct mtk_cirq_chip_data {
  32         void __iomem *base;
  33         unsigned int ext_irq_start;
  34         unsigned int ext_irq_end;
  35         struct irq_domain *domain;
  36 };
  37
  38 static struct mtk_cirq_chip_data *cirq_data;
  39
  40 static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
  41 {
  42         struct mtk_cirq_chip_data *chip_data = data->chip_data;
  43         unsigned int cirq_num = data->hwirq;
  44         u32 mask = 1 << (cirq_num % 32);
  45
  46         writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
  47 }
  48
  49 static void mtk_cirq_mask(struct irq_data *data)
  50 {
  51         mtk_cirq_write_mask(data, CIRQ_MASK_SET);
  52         irq_chip_mask_parent(data);
  53 }
  54
  55 static void mtk_cirq_unmask(struct irq_data *data)
  56 {
  57         mtk_cirq_write_mask(data, CIRQ_MASK_CLR);
  58         irq_chip_unmask_parent(data);
  59 }
  60
  61 static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)
  62 {
  63         int ret;
  64
  65         switch (type & IRQ_TYPE_SENSE_MASK) {
  66         case IRQ_TYPE_EDGE_FALLING:
  67                 mtk_cirq_write_mask(data, CIRQ_POL_CLR);
  68                 mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
  69                 break;
  70         case IRQ_TYPE_EDGE_RISING:
  71                 mtk_cirq_write_mask(data, CIRQ_POL_SET);
  72                 mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
  73                 break;
  74         case IRQ_TYPE_LEVEL_LOW:
  75                 mtk_cirq_write_mask(data, CIRQ_POL_CLR);
  76                 mtk_cirq_write_mask(data, CIRQ_SENS_SET);
  77                 break;
  78         case IRQ_TYPE_LEVEL_HIGH:
  79                 mtk_cirq_write_mask(data, CIRQ_POL_SET);
  80                 mtk_cirq_write_mask(data, CIRQ_SENS_SET);
  81                 break;
  82         default:
  83                 break;
  84         }
  85
  86         data = data->parent_data;
  87         ret = data->chip->irq_set_type(data, type);
  88         return ret;
  89 }
  90
  91 static struct irq_chip mtk_cirq_chip = {
  92         .name                   = "MT_CIRQ",
  93         .irq_mask               = mtk_cirq_mask,
  94         .irq_unmask             = mtk_cirq_unmask,
  95         .irq_eoi                = irq_chip_eoi_parent,
  96         .irq_set_type           = mtk_cirq_set_type,
  97         .irq_retrigger          = irq_chip_retrigger_hierarchy,
  98 #ifdef CONFIG_SMP
  99         .irq_set_affinity       = irq_chip_set_affinity_parent,
 100 #endif
 101 };
 102
 103 static int mtk_cirq_domain_translate(struct irq_domain *d,
 104                                      struct irq_fwspec *fwspec,
 105                                      unsigned long *hwirq,
 106                                      unsigned int *type)
 107 {
 108         if (is_of_node(fwspec->fwnode)) {
 109                 if (fwspec->param_count != 3)
 110                         return -EINVAL;
 111
 112                 /* No PPI should point to this domain */
 113                 if (fwspec->param[0] != 0)
 114                         return -EINVAL;
 115
 116                 /* cirq support irq number check */
 117                 if (fwspec->param[1] < cirq_data->ext_irq_start ||
 118                     fwspec->param[1] > cirq_data->ext_irq_end)
 119                         return -EINVAL;
 120
 121                 *hwirq = fwspec->param[1] - cirq_data->ext_irq_start;
 122                 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
 123                 return 0;
 124         }
 125
 126         return -EINVAL;
 127 }
 128
 129 static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 130                                  unsigned int nr_irqs, void *arg)
 131 {
 132         int ret;
 133         irq_hw_number_t hwirq;
 134         unsigned int type;
 135         struct irq_fwspec *fwspec = arg;
 136         struct irq_fwspec parent_fwspec = *fwspec;
 137
 138         ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);
 139         if (ret)
 140                 return ret;
 141
 142         if (WARN_ON(nr_irqs != 1))
 143                 return -EINVAL;
 144
 145         irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 146                                       &mtk_cirq_chip,
 147                                       domain->host_data);
 148
 149         parent_fwspec.fwnode = domain->parent->fwnode;
 150         return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 151                                             &parent_fwspec);
 152 }
 153
 154 static const struct irq_domain_ops cirq_domain_ops = {
 155         .translate      = mtk_cirq_domain_translate,
 156         .alloc          = mtk_cirq_domain_alloc,
 157         .free           = irq_domain_free_irqs_common,
 158 };
 159
 160 #ifdef CONFIG_PM_SLEEP
 161 static int mtk_cirq_suspend(void)
 162 {
 163         u32 value, mask;
 164         unsigned int irq, hwirq_num;
 165         bool pending, masked;
 166         int i, pendret, maskret;
 167
 168         /*
 169          * When external interrupts happened, CIRQ will record the status
 170          * even CIRQ is not enabled. When execute flush command, CIRQ will
 171          * resend the signals according to the status. So if don't clear the
 172          * status, CIRQ will resend the wrong signals.
 173          *
 174          * arch_suspend_disable_irqs() will be called before CIRQ suspend
 175          * callback. If clear all the status simply, the external interrupts
 176          * which happened between arch_suspend_disable_irqs and CIRQ suspend
 177          * callback will be lost. Using following steps to avoid this issue;
 178          *
 179          * - Iterate over all the CIRQ supported interrupts;
 180          * - For each interrupt, inspect its pending and masked status at GIC
 181          *   level;
 182          * - If pending and unmasked, it happened between
 183          *   arch_suspend_disable_irqs and CIRQ suspend callback, don't ACK
 184          *   it. Otherwise, ACK it.
 185          */
 186         hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
 187         for (i = 0; i < hwirq_num; i++) {
 188                 irq = irq_find_mapping(cirq_data->domain, i);
 189                 if (irq) {
 190                         pendret = irq_get_irqchip_state(irq,
 191                                                         IRQCHIP_STATE_PENDING,
 192                                                         &pending);
 193
 194                         maskret = irq_get_irqchip_state(irq,
 195                                                         IRQCHIP_STATE_MASKED,
 196                                                         &masked);
 197
 198                         if (pendret == 0 && maskret == 0 &&
 199                             (pending && !masked))
 200                                 continue;
 201                 }
 202
 203                 mask = 1 << (i % 32);
 204                 writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
 205         }
 206
 207         /* set edge_only mode, record edge-triggerd interrupts */
 208         /* enable cirq */
 209         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 210         value |= (CIRQ_EDGE | CIRQ_EN);
 211         writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
 212
 213         return 0;
 214 }
 215
 216 static void mtk_cirq_resume(void)
 217 {
 218         u32 value;
 219
 220         /* flush recorded interrupts, will send signals to parent controller */
 221         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 222         writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
 223
 224         /* disable cirq */
 225         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 226         value &= ~(CIRQ_EDGE | CIRQ_EN);
 227         writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
 228 }
 229
 230 static struct syscore_ops mtk_cirq_syscore_ops = {
 231         .suspend        = mtk_cirq_suspend,
 232         .resume         = mtk_cirq_resume,
 233 };
 234
 235 static void mtk_cirq_syscore_init(void)
 236 {
 237         register_syscore_ops(&mtk_cirq_syscore_ops);
 238 }
 239 #else
 240 static inline void mtk_cirq_syscore_init(void) {}
 241 #endif
 242
 243 static int __init mtk_cirq_of_init(struct device_node *node,
 244                                    struct device_node *parent)
 245 {
 246         struct irq_domain *domain, *domain_parent;
 247         unsigned int irq_num;
 248         int ret;
 249
 250         domain_parent = irq_find_host(parent);
 251         if (!domain_parent) {
 252                 pr_err("mtk_cirq: interrupt-parent not found\n");
 253                 return -EINVAL;
 254         }
 255
 256         cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
 257         if (!cirq_data)
 258                 return -ENOMEM;
 259
 260         cirq_data->base = of_iomap(node, 0);
 261         if (!cirq_data->base) {
 262                 pr_err("mtk_cirq: unable to map cirq register\n");
 263                 ret = -ENXIO;
 264                 goto out_free;
 265         }
 266
 267         ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,
 268                                          &cirq_data->ext_irq_start);
 269         if (ret)
 270                 goto out_unmap;
 271
 272         ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,
 273                                          &cirq_data->ext_irq_end);
 274         if (ret)
 275                 goto out_unmap;
 276
 277         irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
 278         domain = irq_domain_add_hierarchy(domain_parent, 0,
 279                                           irq_num, node,
 280                                           &cirq_domain_ops, cirq_data);
 281         if (!domain) {
 282                 ret = -ENOMEM;
 283                 goto out_unmap;
 284         }
 285         cirq_data->domain = domain;
 286
 287         mtk_cirq_syscore_init();
 288
 289         return 0;
 290
 291 out_unmap:
 292         iounmap(cirq_data->base);
 293 out_free:
 294         kfree(cirq_data);
 295         return ret;
 296 }
 297
 298 IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);