drivers/irqchip/irq-mtk-cirq.c

   1 /*
   2  * Copyright (c) 2016 MediaTek Inc.
   3  * Author: Youlin.Pei <youlin.pei@mediatek.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqchip.h>
  19 #include <linux/irqdomain.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_address.h>
  23 #include <linux/slab.h>
  24 #include <linux/syscore_ops.h>
  25
  26 #define CIRQ_ACK        0x40
  27 #define CIRQ_MASK_SET   0xc0
  28 #define CIRQ_MASK_CLR   0x100
  29 #define CIRQ_SENS_SET   0x180
  30 #define CIRQ_SENS_CLR   0x1c0
  31 #define CIRQ_POL_SET    0x240
  32 #define CIRQ_POL_CLR    0x280
  33 #define CIRQ_CONTROL    0x300
  34
  35 #define CIRQ_EN 0x1
  36 #define CIRQ_EDGE       0x2
  37 #define CIRQ_FLUSH      0x4
  38
  39 struct mtk_cirq_chip_data {
  40         void __iomem *base;
  41         unsigned int ext_irq_start;
  42         unsigned int ext_irq_end;
  43         struct irq_domain *domain;
  44 };
  45
  46 static struct mtk_cirq_chip_data *cirq_data;
  47
  48 static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
  49 {
  50         struct mtk_cirq_chip_data *chip_data = data->chip_data;
  51         unsigned int cirq_num = data->hwirq;
  52         u32 mask = 1 << (cirq_num % 32);
  53
  54         writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
  55 }
  56
  57 static void mtk_cirq_mask(struct irq_data *data)
  58 {
  59         mtk_cirq_write_mask(data, CIRQ_MASK_SET);
  60         irq_chip_mask_parent(data);
  61 }
  62
  63 static void mtk_cirq_unmask(struct irq_data *data)
  64 {
  65         mtk_cirq_write_mask(data, CIRQ_MASK_CLR);
  66         irq_chip_unmask_parent(data);
  67 }
  68
  69 static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)
  70 {
  71         int ret;
  72
  73         switch (type & IRQ_TYPE_SENSE_MASK) {
  74         case IRQ_TYPE_EDGE_FALLING:
  75                 mtk_cirq_write_mask(data, CIRQ_POL_CLR);
  76                 mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
  77                 break;
  78         case IRQ_TYPE_EDGE_RISING:
  79                 mtk_cirq_write_mask(data, CIRQ_POL_SET);
  80                 mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
  81                 break;
  82         case IRQ_TYPE_LEVEL_LOW:
  83                 mtk_cirq_write_mask(data, CIRQ_POL_CLR);
  84                 mtk_cirq_write_mask(data, CIRQ_SENS_SET);
  85                 break;
  86         case IRQ_TYPE_LEVEL_HIGH:
  87                 mtk_cirq_write_mask(data, CIRQ_POL_SET);
  88                 mtk_cirq_write_mask(data, CIRQ_SENS_SET);
  89                 break;
  90         default:
  91                 break;
  92         }
  93
  94         data = data->parent_data;
  95         ret = data->chip->irq_set_type(data, type);
  96         return ret;
  97 }
  98
  99 static struct irq_chip mtk_cirq_chip = {
 100         .name                   = "MT_CIRQ",
 101         .irq_mask               = mtk_cirq_mask,
 102         .irq_unmask             = mtk_cirq_unmask,
 103         .irq_eoi                = irq_chip_eoi_parent,
 104         .irq_set_type           = mtk_cirq_set_type,
 105         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 106 #ifdef CONFIG_SMP
 107         .irq_set_affinity       = irq_chip_set_affinity_parent,
 108 #endif
 109 };
 110
 111 static int mtk_cirq_domain_translate(struct irq_domain *d,
 112                                      struct irq_fwspec *fwspec,
 113                                      unsigned long *hwirq,
 114                                      unsigned int *type)
 115 {
 116         if (is_of_node(fwspec->fwnode)) {
 117                 if (fwspec->param_count != 3)
 118                         return -EINVAL;
 119
 120                 /* No PPI should point to this domain */
 121                 if (fwspec->param[0] != 0)
 122                         return -EINVAL;
 123
 124                 /* cirq support irq number check */
 125                 if (fwspec->param[1] < cirq_data->ext_irq_start ||
 126                     fwspec->param[1] > cirq_data->ext_irq_end)
 127                         return -EINVAL;
 128
 129                 *hwirq = fwspec->param[1] - cirq_data->ext_irq_start;
 130                 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
 131                 return 0;
 132         }
 133
 134         return -EINVAL;
 135 }
 136
 137 static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 138                                  unsigned int nr_irqs, void *arg)
 139 {
 140         int ret;
 141         irq_hw_number_t hwirq;
 142         unsigned int type;
 143         struct irq_fwspec *fwspec = arg;
 144         struct irq_fwspec parent_fwspec = *fwspec;
 145
 146         ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);
 147         if (ret)
 148                 return ret;
 149
 150         if (WARN_ON(nr_irqs != 1))
 151                 return -EINVAL;
 152
 153         irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 154                                       &mtk_cirq_chip,
 155                                       domain->host_data);
 156
 157         parent_fwspec.fwnode = domain->parent->fwnode;
 158         return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 159                                             &parent_fwspec);
 160 }
 161
 162 static const struct irq_domain_ops cirq_domain_ops = {
 163         .translate      = mtk_cirq_domain_translate,
 164         .alloc          = mtk_cirq_domain_alloc,
 165         .free           = irq_domain_free_irqs_common,
 166 };
 167
 168 #ifdef CONFIG_PM_SLEEP
 169 static int mtk_cirq_suspend(void)
 170 {
 171         u32 value, mask;
 172         unsigned int irq, hwirq_num;
 173         bool pending, masked;
 174         int i, pendret, maskret;
 175
 176         /*
 177          * When external interrupts happened, CIRQ will record the status
 178          * even CIRQ is not enabled. When execute flush command, CIRQ will
 179          * resend the signals according to the status. So if don't clear the
 180          * status, CIRQ will resend the wrong signals.
 181          *
 182          * arch_suspend_disable_irqs() will be called before CIRQ suspend
 183          * callback. If clear all the status simply, the external interrupts
 184          * which happened between arch_suspend_disable_irqs and CIRQ suspend
 185          * callback will be lost. Using following steps to avoid this issue;
 186          *
 187          * - Iterate over all the CIRQ supported interrupts;
 188          * - For each interrupt, inspect its pending and masked status at GIC
 189          *   level;
 190          * - If pending and unmasked, it happened between
 191          *   arch_suspend_disable_irqs and CIRQ suspend callback, don't ACK
 192          *   it. Otherwise, ACK it.
 193          */
 194         hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
 195         for (i = 0; i < hwirq_num; i++) {
 196                 irq = irq_find_mapping(cirq_data->domain, i);
 197                 if (irq) {
 198                         pendret = irq_get_irqchip_state(irq,
 199                                                         IRQCHIP_STATE_PENDING,
 200                                                         &pending);
 201
 202                         maskret = irq_get_irqchip_state(irq,
 203                                                         IRQCHIP_STATE_MASKED,
 204                                                         &masked);
 205
 206                         if (pendret == 0 && maskret == 0 &&
 207                             (pending && !masked))
 208                                 continue;
 209                 }
 210
 211                 mask = 1 << (i % 32);
 212                 writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
 213         }
 214
 215         /* set edge_only mode, record edge-triggerd interrupts */
 216         /* enable cirq */
 217         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 218         value |= (CIRQ_EDGE | CIRQ_EN);
 219         writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
 220
 221         return 0;
 222 }
 223
 224 static void mtk_cirq_resume(void)
 225 {
 226         u32 value;
 227
 228         /* flush recored interrupts, will send signals to parent controller */
 229         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 230         writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
 231
 232         /* disable cirq */
 233         value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
 234         value &= ~(CIRQ_EDGE | CIRQ_EN);
 235         writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
 236 }
 237
 238 static struct syscore_ops mtk_cirq_syscore_ops = {
 239         .suspend        = mtk_cirq_suspend,
 240         .resume         = mtk_cirq_resume,
 241 };
 242
 243 static void mtk_cirq_syscore_init(void)
 244 {
 245         register_syscore_ops(&mtk_cirq_syscore_ops);
 246 }
 247 #else
 248 static inline void mtk_cirq_syscore_init(void) {}
 249 #endif
 250
 251 static int __init mtk_cirq_of_init(struct device_node *node,
 252                                    struct device_node *parent)
 253 {
 254         struct irq_domain *domain, *domain_parent;
 255         unsigned int irq_num;
 256         int ret;
 257
 258         domain_parent = irq_find_host(parent);
 259         if (!domain_parent) {
 260                 pr_err("mtk_cirq: interrupt-parent not found\n");
 261                 return -EINVAL;
 262         }
 263
 264         cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
 265         if (!cirq_data)
 266                 return -ENOMEM;
 267
 268         cirq_data->base = of_iomap(node, 0);
 269         if (!cirq_data->base) {
 270                 pr_err("mtk_cirq: unable to map cirq register\n");
 271                 ret = -ENXIO;
 272                 goto out_free;
 273         }
 274
 275         ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,
 276                                          &cirq_data->ext_irq_start);
 277         if (ret)
 278                 goto out_unmap;
 279
 280         ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,
 281                                          &cirq_data->ext_irq_end);
 282         if (ret)
 283                 goto out_unmap;
 284
 285         irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
 286         domain = irq_domain_add_hierarchy(domain_parent, 0,
 287                                           irq_num, node,
 288                                           &cirq_domain_ops, cirq_data);
 289         if (!domain) {
 290                 ret = -ENOMEM;
 291                 goto out_unmap;
 292         }
 293         cirq_data->domain = domain;
 294
 295         mtk_cirq_syscore_init();
 296
 297         return 0;
 298
 299 out_unmap:
 300         iounmap(cirq_data->base);
 301 out_free:
 302         kfree(cirq_data);
 303         return ret;
 304 }
 305
 306 IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);