drivers/irqchip/irq-renesas-irqc.c

   1 /*
   2  * Renesas IRQC Driver
   3  *
   4  *  Copyright (C) 2013 Magnus Damm
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/ioport.h>
  25 #include <linux/io.h>
  26 #include <linux/irq.h>
  27 #include <linux/irqdomain.h>
  28 #include <linux/err.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/pm_runtime.h>
  32
  33 #define IRQC_IRQ_MAX    32      /* maximum 32 interrupts per driver instance */
  34
  35 #define IRQC_REQ_STS    0x00    /* Interrupt Request Status Register */
  36 #define IRQC_EN_STS     0x04    /* Interrupt Enable Status Register */
  37 #define IRQC_EN_SET     0x08    /* Interrupt Enable Set Register */
  38 #define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
  39                                 /* SYS-CPU vs. RT-CPU */
  40 #define DETECT_STATUS   0x100   /* IRQn Detect Status Register */
  41 #define MONITOR         0x104   /* IRQn Signal Level Monitor Register */
  42 #define HLVL_STS        0x108   /* IRQn High Level Detect Status Register */
  43 #define LLVL_STS        0x10c   /* IRQn Low Level Detect Status Register */
  44 #define S_R_EDGE_STS    0x110   /* IRQn Sync Rising Edge Detect Status Reg. */
  45 #define S_F_EDGE_STS    0x114   /* IRQn Sync Falling Edge Detect Status Reg. */
  46 #define A_R_EDGE_STS    0x118   /* IRQn Async Rising Edge Detect Status Reg. */
  47 #define A_F_EDGE_STS    0x11c   /* IRQn Async Falling Edge Detect Status Reg. */
  48 #define CHTEN_STS       0x120   /* Chattering Reduction Status Register */
  49 #define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
  50                                 /* IRQn Configuration Register */
  51
  52 struct irqc_irq {
  53         int hw_irq;
  54         int requested_irq;
  55         struct irqc_priv *p;
  56 };
  57
  58 struct irqc_priv {
  59         void __iomem *iomem;
  60         void __iomem *cpu_int_base;
  61         struct irqc_irq irq[IRQC_IRQ_MAX];
  62         unsigned int number_of_irqs;
  63         struct platform_device *pdev;
  64         struct irq_chip_generic *gc;
  65         struct irq_domain *irq_domain;
  66         atomic_t wakeup_path;
  67 };
  68
  69 static struct irqc_priv *irq_data_to_priv(struct irq_data *data)
  70 {
  71         return data->domain->host_data;
  72 }
  73
  74 static void irqc_dbg(struct irqc_irq *i, char *str)
  75 {
  76         dev_dbg(&i->p->pdev->dev, "%s (%d:%d)\n",
  77                 str, i->requested_irq, i->hw_irq);
  78 }
  79
  80 static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
  81         [IRQ_TYPE_LEVEL_LOW]    = 0x01,
  82         [IRQ_TYPE_LEVEL_HIGH]   = 0x02,
  83         [IRQ_TYPE_EDGE_FALLING] = 0x04, /* Synchronous */
  84         [IRQ_TYPE_EDGE_RISING]  = 0x08, /* Synchronous */
  85         [IRQ_TYPE_EDGE_BOTH]    = 0x0c, /* Synchronous */
  86 };
  87
  88 static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
  89 {
  90         struct irqc_priv *p = irq_data_to_priv(d);
  91         int hw_irq = irqd_to_hwirq(d);
  92         unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
  93         u32 tmp;
  94
  95         irqc_dbg(&p->irq[hw_irq], "sense");
  96
  97         if (!value)
  98                 return -EINVAL;
  99
 100         tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
 101         tmp &= ~0x3f;
 102         tmp |= value;
 103         iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
 104         return 0;
 105 }
 106
 107 static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
 108 {
 109         struct irqc_priv *p = irq_data_to_priv(d);
 110         int hw_irq = irqd_to_hwirq(d);
 111
 112         irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
 113         if (on)
 114                 atomic_inc(&p->wakeup_path);
 115         else
 116                 atomic_dec(&p->wakeup_path);
 117
 118         return 0;
 119 }
 120
 121 static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
 122 {
 123         struct irqc_irq *i = dev_id;
 124         struct irqc_priv *p = i->p;
 125         u32 bit = BIT(i->hw_irq);
 126
 127         irqc_dbg(i, "demux1");
 128
 129         if (ioread32(p->iomem + DETECT_STATUS) & bit) {
 130                 iowrite32(bit, p->iomem + DETECT_STATUS);
 131                 irqc_dbg(i, "demux2");
 132                 generic_handle_irq(irq_find_mapping(p->irq_domain, i->hw_irq));
 133                 return IRQ_HANDLED;
 134         }
 135         return IRQ_NONE;
 136 }
 137
 138 static int irqc_probe(struct platform_device *pdev)
 139 {
 140         struct irqc_priv *p;
 141         struct resource *io;
 142         struct resource *irq;
 143         const char *name = dev_name(&pdev->dev);
 144         int ret;
 145         int k;
 146
 147         p = kzalloc(sizeof(*p), GFP_KERNEL);
 148         if (!p) {
 149                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 150                 ret = -ENOMEM;
 151                 goto err0;
 152         }
 153
 154         p->pdev = pdev;
 155         platform_set_drvdata(pdev, p);
 156
 157         pm_runtime_enable(&pdev->dev);
 158         pm_runtime_get_sync(&pdev->dev);
 159
 160         /* get hold of manadatory IOMEM */
 161         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 162         if (!io) {
 163                 dev_err(&pdev->dev, "not enough IOMEM resources\n");
 164                 ret = -EINVAL;
 165                 goto err1;
 166         }
 167
 168         /* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
 169         for (k = 0; k < IRQC_IRQ_MAX; k++) {
 170                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 171                 if (!irq)
 172                         break;
 173
 174                 p->irq[k].p = p;
 175                 p->irq[k].hw_irq = k;
 176                 p->irq[k].requested_irq = irq->start;
 177         }
 178
 179         p->number_of_irqs = k;
 180         if (p->number_of_irqs < 1) {
 181                 dev_err(&pdev->dev, "not enough IRQ resources\n");
 182                 ret = -EINVAL;
 183                 goto err1;
 184         }
 185
 186         /* ioremap IOMEM and setup read/write callbacks */
 187         p->iomem = ioremap_nocache(io->start, resource_size(io));
 188         if (!p->iomem) {
 189                 dev_err(&pdev->dev, "failed to remap IOMEM\n");
 190                 ret = -ENXIO;
 191                 goto err2;
 192         }
 193
 194         p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
 195
 196         p->irq_domain = irq_domain_add_linear(pdev->dev.of_node,
 197                                               p->number_of_irqs,
 198                                               &irq_generic_chip_ops, p);
 199         if (!p->irq_domain) {
 200                 ret = -ENXIO;
 201                 dev_err(&pdev->dev, "cannot initialize irq domain\n");
 202                 goto err2;
 203         }
 204
 205         ret = irq_alloc_domain_generic_chips(p->irq_domain, p->number_of_irqs,
 206                                              1, name, handle_level_irq,
 207                                              0, 0, IRQ_GC_INIT_NESTED_LOCK);
 208         if (ret) {
 209                 dev_err(&pdev->dev, "cannot allocate generic chip\n");
 210                 goto err3;
 211         }
 212
 213         p->gc = irq_get_domain_generic_chip(p->irq_domain, 0);
 214         p->gc->reg_base = p->cpu_int_base;
 215         p->gc->chip_types[0].regs.enable = IRQC_EN_SET;
 216         p->gc->chip_types[0].regs.disable = IRQC_EN_STS;
 217         p->gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
 218         p->gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
 219         p->gc->chip_types[0].chip.irq_set_type  = irqc_irq_set_type;
 220         p->gc->chip_types[0].chip.irq_set_wake  = irqc_irq_set_wake;
 221         p->gc->chip_types[0].chip.flags = IRQCHIP_MASK_ON_SUSPEND;
 222
 223         /* request interrupts one by one */
 224         for (k = 0; k < p->number_of_irqs; k++) {
 225                 if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
 226                                 0, name, &p->irq[k])) {
 227                         dev_err(&pdev->dev, "failed to request IRQ\n");
 228                         ret = -ENOENT;
 229                         goto err4;
 230                 }
 231         }
 232
 233         dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
 234
 235         return 0;
 236 err4:
 237         while (--k >= 0)
 238                 free_irq(p->irq[k].requested_irq, &p->irq[k]);
 239
 240 err3:
 241         irq_domain_remove(p->irq_domain);
 242 err2:
 243         iounmap(p->iomem);
 244 err1:
 245         pm_runtime_put(&pdev->dev);
 246         pm_runtime_disable(&pdev->dev);
 247         kfree(p);
 248 err0:
 249         return ret;
 250 }
 251
 252 static int irqc_remove(struct platform_device *pdev)
 253 {
 254         struct irqc_priv *p = platform_get_drvdata(pdev);
 255         int k;
 256
 257         for (k = 0; k < p->number_of_irqs; k++)
 258                 free_irq(p->irq[k].requested_irq, &p->irq[k]);
 259
 260         irq_domain_remove(p->irq_domain);
 261         iounmap(p->iomem);
 262         pm_runtime_put(&pdev->dev);
 263         pm_runtime_disable(&pdev->dev);
 264         kfree(p);
 265         return 0;
 266 }
 267
 268 static int __maybe_unused irqc_suspend(struct device *dev)
 269 {
 270         struct irqc_priv *p = dev_get_drvdata(dev);
 271
 272         if (atomic_read(&p->wakeup_path))
 273                 device_set_wakeup_path(dev);
 274
 275         return 0;
 276 }
 277
 278 static SIMPLE_DEV_PM_OPS(irqc_pm_ops, irqc_suspend, NULL);
 279
 280 static const struct of_device_id irqc_dt_ids[] = {
 281         { .compatible = "renesas,irqc", },
 282         {},
 283 };
 284 MODULE_DEVICE_TABLE(of, irqc_dt_ids);
 285
 286 static struct platform_driver irqc_device_driver = {
 287         .probe          = irqc_probe,
 288         .remove         = irqc_remove,
 289         .driver         = {
 290                 .name   = "renesas_irqc",
 291                 .of_match_table = irqc_dt_ids,
 292                 .pm     = &irqc_pm_ops,
 293         }
 294 };
 295
 296 static int __init irqc_init(void)
 297 {
 298         return platform_driver_register(&irqc_device_driver);
 299 }
 300 postcore_initcall(irqc_init);
 301
 302 static void __exit irqc_exit(void)
 303 {
 304         platform_driver_unregister(&irqc_device_driver);
 305 }
 306 module_exit(irqc_exit);
 307
 308 MODULE_AUTHOR("Magnus Damm");
 309 MODULE_DESCRIPTION("Renesas IRQC Driver");
 310 MODULE_LICENSE("GPL v2");