linux/drivers/irqchip/irq-keystone.c
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   1/*
   2 * Texas Instruments Keystone IRQ controller IP driver
   3 *
   4 * Copyright (C) 2014 Texas Instruments, Inc.
   5 * Author: Sajesh Kumar Saran <sajesh@ti.com>
   6 *         Grygorii Strashko <grygorii.strashko@ti.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation version 2.
  11 *
  12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13 * kind, whether express or implied; without even the implied warranty
  14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/irq.h>
  19#include <linux/bitops.h>
  20#include <linux/module.h>
  21#include <linux/moduleparam.h>
  22#include <linux/interrupt.h>
  23#include <linux/irqdomain.h>
  24#include <linux/irqchip.h>
  25#include <linux/of.h>
  26#include <linux/of_platform.h>
  27#include <linux/mfd/syscon.h>
  28#include <linux/regmap.h>
  29
  30/* The source ID bits start from 4 to 31 (total 28 bits)*/
  31#define BIT_OFS                 4
  32#define KEYSTONE_N_IRQ          (32 - BIT_OFS)
  33
  34struct keystone_irq_device {
  35        struct device           *dev;
  36        struct irq_chip          chip;
  37        u32                      mask;
  38        int                      irq;
  39        struct irq_domain       *irqd;
  40        struct regmap           *devctrl_regs;
  41        u32                     devctrl_offset;
  42        raw_spinlock_t          wa_lock;
  43};
  44
  45static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
  46{
  47        int ret;
  48        u32 val = 0;
  49
  50        ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
  51        if (ret < 0)
  52                dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
  53        return val;
  54}
  55
  56static inline void
  57keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
  58{
  59        int ret;
  60
  61        ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
  62        if (ret < 0)
  63                dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
  64}
  65
  66static void keystone_irq_setmask(struct irq_data *d)
  67{
  68        struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
  69
  70        kirq->mask |= BIT(d->hwirq);
  71        dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask);
  72}
  73
  74static void keystone_irq_unmask(struct irq_data *d)
  75{
  76        struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
  77
  78        kirq->mask &= ~BIT(d->hwirq);
  79        dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
  80}
  81
  82static void keystone_irq_ack(struct irq_data *d)
  83{
  84        /* nothing to do here */
  85}
  86
  87static irqreturn_t keystone_irq_handler(int irq, void *keystone_irq)
  88{
  89        struct keystone_irq_device *kirq = keystone_irq;
  90        unsigned long wa_lock_flags;
  91        unsigned long pending;
  92        int src, virq;
  93
  94        dev_dbg(kirq->dev, "start irq %d\n", irq);
  95
  96        pending = keystone_irq_readl(kirq);
  97        keystone_irq_writel(kirq, pending);
  98
  99        dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
 100
 101        pending = (pending >> BIT_OFS) & ~kirq->mask;
 102
 103        dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
 104
 105        for (src = 0; src < KEYSTONE_N_IRQ; src++) {
 106                if (BIT(src) & pending) {
 107                        virq = irq_find_mapping(kirq->irqd, src);
 108                        dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
 109                                src, virq);
 110                        if (!virq)
 111                                dev_warn(kirq->dev, "spurious irq detected hwirq %d, virq %d\n",
 112                                         src, virq);
 113                        raw_spin_lock_irqsave(&kirq->wa_lock, wa_lock_flags);
 114                        generic_handle_irq(virq);
 115                        raw_spin_unlock_irqrestore(&kirq->wa_lock,
 116                                                   wa_lock_flags);
 117                }
 118        }
 119
 120        dev_dbg(kirq->dev, "end irq %d\n", irq);
 121        return IRQ_HANDLED;
 122}
 123
 124static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
 125                                irq_hw_number_t hw)
 126{
 127        struct keystone_irq_device *kirq = h->host_data;
 128
 129        irq_set_chip_data(virq, kirq);
 130        irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
 131        irq_set_probe(virq);
 132        return 0;
 133}
 134
 135static const struct irq_domain_ops keystone_irq_ops = {
 136        .map    = keystone_irq_map,
 137        .xlate  = irq_domain_xlate_onecell,
 138};
 139
 140static int keystone_irq_probe(struct platform_device *pdev)
 141{
 142        struct device *dev = &pdev->dev;
 143        struct device_node *np = dev->of_node;
 144        struct keystone_irq_device *kirq;
 145        int ret;
 146
 147        if (np == NULL)
 148                return -EINVAL;
 149
 150        kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
 151        if (!kirq)
 152                return -ENOMEM;
 153
 154        kirq->devctrl_regs =
 155                syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
 156        if (IS_ERR(kirq->devctrl_regs))
 157                return PTR_ERR(kirq->devctrl_regs);
 158
 159        ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
 160                                         &kirq->devctrl_offset);
 161        if (ret) {
 162                dev_err(dev, "couldn't read the devctrl_offset offset!\n");
 163                return ret;
 164        }
 165
 166        kirq->irq = platform_get_irq(pdev, 0);
 167        if (kirq->irq < 0)
 168                return kirq->irq;
 169
 170        kirq->dev = dev;
 171        kirq->mask = ~0x0;
 172        kirq->chip.name         = "keystone-irq";
 173        kirq->chip.irq_ack      = keystone_irq_ack;
 174        kirq->chip.irq_mask     = keystone_irq_setmask;
 175        kirq->chip.irq_unmask   = keystone_irq_unmask;
 176
 177        kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
 178                                           &keystone_irq_ops, kirq);
 179        if (!kirq->irqd) {
 180                dev_err(dev, "IRQ domain registration failed\n");
 181                return -ENODEV;
 182        }
 183
 184        raw_spin_lock_init(&kirq->wa_lock);
 185
 186        platform_set_drvdata(pdev, kirq);
 187
 188        ret = request_irq(kirq->irq, keystone_irq_handler,
 189                          0, dev_name(dev), kirq);
 190        if (ret) {
 191                irq_domain_remove(kirq->irqd);
 192                return ret;
 193        }
 194
 195        /* clear all source bits */
 196        keystone_irq_writel(kirq, ~0x0);
 197
 198        dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
 199
 200        return 0;
 201}
 202
 203static int keystone_irq_remove(struct platform_device *pdev)
 204{
 205        struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
 206        int hwirq;
 207
 208        free_irq(kirq->irq, kirq);
 209
 210        for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
 211                irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
 212
 213        irq_domain_remove(kirq->irqd);
 214        return 0;
 215}
 216
 217static const struct of_device_id keystone_irq_dt_ids[] = {
 218        { .compatible = "ti,keystone-irq", },
 219        {},
 220};
 221MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
 222
 223static struct platform_driver keystone_irq_device_driver = {
 224        .probe          = keystone_irq_probe,
 225        .remove         = keystone_irq_remove,
 226        .driver         = {
 227                .name   = "keystone_irq",
 228                .of_match_table = of_match_ptr(keystone_irq_dt_ids),
 229        }
 230};
 231
 232module_platform_driver(keystone_irq_device_driver);
 233
 234MODULE_AUTHOR("Texas Instruments");
 235MODULE_AUTHOR("Sajesh Kumar Saran");
 236MODULE_AUTHOR("Grygorii Strashko");
 237MODULE_DESCRIPTION("Keystone IRQ chip");
 238MODULE_LICENSE("GPL v2");
 239