drivers/irqchip/irq-keystone.c

   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/irqdomain.h>
  23 #include <linux/irqchip.h>
  24 #include <linux/irqchip/chained_irq.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
  34 struct 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 };
  43
  44 static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
  45 {
  46         int ret;
  47         u32 val = 0;
  48
  49         ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
  50         if (ret < 0)
  51                 dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
  52         return val;
  53 }
  54
  55 static inline void
  56 keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
  57 {
  58         int ret;
  59
  60         ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
  61         if (ret < 0)
  62                 dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
  63 }
  64
  65 static void keystone_irq_setmask(struct irq_data *d)
  66 {
  67         struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
  68
  69         kirq->mask |= BIT(d->hwirq);
  70         dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask);
  71 }
  72
  73 static void keystone_irq_unmask(struct irq_data *d)
  74 {
  75         struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);
  76
  77         kirq->mask &= ~BIT(d->hwirq);
  78         dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
  79 }
  80
  81 static void keystone_irq_ack(struct irq_data *d)
  82 {
  83         /* nothing to do here */
  84 }
  85
  86 static void keystone_irq_handler(struct irq_desc *desc)
  87 {
  88         unsigned int irq = irq_desc_get_irq(desc);
  89         struct keystone_irq_device *kirq = irq_desc_get_handler_data(desc);
  90         unsigned long pending;
  91         int src, virq;
  92
  93         dev_dbg(kirq->dev, "start irq %d\n", irq);
  94
  95         chained_irq_enter(irq_desc_get_chip(desc), desc);
  96
  97         pending = keystone_irq_readl(kirq);
  98         keystone_irq_writel(kirq, pending);
  99
 100         dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);
 101
 102         pending = (pending >> BIT_OFS) & ~kirq->mask;
 103
 104         dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);
 105
 106         for (src = 0; src < KEYSTONE_N_IRQ; src++) {
 107                 if (BIT(src) & pending) {
 108                         virq = irq_find_mapping(kirq->irqd, src);
 109                         dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
 110                                 src, virq);
 111                         if (!virq)
 112                                 dev_warn(kirq->dev, "sporious irq detected hwirq %d, virq %d\n",
 113                                          src, virq);
 114                         generic_handle_irq(virq);
 115                 }
 116         }
 117
 118         chained_irq_exit(irq_desc_get_chip(desc), desc);
 119
 120         dev_dbg(kirq->dev, "end irq %d\n", irq);
 121 }
 122
 123 static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
 124                                 irq_hw_number_t hw)
 125 {
 126         struct keystone_irq_device *kirq = h->host_data;
 127
 128         irq_set_chip_data(virq, kirq);
 129         irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
 130         irq_set_probe(virq);
 131         return 0;
 132 }
 133
 134 static const struct irq_domain_ops keystone_irq_ops = {
 135         .map    = keystone_irq_map,
 136         .xlate  = irq_domain_xlate_onecell,
 137 };
 138
 139 static int keystone_irq_probe(struct platform_device *pdev)
 140 {
 141         struct device *dev = &pdev->dev;
 142         struct device_node *np = dev->of_node;
 143         struct keystone_irq_device *kirq;
 144         int ret;
 145
 146         if (np == NULL)
 147                 return -EINVAL;
 148
 149         kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
 150         if (!kirq)
 151                 return -ENOMEM;
 152
 153         kirq->devctrl_regs =
 154                 syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
 155         if (IS_ERR(kirq->devctrl_regs))
 156                 return PTR_ERR(kirq->devctrl_regs);
 157
 158         ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
 159                                          &kirq->devctrl_offset);
 160         if (ret) {
 161                 dev_err(dev, "couldn't read the devctrl_offset offset!\n");
 162                 return ret;
 163         }
 164
 165         kirq->irq = platform_get_irq(pdev, 0);
 166         if (kirq->irq < 0) {
 167                 dev_err(dev, "no irq resource %d\n", kirq->irq);
 168                 return kirq->irq;
 169         }
 170
 171         kirq->dev = dev;
 172         kirq->mask = ~0x0;
 173         kirq->chip.name         = "keystone-irq";
 174         kirq->chip.irq_ack      = keystone_irq_ack;
 175         kirq->chip.irq_mask     = keystone_irq_setmask;
 176         kirq->chip.irq_unmask   = keystone_irq_unmask;
 177
 178         kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
 179                                            &keystone_irq_ops, kirq);
 180         if (!kirq->irqd) {
 181                 dev_err(dev, "IRQ domain registration failed\n");
 182                 return -ENODEV;
 183         }
 184
 185         platform_set_drvdata(pdev, kirq);
 186
 187         irq_set_chained_handler_and_data(kirq->irq, keystone_irq_handler, kirq);
 188
 189         /* clear all source bits */
 190         keystone_irq_writel(kirq, ~0x0);
 191
 192         dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);
 193
 194         return 0;
 195 }
 196
 197 static int keystone_irq_remove(struct platform_device *pdev)
 198 {
 199         struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
 200         int hwirq;
 201
 202         for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
 203                 irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));
 204
 205         irq_domain_remove(kirq->irqd);
 206         return 0;
 207 }
 208
 209 static const struct of_device_id keystone_irq_dt_ids[] = {
 210         { .compatible = "ti,keystone-irq", },
 211         {},
 212 };
 213 MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);
 214
 215 static struct platform_driver keystone_irq_device_driver = {
 216         .probe          = keystone_irq_probe,
 217         .remove         = keystone_irq_remove,
 218         .driver         = {
 219                 .name   = "keystone_irq",
 220                 .of_match_table = of_match_ptr(keystone_irq_dt_ids),
 221         }
 222 };
 223
 224 module_platform_driver(keystone_irq_device_driver);
 225
 226 MODULE_AUTHOR("Texas Instruments");
 227 MODULE_AUTHOR("Sajesh Kumar Saran");
 228 MODULE_AUTHOR("Grygorii Strashko");
 229 MODULE_DESCRIPTION("Keystone IRQ chip");
 230 MODULE_LICENSE("GPL v2");