drivers/irqchip/irq-dw-apb-ictl.c

   1 /*
   2  * Synopsys DW APB ICTL irqchip driver.
   3  *
   4  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
   5  *
   6  * based on GPL'ed 2.6 kernel sources
   7  *  (c) Marvell International Ltd.
   8  *
   9  * This file is licensed under the terms of the GNU General Public
  10  * License version 2.  This program is licensed "as is" without any
  11  * warranty of any kind, whether express or implied.
  12  */
  13
  14 #include <linux/io.h>
  15 #include <linux/irq.h>
  16 #include <linux/irqchip.h>
  17 #include <linux/irqchip/chained_irq.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_irq.h>
  20
  21 #define APB_INT_ENABLE_L        0x00
  22 #define APB_INT_ENABLE_H        0x04
  23 #define APB_INT_MASK_L          0x08
  24 #define APB_INT_MASK_H          0x0c
  25 #define APB_INT_FINALSTATUS_L   0x30
  26 #define APB_INT_FINALSTATUS_H   0x34
  27 #define APB_INT_BASE_OFFSET     0x04
  28
  29 static void dw_apb_ictl_handler(struct irq_desc *desc)
  30 {
  31         struct irq_domain *d = irq_desc_get_handler_data(desc);
  32         struct irq_chip *chip = irq_desc_get_chip(desc);
  33         int n;
  34
  35         chained_irq_enter(chip, desc);
  36
  37         for (n = 0; n < d->revmap_size; n += 32) {
  38                 struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n);
  39                 u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
  40
  41                 while (stat) {
  42                         u32 hwirq = ffs(stat) - 1;
  43                         u32 virq = irq_find_mapping(d, gc->irq_base + hwirq);
  44
  45                         generic_handle_irq(virq);
  46                         stat &= ~(1 << hwirq);
  47                 }
  48         }
  49
  50         chained_irq_exit(chip, desc);
  51 }
  52
  53 #ifdef CONFIG_PM
  54 static void dw_apb_ictl_resume(struct irq_data *d)
  55 {
  56         struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  57         struct irq_chip_type *ct = irq_data_get_chip_type(d);
  58
  59         irq_gc_lock(gc);
  60         writel_relaxed(~0, gc->reg_base + ct->regs.enable);
  61         writel_relaxed(*ct->mask_cache, gc->reg_base + ct->regs.mask);
  62         irq_gc_unlock(gc);
  63 }
  64 #else
  65 #define dw_apb_ictl_resume      NULL
  66 #endif /* CONFIG_PM */
  67
  68 static int __init dw_apb_ictl_init(struct device_node *np,
  69                                    struct device_node *parent)
  70 {
  71         unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
  72         struct resource r;
  73         struct irq_domain *domain;
  74         struct irq_chip_generic *gc;
  75         void __iomem *iobase;
  76         int ret, nrirqs, irq, i;
  77         u32 reg;
  78
  79         /* Map the parent interrupt for the chained handler */
  80         irq = irq_of_parse_and_map(np, 0);
  81         if (irq <= 0) {
  82                 pr_err("%s: unable to parse irq\n", np->full_name);
  83                 return -EINVAL;
  84         }
  85
  86         ret = of_address_to_resource(np, 0, &r);
  87         if (ret) {
  88                 pr_err("%s: unable to get resource\n", np->full_name);
  89                 return ret;
  90         }
  91
  92         if (!request_mem_region(r.start, resource_size(&r), np->full_name)) {
  93                 pr_err("%s: unable to request mem region\n", np->full_name);
  94                 return -ENOMEM;
  95         }
  96
  97         iobase = ioremap(r.start, resource_size(&r));
  98         if (!iobase) {
  99                 pr_err("%s: unable to map resource\n", np->full_name);
 100                 ret = -ENOMEM;
 101                 goto err_release;
 102         }
 103
 104         /*
 105          * DW IP can be configured to allow 2-64 irqs. We can determine
 106          * the number of irqs supported by writing into enable register
 107          * and look for bits not set, as corresponding flip-flops will
 108          * have been removed by sythesis tool.
 109          */
 110
 111         /* mask and enable all interrupts */
 112         writel_relaxed(~0, iobase + APB_INT_MASK_L);
 113         writel_relaxed(~0, iobase + APB_INT_MASK_H);
 114         writel_relaxed(~0, iobase + APB_INT_ENABLE_L);
 115         writel_relaxed(~0, iobase + APB_INT_ENABLE_H);
 116
 117         reg = readl_relaxed(iobase + APB_INT_ENABLE_H);
 118         if (reg)
 119                 nrirqs = 32 + fls(reg);
 120         else
 121                 nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L));
 122
 123         domain = irq_domain_add_linear(np, nrirqs,
 124                                        &irq_generic_chip_ops, NULL);
 125         if (!domain) {
 126                 pr_err("%s: unable to add irq domain\n", np->full_name);
 127                 ret = -ENOMEM;
 128                 goto err_unmap;
 129         }
 130
 131         ret = irq_alloc_domain_generic_chips(domain, 32, 1, np->name,
 132                                              handle_level_irq, clr, 0,
 133                                              IRQ_GC_INIT_MASK_CACHE);
 134         if (ret) {
 135                 pr_err("%s: unable to alloc irq domain gc\n", np->full_name);
 136                 goto err_unmap;
 137         }
 138
 139         for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) {
 140                 gc = irq_get_domain_generic_chip(domain, i * 32);
 141                 gc->reg_base = iobase + i * APB_INT_BASE_OFFSET;
 142                 gc->chip_types[0].regs.mask = APB_INT_MASK_L;
 143                 gc->chip_types[0].regs.enable = APB_INT_ENABLE_L;
 144                 gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
 145                 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
 146                 gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume;
 147         }
 148
 149         irq_set_chained_handler_and_data(irq, dw_apb_ictl_handler, domain);
 150
 151         return 0;
 152
 153 err_unmap:
 154         iounmap(iobase);
 155 err_release:
 156         release_mem_region(r.start, resource_size(&r));
 157         return ret;
 158 }
 159 IRQCHIP_DECLARE(dw_apb_ictl,
 160                 "snps,dw-apb-ictl", dw_apb_ictl_init);