target/linux/oxnas/files/drivers/irqchip/irq-rps.c

   1 #include <linux/irqdomain.h>
   2 #include <linux/irq.h>
   3 #include <linux/of.h>
   4 #include <linux/of_address.h>
   5 #include <linux/of_irq.h>
   6 #include <linux/irqchip/chained_irq.h>
   7 #include <linux/err.h>
   8 #include <linux/io.h>
   9 #include <linux/irqchip.h>
  10
  11 struct rps_chip_data {
  12         void __iomem *base;
  13         struct irq_chip chip;
  14         struct irq_domain *domain;
  15 } rps_data;
  16
  17 enum {
  18         RPS_IRQ_BASE = 64,
  19         RPS_IRQ_COUNT = 32,
  20         PRS_HWIRQ_BASE = 0,
  21
  22         RPS_STATUS = 0,
  23         RPS_RAW_STATUS = 4,
  24         RPS_UNMASK = 8,
  25         RPS_MASK = 0xc,
  26 };
  27
  28 /*
  29  * Routines to acknowledge, disable and enable interrupts
  30  */
  31 static void rps_mask_irq(struct irq_data *d)
  32 {
  33         struct rps_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  34         u32 mask = BIT(d->hwirq);
  35
  36         iowrite32(mask, chip_data->base + RPS_MASK);
  37 }
  38
  39 static void rps_unmask_irq(struct irq_data *d)
  40 {
  41         struct rps_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  42         u32 mask = BIT(d->hwirq);
  43
  44         iowrite32(mask, chip_data->base + RPS_UNMASK);
  45 }
  46
  47 static struct irq_chip rps_chip = {
  48         .name                   = "RPS",
  49         .irq_mask               = rps_mask_irq,
  50         .irq_unmask             = rps_unmask_irq,
  51 };
  52
  53 static int rps_irq_domain_xlate(struct irq_domain *d,
  54                                 struct device_node *controller,
  55                                 const u32 *intspec, unsigned int intsize,
  56                                 unsigned long *out_hwirq,
  57                                 unsigned int *out_type)
  58 {
  59         if (irq_domain_get_of_node(d) != controller)
  60                 return -EINVAL;
  61         if (intsize < 1)
  62                 return -EINVAL;
  63
  64         *out_hwirq = intspec[0];
  65         /* Honestly I do not know the type */
  66         *out_type = IRQ_TYPE_LEVEL_HIGH;
  67
  68         return 0;
  69 }
  70
  71 static int rps_irq_domain_map(struct irq_domain *d, unsigned int irq,
  72                                 irq_hw_number_t hw)
  73 {
  74         irq_set_chip_and_handler(irq, &rps_chip, handle_level_irq);
  75         irq_set_probe(irq);
  76         irq_set_chip_data(irq, d->host_data);
  77         return 0;
  78 }
  79
  80 const struct irq_domain_ops rps_irq_domain_ops = {
  81         .map = rps_irq_domain_map,
  82         .xlate = rps_irq_domain_xlate,
  83 };
  84
  85 static void rps_handle_cascade_irq(struct irq_desc *desc)
  86 {
  87         struct rps_chip_data *chip_data = irq_desc_get_handler_data(desc);
  88         struct irq_chip *chip = irq_desc_get_chip(desc);
  89         unsigned int cascade_irq, rps_irq;
  90         u32 status;
  91
  92         chained_irq_enter(chip, desc);
  93
  94         status = ioread32(chip_data->base + RPS_STATUS);
  95         rps_irq = __ffs(status);
  96         cascade_irq = irq_find_mapping(chip_data->domain, rps_irq);
  97
  98         if (unlikely(rps_irq >= RPS_IRQ_COUNT))
  99                 handle_bad_irq(desc);
 100         else
 101                 generic_handle_irq(cascade_irq);
 102
 103         chained_irq_exit(chip, desc);
 104 }
 105
 106 #ifdef CONFIG_OF
 107 int __init rps_of_init(struct device_node *node, struct device_node *parent)
 108 {
 109         void __iomem *rps_base;
 110         int irq_start = RPS_IRQ_BASE;
 111         int irq_base;
 112         int irq;
 113
 114         if (WARN_ON(!node))
 115                 return -ENODEV;
 116
 117         rps_base = of_iomap(node, 0);
 118         WARN(!rps_base, "unable to map rps registers\n");
 119         rps_data.base = rps_base;
 120
 121         irq_base = irq_alloc_descs(irq_start, 0, RPS_IRQ_COUNT, numa_node_id());
 122         if (IS_ERR_VALUE(irq_base)) {
 123                 WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
 124                      irq_start);
 125                 irq_base = irq_start;
 126         }
 127
 128         rps_data.domain = irq_domain_add_legacy(node, RPS_IRQ_COUNT, irq_base,
 129                         PRS_HWIRQ_BASE, &rps_irq_domain_ops, &rps_data);
 130
 131         if (WARN_ON(!rps_data.domain))
 132                 return -ENOMEM;
 133
 134         if (parent) {
 135                 irq = irq_of_parse_and_map(node, 0);
 136                 if (irq_set_handler_data(irq, &rps_data) != 0)
 137                         BUG();
 138                 irq_set_chained_handler(irq, rps_handle_cascade_irq);
 139         }
 140         return 0;
 141
 142 }
 143
 144 IRQCHIP_DECLARE(nas782x, "plxtech,nas782x-rps", rps_of_init);
 145 #endif