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/version.h>
  10
  11 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
  12 # include "irqchip.h"
  13 #else
  14 # include <linux/irqchip.h>
  15 #endif
  16
  17 struct rps_chip_data {
  18         void __iomem *base;
  19         struct irq_chip chip;
  20         struct irq_domain *domain;
  21 } rps_data;
  22
  23 enum {
  24         RPS_IRQ_BASE = 64,
  25         RPS_IRQ_COUNT = 32,
  26         PRS_HWIRQ_BASE = 0,
  27
  28         RPS_STATUS = 0,
  29         RPS_RAW_STATUS = 4,
  30         RPS_UNMASK = 8,
  31         RPS_MASK = 0xc,
  32 };
  33
  34 /*
  35  * Routines to acknowledge, disable and enable interrupts
  36  */
  37 static void rps_mask_irq(struct irq_data *d)
  38 {
  39         struct rps_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  40         u32 mask = BIT(d->hwirq);
  41
  42         iowrite32(mask, chip_data->base + RPS_MASK);
  43 }
  44
  45 static void rps_unmask_irq(struct irq_data *d)
  46 {
  47         struct rps_chip_data *chip_data = irq_data_get_irq_chip_data(d);
  48         u32 mask = BIT(d->hwirq);
  49
  50         iowrite32(mask, chip_data->base + RPS_UNMASK);
  51 }
  52
  53 static struct irq_chip rps_chip = {
  54         .name                   = "RPS",
  55         .irq_mask               = rps_mask_irq,
  56         .irq_unmask             = rps_unmask_irq,
  57 };
  58
  59 static int rps_irq_domain_xlate(struct irq_domain *d,
  60                                 struct device_node *controller,
  61                                 const u32 *intspec, unsigned int intsize,
  62                                 unsigned long *out_hwirq,
  63                                 unsigned int *out_type)
  64 {
  65         if (d->of_node != controller)
  66                 return -EINVAL;
  67         if (intsize < 1)
  68                 return -EINVAL;
  69
  70         *out_hwirq = intspec[0];
  71         /* Honestly I do not know the type */
  72         *out_type = IRQ_TYPE_LEVEL_HIGH;
  73
  74         return 0;
  75 }
  76
  77 static int rps_irq_domain_map(struct irq_domain *d, unsigned int irq,
  78                                 irq_hw_number_t hw)
  79 {
  80         irq_set_chip_and_handler(irq, &rps_chip, handle_level_irq);
  81 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
  82         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  83 #else
  84         irq_set_probe(irq);
  85 #endif
  86         irq_set_chip_data(irq, d->host_data);
  87         return 0;
  88 }
  89
  90 const struct irq_domain_ops rps_irq_domain_ops = {
  91         .map = rps_irq_domain_map,
  92         .xlate = rps_irq_domain_xlate,
  93 };
  94
  95 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
  96 static void rps_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
  97 #else
  98 static void rps_handle_cascade_irq(struct irq_desc *desc)
  99 #endif
 100 {
 101         struct rps_chip_data *chip_data = irq_desc_get_handler_data(desc);
 102         struct irq_chip *chip = irq_desc_get_chip(desc);
 103         unsigned int cascade_irq, rps_irq;
 104         u32 status;
 105
 106         chained_irq_enter(chip, desc);
 107
 108         status = ioread32(chip_data->base + RPS_STATUS);
 109         rps_irq = __ffs(status);
 110         cascade_irq = irq_find_mapping(chip_data->domain, rps_irq);
 111
 112         if (unlikely(rps_irq >= RPS_IRQ_COUNT))
 113 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
 114                 handle_bad_irq(cascade_irq, desc);
 115 #else
 116                 handle_bad_irq(desc);
 117 #endif
 118         else
 119                 generic_handle_irq(cascade_irq);
 120
 121         chained_irq_exit(chip, desc);
 122 }
 123
 124 #ifdef CONFIG_OF
 125 int __init rps_of_init(struct device_node *node, struct device_node *parent)
 126 {
 127         void __iomem *rps_base;
 128         int irq_start = RPS_IRQ_BASE;
 129         int irq_base;
 130         int irq;
 131
 132         if (WARN_ON(!node))
 133                 return -ENODEV;
 134
 135         rps_base = of_iomap(node, 0);
 136         WARN(!rps_base, "unable to map rps registers\n");
 137         rps_data.base = rps_base;
 138
 139         irq_base = irq_alloc_descs(irq_start, 0, RPS_IRQ_COUNT, numa_node_id());
 140         if (IS_ERR_VALUE(irq_base)) {
 141                 WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
 142                      irq_start);
 143                 irq_base = irq_start;
 144         }
 145
 146         rps_data.domain = irq_domain_add_legacy(node, RPS_IRQ_COUNT, irq_base,
 147                         PRS_HWIRQ_BASE, &rps_irq_domain_ops, &rps_data);
 148
 149         if (WARN_ON(!rps_data.domain))
 150                 return -ENOMEM;
 151
 152         if (parent) {
 153                 irq = irq_of_parse_and_map(node, 0);
 154                 if (irq_set_handler_data(irq, &rps_data) != 0)
 155                         BUG();
 156                 irq_set_chained_handler(irq, rps_handle_cascade_irq);
 157         }
 158         return 0;
 159
 160 }
 161
 162 IRQCHIP_DECLARE(nas782x, "plxtech,nas782x-rps", rps_of_init);
 163 #endif