arch/arm/plat-versatile/fpga-irq.c

   1 /*
   2  *  Support for Versatile FPGA-based IRQ controllers
   3  */
   4 #include <linux/irq.h>
   5 #include <linux/io.h>
   6
   7 #include <asm/mach/irq.h>
   8 #include <plat/fpga-irq.h>
   9
  10 #define IRQ_STATUS              0x00
  11 #define IRQ_RAW_STATUS          0x04
  12 #define IRQ_ENABLE_SET          0x08
  13 #define IRQ_ENABLE_CLEAR        0x0c
  14
  15 static void fpga_irq_mask(struct irq_data *d)
  16 {
  17         struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
  18         u32 mask = 1 << (d->irq - f->irq_start);
  19
  20         writel(mask, f->base + IRQ_ENABLE_CLEAR);
  21 }
  22
  23 static void fpga_irq_unmask(struct irq_data *d)
  24 {
  25         struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
  26         u32 mask = 1 << (d->irq - f->irq_start);
  27
  28         writel(mask, f->base + IRQ_ENABLE_SET);
  29 }
  30
  31 static void fpga_irq_handle(unsigned int irq, struct irq_desc *desc)
  32 {
  33         struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
  34         u32 status = readl(f->base + IRQ_STATUS);
  35
  36         if (status == 0) {
  37                 do_bad_IRQ(irq, desc);
  38                 return;
  39         }
  40
  41         do {
  42                 irq = ffs(status) - 1;
  43                 status &= ~(1 << irq);
  44
  45                 generic_handle_irq(irq + f->irq_start);
  46         } while (status);
  47 }
  48
  49 void __init fpga_irq_init(int parent_irq, u32 valid, struct fpga_irq_data *f)
  50 {
  51         unsigned int i;
  52
  53         f->chip.irq_ack = fpga_irq_mask;
  54         f->chip.irq_mask = fpga_irq_mask;
  55         f->chip.irq_unmask = fpga_irq_unmask;
  56
  57         if (parent_irq != -1) {
  58                 irq_set_handler_data(parent_irq, f);
  59                 irq_set_chained_handler(parent_irq, fpga_irq_handle);
  60         }
  61
  62         for (i = 0; i < 32; i++) {
  63                 if (valid & (1 << i)) {
  64                         unsigned int irq = f->irq_start + i;
  65
  66                         irq_set_chip_data(irq, f);
  67                         irq_set_chip_and_handler(irq, &f->chip,
  68                                                  handle_level_irq);
  69                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
  70                 }
  71         }
  72 }