arch/arm/plat-spear/shirq.c

   1 /*
   2  * arch/arm/plat-spear/shirq.c
   3  *
   4  * SPEAr platform shared irq layer source file
   5  *
   6  * Copyright (C) 2009 ST Microelectronics
   7  * Viresh Kumar <viresh.linux@gmail.com>
   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/err.h>
  15 #include <linux/io.h>
  16 #include <linux/irq.h>
  17 #include <linux/spinlock.h>
  18 #include <plat/shirq.h>
  19
  20 struct spear_shirq *shirq;
  21 static DEFINE_SPINLOCK(lock);
  22
  23 static void shirq_irq_mask(struct irq_data *d)
  24 {
  25         struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
  26         u32 val, id = d->irq - shirq->dev_config[0].virq;
  27         unsigned long flags;
  28
  29         if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
  30                 return;
  31
  32         spin_lock_irqsave(&lock, flags);
  33         val = readl(shirq->regs.base + shirq->regs.enb_reg);
  34         if (shirq->regs.reset_to_enb)
  35                 val |= shirq->dev_config[id].enb_mask;
  36         else
  37                 val &= ~(shirq->dev_config[id].enb_mask);
  38         writel(val, shirq->regs.base + shirq->regs.enb_reg);
  39         spin_unlock_irqrestore(&lock, flags);
  40 }
  41
  42 static void shirq_irq_unmask(struct irq_data *d)
  43 {
  44         struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
  45         u32 val, id = d->irq - shirq->dev_config[0].virq;
  46         unsigned long flags;
  47
  48         if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
  49                 return;
  50
  51         spin_lock_irqsave(&lock, flags);
  52         val = readl(shirq->regs.base + shirq->regs.enb_reg);
  53         if (shirq->regs.reset_to_enb)
  54                 val &= ~(shirq->dev_config[id].enb_mask);
  55         else
  56                 val |= shirq->dev_config[id].enb_mask;
  57         writel(val, shirq->regs.base + shirq->regs.enb_reg);
  58         spin_unlock_irqrestore(&lock, flags);
  59 }
  60
  61 static struct irq_chip shirq_chip = {
  62         .name           = "spear_shirq",
  63         .irq_ack        = shirq_irq_mask,
  64         .irq_mask       = shirq_irq_mask,
  65         .irq_unmask     = shirq_irq_unmask,
  66 };
  67
  68 static void shirq_handler(unsigned irq, struct irq_desc *desc)
  69 {
  70         u32 i, val, mask;
  71         struct spear_shirq *shirq = irq_get_handler_data(irq);
  72
  73         desc->irq_data.chip->irq_ack(&desc->irq_data);
  74         while ((val = readl(shirq->regs.base + shirq->regs.status_reg) &
  75                                 shirq->regs.status_reg_mask)) {
  76                 for (i = 0; (i < shirq->dev_count) && val; i++) {
  77                         if (!(shirq->dev_config[i].status_mask & val))
  78                                 continue;
  79
  80                         generic_handle_irq(shirq->dev_config[i].virq);
  81
  82                         /* clear interrupt */
  83                         val &= ~shirq->dev_config[i].status_mask;
  84                         if ((shirq->regs.clear_reg == -1) ||
  85                                         shirq->dev_config[i].clear_mask == -1)
  86                                 continue;
  87                         mask = readl(shirq->regs.base + shirq->regs.clear_reg);
  88                         if (shirq->regs.reset_to_clear)
  89                                 mask &= ~shirq->dev_config[i].clear_mask;
  90                         else
  91                                 mask |= shirq->dev_config[i].clear_mask;
  92                         writel(mask, shirq->regs.base + shirq->regs.clear_reg);
  93                 }
  94         }
  95         desc->irq_data.chip->irq_unmask(&desc->irq_data);
  96 }
  97
  98 int spear_shirq_register(struct spear_shirq *shirq)
  99 {
 100         int i;
 101
 102         if (!shirq || !shirq->dev_config || !shirq->regs.base)
 103                 return -EFAULT;
 104
 105         if (!shirq->dev_count)
 106                 return -EINVAL;
 107
 108         irq_set_chained_handler(shirq->irq, shirq_handler);
 109         for (i = 0; i < shirq->dev_count; i++) {
 110                 irq_set_chip_and_handler(shirq->dev_config[i].virq,
 111                                          &shirq_chip, handle_simple_irq);
 112                 set_irq_flags(shirq->dev_config[i].virq, IRQF_VALID);
 113                 irq_set_chip_data(shirq->dev_config[i].virq, shirq);
 114         }
 115
 116         irq_set_handler_data(shirq->irq, shirq);
 117         return 0;
 118 }