arch/sh/kernel/cpu/irq/ipr.c

   1 /*
   2  * Interrupt handling for IPR-based IRQ.
   3  *
   4  * Copyright (C) 1999  Niibe Yutaka & Takeshi Yaegashi
   5  * Copyright (C) 2000  Kazumoto Kojima
   6  * Copyright (C) 2003  Takashi Kusuda <kusuda-takashi@hitachi-ul.co.jp>
   7  * Copyright (C) 2006  Paul Mundt
   8  *
   9  * Supported system:
  10  *      On-chip supporting modules (TMU, RTC, etc.).
  11  *      On-chip supporting modules for SH7709/SH7709A/SH7729.
  12  *      Hitachi SolutionEngine external I/O:
  13  *              MS7709SE01, MS7709ASE01, and MS7750SE01
  14  *
  15  * This file is subject to the terms and conditions of the GNU General Public
  16  * License.  See the file "COPYING" in the main directory of this archive
  17  * for more details.
  18  */
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io.h>
  22 #include <linux/irq.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/topology.h>
  26
  27 static inline struct ipr_desc *get_ipr_desc(struct irq_data *data)
  28 {
  29         struct irq_chip *chip = irq_data_get_irq_chip(data);
  30         return container_of(chip, struct ipr_desc, chip);
  31 }
  32
  33 static void disable_ipr_irq(struct irq_data *data)
  34 {
  35         struct ipr_data *p = irq_data_get_irq_chip_data(data);
  36         unsigned long addr = get_ipr_desc(data)->ipr_offsets[p->ipr_idx];
  37         /* Set the priority in IPR to 0 */
  38         __raw_writew(__raw_readw(addr) & (0xffff ^ (0xf << p->shift)), addr);
  39         (void)__raw_readw(addr);        /* Read back to flush write posting */
  40 }
  41
  42 static void enable_ipr_irq(struct irq_data *data)
  43 {
  44         struct ipr_data *p = irq_data_get_irq_chip_data(data);
  45         unsigned long addr = get_ipr_desc(data)->ipr_offsets[p->ipr_idx];
  46         /* Set priority in IPR back to original value */
  47         __raw_writew(__raw_readw(addr) | (p->priority << p->shift), addr);
  48 }
  49
  50 /*
  51  * The shift value is now the number of bits to shift, not the number of
  52  * bits/4. This is to make it easier to read the value directly from the
  53  * datasheets. The IPR address is calculated using the ipr_offset table.
  54  */
  55 void register_ipr_controller(struct ipr_desc *desc)
  56 {
  57         int i;
  58
  59         desc->chip.irq_mask = disable_ipr_irq;
  60         desc->chip.irq_unmask = enable_ipr_irq;
  61
  62         for (i = 0; i < desc->nr_irqs; i++) {
  63                 struct ipr_data *p = desc->ipr_data + i;
  64                 int res;
  65
  66                 BUG_ON(p->ipr_idx >= desc->nr_offsets);
  67                 BUG_ON(!desc->ipr_offsets[p->ipr_idx]);
  68
  69                 res = irq_alloc_desc_at(p->irq, numa_node_id());
  70                 if (unlikely(res != p->irq && res != -EEXIST)) {
  71                         printk(KERN_INFO "can not get irq_desc for %d\n",
  72                                p->irq);
  73                         continue;
  74                 }
  75
  76                 disable_irq_nosync(p->irq);
  77                 irq_set_chip_and_handler_name(p->irq, &desc->chip,
  78                                               handle_level_irq, "level");
  79                 irq_set_chip_data(p->irq, p);
  80                 disable_ipr_irq(irq_get_irq_data(p->irq));
  81         }
  82 }
  83 EXPORT_SYMBOL(register_ipr_controller);