arch/mips/kernel/irq_txx9.c

   1 /*
   2  * Based on linux/arch/mips/jmr3927/rbhma3100/irq.c,
   3  *          linux/arch/mips/tx4927/common/tx4927_irq.c,
   4  *          linux/arch/mips/tx4938/common/irq.c
   5  *
   6  * Copyright 2001, 2003-2005 MontaVista Software Inc.
   7  * Author: MontaVista Software, Inc.
   8  *         ahennessy@mvista.com
   9  *         source@mvista.com
  10  * Copyright (C) 2000-2001 Toshiba Corporation
  11  *
  12  * This file is subject to the terms and conditions of the GNU General Public
  13  * License.  See the file "COPYING" in the main directory of this archive
  14  * for more details.
  15  */
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/types.h>
  19 #include <linux/irq.h>
  20 #include <asm/txx9irq.h>
  21
  22 struct txx9_irc_reg {
  23         u32 cer;
  24         u32 cr[2];
  25         u32 unused0;
  26         u32 ilr[8];
  27         u32 unused1[4];
  28         u32 imr;
  29         u32 unused2[7];
  30         u32 scr;
  31         u32 unused3[7];
  32         u32 ssr;
  33         u32 unused4[7];
  34         u32 csr;
  35 };
  36
  37 /* IRCER : Int. Control Enable */
  38 #define TXx9_IRCER_ICE  0x00000001
  39
  40 /* IRCR : Int. Control */
  41 #define TXx9_IRCR_LOW   0x00000000
  42 #define TXx9_IRCR_HIGH  0x00000001
  43 #define TXx9_IRCR_DOWN  0x00000002
  44 #define TXx9_IRCR_UP    0x00000003
  45 #define TXx9_IRCR_EDGE(cr)      ((cr) & 0x00000002)
  46
  47 /* IRSCR : Int. Status Control */
  48 #define TXx9_IRSCR_EIClrE       0x00000100
  49 #define TXx9_IRSCR_EIClr_MASK   0x0000000f
  50
  51 /* IRCSR : Int. Current Status */
  52 #define TXx9_IRCSR_IF   0x00010000
  53 #define TXx9_IRCSR_ILV_MASK     0x00000700
  54 #define TXx9_IRCSR_IVL_MASK     0x0000001f
  55
  56 #define irc_dlevel      0
  57 #define irc_elevel      1
  58
  59 static struct txx9_irc_reg __iomem *txx9_ircptr __read_mostly;
  60
  61 static struct {
  62         unsigned char level;
  63         unsigned char mode;
  64 } txx9irq[TXx9_MAX_IR] __read_mostly;
  65
  66 static void txx9_irq_unmask(struct irq_data *d)
  67 {
  68         unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
  69         u32 __iomem *ilrp = &txx9_ircptr->ilr[(irq_nr % 16 ) / 2];
  70         int ofs = irq_nr / 16 * 16 + (irq_nr & 1) * 8;
  71
  72         __raw_writel((__raw_readl(ilrp) & ~(0xff << ofs))
  73                      | (txx9irq[irq_nr].level << ofs),
  74                      ilrp);
  75 }
  76
  77 static inline void txx9_irq_mask(struct irq_data *d)
  78 {
  79         unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
  80         u32 __iomem *ilrp = &txx9_ircptr->ilr[(irq_nr % 16) / 2];
  81         int ofs = irq_nr / 16 * 16 + (irq_nr & 1) * 8;
  82
  83         __raw_writel((__raw_readl(ilrp) & ~(0xff << ofs))
  84                      | (irc_dlevel << ofs),
  85                      ilrp);
  86         mmiowb();
  87 }
  88
  89 static void txx9_irq_mask_ack(struct irq_data *d)
  90 {
  91         unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
  92
  93         txx9_irq_mask(d);
  94         /* clear edge detection */
  95         if (unlikely(TXx9_IRCR_EDGE(txx9irq[irq_nr].mode)))
  96                 __raw_writel(TXx9_IRSCR_EIClrE | irq_nr, &txx9_ircptr->scr);
  97 }
  98
  99 static int txx9_irq_set_type(struct irq_data *d, unsigned int flow_type)
 100 {
 101         unsigned int irq_nr = d->irq - TXX9_IRQ_BASE;
 102         u32 cr;
 103         u32 __iomem *crp;
 104         int ofs;
 105         int mode;
 106
 107         if (flow_type & IRQF_TRIGGER_PROBE)
 108                 return 0;
 109         switch (flow_type & IRQF_TRIGGER_MASK) {
 110         case IRQF_TRIGGER_RISING:       mode = TXx9_IRCR_UP;    break;
 111         case IRQF_TRIGGER_FALLING:      mode = TXx9_IRCR_DOWN;  break;
 112         case IRQF_TRIGGER_HIGH: mode = TXx9_IRCR_HIGH;  break;
 113         case IRQF_TRIGGER_LOW:  mode = TXx9_IRCR_LOW;   break;
 114         default:
 115                 return -EINVAL;
 116         }
 117         crp = &txx9_ircptr->cr[(unsigned int)irq_nr / 8];
 118         cr = __raw_readl(crp);
 119         ofs = (irq_nr & (8 - 1)) * 2;
 120         cr &= ~(0x3 << ofs);
 121         cr |= (mode & 0x3) << ofs;
 122         __raw_writel(cr, crp);
 123         txx9irq[irq_nr].mode = mode;
 124         return 0;
 125 }
 126
 127 static struct irq_chip txx9_irq_chip = {
 128         .name           = "TXX9",
 129         .irq_ack        = txx9_irq_mask_ack,
 130         .irq_mask       = txx9_irq_mask,
 131         .irq_mask_ack   = txx9_irq_mask_ack,
 132         .irq_unmask     = txx9_irq_unmask,
 133         .irq_set_type   = txx9_irq_set_type,
 134 };
 135
 136 void __init txx9_irq_init(unsigned long baseaddr)
 137 {
 138         int i;
 139
 140         txx9_ircptr = ioremap(baseaddr, sizeof(struct txx9_irc_reg));
 141         for (i = 0; i < TXx9_MAX_IR; i++) {
 142                 txx9irq[i].level = 4; /* middle level */
 143                 txx9irq[i].mode = TXx9_IRCR_LOW;
 144                 irq_set_chip_and_handler(TXX9_IRQ_BASE + i, &txx9_irq_chip,
 145                                          handle_level_irq);
 146         }
 147
 148         /* mask all IRC interrupts */
 149         __raw_writel(0, &txx9_ircptr->imr);
 150         for (i = 0; i < 8; i++)
 151                 __raw_writel(0, &txx9_ircptr->ilr[i]);
 152         /* setup IRC interrupt mode (Low Active) */
 153         for (i = 0; i < 2; i++)
 154                 __raw_writel(0, &txx9_ircptr->cr[i]);
 155         /* enable interrupt control */
 156         __raw_writel(TXx9_IRCER_ICE, &txx9_ircptr->cer);
 157         __raw_writel(irc_elevel, &txx9_ircptr->imr);
 158 }
 159
 160 int __init txx9_irq_set_pri(int irc_irq, int new_pri)
 161 {
 162         int old_pri;
 163
 164         if ((unsigned int)irc_irq >= TXx9_MAX_IR)
 165                 return 0;
 166         old_pri = txx9irq[irc_irq].level;
 167         txx9irq[irc_irq].level = new_pri;
 168         return old_pri;
 169 }
 170
 171 int txx9_irq(void)
 172 {
 173         u32 csr = __raw_readl(&txx9_ircptr->csr);
 174
 175         if (likely(!(csr & TXx9_IRCSR_IF)))
 176                 return TXX9_IRQ_BASE + (csr & (TXx9_MAX_IR - 1));
 177         return -1;
 178 }