release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/bcm63xx/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7  * Copyright (C) 2008 Nicolas Schichan <nschichan@freebox.fr>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/module.h>
  14 #include <asm/irq_cpu.h>
  15 #include <asm/mipsregs.h>
  16 #include <bcm63xx_cpu.h>
  17 #include <bcm63xx_regs.h>
  18 #include <bcm63xx_io.h>
  19 #include <bcm63xx_irq.h>
  20
  21 /*
  22  * dispatch internal devices IRQ (uart, enet, watchdog, ...). do not
  23  * prioritize any interrupt relatively to another. the static counter
  24  * will resume the loop where it ended the last time we left this
  25  * function.
  26  */
  27 static void bcm63xx_irq_dispatch_internal(void)
  28 {
  29         u32 pending;
  30         static int i;
  31
  32         pending = bcm_perf_readl(PERF_IRQMASK_REG) &
  33                 bcm_perf_readl(PERF_IRQSTAT_REG);
  34
  35         if (!pending)
  36                 return ;
  37
  38         while (1) {
  39                 int to_call = i;
  40
  41                 i = (i + 1) & 0x1f;
  42                 if (pending & (1 << to_call)) {
  43                         do_IRQ(to_call + IRQ_INTERNAL_BASE);
  44                         break;
  45                 }
  46         }
  47 }
  48
  49 asmlinkage void plat_irq_dispatch(void)
  50 {
  51         u32 cause;
  52
  53         do {
  54                 cause = read_c0_cause() & read_c0_status() & ST0_IM;
  55
  56                 if (!cause)
  57                         break;
  58
  59                 if (cause & CAUSEF_IP7)
  60                         do_IRQ(7);
  61                 if (cause & CAUSEF_IP2)
  62                         bcm63xx_irq_dispatch_internal();
  63                 if (cause & CAUSEF_IP3)
  64                         do_IRQ(IRQ_EXT_0);
  65                 if (cause & CAUSEF_IP4)
  66                         do_IRQ(IRQ_EXT_1);
  67                 if (cause & CAUSEF_IP5)
  68                         do_IRQ(IRQ_EXT_2);
  69                 if (cause & CAUSEF_IP6)
  70                         do_IRQ(IRQ_EXT_3);
  71         } while (1);
  72 }
  73
  74 /*
  75  * internal IRQs operations: only mask/unmask on PERF irq mask
  76  * register.
  77  */
  78 static inline void bcm63xx_internal_irq_mask(unsigned int irq)
  79 {
  80         u32 mask;
  81
  82         irq -= IRQ_INTERNAL_BASE;
  83         mask = bcm_perf_readl(PERF_IRQMASK_REG);
  84         mask &= ~(1 << irq);
  85         bcm_perf_writel(mask, PERF_IRQMASK_REG);
  86 }
  87
  88 static void bcm63xx_internal_irq_unmask(unsigned int irq)
  89 {
  90         u32 mask;
  91
  92         irq -= IRQ_INTERNAL_BASE;
  93         mask = bcm_perf_readl(PERF_IRQMASK_REG);
  94         mask |= (1 << irq);
  95         bcm_perf_writel(mask, PERF_IRQMASK_REG);
  96 }
  97
  98 static unsigned int bcm63xx_internal_irq_startup(unsigned int irq)
  99 {
 100         bcm63xx_internal_irq_unmask(irq);
 101         return 0;
 102 }
 103
 104 /*
 105  * external IRQs operations: mask/unmask and clear on PERF external
 106  * irq control register.
 107  */
 108 static void bcm63xx_external_irq_mask(unsigned int irq)
 109 {
 110         u32 reg;
 111
 112         irq -= IRQ_EXT_BASE;
 113         reg = bcm_perf_readl(PERF_EXTIRQ_CFG_REG);
 114         reg &= ~EXTIRQ_CFG_MASK(irq);
 115         bcm_perf_writel(reg, PERF_EXTIRQ_CFG_REG);
 116 }
 117
 118 static void bcm63xx_external_irq_unmask(unsigned int irq)
 119 {
 120         u32 reg;
 121
 122         irq -= IRQ_EXT_BASE;
 123         reg = bcm_perf_readl(PERF_EXTIRQ_CFG_REG);
 124         reg |= EXTIRQ_CFG_MASK(irq);
 125         bcm_perf_writel(reg, PERF_EXTIRQ_CFG_REG);
 126 }
 127
 128 static void bcm63xx_external_irq_clear(unsigned int irq)
 129 {
 130         u32 reg;
 131
 132         irq -= IRQ_EXT_BASE;
 133         reg = bcm_perf_readl(PERF_EXTIRQ_CFG_REG);
 134         reg |= EXTIRQ_CFG_CLEAR(irq);
 135         bcm_perf_writel(reg, PERF_EXTIRQ_CFG_REG);
 136 }
 137
 138 static unsigned int bcm63xx_external_irq_startup(unsigned int irq)
 139 {
 140         set_c0_status(0x100 << (irq - IRQ_MIPS_BASE));
 141         irq_enable_hazard();
 142         bcm63xx_external_irq_unmask(irq);
 143         return 0;
 144 }
 145
 146 static void bcm63xx_external_irq_shutdown(unsigned int irq)
 147 {
 148         bcm63xx_external_irq_mask(irq);
 149         clear_c0_status(0x100 << (irq - IRQ_MIPS_BASE));
 150         irq_disable_hazard();
 151 }
 152
 153 static int bcm63xx_external_irq_set_type(unsigned int irq,
 154                                          unsigned int flow_type)
 155 {
 156         u32 reg;
 157         struct irq_desc *desc = irq_desc + irq;
 158
 159         irq -= IRQ_EXT_BASE;
 160
 161         flow_type &= IRQ_TYPE_SENSE_MASK;
 162
 163         if (flow_type == IRQ_TYPE_NONE)
 164                 flow_type = IRQ_TYPE_LEVEL_LOW;
 165
 166         reg = bcm_perf_readl(PERF_EXTIRQ_CFG_REG);
 167         switch (flow_type) {
 168         case IRQ_TYPE_EDGE_BOTH:
 169                 reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
 170                 reg |= EXTIRQ_CFG_BOTHEDGE(irq);
 171                 break;
 172
 173         case IRQ_TYPE_EDGE_RISING:
 174                 reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
 175                 reg |= EXTIRQ_CFG_SENSE(irq);
 176                 reg &= ~EXTIRQ_CFG_BOTHEDGE(irq);
 177                 break;
 178
 179         case IRQ_TYPE_EDGE_FALLING:
 180                 reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
 181                 reg &= ~EXTIRQ_CFG_SENSE(irq);
 182                 reg &= ~EXTIRQ_CFG_BOTHEDGE(irq);
 183                 break;
 184
 185         case IRQ_TYPE_LEVEL_HIGH:
 186                 reg |= EXTIRQ_CFG_LEVELSENSE(irq);
 187                 reg |= EXTIRQ_CFG_SENSE(irq);
 188                 break;
 189
 190         case IRQ_TYPE_LEVEL_LOW:
 191                 reg |= EXTIRQ_CFG_LEVELSENSE(irq);
 192                 reg &= ~EXTIRQ_CFG_SENSE(irq);
 193                 break;
 194
 195         default:
 196                 printk(KERN_ERR "bogus flow type combination given !\n");
 197                 return -EINVAL;
 198         }
 199         bcm_perf_writel(reg, PERF_EXTIRQ_CFG_REG);
 200
 201         if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))  {
 202                 desc->status |= IRQ_LEVEL;
 203                 desc->handle_irq = handle_level_irq;
 204         } else {
 205                 desc->handle_irq = handle_edge_irq;
 206         }
 207
 208         return 0;
 209 }
 210
 211 static struct irq_chip bcm63xx_internal_irq_chip = {
 212         .name           = "bcm63xx_ipic",
 213         .startup        = bcm63xx_internal_irq_startup,
 214         .shutdown       = bcm63xx_internal_irq_mask,
 215
 216         .mask           = bcm63xx_internal_irq_mask,
 217         .mask_ack       = bcm63xx_internal_irq_mask,
 218         .unmask         = bcm63xx_internal_irq_unmask,
 219 };
 220
 221 static struct irq_chip bcm63xx_external_irq_chip = {
 222         .name           = "bcm63xx_epic",
 223         .startup        = bcm63xx_external_irq_startup,
 224         .shutdown       = bcm63xx_external_irq_shutdown,
 225
 226         .ack            = bcm63xx_external_irq_clear,
 227
 228         .mask           = bcm63xx_external_irq_mask,
 229         .unmask         = bcm63xx_external_irq_unmask,
 230
 231         .set_type       = bcm63xx_external_irq_set_type,
 232 };
 233
 234 static struct irqaction cpu_ip2_cascade_action = {
 235         .handler        = no_action,
 236         .name           = "cascade_ip2",
 237 };
 238
 239 void __init arch_init_irq(void)
 240 {
 241         int i;
 242
 243         mips_cpu_irq_init();
 244         for (i = IRQ_INTERNAL_BASE; i < NR_IRQS; ++i)
 245                 set_irq_chip_and_handler(i, &bcm63xx_internal_irq_chip,
 246                                          handle_level_irq);
 247
 248         for (i = IRQ_EXT_BASE; i < IRQ_EXT_BASE + 4; ++i)
 249                 set_irq_chip_and_handler(i, &bcm63xx_external_irq_chip,
 250                                          handle_edge_irq);
 251
 252         setup_irq(IRQ_MIPS_BASE + 2, &cpu_ip2_cascade_action);
 253 }