text: /* irq-mb93493.c: MB93493 companion chip interrupt handler
   *
   * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  #include <linux/ptrace.h>
  #include <linux/errno.h>
  #include <linux/signal.h>
  #include <linux/sched.h>
  #include <linux/ioport.h>
  #include <linux/interrupt.h>
  #include <linux/init.h>
  #include <linux/irq.h>
  #include <linux/bitops.h>
  
  #include <asm/io.h>
  #include <asm/system.h>
  #include <asm/delay.h>
  #include <asm/irq.h>
  #include <asm/irc-regs.h>
  #include <asm/mb93493-irqs.h>
  #include <asm/mb93493-regs.h>
  
  #define IRQ_ROUTE_ONE(X) (X##_ROUTE << (X - IRQ_BASE_MB93493))
  
  #define IRQ_ROUTING					\
  	(IRQ_ROUTE_ONE(IRQ_MB93493_VDC)		|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_VCC)		|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_OUT)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_0)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_1)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_USB)		|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_LOCAL_BUS)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_PCMCIA)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_GPIO)	|	\
  	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_IN))
  
  /*
   * daughter board PIC operations
   * - there is no way to ACK interrupts in the MB93493 chip
   */
  static void frv_mb93493_mask(struct irq_data *d)
  {
  	uint32_t iqsr;
  	volatile void *piqsr;
  
  	if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
  		piqsr = __addr_MB93493_IQSR(1);
  	else
  		piqsr = __addr_MB93493_IQSR(0);
  
  	iqsr = readl(piqsr);
  	iqsr &= ~(1 << (d->irq - IRQ_BASE_MB93493 + 16));
  	writel(iqsr, piqsr);
  }
  
  static void frv_mb93493_ack(struct irq_data *d)
  {
  }
  
  static void frv_mb93493_unmask(struct irq_data *d)
  {
  	uint32_t iqsr;
  	volatile void *piqsr;
  
  	if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
  		piqsr = __addr_MB93493_IQSR(1);
  	else
  		piqsr = __addr_MB93493_IQSR(0);
  
  	iqsr = readl(piqsr);
  	iqsr |= 1 << (d->irq - IRQ_BASE_MB93493 + 16);
  	writel(iqsr, piqsr);
  }
  
  static struct irq_chip frv_mb93493_pic = {
  	.name		= "mb93093",
  	.irq_ack	= frv_mb93493_ack,
  	.irq_mask	= frv_mb93493_mask,
  	.irq_mask_ack	= frv_mb93493_mask,
  	.irq_unmask	= frv_mb93493_unmask,
  };
  
  /*
   * MB93493 PIC interrupt handler
   */
  static irqreturn_t mb93493_interrupt(int irq, void *_piqsr)
  {
  	volatile void *piqsr = _piqsr;
  	uint32_t iqsr;
  
  	iqsr = readl(piqsr);
  	iqsr = iqsr & (iqsr >> 16) & 0xffff;
  
  	/* poll all the triggered IRQs */
  	while (iqsr) {
  		int irq;
  
  		asm("scan %1,gr0,%0" : "=r"(irq) : "r"(iqsr));
  		irq = 31 - irq;
  		iqsr &= ~(1 << irq);
  
  		generic_handle_irq(IRQ_BASE_MB93493 + irq);
  	}
  
  	return IRQ_HANDLED;
  }
  
  /*
   * define an interrupt action for each MB93493 PIC output
   * - use dev_id to indicate the MB93493 PIC input to output mappings
   */
  static struct irqaction mb93493_irq[2]  = {
  	[0] = {
  		.handler	= mb93493_interrupt,
  		.flags		= IRQF_DISABLED | IRQF_SHARED,
  		.name		= "mb93493.0",
  		.dev_id		= (void *) __addr_MB93493_IQSR(0),
  	},
  	[1] = {
  		.handler	= mb93493_interrupt,
  		.flags		= IRQF_DISABLED | IRQF_SHARED,
  		.name		= "mb93493.1",
  		.dev_id		= (void *) __addr_MB93493_IQSR(1),
  	}
  };
  
  /*
   * initialise the motherboard MB93493's PIC
   */
  void __init mb93493_init(void)
  {
  	int irq;
  
  	for (irq = IRQ_BASE_MB93493 + 0; irq <= IRQ_BASE_MB93493 + 10; irq++)
  		irq_set_chip_and_handler(irq, &frv_mb93493_pic,
  					 handle_edge_irq);
  
  	/* the MB93493 drives external IRQ inputs on the CPU PIC */
  	setup_irq(IRQ_CPU_MB93493_0, &mb93493_irq[0]);
  	setup_irq(IRQ_CPU_MB93493_1, &mb93493_irq[1]);
  }
  