/*
* Copyright (C) 2000 David J. Mckay (david.mckay@st.com)
*
* May be copied or modified under the terms of the GNU General Public
* License. See linux/COPYING for more information.
*
* Looks after interrupts on the overdrive board.
*
* Bases on the IPR irq system
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/overdrive/overdrive.h>
struct od_data {
int overdrive_irq;
int irq_mask;
};
#define NUM_EXTERNAL_IRQS 16
#define EXTERNAL_IRQ_NOT_IN_USE (-1)
#define EXTERNAL_IRQ_NOT_ASSIGNED (-1)
/*
* This table is used to determine what to program into the FPGA's CT register
* for the specified Linux IRQ.
*
* The irq_mask gives the interrupt number from the PCI board (PCI_Int(6:0))
* but is one greater than that because the because the FPGA treats 0
* as disabled, a value of 1 asserts PCI_Int0, and so on.
*
* The overdrive_irq specifies which of the eight interrupt sources generates
* that interrupt, and but is multiplied by four to give the bit offset into
* the CT register.
*
* The seven interrupts levels (SH4 IRL's) we have available here is hardwired
* by the EPLD. The assignments here of which PCI interrupt generates each
* level is arbitary.
*/
static struct od_data od_data_table[NUM_EXTERNAL_IRQS] = {
/* overdrive_irq , irq_mask */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 0 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 7}, /* 1 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 6}, /* 2 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 3 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 5}, /* 4 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 5 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 6 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 4}, /* 7 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 8 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 9 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 3}, /* 10 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 2}, /* 11 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 12 */
{EXTERNAL_IRQ_NOT_ASSIGNED, 1}, /* 13 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE}, /* 14 */
{EXTERNAL_IRQ_NOT_ASSIGNED, EXTERNAL_IRQ_NOT_IN_USE} /* 15 */
};
static void set_od_data(int overdrive_irq, int irq)
{
if (irq >= NUM_EXTERNAL_IRQS || irq < 0)
return;
od_data_table[irq].overdrive_irq = overdrive_irq << 2;
}
static void enable_od_irq(unsigned int irq);
void disable_od_irq(unsigned int irq);
/* shutdown is same as "disable" */
#define shutdown_od_irq disable_od_irq
static void mask_and_ack_od(unsigned int);
static void end_od_irq(unsigned int irq);
static unsigned int startup_od_irq(unsigned int irq)
{
enable_od_irq(irq);
return 0; /* never anything pending */
}
static struct hw_interrupt_type od_irq_type = {
.typename = "Overdrive-IRQ",
.startup = startup_od_irq,
.shutdown = shutdown_od_irq,
.enable = enable_od_irq,
.disable = disable_od_irq,
.ack = mask_and_ack_od,
.end = end_od_irq
};
static void disable_od_irq(unsigned int irq)
{
unsigned val, flags;
int overdrive_irq;
unsigned mask;
/* Not a valid interrupt */
if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
return;
/* Is is necessary to use a cli here? Would a spinlock not be
* mroe efficient?
*/
local_irq_save(flags);
overdrive_irq = od_data_table[irq].overdrive_irq;
if (overdrive_irq != EXTERNAL_IRQ_NOT_ASSIGNED) {
mask = ~(0x7 << overdrive_irq);
val = ctrl_inl(OVERDRIVE_INT_CT);
val &= mask;
ctrl_outl(val, OVERDRIVE_INT_CT);
}
local_irq_restore(flags);
}
static void enable_od_irq(unsigned int irq)
{
unsigned val, flags;
int overdrive_irq;
unsigned mask;
/* Not a valid interrupt */
if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
return;
/* Set priority in OD back to original value */
local_irq_save(flags);
/* This one is not in use currently */
overdrive_irq = od_data_table[irq].overdrive_irq;
if (overdrive_irq != EXTERNAL_IRQ_NOT_ASSIGNED) {
val = ctrl_inl(OVERDRIVE_INT_CT);
mask = ~(0x7 << overdrive_irq);
val &= mask;
mask = od_data_table[irq].irq_mask << overdrive_irq;
val |= mask;
ctrl_outl(val, OVERDRIVE_INT_CT);
}
local_irq_restore(flags);
}
/* this functions sets the desired irq handler to be an overdrive type */
static void __init make_od_irq(unsigned int irq)
{
disable_irq_nosync(irq);
irq_desc[irq].handler = &od_irq_type;
disable_od_irq(irq);
}
static void mask_and_ack_od(unsigned int irq)
{
disable_od_irq(irq);
}
static void end_od_irq(unsigned int irq)
{
enable_od_irq(irq);
}
void __init init_overdrive_irq(void)
{
int i;
/* Disable all interrupts */
ctrl_outl(0, OVERDRIVE_INT_CT);
/* Update interrupt pin mode to use encoded interrupts */
i = ctrl_inw(INTC_ICR);
i &= ~INTC_ICR_IRLM;
ctrl_outw(i, INTC_ICR);
for (i = 0; i < NUM_EXTERNAL_IRQS; i++) {
if (od_data_table[i].irq_mask != EXTERNAL_IRQ_NOT_IN_USE) {
make_od_irq(i);
} else if (i != 15) { // Cannot use imask on level 15
make_imask_irq(i);
}
}
/* Set up the interrupts */
set_od_data(OVERDRIVE_PCI_INTA, OVERDRIVE_PCI_IRQ1);
set_od_data(OVERDRIVE_PCI_INTB, OVERDRIVE_PCI_IRQ2);
set_od_data(OVERDRIVE_AUDIO_INT, OVERDRIVE_ESS_IRQ);
}
