linux/arch/mips/alchemy/devboards/bcsr.c
Manuel Lauss 95a437966d MIPS: Alchemy: devboards: factor out PB1200 IRQ cascade code.
Move the PB1200 IRQ cascade code out to the BCSR support code:
upcoming DB1300 support can use it too.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27 12:52:50 +01:00

149 lines
3.8 KiB
C

/*
* bcsr.h -- Db1xxx/Pb1xxx Devboard CPLD registers ("BCSR") abstraction.
*
* All Alchemy development boards (except, of course, the weird PB1000)
* have a few registers in a CPLD with standardised layout; they mostly
* only differ in base address.
* All registers are 16bits wide with 32bit spacing.
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/mach-db1x00/bcsr.h>
static struct bcsr_reg {
void __iomem *raddr;
spinlock_t lock;
} bcsr_regs[BCSR_CNT];
static void __iomem *bcsr_virt; /* KSEG1 addr of BCSR base */
static int bcsr_csc_base; /* linux-irq of first cascaded irq */
void __init bcsr_init(unsigned long bcsr1_phys, unsigned long bcsr2_phys)
{
int i;
bcsr1_phys = KSEG1ADDR(CPHYSADDR(bcsr1_phys));
bcsr2_phys = KSEG1ADDR(CPHYSADDR(bcsr2_phys));
bcsr_virt = (void __iomem *)bcsr1_phys;
for (i = 0; i < BCSR_CNT; i++) {
if (i >= BCSR_HEXLEDS)
bcsr_regs[i].raddr = (void __iomem *)bcsr2_phys +
(0x04 * (i - BCSR_HEXLEDS));
else
bcsr_regs[i].raddr = (void __iomem *)bcsr1_phys +
(0x04 * i);
spin_lock_init(&bcsr_regs[i].lock);
}
}
unsigned short bcsr_read(enum bcsr_id reg)
{
unsigned short r;
unsigned long flags;
spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
r = __raw_readw(bcsr_regs[reg].raddr);
spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(bcsr_read);
void bcsr_write(enum bcsr_id reg, unsigned short val)
{
unsigned long flags;
spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
__raw_writew(val, bcsr_regs[reg].raddr);
wmb();
spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
}
EXPORT_SYMBOL_GPL(bcsr_write);
void bcsr_mod(enum bcsr_id reg, unsigned short clr, unsigned short set)
{
unsigned short r;
unsigned long flags;
spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
r = __raw_readw(bcsr_regs[reg].raddr);
r &= ~clr;
r |= set;
__raw_writew(r, bcsr_regs[reg].raddr);
wmb();
spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
}
EXPORT_SYMBOL_GPL(bcsr_mod);
/*
* DB1200/PB1200 CPLD IRQ muxer
*/
static void bcsr_csc_handler(unsigned int irq, struct irq_desc *d)
{
unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT);
for ( ; bisr; bisr &= bisr - 1)
generic_handle_irq(bcsr_csc_base + __ffs(bisr));
}
/* NOTE: both the enable and mask bits must be cleared, otherwise the
* CPLD generates tons of spurious interrupts (at least on my DB1200).
* -- mlau
*/
static void bcsr_irq_mask(unsigned int irq_nr)
{
unsigned short v = 1 << (irq_nr - bcsr_csc_base);
__raw_writew(v, bcsr_virt + BCSR_REG_INTCLR);
__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
wmb();
}
static void bcsr_irq_maskack(unsigned int irq_nr)
{
unsigned short v = 1 << (irq_nr - bcsr_csc_base);
__raw_writew(v, bcsr_virt + BCSR_REG_INTCLR);
__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
__raw_writew(v, bcsr_virt + BCSR_REG_INTSTAT); /* ack */
wmb();
}
static void bcsr_irq_unmask(unsigned int irq_nr)
{
unsigned short v = 1 << (irq_nr - bcsr_csc_base);
__raw_writew(v, bcsr_virt + BCSR_REG_INTSET);
__raw_writew(v, bcsr_virt + BCSR_REG_MASKSET);
wmb();
}
static struct irq_chip bcsr_irq_type = {
.name = "CPLD",
.mask = bcsr_irq_mask,
.mask_ack = bcsr_irq_maskack,
.unmask = bcsr_irq_unmask,
};
void __init bcsr_init_irq(int csc_start, int csc_end, int hook_irq)
{
unsigned int irq;
/* mask & disable & ack all */
__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTCLR);
__raw_writew(0xffff, bcsr_virt + BCSR_REG_MASKCLR);
__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSTAT);
wmb();
bcsr_csc_base = csc_start;
for (irq = csc_start; irq <= csc_end; irq++)
set_irq_chip_and_handler_name(irq, &bcsr_irq_type,
handle_level_irq, "level");
set_irq_chained_handler(hook_irq, bcsr_csc_handler);
}