linux/arch/arm/mach-rpc/irq.c
Arnd Bergmann c1fe8d054c ARM: riscpc: use GENERIC_IRQ_MULTI_HANDLER
This is one of the last platforms using the old entry path.
While this code path is spread over a few files, it is fairly
straightforward to convert it into an equivalent C version,
leaving the existing algorithm and all the priority handling
the same.

Unlike most irqchip drivers, this means reading the status
register(s) in a loop and always handling the highest-priority
irq first.

The IOMD_IRQREQC and IOMD_IRQREQD registers are not actaully
used here, but I left the code in place for the time being,
to keep the conversion as direct as possible. It could be
removed in a cleanup on top.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ardb: drop obsolete IOMD_IRQREQC/IOMD_IRQREQD handling]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03 18:43:38 +01:00

227 lines
6.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.h>
#include <asm/mach/irq.h>
#include <asm/hardware/iomd.h>
#include <asm/irq.h>
#include <asm/fiq.h>
// These are offsets from the stat register for each IRQ bank
#define STAT 0x00
#define REQ 0x04
#define CLR 0x04
#define MASK 0x08
static const u8 irq_prio_h[256] = {
0, 8, 9, 8,10,10,10,10,11,11,11,11,10,10,10,10,
12, 8, 9, 8,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
14,14,14,14,10,10,10,10,11,11,11,11,10,10,10,10,
14,14,14,14,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
15,15,15,15,10,10,10,10,11,11,11,11,10,10,10,10,
15,15,15,15,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
15,15,15,15,10,10,10,10,11,11,11,11,10,10,10,10,
15,15,15,15,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
13,13,13,13,10,10,10,10,11,11,11,11,10,10,10,10,
};
static const u8 irq_prio_d[256] = {
0,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
20,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
22,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
22,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
23,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
23,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
22,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
22,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
21,16,17,16,18,16,17,16,19,16,17,16,18,16,17,16,
};
static const u8 irq_prio_l[256] = {
0, 0, 1, 0, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
4, 0, 1, 0, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3, 3, 3, 3,
6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3, 3, 3, 3,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
};
static int iomd_get_irq_nr(void)
{
int irq;
u8 reg;
/* get highest priority first */
reg = readb(IOC_BASE + IOMD_IRQREQB);
irq = irq_prio_h[reg];
if (irq)
return irq;
/* get DMA */
reg = readb(IOC_BASE + IOMD_DMAREQ);
irq = irq_prio_d[reg];
if (irq)
return irq;
/* get low priority */
reg = readb(IOC_BASE + IOMD_IRQREQA);
irq = irq_prio_l[reg];
if (irq)
return irq;
return 0;
}
static void iomd_handle_irq(struct pt_regs *regs)
{
int irq;
do {
irq = iomd_get_irq_nr();
if (irq)
generic_handle_irq(irq);
} while (irq);
}
static void __iomem *iomd_get_base(struct irq_data *d)
{
void *cd = irq_data_get_irq_chip_data(d);
return (void __iomem *)(unsigned long)cd;
}
static void iomd_set_base_mask(unsigned int irq, void __iomem *base, u32 mask)
{
struct irq_data *d = irq_get_irq_data(irq);
d->mask = mask;
irq_set_chip_data(irq, (void *)(unsigned long)base);
}
static void iomd_irq_mask_ack(struct irq_data *d)
{
void __iomem *base = iomd_get_base(d);
unsigned int val, mask = d->mask;
val = readb(base + MASK);
writeb(val & ~mask, base + MASK);
writeb(mask, base + CLR);
}
static void iomd_irq_mask(struct irq_data *d)
{
void __iomem *base = iomd_get_base(d);
unsigned int val, mask = d->mask;
val = readb(base + MASK);
writeb(val & ~mask, base + MASK);
}
static void iomd_irq_unmask(struct irq_data *d)
{
void __iomem *base = iomd_get_base(d);
unsigned int val, mask = d->mask;
val = readb(base + MASK);
writeb(val | mask, base + MASK);
}
static struct irq_chip iomd_chip_clr = {
.irq_mask_ack = iomd_irq_mask_ack,
.irq_mask = iomd_irq_mask,
.irq_unmask = iomd_irq_unmask,
};
static struct irq_chip iomd_chip_noclr = {
.irq_mask = iomd_irq_mask,
.irq_unmask = iomd_irq_unmask,
};
extern unsigned char rpc_default_fiq_start, rpc_default_fiq_end;
void __init rpc_init_irq(void)
{
unsigned int irq, clr, set;
iomd_writeb(0, IOMD_IRQMASKA);
iomd_writeb(0, IOMD_IRQMASKB);
iomd_writeb(0, IOMD_FIQMASK);
iomd_writeb(0, IOMD_DMAMASK);
set_fiq_handler(&rpc_default_fiq_start,
&rpc_default_fiq_end - &rpc_default_fiq_start);
set_handle_irq(iomd_handle_irq);
for (irq = 0; irq < NR_IRQS; irq++) {
clr = IRQ_NOREQUEST;
set = 0;
if (irq <= 6 || (irq >= 9 && irq <= 15))
clr |= IRQ_NOPROBE;
if (irq == 21 || (irq >= 16 && irq <= 19) ||
irq == IRQ_KEYBOARDTX)
set |= IRQ_NOAUTOEN;
switch (irq) {
case 0 ... 7:
irq_set_chip_and_handler(irq, &iomd_chip_clr,
handle_level_irq);
irq_modify_status(irq, clr, set);
iomd_set_base_mask(irq, IOMD_BASE + IOMD_IRQSTATA,
BIT(irq));
break;
case 8 ... 15:
irq_set_chip_and_handler(irq, &iomd_chip_noclr,
handle_level_irq);
irq_modify_status(irq, clr, set);
iomd_set_base_mask(irq, IOMD_BASE + IOMD_IRQSTATB,
BIT(irq - 8));
break;
case 16 ... 21:
irq_set_chip_and_handler(irq, &iomd_chip_noclr,
handle_level_irq);
irq_modify_status(irq, clr, set);
iomd_set_base_mask(irq, IOMD_BASE + IOMD_DMASTAT,
BIT(irq - 16));
break;
case 64 ... 71:
irq_set_chip(irq, &iomd_chip_noclr);
irq_modify_status(irq, clr, set);
iomd_set_base_mask(irq, IOMD_BASE + IOMD_FIQSTAT,
BIT(irq - 64));
break;
}
}
init_FIQ(FIQ_START);
}