linux-brain/arch/mips/sni/a20r.c
Thomas Bogendoerfer 549efeaa96 MIPS: SNI: Fix spurious interrupts
[ Upstream commit b959b97860d0fee8c8f6a3e641d3c2ad76eab6be ]

On A20R machines the interrupt pending bits in cause register need to be
updated by requesting the chipset to do it. This needs to be done to
find the interrupt cause and after interrupt service. In
commit 0b888c7f3a ("MIPS: SNI: Convert to new irq_chip functions") the
function to do after service update got lost, which caused spurious
interrupts.

Fixes: 0b888c7f3a ("MIPS: SNI: Convert to new irq_chip functions")
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23 12:40:42 +02:00

255 lines
5.1 KiB
C

/*
* A20R specific code
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2006 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/serial_8250.h>
#include <asm/sni.h>
#include <asm/time.h>
#define PORT(_base,_irq) \
{ \
.iobase = _base, \
.irq = _irq, \
.uartclk = 1843200, \
.iotype = UPIO_PORT, \
.flags = UPF_BOOT_AUTOCONF, \
}
static struct plat_serial8250_port a20r_data[] = {
PORT(0x3f8, 4),
PORT(0x2f8, 3),
{ },
};
static struct platform_device a20r_serial8250_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = a20r_data,
},
};
static struct resource a20r_ds1216_rsrc[] = {
{
.start = 0x1c081ffc,
.end = 0x1c081fff,
.flags = IORESOURCE_MEM
}
};
static struct platform_device a20r_ds1216_device = {
.name = "rtc-ds1216",
.num_resources = ARRAY_SIZE(a20r_ds1216_rsrc),
.resource = a20r_ds1216_rsrc
};
static struct resource snirm_82596_rsrc[] = {
{
.start = 0x18000000,
.end = 0x18000004,
.flags = IORESOURCE_MEM
},
{
.start = 0x18010000,
.end = 0x18010004,
.flags = IORESOURCE_MEM
},
{
.start = 0x1ff00000,
.end = 0x1ff00020,
.flags = IORESOURCE_MEM
},
{
.start = 22,
.end = 22,
.flags = IORESOURCE_IRQ
},
{
.flags = 0x01 /* 16bit mpu port access */
}
};
static struct platform_device snirm_82596_pdev = {
.name = "snirm_82596",
.num_resources = ARRAY_SIZE(snirm_82596_rsrc),
.resource = snirm_82596_rsrc
};
static struct resource snirm_53c710_rsrc[] = {
{
.start = 0x19000000,
.end = 0x190fffff,
.flags = IORESOURCE_MEM
},
{
.start = 19,
.end = 19,
.flags = IORESOURCE_IRQ
}
};
static struct platform_device snirm_53c710_pdev = {
.name = "snirm_53c710",
.num_resources = ARRAY_SIZE(snirm_53c710_rsrc),
.resource = snirm_53c710_rsrc
};
static struct resource sc26xx_rsrc[] = {
{
.start = 0x1c070000,
.end = 0x1c0700ff,
.flags = IORESOURCE_MEM
},
{
.start = 20,
.end = 20,
.flags = IORESOURCE_IRQ
}
};
#include <linux/platform_data/serial-sccnxp.h>
static struct sccnxp_pdata sccnxp_data = {
.reg_shift = 2,
.mctrl_cfg[0] = MCTRL_SIG(DTR_OP, LINE_OP7) |
MCTRL_SIG(RTS_OP, LINE_OP3) |
MCTRL_SIG(DSR_IP, LINE_IP5) |
MCTRL_SIG(DCD_IP, LINE_IP6),
.mctrl_cfg[1] = MCTRL_SIG(DTR_OP, LINE_OP2) |
MCTRL_SIG(RTS_OP, LINE_OP1) |
MCTRL_SIG(DSR_IP, LINE_IP0) |
MCTRL_SIG(CTS_IP, LINE_IP1) |
MCTRL_SIG(DCD_IP, LINE_IP2) |
MCTRL_SIG(RNG_IP, LINE_IP3),
};
static struct platform_device sc26xx_pdev = {
.name = "sc2681",
.resource = sc26xx_rsrc,
.num_resources = ARRAY_SIZE(sc26xx_rsrc),
.dev = {
.platform_data = &sccnxp_data,
},
};
/*
* Trigger chipset to update CPU's CAUSE IP field
*/
static u32 a20r_update_cause_ip(void)
{
u32 status = read_c0_status();
write_c0_status(status | 0x00010000);
asm volatile(
" .set push \n"
" .set noat \n"
" .set noreorder \n"
" lw $1, 0(%0) \n"
" sb $0, 0(%1) \n"
" sync \n"
" lb %1, 0(%1) \n"
" b 1f \n"
" ori %1, $1, 2 \n"
" .align 8 \n"
"1: \n"
" nop \n"
" sw %1, 0(%0) \n"
" sync \n"
" li %1, 0x20 \n"
"2: \n"
" nop \n"
" bnez %1,2b \n"
" addiu %1, -1 \n"
" sw $1, 0(%0) \n"
" sync \n"
".set pop \n"
:
: "Jr" (PCIMT_UCONF), "Jr" (0xbc000000));
write_c0_status(status);
return status;
}
static inline void unmask_a20r_irq(struct irq_data *d)
{
set_c0_status(0x100 << (d->irq - SNI_A20R_IRQ_BASE));
irq_enable_hazard();
}
static inline void mask_a20r_irq(struct irq_data *d)
{
clear_c0_status(0x100 << (d->irq - SNI_A20R_IRQ_BASE));
irq_disable_hazard();
}
static struct irq_chip a20r_irq_type = {
.name = "A20R",
.irq_mask = mask_a20r_irq,
.irq_unmask = unmask_a20r_irq,
};
/*
* hwint 0 receive all interrupts
*/
static void a20r_hwint(void)
{
u32 cause, status;
int irq;
clear_c0_status(IE_IRQ0);
status = a20r_update_cause_ip();
cause = read_c0_cause();
irq = ffs(((cause & status) >> 8) & 0xf8);
if (likely(irq > 0))
do_IRQ(SNI_A20R_IRQ_BASE + irq - 1);
a20r_update_cause_ip();
set_c0_status(IE_IRQ0);
}
void __init sni_a20r_irq_init(void)
{
int i;
for (i = SNI_A20R_IRQ_BASE + 2 ; i < SNI_A20R_IRQ_BASE + 8; i++)
irq_set_chip_and_handler(i, &a20r_irq_type, handle_level_irq);
sni_hwint = a20r_hwint;
change_c0_status(ST0_IM, IE_IRQ0);
setup_irq(SNI_A20R_IRQ_BASE + 3, &sni_isa_irq);
}
void sni_a20r_init(void)
{
/* FIXME, remove if not needed */
}
static int __init snirm_a20r_setup_devinit(void)
{
switch (sni_brd_type) {
case SNI_BRD_TOWER_OASIC:
case SNI_BRD_MINITOWER:
platform_device_register(&snirm_82596_pdev);
platform_device_register(&snirm_53c710_pdev);
platform_device_register(&sc26xx_pdev);
platform_device_register(&a20r_serial8250_device);
platform_device_register(&a20r_ds1216_device);
sni_eisa_root_init();
break;
}
return 0;
}
device_initcall(snirm_a20r_setup_devinit);