android_kernel_xiaomi_sm8350/arch/mips/momentum/ocelot_c/uart-irq.c
Franck Bui-Huu e77c232cfc [MIPS] Compile __do_IRQ() when really needed
__do_IRQ() is needed only by irq handlers that can't use
default handlers defined in kernel/irq/chip.c.

For others platforms there's no need to compile this function
since it won't be used. For those platforms this patch defines
GENERIC_HARDIRQS_NO__DO_IRQ symbol which is used exactly for
this purpose.

Futhermore for platforms which do not use __do_IRQ(), end()
method which is part of the 'irq_chip' structure is not used.
This patch simply removes this method in this case.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00

92 lines
2.4 KiB
C

/*
* Copyright 2002 Momentum Computer
* Author: mdharm@momenco.com
*
* arch/mips/momentum/ocelot_c/uart-irq.c
* Interrupt routines for UARTs. Interrupt numbers are assigned from
* 80 to 81 (2 interrupt sources).
*
* 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/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <asm/io.h>
#include <asm/irq.h>
#include "ocelot_c_fpga.h"
static inline int ls1bit8(unsigned int x)
{
int b = 7, s;
s = 4; if (((unsigned char)(x << 4)) == 0) s = 0; b -= s; x <<= s;
s = 2; if (((unsigned char)(x << 2)) == 0) s = 0; b -= s; x <<= s;
s = 1; if (((unsigned char)(x << 1)) == 0) s = 0; b -= s;
return b;
}
/* mask off an interrupt -- 0 is enable, 1 is disable */
static inline void mask_uart_irq(unsigned int irq)
{
uint8_t value;
value = OCELOT_FPGA_READ(UART_INTMASK);
value |= 1 << (irq - 74);
OCELOT_FPGA_WRITE(value, UART_INTMASK);
/* read the value back to assure that it's really been written */
value = OCELOT_FPGA_READ(UART_INTMASK);
}
/* unmask an interrupt -- 0 is enable, 1 is disable */
static inline void unmask_uart_irq(unsigned int irq)
{
uint8_t value;
value = OCELOT_FPGA_READ(UART_INTMASK);
value &= ~(1 << (irq - 74));
OCELOT_FPGA_WRITE(value, UART_INTMASK);
/* read the value back to assure that it's really been written */
value = OCELOT_FPGA_READ(UART_INTMASK);
}
/*
* Interrupt handler for interrupts coming from the FPGA chip.
*/
void ll_uart_irq(void)
{
unsigned int irq_src, irq_mask;
/* read the interrupt status registers */
irq_src = OCELOT_FPGA_READ(UART_INTSTAT);
irq_mask = OCELOT_FPGA_READ(UART_INTMASK);
/* mask for just the interrupts we want */
irq_src &= ~irq_mask;
do_IRQ(ls1bit8(irq_src) + 74);
}
struct irq_chip uart_irq_type = {
.typename = "UART/FPGA",
.ack = mask_uart_irq,
.mask = mask_uart_irq,
.mask_ack = mask_uart_irq,
.unmask = unmask_uart_irq,
};
void uart_irq_init(void)
{
set_irq_chip_and_handler(80, &uart_irq_type, handle_level_irq);
set_irq_chip_and_handler(81, &uart_irq_type, handle_level_irq);
}