144 lines
3.8 KiB
C
144 lines
3.8 KiB
C
/*
|
|
* Copyright (C) 2014 Synopsys, Inc. (www.synopsys.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
*/
|
|
|
|
#include <linux/interrupt.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/irqdomain.h>
|
|
#include <linux/irqchip.h>
|
|
#include "../../drivers/irqchip/irqchip.h"
|
|
#include <asm/irq.h>
|
|
|
|
/*
|
|
* Early Hardware specific Interrupt setup
|
|
* -Called very early (start_kernel -> setup_arch -> setup_processor)
|
|
* -Platform Independent (must for any ARC Core)
|
|
* -Needed for each CPU (hence not foldable into init_IRQ)
|
|
*/
|
|
void arc_init_IRQ(void)
|
|
{
|
|
unsigned int tmp;
|
|
|
|
struct aux_irq_ctrl {
|
|
#ifdef CONFIG_CPU_BIG_ENDIAN
|
|
unsigned int res3:18, save_idx_regs:1, res2:1,
|
|
save_u_to_u:1, save_lp_regs:1, save_blink:1,
|
|
res:4, save_nr_gpr_pairs:5;
|
|
#else
|
|
unsigned int save_nr_gpr_pairs:5, res:4,
|
|
save_blink:1, save_lp_regs:1, save_u_to_u:1,
|
|
res2:1, save_idx_regs:1, res3:18;
|
|
#endif
|
|
} ictrl;
|
|
|
|
*(unsigned int *)&ictrl = 0;
|
|
|
|
ictrl.save_nr_gpr_pairs = 6; /* r0 to r11 (r12 saved manually) */
|
|
ictrl.save_blink = 1;
|
|
ictrl.save_lp_regs = 1; /* LP_COUNT, LP_START, LP_END */
|
|
ictrl.save_u_to_u = 0; /* user ctxt saved on kernel stack */
|
|
ictrl.save_idx_regs = 1; /* JLI, LDI, EI */
|
|
|
|
WRITE_AUX(AUX_IRQ_CTRL, ictrl);
|
|
|
|
/* setup status32, don't enable intr yet as kernel doesn't want */
|
|
tmp = read_aux_reg(0xa);
|
|
tmp |= ISA_INIT_STATUS_BITS;
|
|
tmp &= ~STATUS_IE_MASK;
|
|
asm volatile("flag %0 \n"::"r"(tmp));
|
|
|
|
/*
|
|
* ARCv2 core intc provides multiple interrupt priorities (upto 16).
|
|
* Typical builds though have only two levels (0-high, 1-low)
|
|
* Linux by default uses lower prio 1 for most irqs, reserving 0 for
|
|
* NMI style interrupts in future (say perf)
|
|
*
|
|
* Read the intc BCR to confirm that Linux default priority is avail
|
|
* in h/w
|
|
*
|
|
* Note:
|
|
* IRQ_BCR[27..24] contains N-1 (for N priority levels) and prio level
|
|
* is 0 based.
|
|
*/
|
|
tmp = (read_aux_reg(ARC_REG_IRQ_BCR) >> 24 ) & 0xF;
|
|
if (ARCV2_IRQ_DEF_PRIO > tmp)
|
|
panic("Linux default irq prio incorrect\n");
|
|
}
|
|
|
|
static void arcv2_irq_mask(struct irq_data *data)
|
|
{
|
|
write_aux_reg(AUX_IRQ_SELECT, data->irq);
|
|
write_aux_reg(AUX_IRQ_ENABLE, 0);
|
|
}
|
|
|
|
static void arcv2_irq_unmask(struct irq_data *data)
|
|
{
|
|
write_aux_reg(AUX_IRQ_SELECT, data->irq);
|
|
write_aux_reg(AUX_IRQ_ENABLE, 1);
|
|
}
|
|
|
|
void arcv2_irq_enable(struct irq_data *data)
|
|
{
|
|
/* set default priority */
|
|
write_aux_reg(AUX_IRQ_SELECT, data->irq);
|
|
write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
|
|
|
|
/*
|
|
* hw auto enables (linux unmask) all by default
|
|
* So no need to do IRQ_ENABLE here
|
|
* XXX: However OSCI LAN need it
|
|
*/
|
|
write_aux_reg(AUX_IRQ_ENABLE, 1);
|
|
}
|
|
|
|
static struct irq_chip arcv2_irq_chip = {
|
|
.name = "ARCv2 core Intc",
|
|
.irq_mask = arcv2_irq_mask,
|
|
.irq_unmask = arcv2_irq_unmask,
|
|
.irq_enable = arcv2_irq_enable
|
|
};
|
|
|
|
static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
|
|
irq_hw_number_t hw)
|
|
{
|
|
if (irq == TIMER0_IRQ || irq == IPI_IRQ)
|
|
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_percpu_irq);
|
|
else
|
|
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_level_irq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct irq_domain_ops arcv2_irq_ops = {
|
|
.xlate = irq_domain_xlate_onecell,
|
|
.map = arcv2_irq_map,
|
|
};
|
|
|
|
static struct irq_domain *root_domain;
|
|
|
|
static int __init
|
|
init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
|
|
{
|
|
if (parent)
|
|
panic("DeviceTree incore intc not a root irq controller\n");
|
|
|
|
root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,
|
|
&arcv2_irq_ops, NULL);
|
|
|
|
if (!root_domain)
|
|
panic("root irq domain not avail\n");
|
|
|
|
/* with this we don't need to export root_domain */
|
|
irq_set_default_host(root_domain);
|
|
|
|
return 0;
|
|
}
|
|
|
|
IRQCHIP_DECLARE(arc_intc, "snps,archs-intc", init_onchip_IRQ);
|