linux/drivers/irqchip/irq-csky-apb-intc.c
Guo Ren edff1b4835 irqchip: add C-SKY APB bus interrupt controller
The driver is for C-SKY APB bus interrupt controller. It's a simple
interrupt controller which use pending reg to detect the irq and use
enable/disable reg to mask/unmask interrupt sources.

A lot of SOCs based on C-SKY CPU use the interrupt controller as root
controller.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
2018-10-26 00:54:30 +08:00

275 lines
6.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/module.h>
#include <linux/irqdomain.h>
#include <linux/irqchip.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <asm/irq.h>
#define INTC_IRQS 64
#define CK_INTC_ICR 0x00
#define CK_INTC_PEN31_00 0x14
#define CK_INTC_PEN63_32 0x2c
#define CK_INTC_NEN31_00 0x10
#define CK_INTC_NEN63_32 0x28
#define CK_INTC_SOURCE 0x40
#define CK_INTC_DUAL_BASE 0x100
#define GX_INTC_PEN31_00 0x00
#define GX_INTC_PEN63_32 0x04
#define GX_INTC_NEN31_00 0x40
#define GX_INTC_NEN63_32 0x44
#define GX_INTC_NMASK31_00 0x50
#define GX_INTC_NMASK63_32 0x54
#define GX_INTC_SOURCE 0x60
static void __iomem *reg_base;
static struct irq_domain *root_domain;
static int nr_irq = INTC_IRQS;
/*
* When controller support pulse signal, the PEN_reg will hold on signal
* without software trigger.
*
* So, to support pulse signal we need to clear IFR_reg and the address of
* IFR_offset is NEN_offset - 8.
*/
static void irq_ck_mask_set_bit(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
unsigned long ifr = ct->regs.mask - 8;
u32 mask = d->mask;
irq_gc_lock(gc);
*ct->mask_cache |= mask;
irq_reg_writel(gc, *ct->mask_cache, ct->regs.mask);
irq_reg_writel(gc, irq_reg_readl(gc, ifr) & ~mask, ifr);
irq_gc_unlock(gc);
}
static void __init ck_set_gc(struct device_node *node, void __iomem *reg_base,
u32 mask_reg, u32 irq_base)
{
struct irq_chip_generic *gc;
gc = irq_get_domain_generic_chip(root_domain, irq_base);
gc->reg_base = reg_base;
gc->chip_types[0].regs.mask = mask_reg;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
if (of_find_property(node, "csky,support-pulse-signal", NULL))
gc->chip_types[0].chip.irq_unmask = irq_ck_mask_set_bit;
}
static inline u32 build_channel_val(u32 idx, u32 magic)
{
u32 res;
/*
* Set the same index for each channel
*/
res = idx | (idx << 8) | (idx << 16) | (idx << 24);
/*
* Set the channel magic number in descending order.
* The magic is 0x00010203 for ck-intc
* The magic is 0x03020100 for gx6605s-intc
*/
return res | magic;
}
static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)
{
u32 i;
/* Setup 64 channel slots */
for (i = 0; i < INTC_IRQS; i += 4)
writel_relaxed(build_channel_val(i, magic), reg_addr + i);
}
static int __init
ck_intc_init_comm(struct device_node *node, struct device_node *parent)
{
int ret;
if (parent) {
pr_err("C-SKY Intc not a root irq controller\n");
return -EINVAL;
}
reg_base = of_iomap(node, 0);
if (!reg_base) {
pr_err("C-SKY Intc unable to map: %p.\n", node);
return -EINVAL;
}
root_domain = irq_domain_add_linear(node, nr_irq,
&irq_generic_chip_ops, NULL);
if (!root_domain) {
pr_err("C-SKY Intc irq_domain_add failed.\n");
return -ENOMEM;
}
ret = irq_alloc_domain_generic_chips(root_domain, 32, 1,
"csky_intc", handle_level_irq,
IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN, 0, 0);
if (ret) {
pr_err("C-SKY Intc irq_alloc_gc failed.\n");
return -ENOMEM;
}
return 0;
}
static inline bool handle_irq_perbit(struct pt_regs *regs, u32 hwirq,
u32 irq_base)
{
u32 irq;
if (hwirq == 0)
return 0;
while (hwirq) {
irq = __ffs(hwirq);
hwirq &= ~BIT(irq);
handle_domain_irq(root_domain, irq_base + irq, regs);
}
return 1;
}
/* gx6605s 64 irqs interrupt controller */
static void gx_irq_handler(struct pt_regs *regs)
{
bool ret;
do {
ret = handle_irq_perbit(regs,
readl_relaxed(reg_base + GX_INTC_PEN31_00), 0);
ret |= handle_irq_perbit(regs,
readl_relaxed(reg_base + GX_INTC_PEN63_32), 32);
} while (ret);
}
static int __init
gx_intc_init(struct device_node *node, struct device_node *parent)
{
int ret;
ret = ck_intc_init_comm(node, parent);
if (ret)
return ret;
/*
* Initial enable reg to disable all interrupts
*/
writel_relaxed(0x0, reg_base + GX_INTC_NEN31_00);
writel_relaxed(0x0, reg_base + GX_INTC_NEN63_32);
/*
* Initial mask reg with all unmasked, because we only use enalbe reg
*/
writel_relaxed(0x0, reg_base + GX_INTC_NMASK31_00);
writel_relaxed(0x0, reg_base + GX_INTC_NMASK63_32);
setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);
ck_set_gc(node, reg_base, GX_INTC_NEN31_00, 0);
ck_set_gc(node, reg_base, GX_INTC_NEN63_32, 32);
set_handle_irq(gx_irq_handler);
return 0;
}
IRQCHIP_DECLARE(csky_gx6605s_intc, "csky,gx6605s-intc", gx_intc_init);
/*
* C-SKY simple 64 irqs interrupt controller, dual-together could support 128
* irqs.
*/
static void ck_irq_handler(struct pt_regs *regs)
{
bool ret;
void __iomem *reg_pen_lo = reg_base + CK_INTC_PEN31_00;
void __iomem *reg_pen_hi = reg_base + CK_INTC_PEN63_32;
do {
/* handle 0 - 31 irqs */
ret = handle_irq_perbit(regs, readl_relaxed(reg_pen_lo), 0);
ret |= handle_irq_perbit(regs, readl_relaxed(reg_pen_hi), 32);
if (nr_irq == INTC_IRQS)
continue;
/* handle 64 - 127 irqs */
ret |= handle_irq_perbit(regs,
readl_relaxed(reg_pen_lo + CK_INTC_DUAL_BASE), 64);
ret |= handle_irq_perbit(regs,
readl_relaxed(reg_pen_hi + CK_INTC_DUAL_BASE), 96);
} while (ret);
}
static int __init
ck_intc_init(struct device_node *node, struct device_node *parent)
{
int ret;
ret = ck_intc_init_comm(node, parent);
if (ret)
return ret;
/* Initial enable reg to disable all interrupts */
writel_relaxed(0, reg_base + CK_INTC_NEN31_00);
writel_relaxed(0, reg_base + CK_INTC_NEN63_32);
/* Enable irq intc */
writel_relaxed(BIT(31), reg_base + CK_INTC_ICR);
ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE);
set_handle_irq(ck_irq_handler);
return 0;
}
IRQCHIP_DECLARE(ck_intc, "csky,apb-intc", ck_intc_init);
static int __init
ck_dual_intc_init(struct device_node *node, struct device_node *parent)
{
int ret;
/* dual-apb-intc up to 128 irq sources*/
nr_irq = INTC_IRQS * 2;
ret = ck_intc_init(node, parent);
if (ret)
return ret;
/* Initial enable reg to disable all interrupts */
writel_relaxed(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
writel_relaxed(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
setup_irq_channel(0x00010203,
reg_base + CK_INTC_SOURCE + CK_INTC_DUAL_BASE);
return 0;
}
IRQCHIP_DECLARE(ck_dual_intc, "csky,dual-apb-intc", ck_dual_intc_init);