Skip to content

Commit

Permalink
OF: MIPS: lantiq: implement irq_domain support
Browse files Browse the repository at this point in the history 
Add support for irq_domain on lantiq socs. The conversion is straight forward
as the ICU found inside the socs allows the usage of irq_domain_add_linear.

Harware IRQ 0->7 are the generic MIPS IRQs. 8->199 are the Lantiq IRQ Modules.
Our irq_chip callbacks need to substract 8 (MIPS_CPU_IRQ_CASCADE) from d->hwirq
to find out the correct offset into the Interrupt Modules register range.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3802/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
  • Loading branch information
@ralfbaechle
John Crispin authored and ralfbaechle committed May 21, 2012
1 parent a039222 commit 3645da0
Showing 1 changed file with 102 additions and 76 deletions.
178 changes: 102 additions & 76 deletions arch/mips/lantiq/irq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,14 +9,19 @@

#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/irqdomain.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

#include <asm/bootinfo.h>
#include <asm/irq_cpu.h>

#include <lantiq_soc.h>
#include <irq.h>

/* register definitions */
/* register definitions - internal irqs */
#define LTQ_ICU_IM0_ISR 0x0000
#define LTQ_ICU_IM0_IER 0x0008
#define LTQ_ICU_IM0_IOSR 0x0010
Expand All @@ -25,6 +30,7 @@
#define LTQ_ICU_IM1_ISR 0x0028
#define LTQ_ICU_OFFSET (LTQ_ICU_IM1_ISR - LTQ_ICU_IM0_ISR)

/* register definitions - external irqs */
#define LTQ_EIU_EXIN_C 0x0000
#define LTQ_EIU_EXIN_INIC 0x0004
#define LTQ_EIU_EXIN_INEN 0x000C
Expand All @@ -37,13 +43,14 @@
#define LTQ_EIU_IR4 (INT_NUM_IM1_IRL0 + 1)
#define LTQ_EIU_IR5 (INT_NUM_IM1_IRL0 + 2)
#define LTQ_EIU_IR6 (INT_NUM_IM2_IRL0 + 30)

#define XWAY_EXIN_COUNT 3
#define MAX_EIU 6

/* the performance counter */
#define LTQ_PERF_IRQ (INT_NUM_IM4_IRL0 + 31)

/* irqs generated by device attached to the EBU need to be acked in
/*
* irqs generated by devices attached to the EBU need to be acked in
* a special manner
*/
#define LTQ_ICU_EBU_IRQ 22
Expand All @@ -58,6 +65,9 @@
#define MIPS_CPU_IPI_RESCHED_IRQ 0
#define MIPS_CPU_IPI_CALL_IRQ 1

/* we have a cascade of 8 irqs */
#define MIPS_CPU_IRQ_CASCADE 8

#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
int gic_present;
#endif
Expand All @@ -71,64 +81,51 @@ static unsigned short ltq_eiu_irq[MAX_EIU] = {
LTQ_EIU_IR5,
};

static struct resource ltq_icu_resource = {
.name = "icu",
.start = LTQ_ICU_BASE_ADDR,
.end = LTQ_ICU_BASE_ADDR + LTQ_ICU_SIZE - 1,
.flags = IORESOURCE_MEM,
};

static struct resource ltq_eiu_resource = {
.name = "eiu",
.start = LTQ_EIU_BASE_ADDR,
.end = LTQ_EIU_BASE_ADDR + LTQ_ICU_SIZE - 1,
.flags = IORESOURCE_MEM,
};

static int exin_avail;
static void __iomem *ltq_icu_membase;
static void __iomem *ltq_eiu_membase;

void ltq_disable_irq(struct irq_data *d)
{
u32 ier = LTQ_ICU_IM0_IER;
int irq_nr = d->irq - INT_NUM_IRQ0;
int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;

ier += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
irq_nr %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) & ~(1 << irq_nr), ier);
ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET);
offset %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) & ~BIT(offset), ier);
}

void ltq_mask_and_ack_irq(struct irq_data *d)
{
u32 ier = LTQ_ICU_IM0_IER;
u32 isr = LTQ_ICU_IM0_ISR;
int irq_nr = d->irq - INT_NUM_IRQ0;
int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;

ier += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
isr += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
irq_nr %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) & ~(1 << irq_nr), ier);
ltq_icu_w32((1 << irq_nr), isr);
ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET);
isr += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET);
offset %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) & ~BIT(offset), ier);
ltq_icu_w32(BIT(offset), isr);
}

static void ltq_ack_irq(struct irq_data *d)
{
u32 isr = LTQ_ICU_IM0_ISR;
int irq_nr = d->irq - INT_NUM_IRQ0;
int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;

isr += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
irq_nr %= INT_NUM_IM_OFFSET;
ltq_icu_w32((1 << irq_nr), isr);
isr += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET);
offset %= INT_NUM_IM_OFFSET;
ltq_icu_w32(BIT(offset), isr);
}

void ltq_enable_irq(struct irq_data *d)
{
u32 ier = LTQ_ICU_IM0_IER;
int irq_nr = d->irq - INT_NUM_IRQ0;
int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;

ier += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
irq_nr %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) | (1 << irq_nr), ier);
ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET);
offset %= INT_NUM_IM_OFFSET;
ltq_icu_w32(ltq_icu_r32(ier) | BIT(offset), ier);
}

static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
Expand All @@ -137,15 +134,15 @@ static unsigned int ltq_startup_eiu_irq(struct irq_data *d)

ltq_enable_irq(d);
for (i = 0; i < MAX_EIU; i++) {
if (d->irq == ltq_eiu_irq[i]) {
if (d->hwirq == ltq_eiu_irq[i]) {
/* low level - we should really handle set_type */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) |
(0x6 << (i * 4)), LTQ_EIU_EXIN_C);
/* clear all pending */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INIC) & ~(1 << i),
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INIC) & ~BIT(i),
LTQ_EIU_EXIN_INIC);
/* enable */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | (1 << i),
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
LTQ_EIU_EXIN_INEN);
break;
}
Expand All @@ -160,9 +157,9 @@ static void ltq_shutdown_eiu_irq(struct irq_data *d)

ltq_disable_irq(d);
for (i = 0; i < MAX_EIU; i++) {
if (d->irq == ltq_eiu_irq[i]) {
if (d->hwirq == ltq_eiu_irq[i]) {
/* disable */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~(1 << i),
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
LTQ_EIU_EXIN_INEN);
break;
}
Expand Down Expand Up @@ -199,14 +196,15 @@ static void ltq_hw_irqdispatch(int module)
if (irq == 0)
return;

/* silicon bug causes only the msb set to 1 to be valid. all
/*
* silicon bug causes only the msb set to 1 to be valid. all
* other bits might be bogus
*/
irq = __fls(irq);
do_IRQ((int)irq + INT_NUM_IM0_IRL0 + (INT_NUM_IM_OFFSET * module));
do_IRQ((int)irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module));

/* if this is a EBU irq, we need to ack it or get a deadlock */
if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0))
if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT)
ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
LTQ_EBU_PCC_ISTAT);
}
Expand Down Expand Up @@ -290,38 +288,67 @@ asmlinkage void plat_irq_dispatch(void)
return;
}

static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
struct irq_chip *chip = &ltq_irq_type;
int i;

for (i = 0; i < exin_avail; i++)
if (hw == ltq_eiu_irq[i])
chip = &ltq_eiu_type;

irq_set_chip_and_handler(hw, chip, handle_level_irq);

return 0;
}

static const struct irq_domain_ops irq_domain_ops = {
.xlate = irq_domain_xlate_onetwocell,
.map = icu_map,
};

static struct irqaction cascade = {
.handler = no_action,
.name = "cascade",
};

void __init arch_init_irq(void)
int __init icu_of_init(struct device_node *node, struct device_node *parent)
{
struct device_node *eiu_node;
struct resource res;
int i;

if (insert_resource(&iomem_resource, &ltq_icu_resource) < 0)
panic("Failed to insert icu memory");
if (of_address_to_resource(node, 0, &res))
panic("Failed to get icu memory range");

if (request_mem_region(ltq_icu_resource.start,
resource_size(&ltq_icu_resource), "icu") < 0)
panic("Failed to request icu memory");
if (request_mem_region(res.start, resource_size(&res), res.name) < 0)
pr_err("Failed to request icu memory");

ltq_icu_membase = ioremap_nocache(ltq_icu_resource.start,
resource_size(&ltq_icu_resource));
ltq_icu_membase = ioremap_nocache(res.start, resource_size(&res));
if (!ltq_icu_membase)
panic("Failed to remap icu memory");

if (insert_resource(&iomem_resource, &ltq_eiu_resource) < 0)
panic("Failed to insert eiu memory");

if (request_mem_region(ltq_eiu_resource.start,
resource_size(&ltq_eiu_resource), "eiu") < 0)
panic("Failed to request eiu memory");

ltq_eiu_membase = ioremap_nocache(ltq_eiu_resource.start,
resource_size(&ltq_eiu_resource));
if (!ltq_eiu_membase)
panic("Failed to remap eiu memory");
/* the external interrupts are optional and xway only */
eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu");
if (eiu_node && of_address_to_resource(eiu_node, 0, &res)) {
/* find out how many external irq sources we have */
const __be32 *count = of_get_property(node,
"lantiq,count", NULL);

if (count)
exin_avail = *count;
if (exin_avail > MAX_EIU)
exin_avail = MAX_EIU;

if (request_mem_region(res.start, resource_size(&res),
res.name) < 0)
pr_err("Failed to request eiu memory");

ltq_eiu_membase = ioremap_nocache(res.start,
resource_size(&res));
if (!ltq_eiu_membase)
panic("Failed to remap eiu memory");
}

/* turn off all irqs by default */
for (i = 0; i < 5; i++) {
Expand All @@ -346,20 +373,8 @@ void __init arch_init_irq(void)
set_vi_handler(7, ltq_hw5_irqdispatch);
}

for (i = INT_NUM_IRQ0;
i <= (INT_NUM_IRQ0 + (5 * INT_NUM_IM_OFFSET)); i++)
if ((i == LTQ_EIU_IR0) || (i == LTQ_EIU_IR1) ||
(i == LTQ_EIU_IR2))
irq_set_chip_and_handler(i, &ltq_eiu_type,
handle_level_irq);
/* EIU3-5 only exist on ar9 and vr9 */
else if (((i == LTQ_EIU_IR3) || (i == LTQ_EIU_IR4) ||
(i == LTQ_EIU_IR5)) && (ltq_is_ar9() || ltq_is_vr9()))
irq_set_chip_and_handler(i, &ltq_eiu_type,
handle_level_irq);
else
irq_set_chip_and_handler(i, &ltq_irq_type,
handle_level_irq);
irq_domain_add_linear(node, 6 * INT_NUM_IM_OFFSET,
&irq_domain_ops, 0);

#if defined(CONFIG_MIPS_MT_SMP)
if (cpu_has_vint) {
Expand All @@ -382,9 +397,20 @@ void __init arch_init_irq(void)

/* tell oprofile which irq to use */
cp0_perfcount_irq = LTQ_PERF_IRQ;
return 0;
}

unsigned int __cpuinit get_c0_compare_int(void)
{
return CP0_LEGACY_COMPARE_IRQ;
}

static struct of_device_id __initdata of_irq_ids[] = {
{ .compatible = "lantiq,icu", .data = icu_of_init },
{},
};

void __init arch_init_irq(void)
{
of_irq_init(of_irq_ids);
}

0 comments on commit 3645da0

Please sign in to comment.