[PATCH v6 3/5] irqchip/irq-pruss-intc: Add logic for handling reserved interrupts

Grzegorz Jaszczyk
2020-09-16T00:57:49Z

From: Suman Anna <s-anna@ti.com>

The PRUSS INTC has a fixed number of output interrupt lines that are
connected to a number of processors or other PRUSS instances or other
devices (like DMA) on the SoC. The output interrupt lines 2 through 9
are usually connected to the main Arm host processor and are referred
to as host interrupts 0 through 7 from ARM/MPU perspective.

All of these 8 host interrupts are not always exclusively connected
to the Arm interrupt controller. Some SoCs have some interrupt lines
not connected to the Arm interrupt controller at all, while a few others
have the interrupt lines connected to multiple processors in which they
need to be partitioned as per SoC integration needs. For example, AM437x
and 66AK2G SoCs have 2 PRUSS instances each and have the host interrupt 5
connected to the other PRUSS, while AM335x has host interrupt 0 shared
between MPU and TSC_ADC and host interrupts 6 & 7 shared between MPU and
a DMA controller.

Add logic to the PRUSS INTC driver to ignore both these shared and
invalid interrupts.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
---
v5->v6:
- No change.
v4->v5:
- Rename: s/invalid_intr/irqs_reserved/
v3->v4:
- Due to changes in DT bindings which converts irqs-reserved
property from uint8-array to bitmask requested by Rob introduce
relevant changes in the driver.
- Merge the irqs-reserved and irqs-shared to one property since they
can be handled by one logic (relevant change was introduced to DT
binding).
- Update commit message.
v2->v3:
- Extra checks for (intc->irqs[i]) in error/remove path was moved from
"irqchip/irq-pruss-intc: Add a PRUSS irqchip driver for PRUSS
interrupts" to this patch
v1->v2:
- https://patchwork.kernel.org/patch/11069757/
---
drivers/irqchip/irq-pruss-intc.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-pruss-intc.c b/drivers/irqchip/irq-pruss-intc.c
index 319e431..396dc55 100644
--- a/drivers/irqchip/irq-pruss-intc.c
+++ b/drivers/irqchip/irq-pruss-intc.c
@@ -484,7 +484,7 @@ static int pruss_intc_probe(struct platform_device *pdev)
struct pruss_intc *intc;
struct pruss_host_irq_data *host_data;
int i, irq, ret;
- u8 max_system_events;
+ u8 max_system_events, irqs_reserved = 0;

data = of_device_get_match_data(dev);
if (!data)
@@ -504,6 +504,16 @@ static int pruss_intc_probe(struct platform_device *pdev)
if (IS_ERR(intc->base))
return PTR_ERR(intc->base);

+ ret = of_property_read_u8(dev->of_node, "ti,irqs-reserved",
+ &irqs_reserved);
+
+ /*
+ * The irqs-reserved is used only for some SoC's therefore not having
+ * this property is still valid
+ */
+ if (ret < 0 && ret != -EINVAL)
+ return ret;
+
pruss_intc_init(intc);

mutex_init(&intc->lock);
@@ -514,6 +524,9 @@ static int pruss_intc_probe(struct platform_device *pdev)
return -ENOMEM;

for (i = 0; i < MAX_NUM_HOST_IRQS; i++) {
+ if (irqs_reserved & BIT(i))
+ continue;
+
irq = platform_get_irq_byname(pdev, irq_names[i]);
if (irq <= 0) {
ret = (irq == 0) ? -EINVAL : irq;
@@ -538,8 +551,11 @@ static int pruss_intc_probe(struct platform_device *pdev)
return 0;

fail_irq:
- while (--i >= 0)
- irq_set_chained_handler_and_data(intc->irqs[i], NULL, NULL);
+ while (--i >= 0) {
+ if (intc->irqs[i])
+ irq_set_chained_handler_and_data(intc->irqs[i], NULL,
+ NULL);
+ }

irq_domain_remove(intc->domain);

@@ -553,8 +569,11 @@ static int pruss_intc_remove(struct platform_device *pdev)
unsigned int hwirq;
int i;

- for (i = 0; i < MAX_NUM_HOST_IRQS; i++)
- irq_set_chained_handler_and_data(intc->irqs[i], NULL, NULL);
+ for (i = 0; i < MAX_NUM_HOST_IRQS; i++) {
+ if (intc->irqs[i])
+ irq_set_chained_handler_and_data(intc->irqs[i], NULL,
+ NULL);
+ }

for (hwirq = 0; hwirq < max_system_events; hwirq++)
irq_dispose_mapping(irq_find_mapping(intc->domain, hwirq));
--
2.7.4