[Patch v5 02/12] irqchip: xilinx: Clean up irqdomain argument and read/write

From: Zubair Lutfullah Kakakhel
Date: Mon Oct 17 2016 - 12:53:45 EST


The drivers read/write function handling is a bit quirky.
And the irqmask is passed directly to the handler.

Add a new irqchip struct to pass to the handler and
cleanup read/write handling.

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@xxxxxxxxxx>

---
V4 -> V5
Rebased to v4.9-rc1
Better error handling

V3 -> V4
Better error handling for kzalloc
Erroring out if the axi intc is probed twice as that isn't
supported

V2 -> V3
New patch. Cleans up driver structure
---
drivers/irqchip/irq-xilinx-intc.c | 105 ++++++++++++++++++++++++++------------
1 file changed, 72 insertions(+), 33 deletions(-)

diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c
index 90bec7d..fe533e1 100644
--- a/drivers/irqchip/irq-xilinx-intc.c
+++ b/drivers/irqchip/irq-xilinx-intc.c
@@ -16,8 +16,6 @@
#include <linux/io.h>
#include <linux/bug.h>

-static void __iomem *intc_baseaddr;
-
/* No one else should require these constants, so define them locally here. */
#define ISR 0x00 /* Interrupt Status Register */
#define IPR 0x04 /* Interrupt Pending Register */
@@ -31,8 +29,16 @@
#define MER_ME (1<<0)
#define MER_HIE (1<<1)

-static unsigned int (*read_fn)(void __iomem *);
-static void (*write_fn)(u32, void __iomem *);
+struct xintc_irq_chip {
+ void __iomem *base;
+ struct irq_domain *domain;
+ struct irq_chip chip;
+ u32 intr_mask;
+ unsigned int (*read)(void __iomem *iomem);
+ void (*write)(u32 data, void __iomem *iomem);
+};
+
+static struct xintc_irq_chip *xintc_irqc;

static void intc_write32(u32 val, void __iomem *addr)
{
@@ -54,6 +60,18 @@ static unsigned int intc_read32_be(void __iomem *addr)
return ioread32be(addr);
}

+static inline unsigned int xintc_read(struct xintc_irq_chip *xintc_irqc,
+ int reg)
+{
+ return xintc_irqc->read(xintc_irqc->base + reg);
+}
+
+static inline void xintc_write(struct xintc_irq_chip *xintc_irqc,
+ int reg, u32 data)
+{
+ xintc_irqc->write(data, xintc_irqc->base + reg);
+}
+
static void intc_enable_or_unmask(struct irq_data *d)
{
unsigned long mask = 1 << d->hwirq;
@@ -65,21 +83,21 @@ static void intc_enable_or_unmask(struct irq_data *d)
* acks the irq before calling the interrupt handler
*/
if (irqd_is_level_type(d))
- write_fn(mask, intc_baseaddr + IAR);
+ xintc_write(xintc_irqc, IAR, mask);

- write_fn(mask, intc_baseaddr + SIE);
+ xintc_write(xintc_irqc, SIE, mask);
}

static void intc_disable_or_mask(struct irq_data *d)
{
pr_debug("disable: %ld\n", d->hwirq);
- write_fn(1 << d->hwirq, intc_baseaddr + CIE);
+ xintc_write(xintc_irqc, CIE, 1 << d->hwirq);
}

static void intc_ack(struct irq_data *d)
{
pr_debug("ack: %ld\n", d->hwirq);
- write_fn(1 << d->hwirq, intc_baseaddr + IAR);
+ xintc_write(xintc_irqc, IAR, 1 << d->hwirq);
}

static void intc_mask_ack(struct irq_data *d)
@@ -87,8 +105,8 @@ static void intc_mask_ack(struct irq_data *d)
unsigned long mask = 1 << d->hwirq;

pr_debug("disable_and_ack: %ld\n", d->hwirq);
- write_fn(mask, intc_baseaddr + CIE);
- write_fn(mask, intc_baseaddr + IAR);
+ xintc_write(xintc_irqc, CIE, mask);
+ xintc_write(xintc_irqc, IAR, mask);
}

static struct irq_chip intc_dev = {
@@ -105,7 +123,7 @@ unsigned int get_irq(void)
{
unsigned int hwirq, irq = -1;

- hwirq = read_fn(intc_baseaddr + IVR);
+ hwirq = xintc_read(xintc_irqc, IVR);
if (hwirq != -1U)
irq = irq_find_mapping(root_domain, hwirq);

@@ -116,7 +134,8 @@ unsigned int get_irq(void)

static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
- u32 intr_mask = (u32)d->host_data;
+ struct xintc_irq_chip *irqc = d->host_data;
+ u32 intr_mask = irqc->intr_mask;

if (intr_mask & (1 << hw)) {
irq_set_chip_and_handler_name(irq, &intc_dev,
@@ -138,59 +157,79 @@ static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
static int __init xilinx_intc_of_init(struct device_node *intc,
struct device_node *parent)
{
- u32 nr_irq, intr_mask;
+ u32 nr_irq;
int ret;
+ struct xintc_irq_chip *irqc;
+
+ if (xintc_irqc) {
+ pr_err("%s: Multiple instances of xilinx_intc aren't supported\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
+ if (!irqc)
+ return -ENOMEM;

- intc_baseaddr = of_iomap(intc, 0);
- BUG_ON(!intc_baseaddr);
+ xintc_irqc = irqc;
+
+ irqc->base = of_iomap(intc, 0);
+ BUG_ON(!irqc->base);

ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
if (ret < 0) {
pr_err("%s: unable to read xlnx,num-intr-inputs\n", __func__);
- return ret;
+ goto err_alloc;
}

- ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &intr_mask);
+ ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
if (ret < 0) {
pr_err("%s: unable to read xlnx,kind-of-intr\n", __func__);
- return ret;
+ goto err_alloc;
}

- if (intr_mask >> nr_irq)
+ if (irqc->intr_mask >> nr_irq)
pr_warn("%s: mismatch in kind-of-intr param\n", __func__);

pr_info("%s: num_irq=%d, edge=0x%x\n",
- intc->full_name, nr_irq, intr_mask);
+ intc->full_name, nr_irq, irqc->intr_mask);

- write_fn = intc_write32;
- read_fn = intc_read32;
+ irqc->read = intc_read32;
+ irqc->write = intc_write32;

/*
* Disable all external interrupts until they are
* explicity requested.
*/
- write_fn(0, intc_baseaddr + IER);
+ xintc_write(irqc, IER, 0);

/* Acknowledge any pending interrupts just in case. */
- write_fn(0xffffffff, intc_baseaddr + IAR);
+ xintc_write(irqc, IAR, 0xffffffff);

/* Turn on the Master Enable. */
- write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
- if (!(read_fn(intc_baseaddr + MER) & (MER_HIE | MER_ME))) {
- write_fn = intc_write32_be;
- read_fn = intc_read32_be;
- write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
+ xintc_write(irqc, MER, MER_HIE | MER_ME);
+ if (!(xintc_read(irqc, MER) & (MER_HIE | MER_ME))) {
+ irqc->read = intc_read32_be;
+ irqc->write = intc_write32_be;
+ xintc_write(irqc, MER, MER_HIE | MER_ME);
}

- /* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
- * lazy and Michal can clean it up to something nicer when he tests
- * and commits this patch. ~~gcl */
root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
- (void *)intr_mask);
+ irqc);
+ if (!root_domain) {
+ pr_err("%s: Unable to create IRQ domain\n", __func__);
+ goto err_alloc;
+ }

irq_set_default_host(root_domain);

return 0;
+
+err_alloc:
+ xintc_irqc = NULL;
+ kfree(irqc);
+ return ret;
+
}

IRQCHIP_DECLARE(xilinx_intc, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
--
1.9.1