[PATCH 01/02] irqchip: renesas-intc-irqpin: r8a7779 IRLM setup support

From: Magnus Damm
Date: Wed Dec 03 2014 - 07:15:34 EST

From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>

Add r8a7779 specific support for IRLM bit configuration
in the INTC-IRQPIN driver. Without this code we need
special workaround code in arch/arm/mach-shmobile.

The IRLM bit for the INTC hardware exists on various
older SH-based SoCs and is used to select between two
modes for the external interrupt pins IRQ0 to IRQ3:

IRLM = 0: (default from reset on r8a7779)
In this mode the pins IRQ0 to IRQ3 are used together
to give a value between 0 and 15 to the SoC. External
logic is required for masking. This mode is not
supported by the INTC-IRQPIN driver.

IRLM = 1: (needs this patch or configuration elsewhere)
In this mode IRQ0 to IRQ3 operate as 4 individual
external interrupt pins. In this mode the SMSC ethernet
chip can be used via IRQ1 on r8a7779 Marzen. This mode
is the only supported mode by the INTC-IRQPIN driver.

For this patch to work the r8a7779 DTS needs to pass
the ICR0 register as the last register bank.

Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---

Written against renesas-devel-20141202-v3.18-rc7 which is
basically v3.18-rc7 plus latest arch/arm/mach-shmobile code.

Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt | 5 +
drivers/irqchip/irq-renesas-intc-irqpin.c | 50 ++++++++--
2 files changed, 46 insertions(+), 9 deletions(-)

--- 0001/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
+++ work/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt 2014-12-03 20:25:13.000000000 +0900
@@ -9,6 +9,11 @@ Required properties:
- "renesas,intc-irqpin-r8a7778" (R-Car M1A)
- "renesas,intc-irqpin-r8a7779" (R-Car H1)
- "renesas,intc-irqpin-sh73a0" (SH-Mobile AG5)
+
+- reg: Base address and length of each register bank used by the external
+ IRQ pins driven by the interrupt controller hardware module. The base
+ addresses, length and number of required register banks varies with soctype.
+
- #interrupt-cells: has to be <2>: an interrupt index and flags, as defined in
interrupts.txt in this directory

--- 0001/drivers/irqchip/irq-renesas-intc-irqpin.c
+++ work/drivers/irqchip/irq-renesas-intc-irqpin.c 2014-12-03 20:32:59.000000000 +0900
@@ -30,6 +30,7 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/of_device.h>
#include <linux/platform_data/irq-renesas-intc-irqpin.h>
#include <linux/pm_runtime.h>

@@ -40,7 +41,9 @@
#define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
#define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
#define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
-#define INTC_IRQPIN_REG_NR 5
+#define INTC_IRQPIN_REG_NR_MANDATORY 5
+#define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
+#define INTC_IRQPIN_REG_NR 6

/* INTC external IRQ PIN hardware register access:
*
@@ -82,6 +85,10 @@ struct intc_irqpin_priv {
u8 shared_irq_mask;
};

+struct intc_irqpin_irlm_config {
+ unsigned int irlm_bit;
+};
+
static unsigned long intc_irqpin_read32(void __iomem *iomem)
{
return ioread32(iomem);
@@ -345,10 +352,23 @@ static struct irq_domain_ops intc_irqpin
.xlate = irq_domain_xlate_twocell,
};

+static const struct intc_irqpin_irlm_config intc_irqpin_irlm_r8a7779 = {
+ .irlm_bit = 23, /* ICR0.IRLM0 */
+};
+
+static const struct of_device_id intc_irqpin_dt_ids[] = {
+ { .compatible = "renesas,intc-irqpin", },
+ { .compatible = "renesas,intc-irqpin-r8a7779",
+ .data = &intc_irqpin_irlm_r8a7779 },
+ {},
+};
+MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
+
static int intc_irqpin_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct renesas_intc_irqpin_config *pdata = dev->platform_data;
+ const struct of_device_id *of_id;
struct intc_irqpin_priv *p;
struct intc_irqpin_iomem *i;
struct resource *io[INTC_IRQPIN_REG_NR];
@@ -391,10 +411,11 @@ static int intc_irqpin_probe(struct plat
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);

- /* get hold of manadatory IOMEM */
+ /* get hold of register banks */
+ memset(io, 0, sizeof(io));
for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
- if (!io[k]) {
+ if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
dev_err(dev, "not enough IOMEM resources\n");
ret = -EINVAL;
goto err0;
@@ -422,6 +443,10 @@ static int intc_irqpin_probe(struct plat
for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
i = &p->iomem[k];

+ /* handle optional registers */
+ if (!io[k])
+ continue;
+
switch (resource_size(io[k])) {
case 1:
i->width = 8;
@@ -448,6 +473,19 @@ static int intc_irqpin_probe(struct plat
}
}

+ /* configure "individual IRQ mode" where needed */
+ of_id = of_match_device(intc_irqpin_dt_ids, dev);
+ if (of_id && of_id->data) {
+ const struct intc_irqpin_irlm_config *irlm_config = of_id->data;
+
+ if (io[INTC_IRQPIN_REG_IRLM])
+ intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
+ irlm_config->irlm_bit,
+ 1, 1);
+ else
+ dev_warn(dev, "unable to select IRLM mode\n");
+ }
+
/* mask all interrupts using priority */
for (k = 0; k < p->number_of_irqs; k++)
intc_irqpin_mask_unmask_prio(p, k, 1);
@@ -550,12 +588,6 @@ static int intc_irqpin_remove(struct pla
return 0;
}

-static const struct of_device_id intc_irqpin_dt_ids[] = {
- { .compatible = "renesas,intc-irqpin", },
- {},
-};
-MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
-
static struct platform_driver intc_irqpin_device_driver = {
.probe = intc_irqpin_probe,
.remove = intc_irqpin_remove,
--
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