[PATCH v2 09/16] ARM: pxa: support ICP DAS LP-8x4x FPGA irq

Sergei Ianovich
2013-12-13T02:27:18Z

ICP DAS LP-8x4x contains FPGA chip. The chip functions as a interrupt
source providing 16 additional interrupts among other things. The
interrupt lines are muxed to a GPIO pin. GPIO pins are in turn muxed
to a CPU interrupt line.

Until pxa is completely converted to device tree, it is impossible
to use IRQCHIP_DECLARE() and the irqdomain needs to added manually.

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Linus Walleij <linus.walleij@linaro.org>
---
v0..v2
* extract irqchip and move to drivers/irqchip/
* use device tree
* use devm helpers where possible

.../bindings/interrupt-controller/irq-lp8x4x.txt | 49 +++++
arch/arm/boot/dts/pxa27x-lp8x4x.dts | 10 +
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-lp8x4x.c | 205 +++++++++++++++++++++
5 files changed, 270 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
create mode 100644 drivers/irqchip/irq-lp8x4x.c

diff --git a/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
new file mode 100644
index 0000000..c8940d2
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
@@ -0,0 +1,49 @@
+ICP DAS LP-8x4x FPGA Interrupt Controller
+
+ICP DAS LP-8x4x contains FPGA chip. The chip functions as a interrupt
+source providing 16 additional interrupts among other things.
+
+Required properties:
+- compatible : should be "icpdas,irq-lp8x4x"
+
+- reg: physical base address of the controller and length of memory mapped
+ region.
+
+- interrupt-controller : identifies the node as an interrupt controller
+
+- #interrupt-cells : should be 1
+
+- interrupts : should provide interrupt
+
+- interrupt-parent : should provide a link to interrupt controller either
+ explicitly and implicitly from a parent node
+
+Example:
+
+ fpga: fpga at 17000006 {
+ compatible = "icpdas,irq-lp8x4x";
+ reg = <0x17000006 0x16>;
+ interrupt-parent = <&gpio>;
+ interrupts = <3 IRQ_TYPE_EDGE_RISING>;
+ #interrupt-cells = <1>;
+ interrupt-controller;
+ status = "okay";
+ };
+
+ uart at 17009050 {
+ compatible = "icpdas,uart-lp8x4x";
+ reg = <0x17009050 0x10
+ 0x17009030 0x02>;
+ interrupt-parent = <&fpga>;
+ interrupts = <13>;
+ status = "okay";
+ };
+
+ uart at 17009060 {
+ compatible = "icpdas,uart-lp8x4x";
+ reg = <0x17009060 0x10
+ 0x17009032 0x02>;
+ interrupt-parent = <&fpga>;
+ interrupts = <14>;
+ status = "okay";
+ };
diff --git a/arch/arm/boot/dts/pxa27x-lp8x4x.dts b/arch/arm/boot/dts/pxa27x-lp8x4x.dts
index b7f8cfc..2704760 100644
--- a/arch/arm/boot/dts/pxa27x-lp8x4x.dts
+++ b/arch/arm/boot/dts/pxa27x-lp8x4x.dts
@@ -119,5 +119,15 @@
reg = <0x1700901c 0x1>;
status = "okay";
};
+
+ fpga: fpga at 17009006 {
+ compatible = "icpdas,irq-lp8x4x";
+ reg = <0x17009006 0x16>;
+ interrupt-parent = <&gpio>;
+ interrupts = <3 IRQ_TYPE_EDGE_BOTH>;
+ #interrupt-cells = <1>;
+ interrupt-controller;
+ status = "okay";
+ };
};
};
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3792a1a..7e22729 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -35,6 +35,11 @@ config IMGPDC_IRQ
select GENERIC_IRQ_CHIP
select IRQ_DOMAIN

+config LP8X4X_IRQ
+ bool
+ depends on OF
+ select IRQ_DOMAIN
+
config ORION_IRQCHIP
bool
select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b901..8a28927 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_RENESAS_IRQC) += irq-renesas-irqc.o
obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o
+obj-$(CONFIG_LP8X4X_IRQ) += irq-lp8x4x.o
diff --git a/drivers/irqchip/irq-lp8x4x.c b/drivers/irqchip/irq-lp8x4x.c
new file mode 100644
index 0000000..5d44880b
--- /dev/null
+++ b/drivers/irqchip/irq-lp8x4x.c
@@ -0,0 +1,205 @@
+/*
+ * linux/drivers/irqchip/irq-lp8x4x.c
+ *
+ * Support for ICP DAS LP-8x4x FPGA irq
+ * Copyright (C) 2013 Sergei Ianovich <ynvich@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation or any later version.
+ */
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define EOI 0x00000000
+#define INSINT 0x00000002
+#define ENSYSINT 0x00000004
+#define PRIMINT 0x00000006
+#define SECOINT 0x00000008
+#define ENRISEINT 0x0000000A
+#define CLRRISEINT 0x0000000C
+#define ENHILVINT 0x0000000E
+#define CLRHILVINT 0x00000010
+#define ENFALLINT 0x00000012
+#define CLRFALLINT 0x00000014
+#define LP8X4X_IRQ_MEM_SIZE 0x00000016
+
+static unsigned char irq_sys_enabled;
+static unsigned char irq_high_enabled;
+static void *base;
+static int irq_base;
+static int num_irq = 16;
+
+static void lp8x4x_mask_irq(struct irq_data *d)
+{
+ unsigned mask;
+ int irq = d->irq - irq_base;
+
+ if (irq < 0 || irq > 15) {
+ pr_err("lp8x4x: wrong irq handler for irq %i\n", d->irq);
+ return;
+ }
+
+ if (irq < 8) {
+ irq_high_enabled &= ~(1 << irq);
+
+ mask = ioread8(base + ENHILVINT);
+ mask &= ~(1 << irq);
+ iowrite8(mask, base + ENHILVINT);
+ } else {
+ irq -= 8;
+ irq_sys_enabled &= ~(1 << irq);
+
+ mask = ioread8(base + ENSYSINT);
+ mask &= ~(1 << irq);
+ iowrite8(mask, base + ENSYSINT);
+ }
+}
+
+static void lp8x4x_unmask_irq(struct irq_data *d)
+{
+ unsigned mask;
+ int irq = d->irq - irq_base;
+
+ if (irq < 0 || irq > 15) {
+ pr_err("wrong irq handler for irq %i\n", d->irq);
+ return;
+ }
+
+ if (irq < 8) {
+ irq_high_enabled |= 1 << irq;
+ mask = ioread8(base + CLRHILVINT);
+ mask |= 1 << irq;
+ iowrite8(mask, base + CLRHILVINT);
+
+ mask = ioread8(base + ENHILVINT);
+ mask |= 1 << irq;
+ iowrite8(mask, base + ENHILVINT);
+ } else {
+ irq -= 8;
+ irq_sys_enabled |= 1 << irq;
+
+ mask = ioread8(base + SECOINT);
+ mask |= 1 << irq;
+ iowrite8(mask, base + SECOINT);
+
+ mask = ioread8(base + ENSYSINT);
+ mask |= 1 << irq;
+ iowrite8(mask, base + ENSYSINT);
+ }
+}
+
+static struct irq_chip lp8x4x_irq_chip = {
+ .name = "FPGA",
+ .irq_ack = lp8x4x_mask_irq,
+ .irq_mask = lp8x4x_mask_irq,
+ .irq_mask_ack = lp8x4x_mask_irq,
+ .irq_unmask = lp8x4x_unmask_irq,
+};
+
+static void lp8x4x_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+ int loop, n;
+ unsigned long mask;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ chained_irq_enter(chip, desc);
+
+ do {
+ loop = 0;
+ mask = ioread8(base + CLRHILVINT) & 0xff;
+ mask |= (ioread8(base + SECOINT) & 0x1f) << 8;
+ mask |= (ioread8(base + PRIMINT) & 0xe0) << 8;
+ mask &= (irq_high_enabled | (irq_sys_enabled << 8));
+ for_each_set_bit(n, &mask, BITS_PER_LONG) {
+ loop = 1;
+
+ generic_handle_irq(irq_base + n);
+ }
+ } while (loop);
+
+ iowrite8(0, base + EOI);
+ chained_irq_exit(chip, desc);
+}
+
+static int lp8x4x_irq_domain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(irq, &lp8x4x_irq_chip,
+ handle_level_irq);
+ set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+ return 0;
+}
+
+const struct irq_domain_ops lp8x4x_irq_domain_ops = {
+ .map = lp8x4x_irq_domain_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static struct of_device_id lp8x4x_irq_dt_ids[] = {
+ { .compatible = "icpdas,irq-lp8x4x", },
+ {}
+};
+
+static int lp8x4x_irq_probe(struct platform_device *pdev)
+{
+ struct resource *rm, *ri;
+ struct device_node *np = pdev->dev.of_node;
+ struct irq_domain *domain;
+
+ rm = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ri = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!rm || !ri || resource_size(rm) < LP8X4X_IRQ_MEM_SIZE)
+ return -ENODEV;
+
+ base = devm_ioremap_resource(&pdev->dev, rm);
+ if (!base) {
+ dev_err(&pdev->dev, "Failed to ioremap %p\n", base);
+ return -EFAULT;
+ }
+
+ irq_base = irq_alloc_descs(-1, 0, num_irq, 0);
+ if (irq_base < 0) {
+ dev_err(&pdev->dev, "Failed to allocate IRQ numbers\n");
+ return irq_base;
+ }
+
+ domain = irq_domain_add_legacy(np, num_irq, irq_base, 0,
+ &lp8x4x_irq_domain_ops, NULL);
+ if (!domain) {
+ dev_err(&pdev->dev, "Failed to add IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ iowrite8(0, base + CLRRISEINT);
+ iowrite8(0, base + ENRISEINT);
+ iowrite8(0, base + CLRFALLINT);
+ iowrite8(0, base + ENFALLINT);
+ iowrite8(0, base + CLRHILVINT);
+ iowrite8(0, base + ENHILVINT);
+ iowrite8(0, base + ENSYSINT);
+ iowrite8(0, base + SECOINT);
+
+ irq_set_chained_handler(ri->start, lp8x4x_irq_handler);
+
+ return 0;
+}
+
+static struct platform_driver lp8x4x_irq_driver = {
+ .probe = lp8x4x_irq_probe,
+ .driver = {
+ .name = "irq-lp8x4x",
+ .of_match_table = lp8x4x_irq_dt_ids,
+ },
+};
+
+static int __init lp8x4x_irq_init(void)
+{
+ return platform_driver_register(&lp8x4x_irq_driver);
+}
+postcore_initcall(lp8x4x_irq_init);
--
1.8.4.3