[PATCH v5 3/3] irqchip: add nps Internal and external irqchips

[Noam Camus <noamc@ezchip.com>]

From: Noam Camus <noamc@ezchip.com>

Adding EZchip NPS400 support.
NPS internal interrupts are internally handled at
Multi Thread Manager (MTM) that is signaled for deactivating
an interrupt.
External interrupts is handled also at Global Interrupt
Controller (GIC) e.g. serial and network devices.

Signed-off-by: Noam Camus <noamc@ezchip.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
---
 .../interrupt-controller/ezchip,nps400-ic.txt      |   17 +++
 drivers/irqchip/Kconfig                            |    6 +
 drivers/irqchip/Makefile                           |    1 +
 drivers/irqchip/irq-eznps.c                        |  149 ++++++++++++++++++++
 4 files changed, 173 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ezchip,nps400-ic.txt
 create mode 100644 drivers/irqchip/irq-eznps.c

diff --git a/Documentation/devicetree/bindings/interrupt-controller/ezchip,nps400-ic.txt b/Documentation/devicetree/bindings/interrupt-controller/ezchip,nps400-ic.txt
new file mode 100644
index 0000000..888b2b9
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/ezchip,nps400-ic.txt
@@ -0,0 +1,17 @@
+EZchip NPS Interrupt Controller
+
+Required properties:
+
+- compatible : should be "ezchip,nps400-ic"
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+  interrupt source. The value shall be 1.
+
+
+Example:
+
+intc: interrupt-controller {
+	compatible = "ezchip,nps400-ic";
+	interrupt-controller;
+	#interrupt-cells = <1>;
+};
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 4d7294e..bc5e775 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -193,3 +193,9 @@ config IRQ_MXS
 	def_bool y if MACH_ASM9260 || ARCH_MXS
 	select IRQ_DOMAIN
 	select STMP_DEVICE
+
+config EZNPS_GIC
+	bool "NPS400 Global Interrupt Manager (GIM)"
+	select IRQ_DOMAIN
+	help
+	  Support the EZchip NPS400 global interrupt controller
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 177f78f..1390142 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -55,3 +55,4 @@ obj-$(CONFIG_RENESAS_H8S_INTC)		+= irq-renesas-h8s.o
 obj-$(CONFIG_ARCH_SA1100)		+= irq-sa11x0.o
 obj-$(CONFIG_INGENIC_IRQ)		+= irq-ingenic.o
 obj-$(CONFIG_IMX_GPCV2)			+= irq-imx-gpcv2.o
+obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o
diff --git a/drivers/irqchip/irq-eznps.c b/drivers/irqchip/irq-eznps.c
new file mode 100644
index 0000000..9decd7d
--- /dev/null
+++ b/drivers/irqchip/irq-eznps.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright(c) 2015 EZchip Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <soc/nps/common.h>
+
+#define NPS_NR_CPU_IRQS 8  /* number of interrupt lines of NPS400 CPU */
+#define NPS_TIMER0_IRQ  3
+
+/*
+ * NPS400 core includes an Interrupt Controller (IC) support.
+ * All cores can deactivate level irqs at first level control
+ * at cores mesh layer called MTM.
+ * For devices out side chip e.g. uart, network there is another
+ * level called Global Interrupt Manager (GIM).
+ * This second level can control level and edge interrupt.
+ *
+ * NOTE: AUX_IENABLE and CTOP_AUX_IACK are auxiliary registers
+ * with private HW copy per CPU.
+ */
+
+static void nps400_irq_mask(struct irq_data *irqd)
+{
+	unsigned int ienb;
+	unsigned int irq = irqd_to_hwirq(irqd);
+
+	ienb = read_aux_reg(AUX_IENABLE);
+	ienb &= ~(1 << irq);
+	write_aux_reg(AUX_IENABLE, ienb);
+}
+
+static void nps400_irq_unmask(struct irq_data *irqd)
+{
+	unsigned int ienb;
+	unsigned int irq = irqd_to_hwirq(irqd);
+
+	ienb = read_aux_reg(AUX_IENABLE);
+	ienb |= (1 << irq);
+	write_aux_reg(AUX_IENABLE, ienb);
+}
+
+static void nps400_irq_eoi_global(struct irq_data *irqd)
+{
+	unsigned int __maybe_unused irq = irqd_to_hwirq(irqd);
+
+	write_aux_reg(CTOP_AUX_IACK, 1 << irq);
+
+	/* Don't ack GIC before all device access attempts are done */
+	mb();
+
+	nps_ack_gic();
+}
+
+static void nps400_irq_eoi(struct irq_data *irqd)
+{
+	unsigned int __maybe_unused irq = irqd_to_hwirq(irqd);
+
+	write_aux_reg(CTOP_AUX_IACK, 1 << irq);
+}
+
+static struct irq_chip nps400_irq_chip_fasteoi = {
+	.name		= "NPS400 IC Global",
+	.irq_mask	= nps400_irq_mask,
+	.irq_unmask	= nps400_irq_unmask,
+	.irq_eoi	= nps400_irq_eoi_global,
+};
+
+static struct irq_chip nps400_irq_chip_percpu = {
+	.name		= "NPS400 IC",
+	.irq_mask	= nps400_irq_mask,
+	.irq_unmask	= nps400_irq_unmask,
+	.irq_eoi	= nps400_irq_eoi,
+};
+
+static int nps400_irq_map(struct irq_domain *d, unsigned int virq,
+			  irq_hw_number_t hw)
+{
+	switch (hw) {
+	case NPS_TIMER0_IRQ:
+#ifdef CONFIG_SMP
+	case IPI_IRQ:
+#endif
+		irq_set_percpu_devid(virq);
+		irq_set_chip_and_handler(virq, &nps400_irq_chip_percpu,
+					 handle_percpu_devid_irq);
+		break;
+	default:
+		irq_set_chip_and_handler(virq, &nps400_irq_chip_fasteoi,
+					 handle_fasteoi_irq);
+		break;
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops nps400_irq_ops = {
+	.xlate = irq_domain_xlate_onecell,
+	.map = nps400_irq_map,
+};
+
+static int __init nps400_of_init(struct device_node *node,
+				 struct device_node *parent)
+{
+	static struct irq_domain *nps400_root_domain;
+
+	if (parent) {
+		pr_err("DeviceTree incore ic not a root irq controller\n");
+		return -EINVAL;
+	}
+
+	nps400_root_domain = irq_domain_add_linear(node, NPS_NR_CPU_IRQS,
+						   &nps400_irq_ops, NULL);
+
+	if (!nps400_root_domain) {
+		pr_err("nps400 root irq domain not avail\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * Needed for primary domain lookup to succeed
+	 * This is a primary irqchip, and can never have a parent
+	 */
+	irq_set_default_host(nps400_root_domain);
+
+#ifdef CONFIG_SMP
+	irq_create_mapping(nps400_root_domain, IPI_IRQ);
+#endif
+
+	return 0;
+}
+IRQCHIP_DECLARE(ezchip_nps400_ic, "ezchip,nps400-ic", nps400_of_init);
-- 
1.7.1