irqchip: sunxi: Add irq controller driver

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
CC: Thomas Gleixner <tglx@linutronix.de>

Documentation/devicetree/bindings/interrupt-controller/allwinner,sunxi-ic.txt

+Allwinner Sunxi Interrupt Controller
+
+Required properties:
+
+- compatible : should be "allwinner,sunxi-ic"
+- reg : Specifies base physical address and size of the registers.
+- 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.
+
+The interrupt sources are as follows:
+
+0: ENMI
+1: UART0
+2: UART1
+3: UART2
+4: UART3
+5: IR0
+6: IR1
+7: I2C0
+8: I2C1
+9: I2C2
+10: SPI0
+11: SPI1
+12: SPI2
+13: SPDIF
+14: AC97
+15: TS
+16: I2S
+17: UART4
+18: UART5
+19: UART6
+20: UART7
+21: KEYPAD
+22: TIMER0
+23: TIMER1
+24: TIMER2
+25: TIMER3
+26: CAN
+27: DMA
+28: PIO
+29: TOUCH_PANEL
+30: AUDIO_CODEC
+31: LRADC
+32: SDMC0
+33: SDMC1
+34: SDMC2
+35: SDMC3
+36: MEMSTICK
+37: NAND
+38: USB0
+39: USB1
+40: USB2
+41: SCR
+42: CSI0
+43: CSI1
+44: LCDCTRL0
+45: LCDCTRL1
+46: MP
+47: DEFEBE0
+48: DEFEBE1
+49: PMU
+50: SPI3
+51: TZASC
+52: PATA
+53: VE
+54: SS
+55: EMAC
+56: SATA
+57: GPS
+58: HDMI
+59: TVE
+60: ACE
+61: TVD
+62: PS2_0
+63: PS2_1
+64: USB3
+65: USB4
+66: PLE_PFM
+67: TIMER4
+68: TIMER5
+69: GPU_GP
+70: GPU_GPMMU
+71: GPU_PP0
+72: GPU_PPMMU0
+73: GPU_PMU
+74: GPU_RSV0
+75: GPU_RSV1
+76: GPU_RSV2
+77: GPU_RSV3
+78: GPU_RSV4
+79: GPU_RSV5
+80: GPU_RSV6
+82: SYNC_TIMER0
+83: SYNC_TIMER1
+
+Example:
+
+intc: interrupt-controller {
+	compatible = "allwinner,sunxi-ic";
+	reg = <0x01c20400 0x400>;
+	interrupt-controller;
+	#interrupt-cells = <2>;
+};

drivers/irqchip/Makefile

 obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
+obj-$(CONFIG_ARCH_SUNXI)   += irq-sunxi.o

drivers/irqchip/irq-sunxi.c

+/*
+ * Allwinner A1X SoCs IRQ chip driver.
+ *
+ * Copyright (C) 2012 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * Based on code from
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Benn Huang <benn@allwinnertech.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <linux/irqchip/sunxi.h>
+
+#define SUNXI_IRQ_VECTOR_REG		0x00
+#define SUNXI_IRQ_PROTECTION_REG	0x08
+#define SUNXI_IRQ_NMI_CTRL_REG		0x0c
+#define SUNXI_IRQ_PENDING_REG(x)	(0x10 + 0x4 * x)
+#define SUNXI_IRQ_FIQ_PENDING_REG(x)	(0x20 + 0x4 * x)
+#define SUNXI_IRQ_ENABLE_REG(x)		(0x40 + 0x4 * x)
+#define SUNXI_IRQ_MASK_REG(x)		(0x50 + 0x4 * x)
+
+static void __iomem *sunxi_irq_base;
+static struct irq_domain *sunxi_irq_domain;
+
+void sunxi_irq_ack(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_PENDING_REG(reg));
+	writel(val | (1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_PENDING_REG(reg));
+}
+
+static void sunxi_irq_mask(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+	writel(val & ~(1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+}
+
+static void sunxi_irq_unmask(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+	writel(val | (1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+}
+
+static struct irq_chip sunxi_irq_chip = {
+	.name		= "sunxi_irq",
+	.irq_ack	= sunxi_irq_ack,
+	.irq_mask	= sunxi_irq_mask,
+	.irq_unmask	= sunxi_irq_unmask,
+};
+
+static int sunxi_irq_map(struct irq_domain *d, unsigned int virq,
+			 irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &sunxi_irq_chip,
+				 handle_level_irq);
+	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+	return 0;
+}
+
+static struct irq_domain_ops sunxi_irq_ops = {
+	.map = sunxi_irq_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int __init sunxi_of_init(struct device_node *node,
+				struct device_node *parent)
+{
+	sunxi_irq_base = of_iomap(node, 0);
+	if (!sunxi_irq_base)
+		panic("%s: unable to map IC registers\n",
+			node->full_name);
+
+	/* Disable all interrupts */
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(0));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(1));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(2));
+
+	/* Mask all the interrupts */
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(0));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(1));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(2));
+
+	/* Clear all the pending interrupts */
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(0));
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(1));
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(2));
+
+	/* Enable protection mode */
+	writel(0x01, sunxi_irq_base + SUNXI_IRQ_PROTECTION_REG);
+
+	/* Configure the external interrupt source type */
+	writel(0x00, sunxi_irq_base + SUNXI_IRQ_NMI_CTRL_REG);
+
+	sunxi_irq_domain = irq_domain_add_linear(node, 3 * 32,
+						 &sunxi_irq_ops, NULL);
+	if (!sunxi_irq_domain)
+		panic("%s: unable to create IRQ domain\n", node->full_name);
+
+	return 0;
+}
+
+static struct of_device_id sunxi_irq_dt_ids[] __initconst = {
+	{ .compatible = "allwinner,sunxi-ic", .data = sunxi_of_init }
+};
+
+void __init sunxi_init_irq(void)
+{
+	of_irq_init(sunxi_irq_dt_ids);
+}
+
+asmlinkage void __exception_irq_entry sunxi_handle_irq(struct pt_regs *regs)
+{
+	u32 irq, hwirq;
+
+	hwirq = readl(sunxi_irq_base + SUNXI_IRQ_VECTOR_REG) >> 2;
+	while (hwirq != 0) {
+		irq = irq_find_mapping(sunxi_irq_domain, hwirq);
+		handle_IRQ(irq, regs);
+		hwirq = readl(sunxi_irq_base + SUNXI_IRQ_VECTOR_REG) >> 2;
+	}
+}

include/linux/irqchip/sunxi.h

+/*
+ * Copyright 2012 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#ifndef __LINUX_IRQCHIP_SUNXI_H
+#define __LINUX_IRQCHIP_SUNXI_H
+
+#include <asm/exception.h>
+
+extern void sunxi_init_irq(void);
+
+extern asmlinkage void __exception_irq_entry sunxi_handle_irq(
+	struct pt_regs *regs);
+
+#endif