irqchip: davinci-aintc: move the driver to drivers/irqchip

The aintc driver has now been cleaned up. Move it to drivers/irqchip
where it belongs. There's no device-tree support for any dm* board so
there's no IRQCHIP_OF_DECLARE() - there's only the exported init
function called from machine code.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: David Lechner <david@lechnology.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

3 files changed, 169 insertions, 0 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3d1e60779078..ea0eb82bf1d2 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -129,6 +129,11 @@ config BRCMSTB_L2_IRQ
 	select GENERIC_IRQ_CHIP
 	select IRQ_DOMAIN
 
+config DAVINCI_AINTC
+	bool
+	select GENERIC_IRQ_CHIP
+	select IRQ_DOMAIN
+
 config DW_APB_ICTL
 	bool
 	select GENERIC_IRQ_CHIP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c93713d24b86..623e0ec5f9d0 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_ATH79)			+= irq-ath79-cpu.o
 obj-$(CONFIG_ATH79)			+= irq-ath79-misc.o
 obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2835.o
 obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2836.o
+obj-$(CONFIG_DAVINCI_AINTC)		+= irq-davinci-aintc.o
 obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-combiner.o
 obj-$(CONFIG_FARADAY_FTINTC010)		+= irq-ftintc010.o
 obj-$(CONFIG_ARCH_HIP04)		+= irq-hip04.o
diff --git a/drivers/irqchip/irq-davinci-aintc.c b/drivers/irqchip/irq-davinci-aintc.c
new file mode 100644
index 000000000000..810ccc4fe476
--- /dev/null
+++ b/drivers/irqchip/irq-davinci-aintc.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Copyright (C) 2006, 2019 Texas Instruments.
+//
+// Interrupt handler for DaVinci boards.
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip/irq-davinci-aintc.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+
+#include <asm/exception.h>
+
+#define DAVINCI_AINTC_FIQ_REG0		0x00
+#define DAVINCI_AINTC_FIQ_REG1		0x04
+#define DAVINCI_AINTC_IRQ_REG0		0x08
+#define DAVINCI_AINTC_IRQ_REG1		0x0c
+#define DAVINCI_AINTC_IRQ_IRQENTRY	0x14
+#define DAVINCI_AINTC_IRQ_ENT_REG0	0x18
+#define DAVINCI_AINTC_IRQ_ENT_REG1	0x1c
+#define DAVINCI_AINTC_IRQ_INCTL_REG	0x20
+#define DAVINCI_AINTC_IRQ_EABASE_REG	0x24
+#define DAVINCI_AINTC_IRQ_INTPRI0_REG	0x30
+#define DAVINCI_AINTC_IRQ_INTPRI7_REG	0x4c
+
+static void __iomem *davinci_aintc_base;
+static struct irq_domain *davinci_aintc_irq_domain;
+
+static inline void davinci_aintc_writel(unsigned long value, int offset)
+{
+	writel_relaxed(value, davinci_aintc_base + offset);
+}
+
+static inline unsigned long davinci_aintc_readl(int offset)
+{
+	return readl_relaxed(davinci_aintc_base + offset);
+}
+
+static __init void
+davinci_aintc_setup_gc(void __iomem *base,
+		       unsigned int irq_start, unsigned int num)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	gc = irq_get_domain_generic_chip(davinci_aintc_irq_domain, irq_start);
+	gc->reg_base = base;
+	gc->irq_base = irq_start;
+
+	ct = gc->chip_types;
+	ct->chip.irq_ack = irq_gc_ack_set_bit;
+	ct->chip.irq_mask = irq_gc_mask_clr_bit;
+	ct->chip.irq_unmask = irq_gc_mask_set_bit;
+
+	ct->regs.ack = DAVINCI_AINTC_IRQ_REG0;
+	ct->regs.mask = DAVINCI_AINTC_IRQ_ENT_REG0;
+	irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
+			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+}
+
+static asmlinkage void __exception_irq_entry
+davinci_aintc_handle_irq(struct pt_regs *regs)
+{
+	int irqnr = davinci_aintc_readl(DAVINCI_AINTC_IRQ_IRQENTRY);
+
+	/*
+	 * Use the formula for entry vector index generation from section
+	 * 8.3.3 of the manual.
+	 */
+	irqnr >>= 2;
+	irqnr -= 1;
+
+	handle_domain_irq(davinci_aintc_irq_domain, irqnr, regs);
+}
+
+/* ARM Interrupt Controller Initialization */
+void __init davinci_aintc_init(const struct davinci_aintc_config *config)
+{
+	unsigned int irq_off, reg_off, prio, shift;
+	void __iomem *req;
+	int ret, irq_base;
+	const u8 *prios;
+
+	req = request_mem_region(config->reg.start,
+				 resource_size(&config->reg),
+				 "davinci-cp-intc");
+	if (!req) {
+		pr_err("%s: register range busy\n", __func__);
+		return;
+	}
+
+	davinci_aintc_base = ioremap(config->reg.start,
+				     resource_size(&config->reg));
+	if (!davinci_aintc_base) {
+		pr_err("%s: unable to ioremap register range\n", __func__);
+		return;
+	}
+
+	/* Clear all interrupt requests */
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG0);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG1);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG0);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG1);
+
+	/* Disable all interrupts */
+	davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_ENT_REG0);
+	davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_ENT_REG1);
+
+	/* Interrupts disabled immediately, IRQ entry reflects all */
+	davinci_aintc_writel(0x0, DAVINCI_AINTC_IRQ_INCTL_REG);
+
+	/* we don't use the hardware vector table, just its entry addresses */
+	davinci_aintc_writel(0, DAVINCI_AINTC_IRQ_EABASE_REG);
+
+	/* Clear all interrupt requests */
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG0);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_FIQ_REG1);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG0);
+	davinci_aintc_writel(~0x0, DAVINCI_AINTC_IRQ_REG1);
+
+	prios = config->prios;
+	for (reg_off = DAVINCI_AINTC_IRQ_INTPRI0_REG;
+	     reg_off <= DAVINCI_AINTC_IRQ_INTPRI7_REG; reg_off += 4) {
+		for (shift = 0, prio = 0; shift < 32; shift += 4, prios++)
+			prio |= (*prios & 0x07) << shift;
+		davinci_aintc_writel(prio, reg_off);
+	}
+
+	irq_base = irq_alloc_descs(-1, 0, config->num_irqs, 0);
+	if (irq_base < 0) {
+		pr_err("%s: unable to allocate interrupt descriptors: %d\n",
+		       __func__, irq_base);
+		return;
+	}
+
+	davinci_aintc_irq_domain = irq_domain_add_legacy(NULL,
+						config->num_irqs, irq_base, 0,
+						&irq_domain_simple_ops, NULL);
+	if (!davinci_aintc_irq_domain) {
+		pr_err("%s: unable to create interrupt domain\n", __func__);
+		return;
+	}
+
+	ret = irq_alloc_domain_generic_chips(davinci_aintc_irq_domain, 32, 1,
+					     "AINTC", handle_edge_irq,
+					     IRQ_NOREQUEST | IRQ_NOPROBE, 0, 0);
+	if (ret) {
+		pr_err("%s: unable to allocate generic irq chips for domain\n",
+		       __func__);
+		return;
+	}
+
+	for (irq_off = 0, reg_off = 0;
+	     irq_off < config->num_irqs;
+	     irq_off += 32, reg_off += 0x04)
+		davinci_aintc_setup_gc(davinci_aintc_base + reg_off,
+				       irq_base + irq_off, 32);
+
+	set_handle_irq(davinci_aintc_handle_irq);
+}