1 files changed, 319 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-pic32-evic.c b/drivers/irqchip/irq-pic32-evic.c
new file mode 100644
index 0000000000..1d9bb28d13
--- /dev/null
+++ b/drivers/irqchip/irq-pic32-evic.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cristian Birsan <cristian.birsan@microchip.com>
+ * Joshua Henderson <joshua.henderson@microchip.com>
+ * Copyright (C) 2016 Microchip Technology Inc.  All rights reserved.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/irq.h>
+
+#include <asm/irq.h>
+#include <asm/traps.h>
+#include <asm/mach-pic32/pic32.h>
+
+#define REG_INTCON	0x0000
+#define REG_INTSTAT	0x0020
+#define REG_IFS_OFFSET	0x0040
+#define REG_IEC_OFFSET	0x00C0
+#define REG_IPC_OFFSET	0x0140
+#define REG_OFF_OFFSET	0x0540
+
+#define MAJPRI_MASK	0x07
+#define SUBPRI_MASK	0x03
+#define PRIORITY_MASK	0x1F
+
+#define PIC32_INT_PRI(pri, subpri)				\
+	((((pri) & MAJPRI_MASK) << 2) | ((subpri) & SUBPRI_MASK))
+
+struct evic_chip_data {
+	u32 irq_types[NR_IRQS];
+	u32 ext_irqs[8];
+};
+
+static struct irq_domain *evic_irq_domain;
+static void __iomem *evic_base;
+
+asmlinkage void __weak plat_irq_dispatch(void)
+{
+	unsigned int hwirq;
+
+	hwirq = readl(evic_base + REG_INTSTAT) & 0xFF;
+	do_domain_IRQ(evic_irq_domain, hwirq);
+}
+
+static struct evic_chip_data *irqd_to_priv(struct irq_data *data)
+{
+	return (struct evic_chip_data *)data->domain->host_data;
+}
+
+static int pic32_set_ext_polarity(int bit, u32 type)
+{
+	/*
+	 * External interrupts can be either edge rising or edge falling,
+	 * but not both.
+	 */
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		writel(BIT(bit), evic_base + PIC32_SET(REG_INTCON));
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		writel(BIT(bit), evic_base + PIC32_CLR(REG_INTCON));
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pic32_set_type_edge(struct irq_data *data,
+			       unsigned int flow_type)
+{
+	struct evic_chip_data *priv = irqd_to_priv(data);
+	int ret;
+	int i;
+
+	if (!(flow_type & IRQ_TYPE_EDGE_BOTH))
+		return -EBADR;
+
+	/* set polarity for external interrupts only */
+	for (i = 0; i < ARRAY_SIZE(priv->ext_irqs); i++) {
+		if (priv->ext_irqs[i] == data->hwirq) {
+			ret = pic32_set_ext_polarity(i, flow_type);
+			if (ret)
+				return ret;
+		}
+	}
+
+	irqd_set_trigger_type(data, flow_type);
+
+	return IRQ_SET_MASK_OK;
+}
+
+static void pic32_bind_evic_interrupt(int irq, int set)
+{
+	writel(set, evic_base + REG_OFF_OFFSET + irq * 4);
+}
+
+static void pic32_set_irq_priority(int irq, int priority)
+{
+	u32 reg, shift;
+
+	reg = irq / 4;
+	shift = (irq % 4) * 8;
+
+	writel(PRIORITY_MASK << shift,
+		evic_base + PIC32_CLR(REG_IPC_OFFSET + reg * 0x10));
+	writel(priority << shift,
+		evic_base + PIC32_SET(REG_IPC_OFFSET + reg * 0x10));
+}
+
+#define IRQ_REG_MASK(_hwirq, _reg, _mask)		       \
+	do {						       \
+		_reg = _hwirq / 32;			       \
+		_mask = 1 << (_hwirq % 32);		       \
+	} while (0)
+
+static int pic32_irq_domain_map(struct irq_domain *d, unsigned int virq,
+				irq_hw_number_t hw)
+{
+	struct evic_chip_data *priv = d->host_data;
+	struct irq_data *data;
+	int ret;
+	u32 iecclr, ifsclr;
+	u32 reg, mask;
+
+	ret = irq_map_generic_chip(d, virq, hw);
+	if (ret)
+		return ret;
+
+	/*
+	 * Piggyback on xlate function to move to an alternate chip as necessary
+	 * at time of mapping instead of allowing the flow handler/chip to be
+	 * changed later. This requires all interrupts to be configured through
+	 * DT.
+	 */
+	if (priv->irq_types[hw] & IRQ_TYPE_SENSE_MASK) {
+		data = irq_domain_get_irq_data(d, virq);
+		irqd_set_trigger_type(data, priv->irq_types[hw]);
+		irq_setup_alt_chip(data, priv->irq_types[hw]);
+	}
+
+	IRQ_REG_MASK(hw, reg, mask);
+
+	iecclr = PIC32_CLR(REG_IEC_OFFSET + reg * 0x10);
+	ifsclr = PIC32_CLR(REG_IFS_OFFSET + reg * 0x10);
+
+	/* mask and clear flag */
+	writel(mask, evic_base + iecclr);
+	writel(mask, evic_base + ifsclr);
+
+	/* default priority is required */
+	pic32_set_irq_priority(hw, PIC32_INT_PRI(2, 0));
+
+	return ret;
+}
+
+int pic32_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
+			   const u32 *intspec, unsigned int intsize,
+			   irq_hw_number_t *out_hwirq, unsigned int *out_type)
+{
+	struct evic_chip_data *priv = d->host_data;
+
+	if (WARN_ON(intsize < 2))
+		return -EINVAL;
+
+	if (WARN_ON(intspec[0] >= NR_IRQS))
+		return -EINVAL;
+
+	*out_hwirq = intspec[0];
+	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+
+	priv->irq_types[intspec[0]] = intspec[1] & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static const struct irq_domain_ops pic32_irq_domain_ops = {
+	.map	= pic32_irq_domain_map,
+	.xlate	= pic32_irq_domain_xlate,
+};
+
+static void __init pic32_ext_irq_of_init(struct irq_domain *domain)
+{
+	struct device_node *node = irq_domain_get_of_node(domain);
+	struct evic_chip_data *priv = domain->host_data;
+	struct property *prop;
+	const __le32 *p;
+	u32 hwirq;
+	int i = 0;
+	const char *pname = "microchip,external-irqs";
+
+	of_property_for_each_u32(node, pname, prop, p, hwirq) {
+		if (i >= ARRAY_SIZE(priv->ext_irqs)) {
+			pr_warn("More than %d external irq, skip rest\n",
+				ARRAY_SIZE(priv->ext_irqs));
+			break;
+		}
+
+		priv->ext_irqs[i] = hwirq;
+		i++;
+	}
+}
+
+static int __init pic32_of_init(struct device_node *node,
+				struct device_node *parent)
+{
+	struct irq_chip_generic *gc;
+	struct evic_chip_data *priv;
+	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+	int nchips, ret;
+	int i;
+
+	nchips = DIV_ROUND_UP(NR_IRQS, 32);
+
+	evic_base = of_iomap(node, 0);
+	if (!evic_base)
+		return -ENOMEM;
+
+	priv = kcalloc(nchips, sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		goto err_iounmap;
+	}
+
+	evic_irq_domain = irq_domain_add_linear(node, nchips * 32,
+						&pic32_irq_domain_ops,
+						priv);
+	if (!evic_irq_domain) {
+		ret = -ENOMEM;
+		goto err_free_priv;
+	}
+
+	/*
+	 * The PIC32 EVIC has a linear list of irqs and the type of each
+	 * irq is determined by the hardware peripheral the EVIC is arbitrating.
+	 * These irq types are defined in the datasheet as "persistent" and
+	 * "non-persistent" which are mapped here to level and edge
+	 * respectively. To manage the different flow handler requirements of
+	 * each irq type, different chip_types are used.
+	 */
+	ret = irq_alloc_domain_generic_chips(evic_irq_domain, 32, 2,
+					     "evic-level", handle_level_irq,
+					     clr, 0, 0);
+	if (ret)
+		goto err_domain_remove;
+
+	board_bind_eic_interrupt = &pic32_bind_evic_interrupt;
+
+	for (i = 0; i < nchips; i++) {
+		u32 ifsclr = PIC32_CLR(REG_IFS_OFFSET + (i * 0x10));
+		u32 iec = REG_IEC_OFFSET + (i * 0x10);
+
+		gc = irq_get_domain_generic_chip(evic_irq_domain, i * 32);
+
+		gc->reg_base = evic_base;
+		gc->unused = 0;
+
+		/*
+		 * Level/persistent interrupts have a special requirement that
+		 * the condition generating the interrupt be cleared before the
+		 * interrupt flag (ifs) can be cleared. chip.irq_eoi is used to
+		 * complete the interrupt with an ack.
+		 */
+		gc->chip_types[0].type			= IRQ_TYPE_LEVEL_MASK;
+		gc->chip_types[0].handler		= handle_fasteoi_irq;
+		gc->chip_types[0].regs.ack		= ifsclr;
+		gc->chip_types[0].regs.mask		= iec;
+		gc->chip_types[0].chip.name		= "evic-level";
+		gc->chip_types[0].chip.irq_eoi		= irq_gc_ack_set_bit;
+		gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
+		gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
+		gc->chip_types[0].chip.flags		= IRQCHIP_SKIP_SET_WAKE;
+
+		/* Edge interrupts */
+		gc->chip_types[1].type			= IRQ_TYPE_EDGE_BOTH;
+		gc->chip_types[1].handler		= handle_edge_irq;
+		gc->chip_types[1].regs.ack		= ifsclr;
+		gc->chip_types[1].regs.mask		= iec;
+		gc->chip_types[1].chip.name		= "evic-edge";
+		gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
+		gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
+		gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
+		gc->chip_types[1].chip.irq_set_type	= pic32_set_type_edge;
+		gc->chip_types[1].chip.flags		= IRQCHIP_SKIP_SET_WAKE;
+
+		gc->private = &priv[i];
+	}
+
+	irq_set_default_host(evic_irq_domain);
+
+	/*
+	 * External interrupts have software configurable edge polarity. These
+	 * interrupts are defined in DT allowing polarity to be configured only
+	 * for these interrupts when requested.
+	 */
+	pic32_ext_irq_of_init(evic_irq_domain);
+
+	return 0;
+
+err_domain_remove:
+	irq_domain_remove(evic_irq_domain);
+
+err_free_priv:
+	kfree(priv);
+
+err_iounmap:
+	iounmap(evic_base);
+
+	return ret;
+}
+
+IRQCHIP_DECLARE(pic32_evic, "microchip,pic32mzda-evic", pic32_of_init);