irqchip: atmel-aic: Add atmel AIC/AIC5 drivers

Add AIC (Advanced Interrupt Controller) and AIC5 (AIC5 is an evolution of
the AIC block) drivers.
Put common code in irq-atmel-aic-common.c/.h so that both driver can access
shared functions (this will ease maintenance).

These drivers are only compatible with dt enabled board and replace the
old implementation found in arch/arm/mach-at91/irq.c.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Link: https://lkml.kernel.org/r/1405012462-766-4-git-send-email-boris.brezillon@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 207 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-atmel-aic-common.c b/drivers/irqchip/irq-atmel-aic-common.c
new file mode 100644
index 000000000000..18b76fc03d53
--- /dev/null
+++ b/drivers/irqchip/irq-atmel-aic-common.c
@@ -0,0 +1,207 @@
+/*
+ * Atmel AT91 common AIC (Advanced Interrupt Controller) code shared by
+ * irq-atmel-aic and irq-atmel-aic5 drivers
+ *
+ *  Copyright (C) 2004 SAN People
+ *  Copyright (C) 2004 ATMEL
+ *  Copyright (C) Rick Bronson
+ *  Copyright (C) 2014 Free Electrons
+ *
+ *  Author: Boris BREZILLON <boris.brezillon@free-electrons.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/errno.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "irq-atmel-aic-common.h"
+
+#define AT91_AIC_PRIOR			GENMASK(2, 0)
+#define AT91_AIC_IRQ_MIN_PRIORITY	0
+#define AT91_AIC_IRQ_MAX_PRIORITY	7
+
+#define AT91_AIC_SRCTYPE		GENMASK(7, 6)
+#define AT91_AIC_SRCTYPE_LOW		(0 << 5)
+#define AT91_AIC_SRCTYPE_FALLING	(1 << 5)
+#define AT91_AIC_SRCTYPE_HIGH		(2 << 5)
+#define AT91_AIC_SRCTYPE_RISING		(3 << 5)
+
+struct aic_chip_data {
+	u32 ext_irqs;
+};
+
+static void aic_common_shutdown(struct irq_data *d)
+{
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+
+	ct->chip.irq_mask(d);
+}
+
+int aic_common_set_type(struct irq_data *d, unsigned type, unsigned *val)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct aic_chip_data *aic = gc->private;
+	unsigned aic_type;
+
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		aic_type = AT91_AIC_SRCTYPE_HIGH;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		aic_type = AT91_AIC_SRCTYPE_RISING;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		if (!(d->mask & aic->ext_irqs))
+			return -EINVAL;
+
+		aic_type = AT91_AIC_SRCTYPE_LOW;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		if (!(d->mask & aic->ext_irqs))
+			return -EINVAL;
+
+		aic_type = AT91_AIC_SRCTYPE_FALLING;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*val &= AT91_AIC_SRCTYPE;
+	*val |= aic_type;
+
+	return 0;
+}
+
+int aic_common_set_priority(int priority, unsigned *val)
+{
+	if (priority < AT91_AIC_IRQ_MIN_PRIORITY ||
+	    priority > AT91_AIC_IRQ_MAX_PRIORITY)
+		return -EINVAL;
+
+	*val &= AT91_AIC_PRIOR;
+	*val |= priority;
+
+	return 0;
+}
+
+int aic_common_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)
+{
+	if (WARN_ON(intsize < 3))
+		return -EINVAL;
+
+	if (WARN_ON((intspec[2] < AT91_AIC_IRQ_MIN_PRIORITY) ||
+		    (intspec[2] > AT91_AIC_IRQ_MAX_PRIORITY)))
+		return -EINVAL;
+
+	*out_hwirq = intspec[0];
+	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static void __init aic_common_ext_irq_of_init(struct irq_domain *domain)
+{
+	struct device_node *node = domain->of_node;
+	struct irq_chip_generic *gc;
+	struct aic_chip_data *aic;
+	struct property *prop;
+	const __be32 *p;
+	u32 hwirq;
+
+	gc = irq_get_domain_generic_chip(domain, 0);
+
+	aic = gc->private;
+	aic->ext_irqs |= 1;
+
+	of_property_for_each_u32(node, "atmel,external-irqs", prop, p, hwirq) {
+		gc = irq_get_domain_generic_chip(domain, hwirq);
+		if (!gc) {
+			pr_warn("AIC: external irq %d >= %d skip it\n",
+				hwirq, domain->revmap_size);
+			continue;
+		}
+
+		aic = gc->private;
+		aic->ext_irqs |= (1 << (hwirq % 32));
+	}
+}
+
+struct irq_domain *__init aic_common_of_init(struct device_node *node,
+					     const struct irq_domain_ops *ops,
+					     const char *name, int nirqs)
+{
+	struct irq_chip_generic *gc;
+	struct irq_domain *domain;
+	struct aic_chip_data *aic;
+	void __iomem *reg_base;
+	int nchips;
+	int ret;
+	int i;
+
+	nchips = DIV_ROUND_UP(nirqs, 32);
+
+	reg_base = of_iomap(node, 0);
+	if (!reg_base)
+		return ERR_PTR(-ENOMEM);
+
+	aic = kcalloc(nchips, sizeof(*aic), GFP_KERNEL);
+	if (!aic) {
+		ret = -ENOMEM;
+		goto err_iounmap;
+	}
+
+	domain = irq_domain_add_linear(node, nchips * 32, ops, aic);
+	if (!domain) {
+		ret = -ENOMEM;
+		goto err_free_aic;
+	}
+
+	ret = irq_alloc_domain_generic_chips(domain, 32, 1, name,
+					     handle_level_irq, 0, 0,
+					     IRQCHIP_SKIP_SET_WAKE);
+	if (ret)
+		goto err_domain_remove;
+
+	for (i = 0; i < nchips; i++) {
+		gc = irq_get_domain_generic_chip(domain, i * 32);
+
+		gc->reg_base = reg_base;
+
+		gc->unused = 0;
+		gc->wake_enabled = ~0;
+		gc->chip_types[0].type = IRQ_TYPE_SENSE_MASK;
+		gc->chip_types[0].handler = handle_fasteoi_irq;
+		gc->chip_types[0].chip.irq_eoi = irq_gc_eoi;
+		gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
+		gc->chip_types[0].chip.irq_shutdown = aic_common_shutdown;
+		gc->private = &aic[i];
+	}
+
+	aic_common_ext_irq_of_init(domain);
+
+	return domain;
+
+err_domain_remove:
+	irq_domain_remove(domain);
+
+err_free_aic:
+	kfree(aic);
+
+err_iounmap:
+	iounmap(reg_base);
+
+	return ERR_PTR(ret);
+}