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, 247 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
new file mode 100644
index 000000000000..b15b5667991c
--- /dev/null
+++ b/drivers/irqchip/irq-atmel-aic.c
@@ -0,0 +1,247 @@
+/*
+ * Atmel AT91 AIC (Advanced Interrupt Controller) driver
+ *
+ *  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/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/bitmap.h>
+#include <linux/types.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <asm/exception.h>
+#include <asm/mach/irq.h>
+
+#include "irq-atmel-aic-common.h"
+#include "irqchip.h"
+
+/* Number of irq lines managed by AIC */
+#define NR_AIC_IRQS	32
+
+#define AT91_AIC_SMR(n)			((n) * 4)
+
+#define AT91_AIC_SVR(n)			(0x80 + ((n) * 4))
+#define AT91_AIC_IVR			0x100
+#define AT91_AIC_FVR			0x104
+#define AT91_AIC_ISR			0x108
+
+#define AT91_AIC_IPR			0x10c
+#define AT91_AIC_IMR			0x110
+#define AT91_AIC_CISR			0x114
+
+#define AT91_AIC_IECR			0x120
+#define AT91_AIC_IDCR			0x124
+#define AT91_AIC_ICCR			0x128
+#define AT91_AIC_ISCR			0x12c
+#define AT91_AIC_EOICR			0x130
+#define AT91_AIC_SPU			0x134
+#define AT91_AIC_DCR			0x138
+
+static struct irq_domain *aic_domain;
+
+static asmlinkage void __exception_irq_entry
+aic_handle(struct pt_regs *regs)
+{
+	struct irq_domain_chip_generic *dgc = aic_domain->gc;
+	struct irq_chip_generic *gc = dgc->gc[0];
+	u32 irqnr;
+	u32 irqstat;
+
+	irqnr = irq_reg_readl(gc->reg_base + AT91_AIC_IVR);
+	irqstat = irq_reg_readl(gc->reg_base + AT91_AIC_ISR);
+
+	irqnr = irq_find_mapping(aic_domain, irqnr);
+
+	if (!irqstat)
+		irq_reg_writel(0, gc->reg_base + AT91_AIC_EOICR);
+	else
+		handle_IRQ(irqnr, regs);
+}
+
+static int aic_retrigger(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+
+	/* Enable interrupt on AIC5 */
+	irq_gc_lock(gc);
+	irq_reg_writel(d->mask, gc->reg_base + AT91_AIC_ISCR);
+	irq_gc_unlock(gc);
+
+	return 0;
+}
+
+static int aic_set_type(struct irq_data *d, unsigned type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	unsigned int smr;
+	int ret;
+
+	smr = irq_reg_readl(gc->reg_base + AT91_AIC_SMR(d->hwirq));
+	ret = aic_common_set_type(d, type, &smr);
+	if (ret)
+		return ret;
+
+	irq_reg_writel(smr, gc->reg_base + AT91_AIC_SMR(d->hwirq));
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static void aic_suspend(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(gc->mask_cache, gc->reg_base + AT91_AIC_IDCR);
+	irq_reg_writel(gc->wake_active, gc->reg_base + AT91_AIC_IECR);
+	irq_gc_unlock(gc);
+}
+
+static void aic_resume(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(gc->wake_active, gc->reg_base + AT91_AIC_IDCR);
+	irq_reg_writel(gc->mask_cache, gc->reg_base + AT91_AIC_IECR);
+	irq_gc_unlock(gc);
+}
+
+static void aic_pm_shutdown(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+
+	irq_gc_lock(gc);
+	irq_reg_writel(0xffffffff, gc->reg_base + AT91_AIC_IDCR);
+	irq_reg_writel(0xffffffff, gc->reg_base + AT91_AIC_ICCR);
+	irq_gc_unlock(gc);
+}
+#else
+#define aic_suspend		NULL
+#define aic_resume		NULL
+#define aic_pm_shutdown		NULL
+#endif /* CONFIG_PM */
+
+static void __init aic_hw_init(struct irq_domain *domain)
+{
+	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
+	int i;
+
+	/*
+	 * Perform 8 End Of Interrupt Command to make sure AIC
+	 * will not Lock out nIRQ
+	 */
+	for (i = 0; i < 8; i++)
+		irq_reg_writel(0, gc->reg_base + AT91_AIC_EOICR);
+
+	/*
+	 * Spurious Interrupt ID in Spurious Vector Register.
+	 * When there is no current interrupt, the IRQ Vector Register
+	 * reads the value stored in AIC_SPU
+	 */
+	irq_reg_writel(0xffffffff, gc->reg_base + AT91_AIC_SPU);
+
+	/* No debugging in AIC: Debug (Protect) Control Register */
+	irq_reg_writel(0, gc->reg_base + AT91_AIC_DCR);
+
+	/* Disable and clear all interrupts initially */
+	irq_reg_writel(0xffffffff, gc->reg_base + AT91_AIC_IDCR);
+	irq_reg_writel(0xffffffff, gc->reg_base + AT91_AIC_ICCR);
+
+	for (i = 0; i < 32; i++)
+		irq_reg_writel(i, gc->reg_base + AT91_AIC_SVR(i));
+}
+
+static int aic_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 irq_domain_chip_generic *dgc = d->gc;
+	struct irq_chip_generic *gc;
+	unsigned smr;
+	int idx;
+	int ret;
+
+	if (!dgc)
+		return -EINVAL;
+
+	ret = aic_common_irq_domain_xlate(d, ctrlr, intspec, intsize,
+					  out_hwirq, out_type);
+	if (ret)
+		return ret;
+
+	idx = intspec[0] / dgc->irqs_per_chip;
+	if (idx >= dgc->num_chips)
+		return -EINVAL;
+
+	gc = dgc->gc[idx];
+
+	irq_gc_lock(gc);
+	smr = irq_reg_readl(gc->reg_base + AT91_AIC_SMR(*out_hwirq));
+	ret = aic_common_set_priority(intspec[2], &smr);
+	if (!ret)
+		irq_reg_writel(smr, gc->reg_base + AT91_AIC_SMR(*out_hwirq));
+	irq_gc_unlock(gc);
+
+	return ret;
+}
+
+static const struct irq_domain_ops aic_irq_ops = {
+	.map	= irq_map_generic_chip,
+	.xlate	= aic_irq_domain_xlate,
+};
+
+static int __init aic_of_init(struct device_node *node,
+			      struct device_node *parent)
+{
+	struct irq_chip_generic *gc;
+	struct irq_domain *domain;
+
+	if (aic_domain)
+		return -EEXIST;
+
+	domain = aic_common_of_init(node, &aic_irq_ops, "atmel-aic",
+				    NR_AIC_IRQS);
+	if (IS_ERR(domain))
+		return PTR_ERR(domain);
+
+	aic_domain = domain;
+	gc = irq_get_domain_generic_chip(domain, 0);
+
+	gc->chip_types[0].regs.eoi = AT91_AIC_EOICR;
+	gc->chip_types[0].regs.enable = AT91_AIC_IECR;
+	gc->chip_types[0].regs.disable = AT91_AIC_IDCR;
+	gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
+	gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
+	gc->chip_types[0].chip.irq_retrigger = aic_retrigger;
+	gc->chip_types[0].chip.irq_set_type = aic_set_type;
+	gc->chip_types[0].chip.irq_suspend = aic_suspend;
+	gc->chip_types[0].chip.irq_resume = aic_resume;
+	gc->chip_types[0].chip.irq_pm_shutdown = aic_pm_shutdown;
+
+	aic_hw_init(domain);
+	set_handle_irq(aic_handle);
+
+	return 0;
+}
+IRQCHIP_DECLARE(at91rm9200_aic, "atmel,at91rm9200-aic", aic_of_init);