1 files changed, 238 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-vf610-mscm-ir.c b/drivers/irqchip/irq-vf610-mscm-ir.c
new file mode 100644
index 000000000..56b5e3cb9
--- /dev/null
+++ b/drivers/irqchip/irq-vf610-mscm-ir.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2014-2015 Toradex AG
+ * Author: Stefan Agner <stefan@agner.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *
+ * IRQ chip driver for MSCM interrupt router available on Vybrid SoC's.
+ * The interrupt router is between the CPU's interrupt controller and the
+ * peripheral. The router allows to route the peripheral interrupts to
+ * one of the two available CPU's on Vybrid VF6xx SoC's (Cortex-A5 or
+ * Cortex-M4). The router will be configured transparently on a IRQ
+ * request.
+ *
+ * o All peripheral interrupts of the Vybrid SoC can be routed to
+ *   CPU 0, CPU 1 or both. The routing is useful for dual-core
+ *   variants of Vybrid SoC such as VF6xx. This driver routes the
+ *   requested interrupt to the CPU currently running on.
+ *
+ * o It is required to setup the interrupt router even on single-core
+ *   variants of Vybrid.
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/syscon.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+#define MSCM_CPxNUM		0x4
+
+#define MSCM_IRSPRC(n)		(0x80 + 2 * (n))
+#define MSCM_IRSPRC_CPEN_MASK	0x3
+
+#define MSCM_IRSPRC_NUM		112
+
+struct vf610_mscm_ir_chip_data {
+	void __iomem *mscm_ir_base;
+	u16 cpu_mask;
+	u16 saved_irsprc[MSCM_IRSPRC_NUM];
+	bool is_nvic;
+};
+
+static struct vf610_mscm_ir_chip_data *mscm_ir_data;
+
+static inline void vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data *data)
+{
+	int i;
+
+	for (i = 0; i < MSCM_IRSPRC_NUM; i++)
+		data->saved_irsprc[i] = readw_relaxed(data->mscm_ir_base + MSCM_IRSPRC(i));
+}
+
+static inline void vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data *data)
+{
+	int i;
+
+	for (i = 0; i < MSCM_IRSPRC_NUM; i++)
+		writew_relaxed(data->saved_irsprc[i], data->mscm_ir_base + MSCM_IRSPRC(i));
+}
+
+static int vf610_mscm_ir_notifier(struct notifier_block *self,
+				  unsigned long cmd, void *v)
+{
+	switch (cmd) {
+	case CPU_CLUSTER_PM_ENTER:
+		vf610_mscm_ir_save(mscm_ir_data);
+		break;
+	case CPU_CLUSTER_PM_ENTER_FAILED:
+	case CPU_CLUSTER_PM_EXIT:
+		vf610_mscm_ir_restore(mscm_ir_data);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block mscm_ir_notifier_block = {
+	.notifier_call = vf610_mscm_ir_notifier,
+};
+
+static void vf610_mscm_ir_enable(struct irq_data *data)
+{
+	irq_hw_number_t hwirq = data->hwirq;
+	struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
+	u16 irsprc;
+
+	irsprc = readw_relaxed(chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
+	irsprc &= MSCM_IRSPRC_CPEN_MASK;
+
+	WARN_ON(irsprc & ~chip_data->cpu_mask);
+
+	writew_relaxed(chip_data->cpu_mask,
+		       chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
+
+	irq_chip_enable_parent(data);
+}
+
+static void vf610_mscm_ir_disable(struct irq_data *data)
+{
+	irq_hw_number_t hwirq = data->hwirq;
+	struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
+
+	writew_relaxed(0x0, chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
+
+	irq_chip_disable_parent(data);
+}
+
+static struct irq_chip vf610_mscm_ir_irq_chip = {
+	.name			= "mscm-ir",
+	.irq_mask		= irq_chip_mask_parent,
+	.irq_unmask		= irq_chip_unmask_parent,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_enable		= vf610_mscm_ir_enable,
+	.irq_disable		= vf610_mscm_ir_disable,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+};
+
+static int vf610_mscm_ir_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				      unsigned int nr_irqs, void *arg)
+{
+	int i;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec *fwspec = arg;
+	struct irq_fwspec parent_fwspec;
+
+	if (!irq_domain_get_of_node(domain->parent))
+		return -EINVAL;
+
+	if (fwspec->param_count != 2)
+		return -EINVAL;
+
+	hwirq = fwspec->param[0];
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &vf610_mscm_ir_irq_chip,
+					      domain->host_data);
+
+	parent_fwspec.fwnode = domain->parent->fwnode;
+
+	if (mscm_ir_data->is_nvic) {
+		parent_fwspec.param_count = 1;
+		parent_fwspec.param[0] = fwspec->param[0];
+	} else {
+		parent_fwspec.param_count = 3;
+		parent_fwspec.param[0] = GIC_SPI;
+		parent_fwspec.param[1] = fwspec->param[0];
+		parent_fwspec.param[2] = fwspec->param[1];
+	}
+
+	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
+					    &parent_fwspec);
+}
+
+static int vf610_mscm_ir_domain_translate(struct irq_domain *d,
+					  struct irq_fwspec *fwspec,
+					  unsigned long *hwirq,
+					  unsigned int *type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+	*hwirq = fwspec->param[0];
+	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+
+static const struct irq_domain_ops mscm_irq_domain_ops = {
+	.translate = vf610_mscm_ir_domain_translate,
+	.alloc = vf610_mscm_ir_domain_alloc,
+	.free = irq_domain_free_irqs_common,
+};
+
+static int __init vf610_mscm_ir_of_init(struct device_node *node,
+			       struct device_node *parent)
+{
+	struct irq_domain *domain, *domain_parent;
+	struct regmap *mscm_cp_regmap;
+	int ret, cpuid;
+
+	domain_parent = irq_find_host(parent);
+	if (!domain_parent) {
+		pr_err("vf610_mscm_ir: interrupt-parent not found\n");
+		return -EINVAL;
+	}
+
+	mscm_ir_data = kzalloc(sizeof(*mscm_ir_data), GFP_KERNEL);
+	if (!mscm_ir_data)
+		return -ENOMEM;
+
+	mscm_ir_data->mscm_ir_base = of_io_request_and_map(node, 0, "mscm-ir");
+	if (IS_ERR(mscm_ir_data->mscm_ir_base)) {
+		pr_err("vf610_mscm_ir: unable to map mscm register\n");
+		ret = PTR_ERR(mscm_ir_data->mscm_ir_base);
+		goto out_free;
+	}
+
+	mscm_cp_regmap = syscon_regmap_lookup_by_phandle(node, "fsl,cpucfg");
+	if (IS_ERR(mscm_cp_regmap)) {
+		ret = PTR_ERR(mscm_cp_regmap);
+		pr_err("vf610_mscm_ir: regmap lookup for cpucfg failed\n");
+		goto out_unmap;
+	}
+
+	regmap_read(mscm_cp_regmap, MSCM_CPxNUM, &cpuid);
+	mscm_ir_data->cpu_mask = 0x1 << cpuid;
+
+	domain = irq_domain_add_hierarchy(domain_parent, 0,
+					  MSCM_IRSPRC_NUM, node,
+					  &mscm_irq_domain_ops, mscm_ir_data);
+	if (!domain) {
+		ret = -ENOMEM;
+		goto out_unmap;
+	}
+
+	if (of_device_is_compatible(irq_domain_get_of_node(domain->parent),
+				    "arm,armv7m-nvic"))
+		mscm_ir_data->is_nvic = true;
+
+	cpu_pm_register_notifier(&mscm_ir_notifier_block);
+
+	return 0;
+
+out_unmap:
+	iounmap(mscm_ir_data->mscm_ir_base);
+out_free:
+	kfree(mscm_ir_data);
+	return ret;
+}
+IRQCHIP_DECLARE(vf610_mscm_ir, "fsl,vf610-mscm-ir", vf610_mscm_ir_of_init);