xtensa: add MX irqchip
MX is an interrupt distributor used in some SMP-capable xtensa
configurations.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/drivers/irqchip/irq-xtensa-mx.c b/drivers/irqchip/irq-xtensa-mx.c
new file mode 100644
index 0000000..f693f1b
--- /dev/null
+++ b/drivers/irqchip/irq-xtensa-mx.c
@@ -0,0 +1,164 @@
+/*
+ * Xtensa MX interrupt distributor
+ *
+ * Copyright (C) 2002 - 2013 Tensilica, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+
+#include <asm/mxregs.h>
+
+#include "irqchip.h"
+
+#define HW_IRQ_IPI_COUNT 2
+#define HW_IRQ_MX_BASE 2
+#define HW_IRQ_EXTERN_BASE 3
+
+static DEFINE_PER_CPU(unsigned int, cached_irq_mask);
+
+static int xtensa_mx_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ if (hw < HW_IRQ_IPI_COUNT) {
+ struct irq_chip *irq_chip = d->host_data;
+ irq_set_chip_and_handler_name(irq, irq_chip,
+ handle_percpu_irq, "ipi");
+ irq_set_status_flags(irq, IRQ_LEVEL);
+ return 0;
+ }
+ return xtensa_irq_map(d, irq, hw);
+}
+
+/*
+ * Device Tree IRQ specifier translation function which works with one or
+ * two cell bindings. First cell value maps directly to the hwirq number.
+ * Second cell if present specifies whether hwirq number is external (1) or
+ * internal (0).
+ */
+static int xtensa_mx_irq_domain_xlate(struct irq_domain *d,
+ struct device_node *ctrlr,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq, unsigned int *out_type)
+{
+ return xtensa_irq_domain_xlate(intspec, intsize,
+ intspec[0], intspec[0] + HW_IRQ_EXTERN_BASE,
+ out_hwirq, out_type);
+}
+
+static const struct irq_domain_ops xtensa_mx_irq_domain_ops = {
+ .xlate = xtensa_mx_irq_domain_xlate,
+ .map = xtensa_mx_irq_map,
+};
+
+void secondary_init_irq(void)
+{
+ __this_cpu_write(cached_irq_mask,
+ XCHAL_INTTYPE_MASK_EXTERN_EDGE |
+ XCHAL_INTTYPE_MASK_EXTERN_LEVEL);
+ set_sr(XCHAL_INTTYPE_MASK_EXTERN_EDGE |
+ XCHAL_INTTYPE_MASK_EXTERN_LEVEL, intenable);
+}
+
+static void xtensa_mx_irq_mask(struct irq_data *d)
+{
+ unsigned int mask = 1u << d->hwirq;
+
+ if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
+ XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+ set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
+ HW_IRQ_MX_BASE), MIENG);
+ } else {
+ mask = __this_cpu_read(cached_irq_mask) & ~mask;
+ __this_cpu_write(cached_irq_mask, mask);
+ set_sr(mask, intenable);
+ }
+}
+
+static void xtensa_mx_irq_unmask(struct irq_data *d)
+{
+ unsigned int mask = 1u << d->hwirq;
+
+ if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
+ XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+ set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
+ HW_IRQ_MX_BASE), MIENGSET);
+ } else {
+ mask |= __this_cpu_read(cached_irq_mask);
+ __this_cpu_write(cached_irq_mask, mask);
+ set_sr(mask, intenable);
+ }
+}
+
+static void xtensa_mx_irq_enable(struct irq_data *d)
+{
+ variant_irq_enable(d->hwirq);
+ xtensa_mx_irq_unmask(d);
+}
+
+static void xtensa_mx_irq_disable(struct irq_data *d)
+{
+ xtensa_mx_irq_mask(d);
+ variant_irq_disable(d->hwirq);
+}
+
+static void xtensa_mx_irq_ack(struct irq_data *d)
+{
+ set_sr(1 << d->hwirq, intclear);
+}
+
+static int xtensa_mx_irq_retrigger(struct irq_data *d)
+{
+ set_sr(1 << d->hwirq, intset);
+ return 1;
+}
+
+static int xtensa_mx_irq_set_affinity(struct irq_data *d,
+ const struct cpumask *dest, bool force)
+{
+ unsigned mask = 1u << cpumask_any(dest);
+
+ set_er(mask, MIROUT(d->hwirq - HW_IRQ_MX_BASE));
+ return 0;
+
+}
+
+static struct irq_chip xtensa_mx_irq_chip = {
+ .name = "xtensa-mx",
+ .irq_enable = xtensa_mx_irq_enable,
+ .irq_disable = xtensa_mx_irq_disable,
+ .irq_mask = xtensa_mx_irq_mask,
+ .irq_unmask = xtensa_mx_irq_unmask,
+ .irq_ack = xtensa_mx_irq_ack,
+ .irq_retrigger = xtensa_mx_irq_retrigger,
+ .irq_set_affinity = xtensa_mx_irq_set_affinity,
+};
+
+int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)
+{
+ struct irq_domain *root_domain =
+ irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
+ &xtensa_mx_irq_domain_ops,
+ &xtensa_mx_irq_chip);
+ irq_set_default_host(root_domain);
+ secondary_init_irq();
+ return 0;
+}
+
+static int __init xtensa_mx_init(struct device_node *np,
+ struct device_node *interrupt_parent)
+{
+ struct irq_domain *root_domain =
+ irq_domain_add_linear(np, NR_IRQS, &xtensa_mx_irq_domain_ops,
+ &xtensa_mx_irq_chip);
+ irq_set_default_host(root_domain);
+ secondary_init_irq();
+ return 0;
+}
+IRQCHIP_DECLARE(xtensa_mx_irq_chip, "cdns,xtensa-mx", xtensa_mx_init);