Allwinner A20/A31 SoCs have special registers to control / (un)mask /
acknowledge NMI. This NMI controller is separated and independent from GIC.
This patch adds a new irqchip to manage NMI.
Signed-off-by: Carlo Caione <carlo@xxxxxxxxxx>
---
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-sunxi-nmi.c | 228 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 229 insertions(+)
create mode 100644 drivers/irqchip/irq-sunxi-nmi.c
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b901..e31d4d6 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_METAG_PERFCOUNTER_IRQS) += irq-metag.o
obj-$(CONFIG_ARCH_MOXART) += irq-moxart.o
obj-$(CONFIG_ORION_IRQCHIP) += irq-orion.o
obj-$(CONFIG_ARCH_SUNXI) += irq-sun4i.o
+obj-$(CONFIG_ARCH_SUNXI) += irq-sunxi-nmi.o
obj-$(CONFIG_ARCH_SPEAR3XX) += spear-shirq.o
obj-$(CONFIG_ARM_GIC) += irq-gic.o
obj-$(CONFIG_ARM_NVIC) += irq-nvic.o
diff --git a/drivers/irqchip/irq-sunxi-nmi.c b/drivers/irqchip/irq-sunxi-nmi.c
new file mode 100644
index 0000000..8796ae0
--- /dev/null
+++ b/drivers/irqchip/irq-sunxi-nmi.c
@@ -0,0 +1,228 @@
+/*
+ * Allwinner A20/A31 SoCs NMI IRQ chip driver.
+ *
+ * Carlo Caione <carlo.caione@xxxxxxxxx>
+ *
+ * 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/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/irqchip/chained_irq.h>
+#include "irqchip.h"
+
+#define SUNXI_NMI_SRC_TYPE_MASK 0x00000003
+
+enum {
+ SUNXI_SRC_TYPE_LEVEL_LOW = 0,
+ SUNXI_SRC_TYPE_EDGE_FALLING,
+ SUNXI_SRC_TYPE_LEVEL_HIGH,
+ SUNXI_SRC_TYPE_EDGE_RISING,
+};
+
+struct sunxi_sc_nmi_reg_offs {
+ u32 ctrl;
+ u32 pend;
+ u32 enable;
+};
+
+static struct sunxi_sc_nmi_reg_offs sun7i_reg_offs = {
+ .ctrl = 0x00,
+ .pend = 0x04,
+ .enable = 0x08,
+};
+
+static struct sunxi_sc_nmi_reg_offs sun6i_reg_offs = {
+ .ctrl = 0x00,
+ .pend = 0x04,
+ .enable = 0x34,
+};
+
+/*
+ * Ack level interrupts right before unmask
+ *
+ * In case of level-triggered interrupt, IRQ line must be acked before it
+ * is unmasked or else a double-interrupt is triggered
+ */
+
+static void sunxi_sc_nmi_ack_and_unmask(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = irq_data_get_chip_type(d);
+ u32 mask = d->mask;
+
+ if (irqd_get_trigger_type(d) & IRQ_TYPE_LEVEL_MASK)
+ ct->chip.irq_ack(d);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + ct->regs.mask);
+ irq_gc_unlock(gc);
+}
+
+static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
+ u32 val)
+{
+ irq_reg_writel(val, gc->reg_base + off);
+}
+
+static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
+{
+ return irq_reg_readl(gc->reg_base + off);
+}
+
+static void sunxi_sc_nmi_handle_irq(unsigned int irq, struct irq_desc *desc)
+{
+ struct irq_domain *domain = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_get_chip(irq);
+ unsigned int virq = irq_find_mapping(domain, 0);
+
+ chained_irq_enter(chip, desc);
+ generic_handle_irq(virq);
+ chained_irq_exit(chip, desc);
+}
+
+static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct irq_chip_type *ct = gc->chip_types;
+ u32 src_type_reg;
+ u32 ctrl_off = ct->regs.type;
+ unsigned int src_type;
+ unsigned int i;
+
+ irq_gc_lock(gc);
+
+ switch (flow_type & IRQF_TRIGGER_MASK) {
+ case IRQ_TYPE_EDGE_FALLING:
+ src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ src_type = SUNXI_SRC_TYPE_EDGE_RISING;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
+ break;
+ case IRQ_TYPE_NONE:
+ case IRQ_TYPE_LEVEL_LOW:
+ src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
+ break;
+ default:
+ irq_gc_unlock(gc);
+ pr_err("%s: Cannot assign multiple trigger modes to IRQ %d.\n",
+ __func__, data->irq);
+ return -EBADR;
+ }
+
+ irqd_set_trigger_type(data, flow_type);
+ irq_setup_alt_chip(data, flow_type);
+
+ for (i = 0; i <= gc->num_ct; i++, ct++)
+ if (ct->type & flow_type)
+ ctrl_off = ct->regs.type;
+
+ src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
+ src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
+ src_type_reg |= src_type;
+ sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
+
+ irq_gc_unlock(gc);
+
+ return IRQ_SET_MASK_OK;
+}
+
+static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
+ struct sunxi_sc_nmi_reg_offs *reg_offs)
+{
+ struct irq_domain *domain;
+ struct irq_chip_generic *gc;
+ unsigned int irq;
+ unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+ int ret;
+
+
+ domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
+ if (!domain) {
+ pr_err("%s: Could not register interrupt domain.\n", node->name);
+ return -ENOMEM;
+ }
+
+ ret = irq_alloc_domain_generic_chips(domain, 1, 2, node->name,
+ handle_level_irq, clr, 0,
+ IRQ_GC_INIT_MASK_CACHE);
+ if (ret) {
+ pr_err("%s: Could not allocate generic interrupt chip.\n",
+ node->name);
+ goto fail_irqd_remove;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ pr_err("%s: unable to parse irq\n", node->name);
+ ret = -EINVAL;
+ goto fail_irqd_remove;
+ }
+
+ gc = irq_get_domain_generic_chip(domain, 0);
+ gc->reg_base = of_iomap(node, 0);
+ if (!gc->reg_base) {
+ pr_err("%s: unable to map resource\n", node->name);
+ ret = -ENOMEM;
+ goto fail_irqd_remove;
+ }
+
+ gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
+ gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
+ gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
+ gc->chip_types[0].chip.irq_unmask = sunxi_sc_nmi_ack_and_unmask;
+ gc->chip_types[0].chip.irq_set_type = sunxi_sc_nmi_set_type;
+ gc->chip_types[0].regs.ack = reg_offs->pend;
+ gc->chip_types[0].regs.mask = reg_offs->enable;
+ gc->chip_types[0].regs.type = reg_offs->ctrl;
+
+ gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
+ gc->chip_types[1].chip.name = gc->chip_types[0].chip.name;
+ 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 = sunxi_sc_nmi_ack_and_unmask;
+ gc->chip_types[1].chip.irq_set_type = sunxi_sc_nmi_set_type;
+ gc->chip_types[1].regs.ack = reg_offs->pend;
+ gc->chip_types[1].regs.mask = reg_offs->enable;
+ gc->chip_types[1].regs.type = reg_offs->ctrl;
+ gc->chip_types[1].handler = handle_edge_irq;
+
+ irq_set_handler_data(irq, domain);
+ irq_set_chained_handler(irq, sunxi_sc_nmi_handle_irq);
+
+ sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
+ sunxi_sc_nmi_write(gc, reg_offs->pend, 0x1);
+
+ return 0;
+
+fail_irqd_remove:
+ irq_domain_remove(domain);
+
+ return ret;
+}
+
+static int __init sun6i_sc_nmi_irq_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return sunxi_sc_nmi_irq_init(node, &sun6i_reg_offs);
+}
+IRQCHIP_DECLARE(sun6i_sc_nmi, "allwinner,sun6i-a31-sc-nmi", sun6i_sc_nmi_irq_init);
+
+static int __init sun7i_sc_nmi_irq_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return sunxi_sc_nmi_irq_init(node, &sun7i_reg_offs);
+}
+IRQCHIP_DECLARE(sun7i_sc_nmi, "allwinner,sun7i-a20-sc-nmi", sun7i_sc_nmi_irq_init);
--
1.8.3.2
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