From: Cristian Birsan <[email protected]>

This adds support for the EVIC present on a PIC32MZDA.

The following features are supported:
 - DT properties for EVIC and for devices that use interrupt lines
 - persistent and non-persistent interrupt handling
 - Priority, sub-priority and polariy settings for each interrupt line
 - irqdomain support

Signed-off-by: Cristian Birsan <[email protected]>
Signed-off-by: Joshua Henderson <[email protected]>
---
 drivers/irqchip/Makefile           |    1 +
 drivers/irqchip/irq-pic32-evic.c   |  309 ++++++++++++++++++++++++++++++++++++
 include/linux/irqchip/pic32-evic.h |   19 +++
 3 files changed, 329 insertions(+)
 create mode 100644 drivers/irqchip/irq-pic32-evic.c
 create mode 100644 include/linux/irqchip/pic32-evic.h

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 177f78f..e3608fc 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -55,3 +55,4 @@ obj-$(CONFIG_RENESAS_H8S_INTC)                += 
irq-renesas-h8s.o
 obj-$(CONFIG_ARCH_SA1100)              += irq-sa11x0.o
 obj-$(CONFIG_INGENIC_IRQ)              += irq-ingenic.o
 obj-$(CONFIG_IMX_GPCV2)                        += irq-imx-gpcv2.o
+obj-$(CONFIG_MACH_PIC32)               += irq-pic32-evic.o
diff --git a/drivers/irqchip/irq-pic32-evic.c b/drivers/irqchip/irq-pic32-evic.c
new file mode 100644
index 0000000..7b87b43
--- /dev/null
+++ b/drivers/irqchip/irq-pic32-evic.c
@@ -0,0 +1,309 @@
+/*
+ * Cristian Birsan <[email protected]>
+ * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/irqchip.h>
+
+#include <asm/irq.h>
+#include <asm/traps.h>
+#include <dt-bindings/interrupt-controller/microchip,pic32mz-evic.h>
+
+struct irq_domain *evic_irq_domain;
+static struct evic __iomem *evic_base;
+
+static unsigned int *evic_irq_prio;
+
+struct pic_reg {
+       u32 val; /* value register*/
+       u32 clr; /* clear register */
+       u32 set; /* set register */
+       u32 inv; /* inv register */
+} __packed;
+
+struct evic {
+       struct pic_reg intcon;
+       struct pic_reg priss;
+       struct pic_reg intstat;
+       struct pic_reg iptmr;
+       struct pic_reg ifs[6];
+       u32 reserved1[8];
+       struct pic_reg iec[6];
+       u32 reserved2[8];
+       struct pic_reg ipc[48];
+       u32 reserved3[64];
+       u32 off[191];
+} __packed;
+
+static int get_ext_irq_index(irq_hw_number_t hw);
+static void evic_set_ext_irq_polarity(int ext_irq, u32 type);
+
+#define BIT_REG_MASK(bit, reg, mask)           \
+       do {                                    \
+               reg = bit/32;                   \
+               mask = 1 << (bit % 32);         \
+       } while (0)
+
+asmlinkage void __weak plat_irq_dispatch(void)
+{
+       unsigned int irq, hwirq;
+       u32 reg, mask;
+
+       hwirq = readl(&evic_base->intstat.val) & 0xFF;
+
+       /* Check if the interrupt was really triggered by hardware*/
+       BIT_REG_MASK(hwirq, reg, mask);
+       if (likely(readl(&evic_base->ifs[reg].val) &
+                       readl(&evic_base->iec[reg].val) & mask)) {
+               irq = irq_linear_revmap(evic_irq_domain, hwirq);
+               do_IRQ(irq);
+       } else
+               spurious_interrupt();
+}
+
+/* mask off an interrupt */
+static inline void mask_pic32_irq(struct irq_data *irqd)
+{
+       u32 reg, mask;
+       unsigned int hwirq = irqd_to_hwirq(irqd);
+
+       BIT_REG_MASK(hwirq, reg, mask);
+       writel(mask, &evic_base->iec[reg].clr);
+}
+
+/* unmask an interrupt */
+static inline void unmask_pic32_irq(struct irq_data *irqd)
+{
+       u32 reg, mask;
+       unsigned int hwirq = irqd_to_hwirq(irqd);
+
+       BIT_REG_MASK(hwirq, reg, mask);
+       writel(mask, &evic_base->iec[reg].set);
+}
+
+/* acknowledge an interrupt */
+static void ack_pic32_irq(struct irq_data *irqd)
+{
+       u32 reg, mask;
+       unsigned int hwirq = irqd_to_hwirq(irqd);
+
+       BIT_REG_MASK(hwirq, reg, mask);
+       writel(mask, &evic_base->ifs[reg].clr);
+}
+
+/* mask off and acknowledge an interrupt */
+static inline void mask_ack_pic32_irq(struct irq_data *irqd)
+{
+       u32 reg, mask;
+       unsigned int hwirq = irqd_to_hwirq(irqd);
+
+       BIT_REG_MASK(hwirq, reg, mask);
+       writel(mask, &evic_base->iec[reg].clr);
+       writel(mask, &evic_base->ifs[reg].clr);
+}
+
+static int set_type_pic32_irq(struct irq_data *data, unsigned int flow_type)
+{
+       int index;
+
+       switch (flow_type) {
+
+       case IRQ_TYPE_EDGE_RISING:
+       case IRQ_TYPE_EDGE_FALLING:
+               irq_set_handler_locked(data, handle_edge_irq);
+               break;
+
+       case IRQ_TYPE_LEVEL_HIGH:
+       case IRQ_TYPE_LEVEL_LOW:
+               irq_set_handler_locked(data, handle_fasteoi_irq);
+               break;
+
+       default:
+               pr_err("Invalid interrupt type !\n");
+               return -EINVAL;
+       }
+
+       /* set polarity for external interrupts only */
+       index = get_ext_irq_index(data->hwirq);
+       if (index >= 0)
+               evic_set_ext_irq_polarity(index, flow_type);
+
+       return IRQ_SET_MASK_OK;
+}
+
+static void pic32_bind_evic_interrupt(int irq, int set)
+{
+       writel(set, &evic_base->off[irq]);
+}
+
+int pic32_get_c0_compare_int(void)
+{
+       int virq;
+
+       virq = irq_create_mapping(evic_irq_domain, CORE_TIMER_INTERRUPT);
+       irq_set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
+       return virq;
+}
+
+static struct irq_chip pic32_irq_chip = {
+       .name = "PIC32-EVIC",
+       .irq_ack = ack_pic32_irq,
+       .irq_mask = mask_pic32_irq,
+       .irq_mask_ack = mask_ack_pic32_irq,
+       .irq_unmask = unmask_pic32_irq,
+       .irq_eoi = ack_pic32_irq,
+       .irq_set_type = set_type_pic32_irq,
+       .irq_enable = unmask_pic32_irq,
+       .irq_disable = mask_pic32_irq,
+};
+
+static void evic_set_irq_priority(int irq, int priority)
+{
+       u32 reg, shift;
+
+       reg = irq / 4;
+       shift = (irq % 4) * 8;
+
+       /* set priority */
+       writel(INT_MASK << shift, &evic_base->ipc[reg].clr);
+       writel(priority << shift, &evic_base->ipc[reg].set);
+}
+
+static void evic_set_ext_irq_polarity(int ext_irq, u32 type)
+{
+       if (WARN_ON(ext_irq >= NR_EXT_IRQS))
+               return;
+       switch (type) {
+       case IRQ_TYPE_EDGE_RISING:
+               writel(1 << ext_irq, &evic_base->intcon.set);
+               break;
+       case IRQ_TYPE_EDGE_FALLING:
+               writel(1 << ext_irq, &evic_base->intcon.clr);
+               break;
+       default:
+               pr_err("Invalid external interrupt polarity !\n");
+       }
+}
+
+static int get_ext_irq_index(irq_hw_number_t hw)
+{
+       switch (hw) {
+       case EXTERNAL_INTERRUPT_0:
+               return 0;
+       case EXTERNAL_INTERRUPT_1:
+               return 1;
+       case EXTERNAL_INTERRUPT_2:
+               return 2;
+       case EXTERNAL_INTERRUPT_3:
+               return 3;
+       case EXTERNAL_INTERRUPT_4:
+               return 4;
+       default:
+               return -1;
+       }
+}
+
+static int evic_intc_map(struct irq_domain *irqd, unsigned int virq,
+                       irq_hw_number_t hw)
+{
+       u32 reg, mask;
+
+       irq_set_chip(virq, &pic32_irq_chip);
+
+       BIT_REG_MASK(hw, reg, mask);
+
+       /* disable */
+       writel(mask, &evic_base->iec[reg].clr);
+
+       /* clear flag */
+       writel(mask, &evic_base->ifs[reg].clr);
+
+       evic_set_irq_priority(hw, evic_irq_prio[hw]);
+
+       return 0;
+}
+
+static int evic_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)
+{
+       /* Check for number of params */
+       if (WARN_ON(intsize < 3))
+               return -EINVAL;
+       if (WARN_ON(intspec[0] >= NR_IRQS))
+               return -EINVAL;
+       /* Check for correct priority settings */
+       if (WARN_ON((intspec[1] < MICROCHIP_EVIC_MIN_PRIORITY)
+                       || (intspec[1] > MICROCHIP_EVIC_MAX_PRIORITY)))
+               return -EINVAL;
+
+       *out_hwirq = intspec[0];
+
+       evic_irq_prio[*out_hwirq] = intspec[1];
+
+       *out_type = intspec[2];
+
+       return 0;
+}
+
+static const struct irq_domain_ops evic_intc_irq_domain_ops = {
+               .map = evic_intc_map,
+               .xlate = evic_irq_domain_xlate,
+};
+
+#ifdef CONFIG_OF
+
+static int __init
+microchip_evic_of_init(struct device_node *node, struct device_node *parent)
+{
+       struct resource res;
+
+       if (WARN_ON(!node))
+               return -ENODEV;
+
+       evic_irq_prio = kcalloc(NR_IRQS, sizeof(*evic_irq_prio),
+                               GFP_KERNEL);
+       if (!evic_irq_prio)
+               return -ENOMEM;
+
+       evic_irq_prio[CORE_TIMER_INTERRUPT] = DEFAULT_INT_PRI; /* Default IRQ*/
+
+       if (of_address_to_resource(node, 0, &res))
+               panic("Failed to get evic memory range");
+
+       if (request_mem_region(res.start, resource_size(&res),
+                               res.name) == NULL)
+               panic("Failed to request evic memory");
+
+       evic_base = ioremap_nocache(res.start, resource_size(&res));
+       if (!evic_base)
+               panic("Failed to remap evic memory");
+
+       board_bind_eic_interrupt = &pic32_bind_evic_interrupt;
+
+       evic_irq_domain = irq_domain_add_linear(node, NR_IRQS,
+                       &evic_intc_irq_domain_ops, NULL);
+       if (!evic_irq_domain)
+               panic("Failed to add linear irqdomain for EVIC");
+
+       irq_set_default_host(evic_irq_domain);
+
+       return 0;
+}
+
+IRQCHIP_DECLARE(microchip_evic, "microchip,evic-v2", microchip_evic_of_init);
+#endif
diff --git a/include/linux/irqchip/pic32-evic.h 
b/include/linux/irqchip/pic32-evic.h
new file mode 100644
index 0000000..c514bae
--- /dev/null
+++ b/include/linux/irqchip/pic32-evic.h
@@ -0,0 +1,19 @@
+/*
+ * Joshua Henderson, <[email protected]>
+ * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ */
+#ifndef __LINUX_IRQCHIP_PIC32_EVIC_H
+#define __LINUX_IRQCHIP_PIC32_EVIC_H
+
+extern int pic32_get_c0_compare_int(void);
+
+#endif /* __LINUX_IRQCHIP_PIC32_EVIC_H */
-- 
1.7.9.5

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