--- /dev/null
+/*
+ * Copyright (C) 2015 - Ben Herrenschmidt, IBM Corp.
+ *
+ * Driver for Aspeed "new" VIC as found in SoC generation 3 and later
+ *
+ * Based on irq-vic.c:
+ *
+ * Copyright (C) 1999 - 2003 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/syscore_ops.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include <asm/exception.h>
+#include <asm/irq.h>
+
+/* These definitions correspond to the "new mapping" of the
+ * register set that interleaves "high" and "low". The offsets
+ * below are for the "low" register, add 4 to get to the high one
+ */
+#define AVIC_IRQ_STATUS 0x00
+#define AVIC_FIQ_STATUS 0x08
+#define AVIC_RAW_STATUS 0x10
+#define AVIC_INT_SELECT 0x18
+#define AVIC_INT_ENABLE 0x20
+#define AVIC_INT_ENABLE_CLR 0x28
+#define AVIC_INT_TRIGGER 0x30
+#define AVIC_INT_TRIGGER_CLR 0x38
+#define AVIC_INT_SENSE 0x40
+#define AVIC_INT_DUAL_EDGE 0x48
+#define AVIC_INT_EVENT 0x50
+#define AVIC_EDGE_CLR 0x58
+#define AVIC_EDGE_STATUS 0x60
+
+#define NUM_IRQS 64
+
+struct aspeed_vic {
+ void __iomem *base;
+ u32 edge_sources[2];
+ struct irq_domain *dom;
+};
+static struct aspeed_vic *system_avic;
+
+static void vic_init_hw(struct aspeed_vic *vic)
+{
+ u32 sense;
+
+ /* Disable all interrupts */
+ writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR);
+ writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR + 4);
+
+ /* Make sure no soft trigger is on */
+ writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR);
+ writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR + 4);
+
+ /* Set everything to be IRQ */
+ writel(0, vic->base + AVIC_INT_SELECT);
+ writel(0, vic->base + AVIC_INT_SELECT + 4);
+
+ /* Some interrupts have a programable high/low level trigger
+ * (4 GPIO direct inputs), for now we assume this was configured
+ * by firmware. We read which ones are edge now.
+ */
+ sense = readl(vic->base + AVIC_INT_SENSE);
+ vic->edge_sources[0] = ~sense;
+ sense = readl(vic->base + AVIC_INT_SENSE + 4);
+ vic->edge_sources[1] = ~sense;
+
+ /* Clear edge detection latches */
+ writel(0xffffffff, vic->base + AVIC_EDGE_CLR);
+ writel(0xffffffff, vic->base + AVIC_EDGE_CLR + 4);
+}
+
+static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
+{
+ struct aspeed_vic *vic = system_avic;
+ u32 stat, irq;
+
+ for (;;) {
+ irq = 0;
+ stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS);
+ if (!stat) {
+ stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS + 4);
+ irq = 32;
+ }
+ if (stat == 0)
+ break;
+ irq += ffs(stat) - 1;
+ handle_domain_irq(vic->dom, irq, regs);
+ }
+}
+
+static void avic_ack_irq(struct irq_data *d)
+{
+ struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
+ unsigned int sidx = d->hwirq >> 5;
+ unsigned int sbit = 1u << (d->hwirq & 0x1f);
+
+ /* Clear edge latch for edge interrupts, nop for level */
+ if (vic->edge_sources[sidx] & sbit)
+ writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
+}
+
+static void avic_mask_irq(struct irq_data *d)
+{
+ struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
+ unsigned int sidx = d->hwirq >> 5;
+ unsigned int sbit = 1u << (d->hwirq & 0x1f);
+
+ writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);
+}
+
+static void avic_unmask_irq(struct irq_data *d)
+{
+ struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
+ unsigned int sidx = d->hwirq >> 5;
+ unsigned int sbit = 1u << (d->hwirq & 0x1f);
+
+ writel(sbit, vic->base + AVIC_INT_ENABLE + sidx * 4);
+}
+
+/* For level irq, faster than going through a nop "ack" and mask */
+static void avic_mask_ack_irq(struct irq_data *d)
+{
+ struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
+ unsigned int sidx = d->hwirq >> 5;
+ unsigned int sbit = 1u << (d->hwirq & 0x1f);
+
+ /* First mask */
+ writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);
+
+ /* Then clear edge latch for edge interrupts */
+ if (vic->edge_sources[sidx] & sbit)
+ writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
+}
+
+static struct irq_chip avic_chip = {
+ .name = "AVIC",
+ .irq_ack = avic_ack_irq,
+ .irq_mask = avic_mask_irq,
+ .irq_unmask = avic_unmask_irq,
+ .irq_mask_ack = avic_mask_ack_irq,
+};
+
+static int avic_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct aspeed_vic *vic = d->host_data;
+ unsigned int sidx = hwirq >> 5;
+ unsigned int sbit = 1u << (hwirq & 0x1f);
+
+ /* Check if interrupt exists */
+ if (sidx > 1)
+ return -EPERM;
+
+ if (vic->edge_sources[sidx] & sbit)
+ irq_set_chip_and_handler(irq, &avic_chip, handle_edge_irq);
+ else
+ irq_set_chip_and_handler(irq, &avic_chip, handle_level_irq);
+ irq_set_chip_data(irq, vic);
+ irq_set_probe(irq);
+ return 0;
+}
+
+static struct irq_domain_ops avic_dom_ops = {
+ .map = avic_map,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+static int __init avic_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ void __iomem *regs;
+ struct aspeed_vic *vic;
+
+ if (WARN(parent, "non-root Aspeed VIC not supported"))
+ return -EINVAL;
+ if (WARN(system_avic, "duplicate Aspeed VIC not supported"))
+ return -EINVAL;
+
+ regs = of_iomap(node, 0);
+ if (WARN_ON(!regs))
+ return -EIO;
+
+ vic = kzalloc(sizeof(struct aspeed_vic), GFP_KERNEL);
+ if (WARN_ON(!vic)) {
+ iounmap(regs);
+ return -ENOMEM;
+ }
+ vic->base = regs;
+
+ /* Initialize soures, all masked */
+ vic_init_hw(vic);
+
+ /* Ready to receive interrupts */
+ system_avic = vic;
+ set_handle_irq(avic_handle_irq);
+
+ /* Register our domain */
+ vic->dom = irq_domain_add_simple(node, NUM_IRQS, 0,
+ &avic_dom_ops, vic);
+
+ return 0;
+}
+
+IRQCHIP_DECLARE(aspeed_new_vic, "aspeed,ast2400-vic", avic_of_init);
projects / cascardo / linux.git / commitdiff