aboutsummaryrefslogtreecommitdiffstats
path: root/arch/c6x/platforms/megamod-pic.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/c6x/platforms/megamod-pic.c')
-rw-r--r--arch/c6x/platforms/megamod-pic.c349
1 files changed, 349 insertions, 0 deletions
diff --git a/arch/c6x/platforms/megamod-pic.c b/arch/c6x/platforms/megamod-pic.c
new file mode 100644
index 00000000000..7c37a947fb1
--- /dev/null
+++ b/arch/c6x/platforms/megamod-pic.c
@@ -0,0 +1,349 @@
+/*
+ * Support for C64x+ Megamodule Interrupt Controller
+ *
+ * Copyright (C) 2010, 2011 Texas Instruments Incorporated
+ * Contributed by: Mark Salter <msalter@redhat.com>
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <asm/soc.h>
+#include <asm/megamod-pic.h>
+
+#define NR_COMBINERS 4
+#define NR_MUX_OUTPUTS 12
+
+#define IRQ_UNMAPPED 0xffff
+
+/*
+ * Megamodule Interrupt Controller register layout
+ */
+struct megamod_regs {
+ u32 evtflag[8];
+ u32 evtset[8];
+ u32 evtclr[8];
+ u32 reserved0[8];
+ u32 evtmask[8];
+ u32 mevtflag[8];
+ u32 expmask[8];
+ u32 mexpflag[8];
+ u32 intmux_unused;
+ u32 intmux[7];
+ u32 reserved1[8];
+ u32 aegmux[2];
+ u32 reserved2[14];
+ u32 intxstat;
+ u32 intxclr;
+ u32 intdmask;
+ u32 reserved3[13];
+ u32 evtasrt;
+};
+
+struct megamod_pic {
+ struct irq_host *irqhost;
+ struct megamod_regs __iomem *regs;
+ raw_spinlock_t lock;
+
+ /* hw mux mapping */
+ unsigned int output_to_irq[NR_MUX_OUTPUTS];
+};
+
+static struct megamod_pic *mm_pic;
+
+struct megamod_cascade_data {
+ struct megamod_pic *pic;
+ int index;
+};
+
+static struct megamod_cascade_data cascade_data[NR_COMBINERS];
+
+static void mask_megamod(struct irq_data *data)
+{
+ struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t src = irqd_to_hwirq(data);
+ u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];
+
+ raw_spin_lock(&pic->lock);
+ soc_writel(soc_readl(evtmask) | (1 << (src & 31)), evtmask);
+ raw_spin_unlock(&pic->lock);
+}
+
+static void unmask_megamod(struct irq_data *data)
+{
+ struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t src = irqd_to_hwirq(data);
+ u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];
+
+ raw_spin_lock(&pic->lock);
+ soc_writel(soc_readl(evtmask) & ~(1 << (src & 31)), evtmask);
+ raw_spin_unlock(&pic->lock);
+}
+
+static struct irq_chip megamod_chip = {
+ .name = "megamod",
+ .irq_mask = mask_megamod,
+ .irq_unmask = unmask_megamod,
+};
+
+static void megamod_irq_cascade(unsigned int irq, struct irq_desc *desc)
+{
+ struct megamod_cascade_data *cascade;
+ struct megamod_pic *pic;
+ u32 events;
+ int n, idx;
+
+ cascade = irq_desc_get_handler_data(desc);
+
+ pic = cascade->pic;
+ idx = cascade->index;
+
+ while ((events = soc_readl(&pic->regs->mevtflag[idx])) != 0) {
+ n = __ffs(events);
+
+ irq = irq_linear_revmap(pic->irqhost, idx * 32 + n);
+
+ soc_writel(1 << n, &pic->regs->evtclr[idx]);
+
+ generic_handle_irq(irq);
+ }
+}
+
+static int megamod_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct megamod_pic *pic = h->host_data;
+ int i;
+
+ /* We shouldn't see a hwirq which is muxed to core controller */
+ for (i = 0; i < NR_MUX_OUTPUTS; i++)
+ if (pic->output_to_irq[i] == hw)
+ return -1;
+
+ irq_set_chip_data(virq, pic);
+ irq_set_chip_and_handler(virq, &megamod_chip, handle_level_irq);
+
+ /* Set default irq type */
+ irq_set_irq_type(virq, IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+static int megamod_xlate(struct irq_host *h, struct device_node *ct,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq, unsigned int *out_type)
+
+{
+ /* megamod intspecs must have 1 cell */
+ BUG_ON(intsize != 1);
+ *out_hwirq = intspec[0];
+ *out_type = IRQ_TYPE_NONE;
+ return 0;
+}
+
+static struct irq_host_ops megamod_host_ops = {
+ .map = megamod_map,
+ .xlate = megamod_xlate,
+};
+
+static void __init set_megamod_mux(struct megamod_pic *pic, int src, int output)
+{
+ int index, offset;
+ u32 val;
+
+ if (src < 0 || src >= (NR_COMBINERS * 32)) {
+ pic->output_to_irq[output] = IRQ_UNMAPPED;
+ return;
+ }
+
+ /* four mappings per mux register */
+ index = output / 4;
+ offset = (output & 3) * 8;
+
+ val = soc_readl(&pic->regs->intmux[index]);
+ val &= ~(0xff << offset);
+ val |= src << offset;
+ soc_writel(val, &pic->regs->intmux[index]);
+}
+
+/*
+ * Parse the MUX mapping, if one exists.
+ *
+ * The MUX map is an array of up to 12 cells; one for each usable core priority
+ * interrupt. The value of a given cell is the megamodule interrupt source
+ * which is to me MUXed to the output corresponding to the cell position
+ * withing the array. The first cell in the array corresponds to priority
+ * 4 and the last (12th) cell corresponds to priority 15. The allowed
+ * values are 4 - ((NR_COMBINERS * 32) - 1). Note that the combined interrupt
+ * sources (0 - 3) are not allowed to be mapped through this property. They
+ * are handled through the "interrupts" property. This allows us to use a
+ * value of zero as a "do not map" placeholder.
+ */
+static void __init parse_priority_map(struct megamod_pic *pic,
+ int *mapping, int size)
+{
+ struct device_node *np = pic->irqhost->of_node;
+ const __be32 *map;
+ int i, maplen;
+ u32 val;
+
+ map = of_get_property(np, "ti,c64x+megamod-pic-mux", &maplen);
+ if (map) {
+ maplen /= 4;
+ if (maplen > size)
+ maplen = size;
+
+ for (i = 0; i < maplen; i++) {
+ val = be32_to_cpup(map);
+ if (val && val >= 4)
+ mapping[i] = val;
+ ++map;
+ }
+ }
+}
+
+static struct megamod_pic * __init init_megamod_pic(struct device_node *np)
+{
+ struct megamod_pic *pic;
+ int i, irq;
+ int mapping[NR_MUX_OUTPUTS];
+
+ pr_info("Initializing C64x+ Megamodule PIC\n");
+
+ pic = kzalloc(sizeof(struct megamod_pic), GFP_KERNEL);
+ if (!pic) {
+ pr_err("%s: Could not alloc PIC structure.\n", np->full_name);
+ return NULL;
+ }
+
+ pic->irqhost = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
+ NR_COMBINERS * 32, &megamod_host_ops,
+ IRQ_UNMAPPED);
+ if (!pic->irqhost) {
+ pr_err("%s: Could not alloc host.\n", np->full_name);
+ goto error_free;
+ }
+
+ pic->irqhost->host_data = pic;
+
+ raw_spin_lock_init(&pic->lock);
+
+ pic->regs = of_iomap(np, 0);
+ if (!pic->regs) {
+ pr_err("%s: Could not map registers.\n", np->full_name);
+ goto error_free;
+ }
+
+ /* Initialize MUX map */
+ for (i = 0; i < ARRAY_SIZE(mapping); i++)
+ mapping[i] = IRQ_UNMAPPED;
+
+ parse_priority_map(pic, mapping, ARRAY_SIZE(mapping));
+
+ /*
+ * We can have up to 12 interrupts cascading to the core controller.
+ * These cascades can be from the combined interrupt sources or for
+ * individual interrupt sources. The "interrupts" property only
+ * deals with the cascaded combined interrupts. The individual
+ * interrupts muxed to the core controller use the core controller
+ * as their interrupt parent.
+ */
+ for (i = 0; i < NR_COMBINERS; i++) {
+
+ irq = irq_of_parse_and_map(np, i);
+ if (irq == NO_IRQ)
+ continue;
+
+ /*
+ * We count on the core priority interrupts (4 - 15) being
+ * direct mapped. Check that device tree provided something
+ * in that range.
+ */
+ if (irq < 4 || irq >= NR_PRIORITY_IRQS) {
+ pr_err("%s: combiner-%d virq %d out of range!\n",
+ np->full_name, i, irq);
+ continue;
+ }
+
+ /* record the mapping */
+ mapping[irq - 4] = i;
+
+ pr_debug("%s: combiner-%d cascading to virq %d\n",
+ np->full_name, i, irq);
+
+ cascade_data[i].pic = pic;
+ cascade_data[i].index = i;
+
+ /* mask and clear all events in combiner */
+ soc_writel(~0, &pic->regs->evtmask[i]);
+ soc_writel(~0, &pic->regs->evtclr[i]);
+
+ irq_set_handler_data(irq, &cascade_data[i]);
+ irq_set_chained_handler(irq, megamod_irq_cascade);
+ }
+
+ /* Finally, set up the MUX registers */
+ for (i = 0; i < NR_MUX_OUTPUTS; i++) {
+ if (mapping[i] != IRQ_UNMAPPED) {
+ pr_debug("%s: setting mux %d to priority %d\n",
+ np->full_name, mapping[i], i + 4);
+ set_megamod_mux(pic, mapping[i], i);
+ }
+ }
+
+ return pic;
+
+error_free:
+ kfree(pic);
+
+ return NULL;
+}
+
+/*
+ * Return next active event after ACK'ing it.
+ * Return -1 if no events active.
+ */
+static int get_exception(void)
+{
+ int i, bit;
+ u32 mask;
+
+ for (i = 0; i < NR_COMBINERS; i++) {
+ mask = soc_readl(&mm_pic->regs->mexpflag[i]);
+ if (mask) {
+ bit = __ffs(mask);
+ soc_writel(1 << bit, &mm_pic->regs->evtclr[i]);
+ return (i * 32) + bit;
+ }
+ }
+ return -1;
+}
+
+static void assert_event(unsigned int val)
+{
+ soc_writel(val, &mm_pic->regs->evtasrt);
+}
+
+void __init megamod_pic_init(void)
+{
+ struct device_node *np;
+
+ np = of_find_compatible_node(NULL, NULL, "ti,c64x+megamod-pic");
+ if (!np)
+ return;
+
+ mm_pic = init_megamod_pic(np);
+ of_node_put(np);
+
+ soc_ops.get_exception = get_exception;
+ soc_ops.assert_event = assert_event;
+
+ return;
+}