[PATCH v4 02/21] irqchip: tegra: add DT-based support for legacy interrupt controller
Marc Zyngier
marc.zyngier at arm.com
Mon Jan 19 01:43:56 PST 2015
Tegra's LIC (Legacy Interrupt Controller) has been so far only
supported as a weird extension of the GIC, which is not exactly
pretty.
The stacked IRQ domain framework fits this pretty well, and allows
the LIC code to be turned into a standalone irqchip. In the process,
make the driver DT aware, something that was sorely missing from
the mach-tegra implementation.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-tegra.c | 368 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 369 insertions(+)
create mode 100644 drivers/irqchip/irq-tegra.c
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 9516a32..59f34be 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_ARCH_HIP04) += irq-hip04.o
obj-$(CONFIG_ARCH_MMP) += irq-mmp.o
obj-$(CONFIG_ARCH_MVEBU) += irq-armada-370-xp.o
obj-$(CONFIG_ARCH_MXS) += irq-mxs.o
+obj-$(CONFIG_ARCH_TEGRA) += irq-tegra.o
obj-$(CONFIG_ARCH_S3C24XX) += irq-s3c24xx.o
obj-$(CONFIG_DW_APB_ICTL) += irq-dw-apb-ictl.o
obj-$(CONFIG_METAG) += irq-metag-ext.o
diff --git a/drivers/irqchip/irq-tegra.c b/drivers/irqchip/irq-tegra.c
new file mode 100644
index 0000000..e1ac65e
--- /dev/null
+++ b/drivers/irqchip/irq-tegra.c
@@ -0,0 +1,368 @@
+/*
+ * Driver code for Tegra's Legacy Interrupt Controller
+ *
+ * Author: Marc Zyngier <marc.zyngier at arm.com>
+ *
+ * Heavily based on the original arch/arm/mach-tegra/irq.c code:
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross at android.com>
+ *
+ * Copyright (C) 2010,2013, NVIDIA Corporation
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+#include "irqchip.h"
+
+#define ICTLR_CPU_IEP_VFIQ 0x08
+#define ICTLR_CPU_IEP_FIR 0x14
+#define ICTLR_CPU_IEP_FIR_SET 0x18
+#define ICTLR_CPU_IEP_FIR_CLR 0x1c
+
+#define ICTLR_CPU_IER 0x20
+#define ICTLR_CPU_IER_SET 0x24
+#define ICTLR_CPU_IER_CLR 0x28
+#define ICTLR_CPU_IEP_CLASS 0x2C
+
+#define ICTLR_COP_IER 0x30
+#define ICTLR_COP_IER_SET 0x34
+#define ICTLR_COP_IER_CLR 0x38
+#define ICTLR_COP_IEP_CLASS 0x3c
+
+#define TEGRA_MAX_NUM_ICTLRS 5
+
+static unsigned int num_ictlrs;
+
+struct tegra_ictlr_soc {
+ unsigned int num_ictlrs;
+};
+
+static const struct tegra_ictlr_soc tegra20_ictlr_soc = {
+ .num_ictlrs = 4,
+};
+
+static const struct tegra_ictlr_soc tegra30_ictlr_soc = {
+ .num_ictlrs = 5,
+};
+
+static const struct of_device_id ictlr_matches[] = {
+ { .compatible = "nvidia,tegra30-ictlr", .data = &tegra30_ictlr_soc },
+ { .compatible = "nvidia,tegra20-ictlr", .data = &tegra20_ictlr_soc },
+ { }
+};
+
+struct tegra_ictlr_info {
+ void __iomem *base[TEGRA_MAX_NUM_ICTLRS];
+#ifdef CONFIG_PM_SLEEP
+ u32 cop_ier[TEGRA_MAX_NUM_ICTLRS];
+ u32 cop_iep[TEGRA_MAX_NUM_ICTLRS];
+ u32 cpu_ier[TEGRA_MAX_NUM_ICTLRS];
+ u32 cpu_iep[TEGRA_MAX_NUM_ICTLRS];
+
+ u32 ictlr_wake_mask[TEGRA_MAX_NUM_ICTLRS];
+#endif
+};
+
+static struct tegra_ictlr_info *lic;
+
+static inline void tegra_ictlr_write_mask(struct irq_data *d, unsigned long reg)
+{
+ void __iomem *base = d->chip_data;
+ u32 mask;
+
+ mask = BIT(d->hwirq % 32);
+ writel_relaxed(mask, base + reg);
+}
+
+static void tegra_mask(struct irq_data *d)
+{
+ tegra_ictlr_write_mask(d, ICTLR_CPU_IER_CLR);
+ irq_chip_mask_parent(d);
+}
+
+static void tegra_unmask(struct irq_data *d)
+{
+ tegra_ictlr_write_mask(d, ICTLR_CPU_IER_SET);
+ irq_chip_unmask_parent(d);
+}
+
+static void tegra_eoi(struct irq_data *d)
+{
+ tegra_ictlr_write_mask(d, ICTLR_CPU_IEP_FIR_CLR);
+ irq_chip_eoi_parent(d);
+}
+
+static int tegra_retrigger(struct irq_data *d)
+{
+ tegra_ictlr_write_mask(d, ICTLR_CPU_IEP_FIR_SET);
+ return irq_chip_retrigger_hierarchy(d);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_set_wake(struct irq_data *d, unsigned int enable)
+{
+ u32 irq = d->hwirq;
+ u32 index, mask;
+
+ index = (irq / 32);
+ mask = BIT(irq % 32);
+ if (enable)
+ lic->ictlr_wake_mask[index] |= mask;
+ else
+ lic->ictlr_wake_mask[index] &= ~mask;
+
+ /*
+ * Do *not* call into the parent, as the GIC doesn't have any
+ * wake-up facility...
+ */
+ return 0;
+}
+
+static int tegra_ictlr_suspend(void)
+{
+ unsigned long flags;
+ unsigned int i;
+
+ local_irq_save(flags);
+ for (i = 0; i < num_ictlrs; i++) {
+ void __iomem *ictlr = lic->base[i];
+
+ /* Save interrupt state */
+ lic->cpu_ier[i] = readl_relaxed(ictlr + ICTLR_CPU_IER);
+ lic->cpu_iep[i] = readl_relaxed(ictlr + ICTLR_CPU_IEP_CLASS);
+ lic->cop_ier[i] = readl_relaxed(ictlr + ICTLR_COP_IER);
+ lic->cop_iep[i] = readl_relaxed(ictlr + ICTLR_COP_IEP_CLASS);
+
+ /* Disable COP interrupts */
+ writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
+
+ /* Disable CPU interrupts */
+ writel_relaxed(~0ul, ictlr + ICTLR_CPU_IER_CLR);
+
+ /* Enable the wakeup sources of ictlr */
+ writel_relaxed(lic->ictlr_wake_mask[i], ictlr + ICTLR_CPU_IER_SET);
+ }
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static void tegra_ictlr_resume(void)
+{
+ unsigned long flags;
+ unsigned int i;
+
+ local_irq_save(flags);
+ for (i = 0; i < num_ictlrs; i++) {
+ void __iomem *ictlr = lic->base[i];
+
+ writel_relaxed(lic->cpu_iep[i],
+ ictlr + ICTLR_CPU_IEP_CLASS);
+ writel_relaxed(~0ul, ictlr + ICTLR_CPU_IER_CLR);
+ writel_relaxed(lic->cpu_ier[i],
+ ictlr + ICTLR_CPU_IER_SET);
+ writel_relaxed(lic->cop_iep[i],
+ ictlr + ICTLR_COP_IEP_CLASS);
+ writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
+ writel_relaxed(lic->cop_ier[i],
+ ictlr + ICTLR_COP_IER_SET);
+ }
+ local_irq_restore(flags);
+}
+
+static struct syscore_ops tegra_ictlr_syscore_ops = {
+ .suspend = tegra_ictlr_suspend,
+ .resume = tegra_ictlr_resume,
+};
+
+static void tegra_ictlr_syscore_init(void)
+{
+ register_syscore_ops(&tegra_ictlr_syscore_ops);
+}
+#else
+#define tegra_set_wake NULL
+static inline void tegra_ictlr_syscore_init(void) {}
+#endif
+
+static struct irq_chip tegra_ictlr_chip = {
+ .name = "LIC",
+ .irq_eoi = tegra_eoi,
+ .irq_mask = tegra_mask,
+ .irq_unmask = tegra_unmask,
+ .irq_retrigger = tegra_retrigger,
+ .irq_set_wake = tegra_set_wake,
+ .flags = IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int tegra_ictlr_domain_xlate(struct irq_domain *domain,
+ struct device_node *controller,
+ const u32 *intspec,
+ unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ if (domain->of_node != controller)
+ return -EINVAL; /* Shouldn't happen, really... */
+ if (intsize != 3)
+ return -EINVAL; /* Not GIC compliant */
+ if (intspec[0] != GIC_SPI)
+ return -EINVAL; /* No PPI should point to this domain */
+
+ *out_hwirq = intspec[1];
+ *out_type = intspec[2];
+ return 0;
+}
+
+static int tegra_ictlr_domain_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs, void *data)
+{
+ struct of_phandle_args *args = data;
+ struct of_phandle_args parent_args;
+ struct tegra_ictlr_info *info = domain->host_data;
+ irq_hw_number_t hwirq;
+ unsigned int i;
+
+ if (args->args_count != 3)
+ return -EINVAL; /* Not GIC compliant */
+ if (args->args[0] != GIC_SPI)
+ return -EINVAL; /* No PPI should point to this domain */
+
+ hwirq = args->args[1];
+ if (hwirq >= (num_ictlrs * 32))
+ return -EINVAL;
+
+ for (i = 0; i < nr_irqs; i++) {
+ int ictlr = (hwirq + i) / 32;
+
+ irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+ &tegra_ictlr_chip,
+ &info->base[ictlr]);
+ }
+
+ parent_args = *args;
+ parent_args.np = domain->parent->of_node;
+ return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &parent_args);
+}
+
+static void tegra_ictlr_domain_free(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs)
+{
+ unsigned int i;
+
+ for (i = 0; i < nr_irqs; i++) {
+ struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
+ irq_domain_reset_irq_data(d);
+ }
+}
+
+static const struct irq_domain_ops tegra_ictlr_domain_ops = {
+ .xlate = tegra_ictlr_domain_xlate,
+ .alloc = tegra_ictlr_domain_alloc,
+ .free = tegra_ictlr_domain_free,
+};
+
+static int __init tegra_ictlr_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct irq_domain *parent_domain, *domain;
+ const struct of_device_id *match;
+ const struct tegra_ictlr_soc *soc;
+ unsigned int i;
+ int err;
+
+ if (!parent) {
+ pr_err("%s: no parent, giving up\n", node->full_name);
+ return -ENODEV;
+ }
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain) {
+ pr_err("%s: unable to obtain parent domain\n", node->full_name);
+ return -ENXIO;
+ }
+
+ match = of_match_node(ictlr_matches, node);
+ if (!match) /* Should never happen... */
+ return -ENODEV;
+
+ soc = match->data;
+
+ lic = kzalloc(sizeof(*lic), GFP_KERNEL);
+ if (!lic)
+ return -ENOMEM;
+
+ for (i = 0; i < TEGRA_MAX_NUM_ICTLRS; i++) {
+ void __iomem *base;
+
+ base = of_iomap(node, i);
+ if (!base)
+ break;
+
+ lic->base[i] = base;
+
+ /* Disable all interrupts */
+ writel_relaxed(~0UL, base + ICTLR_CPU_IER_CLR);
+ /* All interrupts target IRQ */
+ writel_relaxed(0, base + ICTLR_CPU_IEP_CLASS);
+
+ num_ictlrs++;
+ }
+
+ if (!num_ictlrs) {
+ pr_err("%s: no valid regions, giving up\n", node->full_name);
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ WARN(num_ictlrs != soc->num_ictlrs,
+ "%s: Found %u interrupt controllers in DT; expected %u.\n",
+ node->full_name, num_ictlrs, soc->num_ictlrs);
+
+
+ domain = irq_domain_add_hierarchy(parent_domain, 0, num_ictlrs * 32,
+ node, &tegra_ictlr_domain_ops,
+ lic);
+ if (!domain) {
+ pr_err("%s: failed to allocated domain\n", node->full_name);
+ err = -ENOMEM;
+ goto out_unmap;
+ }
+
+ tegra_ictlr_syscore_init();
+
+ pr_info("%s: %d interrupts forwarded to %s\n",
+ node->full_name, num_ictlrs * 32, parent->full_name);
+
+ return 0;
+
+out_unmap:
+ for (i = 0; i < num_ictlrs; i++)
+ iounmap(lic->base[i]);
+out_free:
+ kfree(lic);
+ return err;
+}
+
+IRQCHIP_DECLARE(tegra20_ictlr, "nvidia,tegra20-ictlr", tegra_ictlr_init);
+IRQCHIP_DECLARE(tegra30_ictlr, "nvidia,tegra30-ictlr", tegra_ictlr_init);
--
2.1.4
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