[PATCH v4 08/11] powerpc: wiiu: latte interrupt controller support
From: Ash Logan
Date: Sat Nov 19 2022 - 06:32:32 EST
Add support for the "Latte" interrupt controller in the Nintendo Wii U.
This controller is used for the entire SoC and is wired to a cascade
interrupt on the Espresso controller.
Signed-off-by: Ash Logan <ash@xxxxxxxxxxxx>
Co-developed-by: Roberto Van Eeden <rw-r-r-0644@xxxxxxxxxxxxxx>
Signed-off-by: Roberto Van Eeden <rw-r-r-0644@xxxxxxxxxxxxxx>
---
v2->v3: Make latte_pic_get_irq static.
arch/powerpc/platforms/wiiu/Kconfig | 1 +
arch/powerpc/platforms/wiiu/Makefile | 2 +-
arch/powerpc/platforms/wiiu/latte-pic.c | 259 ++++++++++++++++++++++++
arch/powerpc/platforms/wiiu/latte-pic.h | 23 +++
4 files changed, 284 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/platforms/wiiu/latte-pic.c
create mode 100644 arch/powerpc/platforms/wiiu/latte-pic.h
diff --git a/arch/powerpc/platforms/wiiu/Kconfig b/arch/powerpc/platforms/wiiu/Kconfig
index 8dfd6ac8774d..40ecba8396a7 100644
--- a/arch/powerpc/platforms/wiiu/Kconfig
+++ b/arch/powerpc/platforms/wiiu/Kconfig
@@ -3,6 +3,7 @@
config WIIU
bool "Nintendo Wii U"
depends on PPC_BOOK3S_32
+ select IRQ_DOMAIN_HIERARCHY
help
Select WIIU if configuring for the Nintendo Wii U.
More information at: <https://linux-wiiu.org/>
diff --git a/arch/powerpc/platforms/wiiu/Makefile b/arch/powerpc/platforms/wiiu/Makefile
index aabf4b43e806..fa16c60261e6 100644
--- a/arch/powerpc/platforms/wiiu/Makefile
+++ b/arch/powerpc/platforms/wiiu/Makefile
@@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_WIIU) += espresso-pic.o
+obj-$(CONFIG_WIIU) += espresso-pic.o latte-pic.o
obj-$(CONFIG_LATTEIPC_UDBG) += udbg_latteipc.o
diff --git a/arch/powerpc/platforms/wiiu/latte-pic.c b/arch/powerpc/platforms/wiiu/latte-pic.c
new file mode 100644
index 000000000000..7e3f49844166
--- /dev/null
+++ b/arch/powerpc/platforms/wiiu/latte-pic.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Nintendo Wii U "Latte" interrupt controller support.
+ * This is the controller for all the SoC devices, and has a cascade interrupt for the Espresso
+ * CPU interrupt controller.
+ *
+ * Copyright (C) 2022 The linux-wiiu Team
+ *
+ * Based on hlwd-pic.c
+ * Copyright (C) 2009 The GameCube Linux Team
+ * Copyright (C) 2009 Albert Herranz
+ */
+
+#define DRV_MODULE_NAME "latte-pic"
+#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/io.h>
+#include "latte-pic.h"
+
+static DEFINE_PER_CPU(struct lt_pic *, lt_pic_cpu);
+
+/*
+ * IRQ chip operations
+ * These handle both AHBALL and AHBLT IRQs, with AHBLT mapped above 32
+ */
+
+static void latte_pic_mask_and_ack(struct irq_data *d)
+{
+ struct lt_pic *pic = *this_cpu_ptr(<_pic_cpu);
+ u32 irq = irqd_to_hwirq(d);
+
+ if (irq < LATTE_AHBALL_NR_IRQS) {
+ u32 mask = 1 << irq;
+
+ out_be32(&pic->ahball_icr, mask);
+ clrbits32(&pic->ahball_imr, mask);
+ } else {
+ u32 mask = 1 << (irq - 32);
+
+ out_be32(&pic->ahblt_icr, mask);
+ clrbits32(&pic->ahblt_imr, mask);
+ }
+}
+
+static void latte_pic_ack(struct irq_data *d)
+{
+ struct lt_pic *pic = *this_cpu_ptr(<_pic_cpu);
+ u32 irq = irqd_to_hwirq(d);
+
+ if (irq < LATTE_AHBALL_NR_IRQS) {
+ u32 mask = 1 << irq;
+
+ out_be32(&pic->ahball_icr, mask);
+ } else {
+ u32 mask = 1 << (irq - 32);
+
+ out_be32(&pic->ahblt_icr, mask);
+ }
+}
+
+static void latte_pic_mask(struct irq_data *d)
+{
+ struct lt_pic *pic = *this_cpu_ptr(<_pic_cpu);
+ u32 irq = irqd_to_hwirq(d);
+
+ if (irq < LATTE_AHBALL_NR_IRQS) {
+ u32 mask = 1 << irq;
+
+ clrbits32(&pic->ahball_imr, mask);
+ } else {
+ u32 mask = 1 << (irq - 32);
+
+ clrbits32(&pic->ahblt_imr, mask);
+ }
+}
+
+static void latte_pic_unmask(struct irq_data *d)
+{
+ struct lt_pic *pic = *this_cpu_ptr(<_pic_cpu);
+ u32 irq = irqd_to_hwirq(d);
+
+ if (irq < LATTE_AHBALL_NR_IRQS) {
+ u32 mask = 1 << irq;
+
+ setbits32(&pic->ahball_imr, mask);
+ } else {
+ u32 mask = 1 << (irq - 32);
+
+ setbits32(&pic->ahblt_imr, mask);
+ }
+}
+
+static struct irq_chip latte_pic = {
+ .name = "latte-pic",
+ .irq_ack = latte_pic_ack,
+ .irq_mask_ack = latte_pic_mask_and_ack,
+ .irq_mask = latte_pic_mask,
+ .irq_unmask = latte_pic_unmask,
+};
+
+/*
+ * Domain ops
+ */
+
+static int latte_pic_match(struct irq_domain *h, struct device_node *node,
+ enum irq_domain_bus_token bus_token)
+{
+ if (h->fwnode == &node->fwnode) {
+ pr_debug("%s IRQ matches with this driver\n", node->name);
+ return 1;
+ }
+ return 0;
+}
+
+static int latte_pic_alloc(struct irq_domain *h, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ unsigned int i;
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq = fwspec->param[0];
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_set_chip_data(virq + i, h->host_data);
+ irq_set_status_flags(virq + i, IRQ_LEVEL);
+ irq_set_chip_and_handler(virq + i, &latte_pic,
+ handle_level_irq);
+ irq_domain_set_hwirq_and_chip(h, virq + i, hwirq + i,
+ &latte_pic, h->host_data);
+ }
+ return 0;
+}
+
+static void latte_pic_free(struct irq_domain *h, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ pr_debug("free\n");
+}
+
+const struct irq_domain_ops latte_pic_ops = {
+ .match = latte_pic_match,
+ .alloc = latte_pic_alloc,
+ .free = latte_pic_free,
+};
+
+/*
+ * Determinate if there are interrupts pending
+ * Checks AHBALL (0-32) and AHBLT (32-64)
+ */
+static unsigned int latte_pic_get_irq(struct irq_domain *h)
+{
+ struct lt_pic *pic = *this_cpu_ptr(<_pic_cpu);
+ u32 irq_status, irq;
+
+ /* Check AHBALL first */
+ irq_status = in_be32(&pic->ahball_icr) & in_be32(&pic->ahball_imr);
+
+ if (irq_status == 0) {
+ /* Try AHBLT */
+ irq_status =
+ in_be32(&pic->ahblt_icr) & in_be32(&pic->ahblt_imr);
+ if (irq_status == 0)
+ return 0; /* No IRQs pending */
+
+ /* AHBLT is mapped above 32 (LATTE_AHBALL_NR_IRQS) */
+ irq = __ffs(irq_status) + LATTE_AHBALL_NR_IRQS;
+ return irq_linear_revmap(h, irq);
+ }
+
+ irq = __ffs(irq_status);
+ return irq_linear_revmap(h, irq);
+}
+
+/*
+ * Cascade IRQ handler
+ */
+static void latte_irq_cascade(struct irq_desc *desc)
+{
+ struct irq_domain *irq_domain = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ unsigned int virq;
+
+ raw_spin_lock(&desc->lock);
+ chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */
+ raw_spin_unlock(&desc->lock);
+
+ virq = latte_pic_get_irq(irq_domain);
+ if (virq)
+ generic_handle_irq(virq);
+ else
+ pr_err("spurious interrupt!\n");
+
+ raw_spin_lock(&desc->lock);
+ chip->irq_ack(&desc->irq_data); /* IRQ_LEVEL */
+ if (!irqd_irq_disabled(&desc->irq_data) && chip->irq_unmask)
+ chip->irq_unmask(&desc->irq_data);
+ raw_spin_unlock(&desc->lock);
+}
+
+void __init latte_pic_init(void)
+{
+ struct device_node *np =
+ of_find_compatible_node(NULL, NULL, "nintendo,latte-pic");
+ struct irq_domain *host;
+ struct resource res;
+ int irq_cascade;
+ void __iomem *regbase;
+ unsigned int cpu;
+
+ if (!np) {
+ pr_err("could not find device node\n");
+ return;
+ }
+ if (!of_get_property(np, "interrupts", NULL)) {
+ pr_err("could not find cascade interrupt!\n");
+ goto out;
+ }
+
+ if (of_address_to_resource(np, 0, &res)) {
+ pr_err("could not find resource address\n");
+ goto out;
+ }
+
+ regbase = ioremap(res.start, resource_size(&res));
+ if (IS_ERR(regbase)) {
+ pr_err("could not map controller\n");
+ goto out;
+ }
+
+ for_each_present_cpu(cpu) {
+ struct lt_pic **pic = per_cpu_ptr(<_pic_cpu, cpu);
+
+ /* Compute pic address */
+ *pic = regbase + (sizeof(struct lt_pic) * cpu);
+
+ /* Mask and Ack CPU IRQs */
+ out_be32(&(*pic)->ahball_imr, 0);
+ out_be32(&(*pic)->ahball_icr, 0xFFFFFFFF);
+ }
+
+ host = irq_domain_add_linear(np,
+ LATTE_AHBALL_NR_IRQS + LATTE_AHBLT_NR_IRQS,
+ &latte_pic_ops, NULL);
+ if (!host) {
+ pr_err("failed to allocate irq_domain\n");
+ goto out;
+ }
+
+ irq_cascade = irq_of_parse_and_map(np, 0);
+ irq_set_chained_handler_and_data(irq_cascade, latte_irq_cascade, host);
+
+out:
+ of_node_put(np);
+}
diff --git a/arch/powerpc/platforms/wiiu/latte-pic.h b/arch/powerpc/platforms/wiiu/latte-pic.h
new file mode 100644
index 000000000000..7021d9497d35
--- /dev/null
+++ b/arch/powerpc/platforms/wiiu/latte-pic.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Nintendo Wii U "Latte" interrupt controller support
+ *
+ * Copyright (C) 2022 The linux-wiiu Team
+ */
+
+#ifndef __LATTE_PIC_H
+#define __LATTE_PIC_H
+
+struct lt_pic {
+ __be32 ahball_icr; /* Triggered AHB IRQs (all) */
+ __be32 ahblt_icr; /* Triggered AHB IRQs (latte only) */
+ __be32 ahball_imr; /* Allowed AHB IRQs (all) */
+ __be32 ahblt_imr; /* Allowed AHB IRQs (latte only) */
+} __packed;
+
+#define LATTE_AHBALL_NR_IRQS 32
+#define LATTE_AHBLT_NR_IRQS 32
+
+void latte_pic_init(void);
+
+#endif
--
2.38.1