[RFC PATCH 4/7] irqchip/apple-aic: Add support for Apple AIC
From: Mohamed Mediouni
Date: Wed Jan 20 2021 - 08:58:53 EST
From: Stan Skowronek <stan@xxxxxxxxxxxxx>
Apple SoCs use the Apple AIC interrupt controller.
The Arm architectural timers is wired over FIQ on that hardware.
Signed-off-by: Stan Skowronek <stan@xxxxxxxxxxxxx>
Signed-off-by: Mohamed Mediouni <mohamed.mediouni@xxxxxxxxxxxx>
---
.../interrupt-controller/apple,aic.yaml | 49 ++++
MAINTAINERS | 6 +
drivers/irqchip/Kconfig | 6 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-apple-aic.c | 211 ++++++++++++++++++
5 files changed, 273 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
create mode 100644 drivers/irqchip/irq-apple-aic.c
diff --git a/Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml b/Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
new file mode 100644
index 000000000000..e615eaaca869
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/apple,aic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple Advanced Interrupt Controller (AIC)
+
+description:
+ Interrupt controller present on Apple processors. AIC
+ is used by Apple on their AArch64 SoCs since the Apple A7.
+
+maintainers:
+ - Stan Skowronek <stan@xxxxxxxxxxxxx>
+
+properties:
+ compatible:
+ items:
+ - const: apple,aic
+
+ reg:
+ maxItems: 1
+
+ '#interrupt-cells':
+ const: 3
+
+ interrupt-controller: true
+
+ fast-ipi:
+ description:
+ Fast IPI support.
+
+required:
+ - compatible
+ - '#interrupt-cells'
+ - interrupt-controller
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ aic: interrupt-controller@23b100000 {
+ compatible = "apple,aic";
+ #interrupt-cells = <3>;
+ interrupt-controller;
+ reg = <0x2 0x3b100000 0x0 0x8000>;
+ fast-ipi;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 00836f6452f0..e609ede99dd4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1218,6 +1218,12 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
F: Documentation/admin-guide/LSM/apparmor.rst
F: security/apparmor/
+APPLE ADVANCED INTERRUPT CONTROLLER DRIVER
+M: Stan Skowronek <stan@xxxxxxxxxxxxx>
+L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/irqchip/irq-apple-aic.c
+
APPLE BCM5974 MULTITOUCH DRIVER
M: Henrik Rydberg <rydberg@xxxxxxxxxxx>
L: linux-input@xxxxxxxxxxxxxxx
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 94920a51c628..3aa9e711324b 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -56,6 +56,12 @@ config ARM_GIC_V3_ITS_FSL_MC
depends on FSL_MC_BUS
default ARM_GIC_V3_ITS
+config APPLE_AIC
+ bool
+ select IRQ_DOMAIN_HIERARCHY
+ select GENERIC_IRQ_MULTI_HANDLER
+ select GENERIC_IRQ_EFFECTIVE_AFF_MASK
+
config ARM_NVIC
bool
select IRQ_DOMAIN_HIERARCHY
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 0ac93bfaec61..2f5a9a0cf40f 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-v3-mbi.o irq-gic-common.o
obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o irq-gic-v3-its-platform-msi.o irq-gic-v4.o
obj-$(CONFIG_ARM_GIC_V3_ITS_PCI) += irq-gic-v3-its-pci-msi.o
obj-$(CONFIG_ARM_GIC_V3_ITS_FSL_MC) += irq-gic-v3-its-fsl-mc-msi.o
+obj-$(CONFIG_APPLE_AIC) += irq-apple-aic.o
obj-$(CONFIG_PARTITION_PERCPU) += irq-partition-percpu.o
obj-$(CONFIG_HISILICON_IRQ_MBIGEN) += irq-mbigen.o
obj-$(CONFIG_ARM_NVIC) += irq-nvic.o
diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
new file mode 100644
index 000000000000..c601bc4b501a
--- /dev/null
+++ b/drivers/irqchip/irq-apple-aic.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple chip interrupt controller
+ *
+ * Copyright (C) 2020 Corellium LLC
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/exception.h>
+#include <asm/irq.h>
+
+#define REG_ID_REVISION 0x0000
+#define REG_ID_CONFIG 0x0004
+#define REG_GLOBAL_CFG 0x0010
+#define REG_TIME_LO 0x0020
+#define REG_TIME_HI 0x0028
+#define REG_ID_CPUID 0x2000
+#define REG_IRQ_ACK 0x2004
+#define REG_IRQ_ACK_TYPE_MASK (15 << 16)
+#define REG_IRQ_ACK_TYPE_NONE (0 << 16)
+#define REG_IRQ_ACK_TYPE_IRQ (1 << 16)
+#define REG_IRQ_ACK_TYPE_IPI (4 << 16)
+#define REG_IRQ_ACK_IPI_OTHER 0x40001
+#define REG_IRQ_ACK_IPI_SELF 0x40002
+#define REG_IRQ_ACK_NUM_MASK (4095)
+#define REG_IPI_SET 0x2008
+#define REG_IPI_FLAG_SELF (1 << 31)
+#define REG_IPI_FLAG_OTHER (1 << 0)
+#define REG_IPI_CLEAR 0x200C
+#define REG_IPI_DISABLE 0x2024
+#define REG_IPI_ENABLE 0x2028
+#define REG_IPI_DEFER_SET 0x202C
+#define REG_IPI_DEFER_CLEAR 0x2030
+#define REG_TSTAMP_CTRL 0x2040
+#define REG_TSTAMP_LO 0x2048
+#define REG_TSTAMP_HI 0x204C
+#define REG_IRQ_AFFINITY(i) (0x3000 + ((i) << 2))
+#define REG_IRQ_DISABLE(i) (0x4100 + (((i) >> 5) << 2))
+#define REG_IRQ_xABLE_MASK(i) (1 << ((i)&31))
+#define REG_IRQ_ENABLE(i) (0x4180 + (((i) >> 5) << 2))
+#define REG_CPU_REGION 0x5000
+#define REG_CPU_LOCAL 0x2000
+#define REG_CPU_SHIFT 7
+#define REG_PERCPU(r, c) \
+ ((r) + REG_CPU_REGION - REG_CPU_LOCAL + ((c) << REG_CPU_SHIFT))
+
+static struct aic_chip_data {
+ void __iomem *base;
+ struct irq_domain *domain;
+ unsigned int num_irqs;
+} aic;
+
+static void apple_aic_irq_mask(struct irq_data *d)
+{
+ writel(REG_IRQ_xABLE_MASK(d->hwirq),
+ aic.base + REG_IRQ_DISABLE(d->hwirq));
+}
+
+static void apple_aic_irq_unmask(struct irq_data *d)
+{
+ writel(REG_IRQ_xABLE_MASK(d->hwirq),
+ aic.base + REG_IRQ_ENABLE(d->hwirq));
+}
+
+static struct irq_chip apple_aic_irq_chip = {
+ .name = "apple_aic",
+ .irq_mask = apple_aic_irq_mask,
+ .irq_mask_ack = apple_aic_irq_mask,
+ .irq_unmask = apple_aic_irq_unmask,
+};
+
+static void apple_aic_fiq_mask(struct irq_data *d)
+{
+}
+
+static void apple_aic_fiq_unmask(struct irq_data *d)
+{
+}
+
+static struct irq_chip apple_aic_irq_chip_fiq = {
+ .name = "apple_aic_fiq",
+ .irq_mask = apple_aic_fiq_mask,
+ .irq_unmask = apple_aic_fiq_unmask,
+};
+
+static int apple_aic_irq_domain_xlate(struct irq_domain *d,
+ struct device_node *ctrlr,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ if (intspec[0]) { /* FIQ */
+ if (intspec[1] >= 2)
+ return -EINVAL;
+ if (out_hwirq)
+ *out_hwirq = aic.num_irqs + intspec[1];
+ } else {
+ if (intspec[1] >= aic.num_irqs)
+ return -EINVAL;
+ if (out_hwirq)
+ *out_hwirq = intspec[1];
+ }
+
+ if (out_type)
+ *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+ return 0;
+}
+
+static int apple_aic_irq_domain_map(struct irq_domain *d, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ if (hw >= aic.num_irqs) {
+ irq_set_percpu_devid(virq);
+ irq_domain_set_info(d, virq, hw, &apple_aic_irq_chip_fiq,
+ d->host_data, handle_percpu_devid_irq, NULL,
+ NULL);
+ irq_set_status_flags(virq, IRQ_NOAUTOEN);
+ } else {
+ irq_domain_set_info(d, virq, hw, &apple_aic_irq_chip,
+ d->host_data, handle_level_irq, NULL, NULL);
+ irq_set_probe(virq);
+ irqd_set_single_target(
+ irq_desc_get_irq_data(irq_to_desc(virq)));
+ }
+ return 0;
+}
+
+static const struct irq_domain_ops apple_aic_irq_domain_ops = {
+ .xlate = apple_aic_irq_domain_xlate,
+ .map = apple_aic_irq_domain_map,
+};
+
+static void __exception_irq_entry apple_aic_handle_irq(struct pt_regs *regs)
+{
+ uint32_t ack;
+ unsigned done = 0;
+
+ while (1) {
+ ack = readl(aic.base + REG_IRQ_ACK);
+ switch (ack & REG_IRQ_ACK_TYPE_MASK) {
+ case REG_IRQ_ACK_TYPE_NONE:
+ done = 1;
+ break;
+ case REG_IRQ_ACK_TYPE_IRQ:
+ handle_domain_irq(aic.domain,
+ ack & REG_IRQ_ACK_NUM_MASK, regs);
+ break;
+ }
+ if (done)
+ break;
+ }
+}
+
+static void __exception_irq_entry apple_aic_handle_fiq(struct pt_regs *regs)
+{
+ handle_domain_irq(aic.domain, aic.num_irqs, regs);
+}
+
+void apple_aic_cpu_prepare(unsigned int cpu)
+{
+ unsigned i;
+
+ for (i = 0; i < aic.num_irqs; i++)
+ writel(readl(aic.base + REG_IRQ_AFFINITY(i)) | (1u << cpu),
+ aic.base + REG_IRQ_AFFINITY(i));
+}
+
+static int __init apple_aic_init(struct device_node *node,
+ struct device_node *interrupt_parent)
+{
+ unsigned i;
+
+ if (!node)
+ return -ENODEV;
+
+ aic.base = of_iomap(node, 0);
+ if (WARN(!aic.base, "unable to map aic registers\n"))
+ return -EINVAL;
+
+ aic.num_irqs = readl(aic.base + REG_ID_CONFIG) & 0xFFFF;
+ pr_info("Apple AIC: %d IRQs + 1 FIQ + 1 dummy\n", aic.num_irqs);
+
+ for (i = 0; i < aic.num_irqs; i++)
+ writel(1, aic.base + REG_IRQ_AFFINITY(i));
+ for (i = 0; i < aic.num_irqs; i += 32)
+ writel(-1u, aic.base + REG_IRQ_DISABLE(i));
+ writel((readl(aic.base + REG_GLOBAL_CFG) & ~0xF00000) | 0x700000,
+ aic.base + REG_GLOBAL_CFG);
+
+ set_handle_irq(apple_aic_handle_irq);
+ set_handle_fiq(apple_aic_handle_fiq);
+
+ apple_aic_cpu_prepare(0);
+
+ aic.domain = irq_domain_add_linear(node, aic.num_irqs + 2,
+ &apple_aic_irq_domain_ops,
+ &apple_aic_irq_chip);
+ irq_set_default_host(aic.domain);
+ return 0;
+}
+
+IRQCHIP_DECLARE(apple_aic_irq_chip, "apple,aic", apple_aic_init);
--
2.29.2