realtek: backport irq-realtek-rtl driver from 5.12 to 5.10

This patch backports "irq-realtek-rtl" driver to Kernel 5.10 from 5.12.
"MACH_REALTEK_RTL" is used as a platform name in upstream, but "RTL838X"
is used in OpenWrt, so update the dependency by the additional patch.

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>

3 files changed, 303 insertions, 0 deletions

diff --git a/target/linux/realtek/patches-5.10/005-5.12-dt-bindings-interrupt-controller-add-realtek-rtl838x-rtl839x-support.patch b/target/linux/realtek/patches-5.10/005-5.12-dt-bindings-interrupt-controller-add-realtek-rtl838x-rtl839x-support.patch
new file mode 100644
index 0000000000..d6817d209d
--- /dev/null
+++ b/target/linux/realtek/patches-5.10/005-5.12-dt-bindings-interrupt-controller-add-realtek-rtl838x-rtl839x-support.patch
@@ -0,0 +1,84 @@
+From 4a2b92a5d3519fc2c1edda4d4aa0e05bff41e8de Mon Sep 17 00:00:00 2001
+From: Bert Vermeulen <bert@biot.com>
+Date: Fri, 22 Jan 2021 21:42:23 +0100
+Subject: dt-bindings: interrupt-controller: Add Realtek RTL838x/RTL839x
+ support
+
+Document the binding for the Realtek RTL838x/RTL839x interrupt controller.
+
+Reviewed-by: Rob Herring <robh@kernel.org>
+Signed-off-by: Bert Vermeulen <bert@biot.com>
+[maz: Add a commit message, as the author couldn't be bothered...]
+Signed-off-by: Marc Zyngier <maz@kernel.org>
+Link: https://lore.kernel.org/r/20210122204224.509124-2-bert@biot.com
+---
+ .../interrupt-controller/realtek,rtl-intc.yaml     | 57 ++++++++++++++++++++++
+ 1 file changed, 57 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
+
+diff --git a/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml b/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
+new file mode 100644
+index 0000000000000..9e76fff20323c
+--- /dev/null
++++ b/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
+@@ -0,0 +1,57 @@
++# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
++%YAML 1.2
++---
++$id: http://devicetree.org/schemas/interrupt-controller/realtek,rtl-intc.yaml#
++$schema: http://devicetree.org/meta-schemas/core.yaml#
++
++title: Realtek RTL SoC interrupt controller devicetree bindings
++
++maintainers:
++  - Birger Koblitz <mail@birger-koblitz.de>
++  - Bert Vermeulen <bert@biot.com>
++  - John Crispin <john@phrozen.org>
++
++properties:
++  compatible:
++    const: realtek,rtl-intc
++
++  "#interrupt-cells":
++    const: 1
++
++  reg:
++    maxItems: 1
++
++  interrupts:
++    maxItems: 1
++
++  interrupt-controller: true
++
++  "#address-cells":
++    const: 0
++
++  interrupt-map:
++    description: Describes mapping from SoC interrupts to CPU interrupts
++
++required:
++  - compatible
++  - reg
++  - "#interrupt-cells"
++  - interrupt-controller
++  - "#address-cells"
++  - interrupt-map
++
++additionalProperties: false
++
++examples:
++  - |
++    intc: interrupt-controller@3000 {
++      compatible = "realtek,rtl-intc";
++      #interrupt-cells = <1>;
++      interrupt-controller;
++      reg = <0x3000 0x20>;
++      #address-cells = <0>;
++      interrupt-map =
++              <31 &cpuintc 2>,
++              <30 &cpuintc 1>,
++              <29 &cpuintc 5>;
++    };
+-- 
+cgit 1.2.3-1.el7
+
diff --git a/target/linux/realtek/patches-5.10/006-5.12-irqchip-add-support-for-realtek-rtl838x-rtl839x-interrupt-controller.patch b/target/linux/realtek/patches-5.10/006-5.12-irqchip-add-support-for-realtek-rtl838x-rtl839x-interrupt-controller.patch
new file mode 100644
index 0000000000..753c41eb2f
--- /dev/null
+++ b/target/linux/realtek/patches-5.10/006-5.12-irqchip-add-support-for-realtek-rtl838x-rtl839x-interrupt-controller.patch
@@ -0,0 +1,211 @@
+From 9f3a0f34b84ad1b9a8f2bdae44b66f16685b2143 Mon Sep 17 00:00:00 2001
+From: Bert Vermeulen <bert@biot.com>
+Date: Fri, 22 Jan 2021 21:42:24 +0100
+Subject: irqchip: Add support for Realtek RTL838x/RTL839x interrupt controller
+
+This is a standard IRQ driver with only status and mask registers.
+
+The mapping from SoC interrupts (18-31) to MIPS core interrupts is
+done via an interrupt-map in device tree.
+
+Signed-off-by: Bert Vermeulen <bert@biot.com>
+Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
+Acked-by: John Crispin <john@phrozen.org>
+Signed-off-by: Marc Zyngier <maz@kernel.org>
+Link: https://lore.kernel.org/r/20210122204224.509124-3-bert@biot.com
+---
+ drivers/irqchip/Makefile          |   1 +
+ drivers/irqchip/irq-realtek-rtl.c | 180 ++++++++++++++++++++++++++++++++++++++
+ 2 files changed, 181 insertions(+)
+ create mode 100644 drivers/irqchip/irq-realtek-rtl.c
+
+--- a/drivers/irqchip/Makefile
++++ b/drivers/irqchip/Makefile
+@@ -114,3 +114,4 @@ obj-$(CONFIG_LOONGSON_PCH_PIC)		+= irq-l
+ obj-$(CONFIG_LOONGSON_PCH_MSI)		+= irq-loongson-pch-msi.o
+ obj-$(CONFIG_MST_IRQ)			+= irq-mst-intc.o
+ obj-$(CONFIG_SL28CPLD_INTC)		+= irq-sl28cpld.o
++obj-$(CONFIG_MACH_REALTEK_RTL)		+= irq-realtek-rtl.o
+--- /dev/null
++++ b/drivers/irqchip/irq-realtek-rtl.c
+@@ -0,0 +1,180 @@
++// SPDX-License-Identifier: GPL-2.0-only
++/*
++ * Copyright (C) 2020 Birger Koblitz <mail@birger-koblitz.de>
++ * Copyright (C) 2020 Bert Vermeulen <bert@biot.com>
++ * Copyright (C) 2020 John Crispin <john@phrozen.org>
++ */
++
++#include <linux/of_irq.h>
++#include <linux/irqchip.h>
++#include <linux/spinlock.h>
++#include <linux/of_address.h>
++#include <linux/irqchip/chained_irq.h>
++
++/* Global Interrupt Mask Register */
++#define RTL_ICTL_GIMR		0x00
++/* Global Interrupt Status Register */
++#define RTL_ICTL_GISR		0x04
++/* Interrupt Routing Registers */
++#define RTL_ICTL_IRR0		0x08
++#define RTL_ICTL_IRR1		0x0c
++#define RTL_ICTL_IRR2		0x10
++#define RTL_ICTL_IRR3		0x14
++
++#define REG(x)		(realtek_ictl_base + x)
++
++static DEFINE_RAW_SPINLOCK(irq_lock);
++static void __iomem *realtek_ictl_base;
++
++static void realtek_ictl_unmask_irq(struct irq_data *i)
++{
++	unsigned long flags;
++	u32 value;
++
++	raw_spin_lock_irqsave(&irq_lock, flags);
++
++	value = readl(REG(RTL_ICTL_GIMR));
++	value |= BIT(i->hwirq);
++	writel(value, REG(RTL_ICTL_GIMR));
++
++	raw_spin_unlock_irqrestore(&irq_lock, flags);
++}
++
++static void realtek_ictl_mask_irq(struct irq_data *i)
++{
++	unsigned long flags;
++	u32 value;
++
++	raw_spin_lock_irqsave(&irq_lock, flags);
++
++	value = readl(REG(RTL_ICTL_GIMR));
++	value &= ~BIT(i->hwirq);
++	writel(value, REG(RTL_ICTL_GIMR));
++
++	raw_spin_unlock_irqrestore(&irq_lock, flags);
++}
++
++static struct irq_chip realtek_ictl_irq = {
++	.name = "realtek-rtl-intc",
++	.irq_mask = realtek_ictl_mask_irq,
++	.irq_unmask = realtek_ictl_unmask_irq,
++};
++
++static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
++{
++	irq_set_chip_and_handler(hw, &realtek_ictl_irq, handle_level_irq);
++
++	return 0;
++}
++
++static const struct irq_domain_ops irq_domain_ops = {
++	.map = intc_map,
++	.xlate = irq_domain_xlate_onecell,
++};
++
++static void realtek_irq_dispatch(struct irq_desc *desc)
++{
++	struct irq_chip *chip = irq_desc_get_chip(desc);
++	struct irq_domain *domain;
++	unsigned int pending;
++
++	chained_irq_enter(chip, desc);
++	pending = readl(REG(RTL_ICTL_GIMR)) & readl(REG(RTL_ICTL_GISR));
++	if (unlikely(!pending)) {
++		spurious_interrupt();
++		goto out;
++	}
++	domain = irq_desc_get_handler_data(desc);
++	generic_handle_irq(irq_find_mapping(domain, __ffs(pending)));
++
++out:
++	chained_irq_exit(chip, desc);
++}
++
++/*
++ * SoC interrupts are cascaded to MIPS CPU interrupts according to the
++ * interrupt-map in the device tree. Each SoC interrupt gets 4 bits for
++ * the CPU interrupt in an Interrupt Routing Register. Max 32 SoC interrupts
++ * thus go into 4 IRRs.
++ */
++static int __init map_interrupts(struct device_node *node, struct irq_domain *domain)
++{
++	struct device_node *cpu_ictl;
++	const __be32 *imap;
++	u32 imaplen, soc_int, cpu_int, tmp, regs[4];
++	int ret, i, irr_regs[] = {
++		RTL_ICTL_IRR3,
++		RTL_ICTL_IRR2,
++		RTL_ICTL_IRR1,
++		RTL_ICTL_IRR0,
++	};
++	u8 mips_irqs_set;
++
++	ret = of_property_read_u32(node, "#address-cells", &tmp);
++	if (ret || tmp)
++		return -EINVAL;
++
++	imap = of_get_property(node, "interrupt-map", &imaplen);
++	if (!imap || imaplen % 3)
++		return -EINVAL;
++
++	mips_irqs_set = 0;
++	memset(regs, 0, sizeof(regs));
++	for (i = 0; i < imaplen; i += 3 * sizeof(u32)) {
++		soc_int = be32_to_cpup(imap);
++		if (soc_int > 31)
++			return -EINVAL;
++
++		cpu_ictl = of_find_node_by_phandle(be32_to_cpup(imap + 1));
++		if (!cpu_ictl)
++			return -EINVAL;
++		ret = of_property_read_u32(cpu_ictl, "#interrupt-cells", &tmp);
++		if (ret || tmp != 1)
++			return -EINVAL;
++		of_node_put(cpu_ictl);
++
++		cpu_int = be32_to_cpup(imap + 2);
++		if (cpu_int > 7)
++			return -EINVAL;
++
++		if (!(mips_irqs_set & BIT(cpu_int))) {
++			irq_set_chained_handler_and_data(cpu_int, realtek_irq_dispatch,
++							 domain);
++			mips_irqs_set |= BIT(cpu_int);
++		}
++
++		regs[(soc_int * 4) / 32] |= cpu_int << (soc_int * 4) % 32;
++		imap += 3;
++	}
++
++	for (i = 0; i < 4; i++)
++		writel(regs[i], REG(irr_regs[i]));
++
++	return 0;
++}
++
++static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent)
++{
++	struct irq_domain *domain;
++	int ret;
++
++	realtek_ictl_base = of_iomap(node, 0);
++	if (!realtek_ictl_base)
++		return -ENXIO;
++
++	/* Disable all cascaded interrupts */
++	writel(0, REG(RTL_ICTL_GIMR));
++
++	domain = irq_domain_add_simple(node, 32, 0,
++				       &irq_domain_ops, NULL);
++
++	ret = map_interrupts(node, domain);
++	if (ret) {
++		pr_err("invalid interrupt map\n");
++		return ret;
++	}
++
++	return 0;
++}
++
++IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init);
diff --git a/target/linux/realtek/patches-5.10/305-irqchip-update-dependency-for-irq-realtek-rtl.patch b/target/linux/realtek/patches-5.10/305-irqchip-update-dependency-for-irq-realtek-rtl.patch
new file mode 100644
index 0000000000..96321f0bba
--- /dev/null
+++ b/target/linux/realtek/patches-5.10/305-irqchip-update-dependency-for-irq-realtek-rtl.patch
@@ -0,0 +1,8 @@
+--- a/drivers/irqchip/Makefile
++++ b/drivers/irqchip/Makefile
+@@ -114,4 +114,4 @@ obj-$(CONFIG_LOONGSON_PCH_PIC)		+= irq-l
+ obj-$(CONFIG_LOONGSON_PCH_MSI)		+= irq-loongson-pch-msi.o
+ obj-$(CONFIG_MST_IRQ)			+= irq-mst-intc.o
+ obj-$(CONFIG_SL28CPLD_INTC)		+= irq-sl28cpld.o
+-obj-$(CONFIG_MACH_REALTEK_RTL)		+= irq-realtek-rtl.o
++obj-$(CONFIG_RTL838X)			+= irq-realtek-rtl.o