2021-01-20 11:02:30

by Bert Vermeulen

[permalink] [raw]
Subject: [PATCH v3 0/2] Realtek RTL838x/RTL839x interrupt controller driver

v3:
- Fixed syntax and maxItems problems in DT bindings.
v2:
- Addressed all comments by Marc Zyngier.
- Moved interrupt routing symbols to device tree interrupt-map. Parsing
is done similar to the renesas,rza1-irqc driver.


Bert Vermeulen (2):
dt-bindings: interrupt-controller: Add Realtek RTL838x/RTL839x support
irqchip: Add support for Realtek RTL838x/RTL839x interrupt controller

.../realtek,rtl-intc.yaml | 57 ++++++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-realtek-rtl.c | 180 ++++++++++++++++++
3 files changed, 238 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
create mode 100644 drivers/irqchip/irq-realtek-rtl.c

--
2.25.1


2021-01-20 11:02:30

by Bert Vermeulen

[permalink] [raw]
Subject: [PATCH v3 2/2] irqchip: Add support for Realtek RTL838x/RTL839x interrupt controller

Signed-off-by: Bert Vermeulen <[email protected]>
---
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

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 0ac93bfaec61..4fc1086bed7e 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -113,3 +113,4 @@ obj-$(CONFIG_LOONGSON_PCH_PIC) += irq-loongson-pch-pic.o
obj-$(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
diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c
new file mode 100644
index 000000000000..bafe9ee4a85a
--- /dev/null
+++ b/drivers/irqchip/irq-realtek-rtl.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2006-2012 Tony Wu <[email protected]>
+ * Copyright (C) 2020 Birger Koblitz <[email protected]>
+ * Copyright (C) 2020 Bert Vermeulen <[email protected]>
+ * Copyright (C) 2020 John Crispin <[email protected]>
+ */
+
+#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 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,
+ };
+
+ 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;
+
+ 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;
+
+ 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;
+
+ domain = irq_domain_add_simple(node, 32, 0,
+ &irq_domain_ops, NULL);
+ irq_set_chained_handler_and_data(2, realtek_irq_dispatch, domain);
+ irq_set_chained_handler_and_data(3, realtek_irq_dispatch, domain);
+ irq_set_chained_handler_and_data(4, realtek_irq_dispatch, domain);
+ irq_set_chained_handler_and_data(5, realtek_irq_dispatch, domain);
+
+ realtek_ictl_base = of_iomap(node, 0);
+ if (!realtek_ictl_base)
+ return -ENXIO;
+
+ /* Disable all cascaded interrupts */
+ writel(0, REG(RTL_ICTL_GIMR));
+
+ ret = map_interrupts(node);
+ if (ret) {
+ pr_err("invalid interrupt map\n");
+ return ret;
+ }
+
+ /* Clear timer interrupt */
+ write_c0_compare(0);
+
+ return 0;
+}
+
+IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init);
--
2.25.1

2021-01-21 19:45:36

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v3 2/2] irqchip: Add support for Realtek RTL838x/RTL839x interrupt controller

On Wed, 20 Jan 2021 10:10:18 +0000,
Bert Vermeulen <[email protected]> wrote:
>
> Signed-off-by: Bert Vermeulen <[email protected]>

Please write a decent commit message.

> ---
> 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
>
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 0ac93bfaec61..4fc1086bed7e 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -113,3 +113,4 @@ obj-$(CONFIG_LOONGSON_PCH_PIC) += irq-loongson-pch-pic.o
> obj-$(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
> diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c
> new file mode 100644
> index 000000000000..bafe9ee4a85a
> --- /dev/null
> +++ b/drivers/irqchip/irq-realtek-rtl.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2006-2012 Tony Wu <[email protected]>
> + * Copyright (C) 2020 Birger Koblitz <[email protected]>
> + * Copyright (C) 2020 Bert Vermeulen <[email protected]>
> + * Copyright (C) 2020 John Crispin <[email protected]>

Given the list of copyright owners, shouldn't this be reflected in the
SoB chain one way or another?

> + */
> +
> +#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 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,
> + };
> +
> + 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;
> +
> + 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;
> +
> + 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;
> +
> + domain = irq_domain_add_simple(node, 32, 0,
> + &irq_domain_ops, NULL);
> + irq_set_chained_handler_and_data(2, realtek_irq_dispatch, domain);
> + irq_set_chained_handler_and_data(3, realtek_irq_dispatch, domain);
> + irq_set_chained_handler_and_data(4, realtek_irq_dispatch, domain);
> + irq_set_chained_handler_and_data(5, realtek_irq_dispatch, domain);

Where are these numbers coming from? Are they hard-coded? There isn't
an interrupt-parent to link this to the root controller?

> +
> + realtek_ictl_base = of_iomap(node, 0);
> + if (!realtek_ictl_base)
> + return -ENXIO;
> +
> + /* Disable all cascaded interrupts */
> + writel(0, REG(RTL_ICTL_GIMR));

This really should happen before you enable the chained handler...

> +
> + ret = map_interrupts(node);

Why are all mappings done ahead of time, and not at the point where
the interrupt gets mapped (in the irqdomain sense)? Not necessarily a
deal-breaker, but we usually try to do things on demand rather than
upfront.

> + if (ret) {
> + pr_err("invalid interrupt map\n");
> + return ret;
> + }
> +
> + /* Clear timer interrupt */
> + write_c0_compare(0);

What is the timer interrupt doing here?

> +
> + return 0;
> +}
> +
> +IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init);
> --
> 2.25.1
>
>

Thanks,

M.

--
Without deviation from the norm, progress is not possible.