On Wed, 20 Jan 2021 10:10:18 +0000,
Bert Vermeulen <b...@biot.com> wrote:
>
> Signed-off-by: Bert Vermeulen <b...@biot.com>
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 <ton...@realtek.com>
> + * Copyright (C) 2020 Birger Koblitz <m...@birger-koblitz.de>
> + * Copyright (C) 2020 Bert Vermeulen <b...@biot.com>
> + * Copyright (C) 2020 John Crispin <j...@phrozen.org>
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.
