diff options
Diffstat (limited to 'drivers/irqchip/irq-realtek-rtl.c')
| -rw-r--r-- | drivers/irqchip/irq-realtek-rtl.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c new file mode 100644 index 000000000000..b57c67dfab5b --- /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); |