diff options
Diffstat (limited to 'drivers/irqchip/irq-realtek-rtl.c')
| -rw-r--r-- | drivers/irqchip/irq-realtek-rtl.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c new file mode 100644 index 0000000000..2a349082af --- /dev/null +++ b/drivers/irqchip/irq-realtek-rtl.c @@ -0,0 +1,174 @@ +// 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 RTL_ICTL_NUM_INPUTS 32 + +#define REG(x) (realtek_ictl_base + x) + +static DEFINE_RAW_SPINLOCK(irq_lock); +static void __iomem *realtek_ictl_base; + +/* + * IRR0-IRR3 store 4 bits per interrupt, but Realtek uses inverted numbering, + * placing IRQ 31 in the first four bits. A routing value of '0' means the + * interrupt is left disconnected. Routing values {1..15} connect to output + * lines {0..14}. + */ +#define IRR_OFFSET(idx) (4 * (3 - (idx * 4) / 32)) +#define IRR_SHIFT(idx) ((idx * 4) % 32) + +static void write_irr(void __iomem *irr0, int idx, u32 value) +{ + unsigned int offset = IRR_OFFSET(idx); + unsigned int shift = IRR_SHIFT(idx); + u32 irr; + + irr = readl(irr0 + offset) & ~(0xf << shift); + irr |= (value & 0xf) << shift; + writel(irr, irr0 + offset); +} + +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) +{ + unsigned long flags; + + irq_set_chip_and_handler(irq, &realtek_ictl_irq, handle_level_irq); + + raw_spin_lock_irqsave(&irq_lock, flags); + write_irr(REG(RTL_ICTL_IRR0), hw, 1); + raw_spin_unlock_irqrestore(&irq_lock, flags); + + 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 long pending; + unsigned int soc_int; + + 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); + for_each_set_bit(soc_int, &pending, 32) + generic_handle_domain_irq(domain, soc_int); + +out: + chained_irq_exit(chip, desc); +} + +static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent) +{ + struct of_phandle_args oirq; + struct irq_domain *domain; + unsigned int soc_irq; + int parent_irq; + + realtek_ictl_base = of_iomap(node, 0); + if (!realtek_ictl_base) + return -ENXIO; + + /* Disable all cascaded interrupts and clear routing */ + writel(0, REG(RTL_ICTL_GIMR)); + for (soc_irq = 0; soc_irq < RTL_ICTL_NUM_INPUTS; soc_irq++) + write_irr(REG(RTL_ICTL_IRR0), soc_irq, 0); + + if (WARN_ON(!of_irq_count(node))) { + /* + * If DT contains no parent interrupts, assume MIPS CPU IRQ 2 + * (HW0) is connected to the first output. This is the case for + * all known hardware anyway. "interrupt-map" is deprecated, so + * don't bother trying to parse that. + */ + oirq.np = of_find_compatible_node(NULL, NULL, "mti,cpu-interrupt-controller"); + oirq.args_count = 1; + oirq.args[0] = 2; + + parent_irq = irq_create_of_mapping(&oirq); + + of_node_put(oirq.np); + } else { + parent_irq = of_irq_get(node, 0); + } + + if (parent_irq < 0) + return parent_irq; + else if (!parent_irq) + return -ENODEV; + + domain = irq_domain_add_linear(node, RTL_ICTL_NUM_INPUTS, &irq_domain_ops, NULL); + if (!domain) + return -ENOMEM; + + irq_set_chained_handler_and_data(parent_irq, realtek_irq_dispatch, domain); + + return 0; +} + +IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init); |