diff options
Diffstat (limited to 'drivers/irqchip/irq-mst-intc.c')
| -rw-r--r-- | drivers/irqchip/irq-mst-intc.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-mst-intc.c b/drivers/irqchip/irq-mst-intc.c new file mode 100644 index 000000000..f6133ae28 --- /dev/null +++ b/drivers/irqchip/irq-mst-intc.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +/* + * Copyright (c) 2020 MediaTek Inc. + * Author Mark-PK Tsai <mark-pk.tsai@mediatek.com> + */ +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/syscore_ops.h> + +#define MST_INTC_MAX_IRQS 64 + +#define INTC_MASK 0x0 +#define INTC_REV_POLARITY 0x10 +#define INTC_EOI 0x20 + +#ifdef CONFIG_PM_SLEEP +static LIST_HEAD(mst_intc_list); +#endif + +struct mst_intc_chip_data { + raw_spinlock_t lock; + unsigned int irq_start, nr_irqs; + void __iomem *base; + bool no_eoi; +#ifdef CONFIG_PM_SLEEP + struct list_head entry; + u16 saved_polarity_conf[DIV_ROUND_UP(MST_INTC_MAX_IRQS, 16)]; +#endif +}; + +static void mst_set_irq(struct irq_data *d, u32 offset) +{ + irq_hw_number_t hwirq = irqd_to_hwirq(d); + struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d); + u16 val, mask; + unsigned long flags; + + mask = 1 << (hwirq % 16); + offset += (hwirq / 16) * 4; + + raw_spin_lock_irqsave(&cd->lock, flags); + val = readw_relaxed(cd->base + offset) | mask; + writew_relaxed(val, cd->base + offset); + raw_spin_unlock_irqrestore(&cd->lock, flags); +} + +static void mst_clear_irq(struct irq_data *d, u32 offset) +{ + irq_hw_number_t hwirq = irqd_to_hwirq(d); + struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d); + u16 val, mask; + unsigned long flags; + + mask = 1 << (hwirq % 16); + offset += (hwirq / 16) * 4; + + raw_spin_lock_irqsave(&cd->lock, flags); + val = readw_relaxed(cd->base + offset) & ~mask; + writew_relaxed(val, cd->base + offset); + raw_spin_unlock_irqrestore(&cd->lock, flags); +} + +static void mst_intc_mask_irq(struct irq_data *d) +{ + mst_set_irq(d, INTC_MASK); + irq_chip_mask_parent(d); +} + +static void mst_intc_unmask_irq(struct irq_data *d) +{ + mst_clear_irq(d, INTC_MASK); + irq_chip_unmask_parent(d); +} + +static void mst_intc_eoi_irq(struct irq_data *d) +{ + struct mst_intc_chip_data *cd = irq_data_get_irq_chip_data(d); + + if (!cd->no_eoi) + mst_set_irq(d, INTC_EOI); + + irq_chip_eoi_parent(d); +} + +static int mst_irq_chip_set_type(struct irq_data *data, unsigned int type) +{ + switch (type) { + case IRQ_TYPE_LEVEL_LOW: + case IRQ_TYPE_EDGE_FALLING: + mst_set_irq(data, INTC_REV_POLARITY); + break; + case IRQ_TYPE_LEVEL_HIGH: + case IRQ_TYPE_EDGE_RISING: + mst_clear_irq(data, INTC_REV_POLARITY); + break; + default: + return -EINVAL; + } + + return irq_chip_set_type_parent(data, IRQ_TYPE_LEVEL_HIGH); +} + +static struct irq_chip mst_intc_chip = { + .name = "mst-intc", + .irq_mask = mst_intc_mask_irq, + .irq_unmask = mst_intc_unmask_irq, + .irq_eoi = mst_intc_eoi_irq, + .irq_get_irqchip_state = irq_chip_get_parent_state, + .irq_set_irqchip_state = irq_chip_set_parent_state, + .irq_set_affinity = irq_chip_set_affinity_parent, + .irq_set_vcpu_affinity = irq_chip_set_vcpu_affinity_parent, + .irq_set_type = mst_irq_chip_set_type, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .flags = IRQCHIP_SET_TYPE_MASKED | + IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_MASK_ON_SUSPEND, +}; + +#ifdef CONFIG_PM_SLEEP +static void mst_intc_polarity_save(struct mst_intc_chip_data *cd) +{ + int i; + void __iomem *addr = cd->base + INTC_REV_POLARITY; + + for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++) + cd->saved_polarity_conf[i] = readw_relaxed(addr + i * 4); +} + +static void mst_intc_polarity_restore(struct mst_intc_chip_data *cd) +{ + int i; + void __iomem *addr = cd->base + INTC_REV_POLARITY; + + for (i = 0; i < DIV_ROUND_UP(cd->nr_irqs, 16); i++) + writew_relaxed(cd->saved_polarity_conf[i], addr + i * 4); +} + +static void mst_irq_resume(void) +{ + struct mst_intc_chip_data *cd; + + list_for_each_entry(cd, &mst_intc_list, entry) + mst_intc_polarity_restore(cd); +} + +static int mst_irq_suspend(void) +{ + struct mst_intc_chip_data *cd; + + list_for_each_entry(cd, &mst_intc_list, entry) + mst_intc_polarity_save(cd); + return 0; +} + +static struct syscore_ops mst_irq_syscore_ops = { + .suspend = mst_irq_suspend, + .resume = mst_irq_resume, +}; + +static int __init mst_irq_pm_init(void) +{ + register_syscore_ops(&mst_irq_syscore_ops); + return 0; +} +late_initcall(mst_irq_pm_init); +#endif + +static int mst_intc_domain_translate(struct irq_domain *d, + struct irq_fwspec *fwspec, + unsigned long *hwirq, + unsigned int *type) +{ + struct mst_intc_chip_data *cd = d->host_data; + + if (is_of_node(fwspec->fwnode)) { + if (fwspec->param_count != 3) + return -EINVAL; + + /* No PPI should point to this domain */ + if (fwspec->param[0] != 0) + return -EINVAL; + + if (fwspec->param[1] >= cd->nr_irqs) + return -EINVAL; + + *hwirq = fwspec->param[1]; + *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK; + return 0; + } + + return -EINVAL; +} + +static int mst_intc_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *data) +{ + int i; + irq_hw_number_t hwirq; + struct irq_fwspec parent_fwspec, *fwspec = data; + struct mst_intc_chip_data *cd = domain->host_data; + + /* Not GIC compliant */ + if (fwspec->param_count != 3) + return -EINVAL; + + /* No PPI should point to this domain */ + if (fwspec->param[0]) + return -EINVAL; + + hwirq = fwspec->param[1]; + for (i = 0; i < nr_irqs; i++) + irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, + &mst_intc_chip, + domain->host_data); + + parent_fwspec = *fwspec; + parent_fwspec.fwnode = domain->parent->fwnode; + parent_fwspec.param[1] = cd->irq_start + hwirq; + + /* + * mst-intc latch the interrupt request if it's edge triggered, + * so the output signal to parent GIC is always level sensitive. + * And if the irq signal is active low, configure it to active high + * to meet GIC SPI spec in mst_irq_chip_set_type via REV_POLARITY bit. + */ + parent_fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH; + + return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &parent_fwspec); +} + +static const struct irq_domain_ops mst_intc_domain_ops = { + .translate = mst_intc_domain_translate, + .alloc = mst_intc_domain_alloc, + .free = irq_domain_free_irqs_common, +}; + +static int __init mst_intc_of_init(struct device_node *dn, + struct device_node *parent) +{ + struct irq_domain *domain, *domain_parent; + struct mst_intc_chip_data *cd; + u32 irq_start, irq_end; + + domain_parent = irq_find_host(parent); + if (!domain_parent) { + pr_err("mst-intc: interrupt-parent not found\n"); + return -EINVAL; + } + + if (of_property_read_u32_index(dn, "mstar,irqs-map-range", 0, &irq_start) || + of_property_read_u32_index(dn, "mstar,irqs-map-range", 1, &irq_end)) + return -EINVAL; + + cd = kzalloc(sizeof(*cd), GFP_KERNEL); + if (!cd) + return -ENOMEM; + + cd->base = of_iomap(dn, 0); + if (!cd->base) { + kfree(cd); + return -ENOMEM; + } + + cd->no_eoi = of_property_read_bool(dn, "mstar,intc-no-eoi"); + raw_spin_lock_init(&cd->lock); + cd->irq_start = irq_start; + cd->nr_irqs = irq_end - irq_start + 1; + domain = irq_domain_add_hierarchy(domain_parent, 0, cd->nr_irqs, dn, + &mst_intc_domain_ops, cd); + if (!domain) { + iounmap(cd->base); + kfree(cd); + return -ENOMEM; + } + +#ifdef CONFIG_PM_SLEEP + INIT_LIST_HEAD(&cd->entry); + list_add_tail(&cd->entry, &mst_intc_list); +#endif + return 0; +} + +IRQCHIP_DECLARE(mst_intc, "mstar,mst-intc", mst_intc_of_init); 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