diff options
Diffstat (limited to 'drivers/irqchip/irq-stm32-exti.c')
| -rw-r--r-- | drivers/irqchip/irq-stm32-exti.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-stm32-exti.c b/drivers/irqchip/irq-stm32-exti.c new file mode 100644 index 000000000000..491568c95aa5 --- /dev/null +++ b/drivers/irqchip/irq-stm32-exti.c @@ -0,0 +1,201 @@ +/* + * Copyright (C) Maxime Coquelin 2015 + * Author: Maxime Coquelin <mcoquelin.stm32@gmail.com> + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/bitops.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#define EXTI_IMR 0x0 +#define EXTI_EMR 0x4 +#define EXTI_RTSR 0x8 +#define EXTI_FTSR 0xc +#define EXTI_SWIER 0x10 +#define EXTI_PR 0x14 + +static void stm32_irq_handler(struct irq_desc *desc) +{ + struct irq_domain *domain = irq_desc_get_handler_data(desc); + struct irq_chip_generic *gc = domain->gc->gc[0]; + struct irq_chip *chip = irq_desc_get_chip(desc); + unsigned long pending; + int n; + + chained_irq_enter(chip, desc); + + while ((pending = irq_reg_readl(gc, EXTI_PR))) { + for_each_set_bit(n, &pending, BITS_PER_LONG) { + generic_handle_irq(irq_find_mapping(domain, n)); + irq_reg_writel(gc, BIT(n), EXTI_PR); + } + } + + chained_irq_exit(chip, desc); +} + +static int stm32_irq_set_type(struct irq_data *data, unsigned int type) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); + int pin = data->hwirq; + u32 rtsr, ftsr; + + irq_gc_lock(gc); + + rtsr = irq_reg_readl(gc, EXTI_RTSR); + ftsr = irq_reg_readl(gc, EXTI_FTSR); + + switch (type) { + case IRQ_TYPE_EDGE_RISING: + rtsr |= BIT(pin); + ftsr &= ~BIT(pin); + break; + case IRQ_TYPE_EDGE_FALLING: + rtsr &= ~BIT(pin); + ftsr |= BIT(pin); + break; + case IRQ_TYPE_EDGE_BOTH: + rtsr |= BIT(pin); + ftsr |= BIT(pin); + break; + default: + irq_gc_unlock(gc); + return -EINVAL; + } + + irq_reg_writel(gc, rtsr, EXTI_RTSR); + irq_reg_writel(gc, ftsr, EXTI_FTSR); + + irq_gc_unlock(gc); + + return 0; +} + +static int stm32_irq_set_wake(struct irq_data *data, unsigned int on) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); + int pin = data->hwirq; + u32 emr; + + irq_gc_lock(gc); + + emr = irq_reg_readl(gc, EXTI_EMR); + if (on) + emr |= BIT(pin); + else + emr &= ~BIT(pin); + irq_reg_writel(gc, emr, EXTI_EMR); + + irq_gc_unlock(gc); + + return 0; +} + +static int stm32_exti_alloc(struct irq_domain *d, unsigned int virq, + unsigned int nr_irqs, void *data) +{ + struct irq_chip_generic *gc = d->gc->gc[0]; + struct irq_fwspec *fwspec = data; + irq_hw_number_t hwirq; + + hwirq = fwspec->param[0]; + + irq_map_generic_chip(d, virq, hwirq); + irq_domain_set_info(d, virq, hwirq, &gc->chip_types->chip, gc, + handle_simple_irq, NULL, NULL); + + return 0; +} + +static void stm32_exti_free(struct irq_domain *d, unsigned int virq, + unsigned int nr_irqs) +{ + struct irq_data *data = irq_domain_get_irq_data(d, virq); + + irq_domain_reset_irq_data(data); +} + +struct irq_domain_ops irq_exti_domain_ops = { + .map = irq_map_generic_chip, + .xlate = irq_domain_xlate_onetwocell, + .alloc = stm32_exti_alloc, + .free = stm32_exti_free, +}; + +static int __init stm32_exti_init(struct device_node *node, + struct device_node *parent) +{ + unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; + int nr_irqs, nr_exti, ret, i; + struct irq_chip_generic *gc; + struct irq_domain *domain; + void *base; + + base = of_iomap(node, 0); + if (!base) { + pr_err("%s: Unable to map registers\n", node->full_name); + return -ENOMEM; + } + + /* Determine number of irqs supported */ + writel_relaxed(~0UL, base + EXTI_RTSR); + nr_exti = fls(readl_relaxed(base + EXTI_RTSR)); + writel_relaxed(0, base + EXTI_RTSR); + + pr_info("%s: %d External IRQs detected\n", node->full_name, nr_exti); + + domain = irq_domain_add_linear(node, nr_exti, + &irq_exti_domain_ops, NULL); + if (!domain) { + pr_err("%s: Could not register interrupt domain.\n", + node->name); + ret = -ENOMEM; + goto out_unmap; + } + + ret = irq_alloc_domain_generic_chips(domain, nr_exti, 1, "exti", + handle_edge_irq, clr, 0, 0); + if (ret) { + pr_err("%s: Could not allocate generic interrupt chip.\n", + node->full_name); + goto out_free_domain; + } + + gc = domain->gc->gc[0]; + gc->reg_base = base; + gc->chip_types->type = IRQ_TYPE_EDGE_BOTH; + gc->chip_types->chip.name = gc->chip_types[0].chip.name; + gc->chip_types->chip.irq_ack = irq_gc_ack_set_bit; + gc->chip_types->chip.irq_mask = irq_gc_mask_clr_bit; + gc->chip_types->chip.irq_unmask = irq_gc_mask_set_bit; + gc->chip_types->chip.irq_set_type = stm32_irq_set_type; + gc->chip_types->chip.irq_set_wake = stm32_irq_set_wake; + gc->chip_types->regs.ack = EXTI_PR; + gc->chip_types->regs.mask = EXTI_IMR; + gc->chip_types->handler = handle_edge_irq; + + nr_irqs = of_irq_count(node); + for (i = 0; i < nr_irqs; i++) { + unsigned int irq = irq_of_parse_and_map(node, i); + + irq_set_handler_data(irq, domain); + irq_set_chained_handler(irq, stm32_irq_handler); + } + + return 0; + +out_free_domain: + irq_domain_remove(domain); +out_unmap: + iounmap(base); + return ret; +} + +IRQCHIP_DECLARE(stm32_exti, "st,stm32-exti", stm32_exti_init); |