[PATCH v4 2/9] drivers: irqchip: Add STM32 external interrupts support
Jason Cooper
jason at lakedaemon.net
Tue Sep 6 10:37:37 PDT 2016
On Tue, Sep 06, 2016 at 06:45:34PM +0200, Alexandre TORGUE wrote:
> The STM32 external interrupt controller consists of edge detectors that
> generate interrupts requests or wake-up events.
>
> Each line can be independently configured as interrupt or wake-up source,
> and triggers either on rising, falling or both edges. Each line can also
> be masked independently.
>
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
> Signed-off-by: Alexandre TORGUE <alexandre.torgue at st.com>
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 7f87289..bc62d1f 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -264,3 +264,7 @@ config EZNPS_GIC
> select IRQ_DOMAIN
> help
> Support the EZchip NPS400 global interrupt controller
> +
> +config STM32_EXTI
> + bool
> + select IRQ_DOMAIN
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 4c203b6..96383b2 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -71,3 +71,4 @@ obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
> obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
> obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
> obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o
> +obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
> diff --git a/drivers/irqchip/irq-stm32-exti.c b/drivers/irqchip/irq-stm32-exti.c
> new file mode 100644
> index 0000000..763c17c
> --- /dev/null
> +++ b/drivers/irqchip/irq-stm32-exti.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright (C) Maxime Coquelin 2015
> + * Author: Maxime Coquelin <mcoquelin.stm32 at 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/irqchip/chained_irq.h>
double paste?
double paste?
If there are no other critiques, I'll fix this up when I pull in patches
1 and 2.
thx,
Jason.
> +#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_get_irq_data(virq);
> +
> + irq_gc_mask_clr_bit(data->parent_data);
> + 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);
> --
> 1.9.1
>
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