Re: [PATCH v4 2/9] drivers: irqchip: Add STM32 external interrupts support

[Alexandre Torgue <alexandre.torgue@st.com>]

Hi Jason,

On 09/06/2016 07:37 PM, Jason Cooper wrote:
> 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@gmail.com>
>> Signed-off-by: Alexandre TORGUE <alexandre.torgue@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@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.
>
Yes bad copy/paste. I have to send a v5 with Linus (W) remarks. So I 
will fix it in the v5.

Thanks

Alex


> 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
>>