Subject: [PATCH v2 4/5] pinctrl: sunxi: Properly handle level triggered gpio interrupts

From: [email-masked] (Hans de Goede)
Date: Tue, 03 Jun 2014 17:13:17 +0200

Hi,

On 06/03/2014 03:30 PM, Maxime Ripard wrote:
> On Sat, May 31, 2014 at 04:01:38PM +0200, Hans de Goede wrote:
>> For level triggered gpio interrupts we need to use handle_fasteoi_irq,
>> like we do with the irq-sunxi-nmi driver. This is necessary to give threaded
>> interrupt handlers a chance to actuall clear the source of the interrupt
>> (which may involve sleeping waiting for i2c / spi / mmc transfers), before
>> acknowledging the interrupt.
>>
>> Signed-off-by: Hans de Goede <[email-masked]>
>> ---
>>   drivers/pinctrl/sunxi/pinctrl-sunxi.c | 57 +++++++++++++++++++++++++----------
>>   1 file changed, 41 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
>> index 61d3246..418a430 100644
>> --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
>> +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
>> @@ -31,6 +31,11 @@
>>   #include "../core.h"
>>   #include "pinctrl-sunxi.h"
>>
>> +static void sunxi_pinctrl_irq_ack(struct irq_data *d);
>> +static void sunxi_pinctrl_irq_mask(struct irq_data *d);
>> +static void sunxi_pinctrl_irq_unmask(struct irq_data *d);
>> +static int sunxi_pinctrl_irq_set_type(struct irq_data *d, unsigned int type);
>> +
>>   static struct sunxi_pinctrl_group *
>>   sunxi_pinctrl_find_group_by_name(struct sunxi_pinctrl *pctl, const char *group)
>>   {
>> @@ -545,10 +550,29 @@ static int sunxi_pinctrl_irq_request_resources(struct irq_data *d)
>>   	return 0;
>>   }
>>
>> -static int sunxi_pinctrl_irq_set_type(struct irq_data *d,
>> -				      unsigned int type)
>> +static struct irq_chip sunxi_pinctrl_edge_irq_chip = {
>> +	.irq_ack		= sunxi_pinctrl_irq_ack,
>> +	.irq_mask		= sunxi_pinctrl_irq_mask,
>> +	.irq_unmask		= sunxi_pinctrl_irq_unmask,
>> +	.irq_request_resources	= sunxi_pinctrl_irq_request_resources,
>> +	.irq_set_type		= sunxi_pinctrl_irq_set_type,
>> +	.flags			= IRQCHIP_SKIP_SET_WAKE,
>> +};
>> +
>> +static struct irq_chip sunxi_pinctrl_level_irq_chip = {
>> +	.irq_eoi		= sunxi_pinctrl_irq_ack,
>> +	.irq_mask		= sunxi_pinctrl_irq_mask,
>> +	.irq_unmask		= sunxi_pinctrl_irq_unmask,
>> +	.irq_request_resources	= sunxi_pinctrl_irq_request_resources,
>> +	.irq_set_type		= sunxi_pinctrl_irq_set_type,
>> +	.flags			= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_EOI_THREADED
>> +				  | IRQCHIP_EOI_IF_HANDLED,
>> +};
>
> Maybe we can just forward declare these two structures, instead of all
> their functions.

Variables cannot be forward declared, they can be declared extern, but last
time I checked extern and static don't mix.

>
>> +
>> +static int sunxi_pinctrl_irq_set_type(struct irq_data *d, unsigned int type)
>>   {
>>   	struct sunxi_pinctrl *pctl = irq_data_get_irq_chip_data(d);
>> +	struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
>>   	u32 reg = sunxi_irq_cfg_reg(d->hwirq);
>>   	u8 index = sunxi_irq_cfg_offset(d->hwirq);
>>   	unsigned long flags;
>> @@ -575,6 +599,14 @@ static int sunxi_pinctrl_irq_set_type(struct irq_data *d,
>>   		return -EINVAL;
>>   	}
>>
>> +	if (type & IRQ_TYPE_LEVEL_MASK) {
>> +		d->chip = &sunxi_pinctrl_level_irq_chip;
>> +		desc->handle_irq = handle_fasteoi_irq;
>> +	} else {
>> +		d->chip = &sunxi_pinctrl_edge_irq_chip;
>> +		desc->handle_irq = handle_edge_irq;
>
> irq_set_chip_and_handler?

Does a lookup of the irqdata which we already have here, and
that lookup takes a lock which is already held here.

>
>> +	}
>> +
>>   	spin_lock_irqsave(&pctl->lock, flags);
>>
>>   	regval = readl(pctl->membase + reg);
>> @@ -630,15 +662,6 @@ static void sunxi_pinctrl_irq_unmask(struct irq_data *d)
>>   	spin_unlock_irqrestore(&pctl->lock, flags);
>>   }
>>
>> -static struct irq_chip sunxi_pinctrl_irq_chip = {
>> -	.irq_ack	= sunxi_pinctrl_irq_ack,
>> -	.irq_mask	= sunxi_pinctrl_irq_mask,
>> -	.irq_unmask	= sunxi_pinctrl_irq_unmask,
>> -	.irq_request_resources = sunxi_pinctrl_irq_request_resources,
>> -	.irq_set_type	= sunxi_pinctrl_irq_set_type,
>> -	.flags		= IRQCHIP_SKIP_SET_WAKE,
>> -};
>> -
>>   static void sunxi_pinctrl_irq_handler(unsigned irq, struct irq_desc *desc)
>>   {
>>   	struct irq_chip *chip = irq_get_chip(irq);
>> @@ -655,9 +678,6 @@ static void sunxi_pinctrl_irq_handler(unsigned irq, struct irq_desc *desc)
>>   	reg = sunxi_irq_status_reg_from_bank(bank);
>>   	val = readl(pctl->membase + reg);
>>
>> -	/* Clear all interrupts */
>> -	writel(val, pctl->membase + reg);
>> -
>>   	if (val) {
>>   		int irqoffset;
>>
>> @@ -927,12 +947,17 @@ int sunxi_pinctrl_init(struct platform_device *pdev,
>>   	for (i = 0; i < (pctl->desc->irq_banks * IRQ_PER_BANK); i++) {
>>   		int irqno = irq_create_mapping(pctl->domain, i);
>>
>> -		irq_set_chip_and_handler(irqno, &sunxi_pinctrl_irq_chip,
>> -					 handle_simple_irq);
>> +		irq_set_chip_and_handler(irqno, &sunxi_pinctrl_edge_irq_chip,
>> +					 handle_edge_irq);
>>   		irq_set_chip_data(irqno, pctl);
>>   	};
>>
>>   	for (i = 0; i < pctl->desc->irq_banks; i++) {
>> +		/* Mask and clear all IRQs before registering a handler */
>> +		writel(0, pctl->membase + sunxi_irq_ctrl_reg_from_bank(i));
>> +		writel(0xffffffff,
>> +			pctl->membase + sunxi_irq_status_reg_from_bank(i));
>> +
>>   		irq_set_chained_handler(pctl->irq[i],
>>   					sunxi_pinctrl_irq_handler);
>>   		irq_set_handler_data(pctl->irq[i], pctl);
>> --
>> 2.0.0
>>
>
> Looks fine otherwise, thanks.

Regards,

Hans