Re: [PATCH] irqchip: bcm2835: Add FIQ support

Noralf Trønnes
2015-09-13T19:25:00Z

Den 22.07.2015 23:32, skrev Eric Anholt:
> Noralf Trønnes <noralf@tronnes.org> writes:
>
>> Add a duplicate irq range with an offset on the hwirq's so the
>> driver can detect that enable_fiq() is used.
>> Tested with downstream dwc_otg USB controller driver.
>>
>> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
>> ---
>> arch/arm/mach-bcm/Kconfig | 1 +
>> drivers/irqchip/irq-bcm2835.c | 53 ++++++++++++++++++++++++++++++++++++++-----
>> 2 files changed, 48 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
>> index 8b11f44..7cfef7b 100644
>> --- a/arch/arm/mach-bcm/Kconfig
>> +++ b/arch/arm/mach-bcm/Kconfig
>> @@ -114,6 +114,7 @@ config ARCH_BCM2835
>> select ARM_ERRATA_411920
>> select ARM_TIMER_SP804
>> select CLKSRC_OF
>> + select FIQ
>> select PINCTRL
>> select PINCTRL_BCM2835
>> help
>> diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c
>> index 5916d6c..db66246 100644
>> --- a/drivers/irqchip/irq-bcm2835.c
>> +++ b/drivers/irqchip/irq-bcm2835.c
>> @@ -56,7 +56,7 @@
>> #include "irqchip.h"
>>
>> /* Put the bank and irq (32 bits) into the hwirq */
>> -#define MAKE_HWIRQ(b, n) ((b << 5) | (n))
>> +#define MAKE_HWIRQ(b, n) (((b) << 5) | (n))
>> #define HWIRQ_BANK(i) (i >> 5)
>> #define HWIRQ_BIT(i) BIT(i & 0x1f)
>>
>> @@ -72,9 +72,13 @@
>> | SHORTCUT1_MASK | SHORTCUT2_MASK)
>>
>> #define REG_FIQ_CONTROL 0x0c
>> +#define REG_FIQ_ENABLE 0x80
>> +#define REG_FIQ_DISABLE 0
>>
>> #define NR_BANKS 3
>> #define IRQS_PER_BANK 32
>> +#define NUMBER_IRQS MAKE_HWIRQ(NR_BANKS, 0)
>> +#define FIQ_START (NR_IRQS_BANK0 + MAKE_HWIRQ(NR_BANKS - 1, 0))
>>
>> static int reg_pending[] __initconst = { 0x00, 0x04, 0x08 };
>> static int reg_enable[] __initconst = { 0x18, 0x10, 0x14 };
>> @@ -98,14 +102,38 @@ static struct armctrl_ic intc __read_mostly;
>> static void __exception_irq_entry bcm2835_handle_irq(
>> struct pt_regs *regs);
>>
>> +static inline unsigned int hwirq_to_fiq(unsigned long hwirq)
>> +{
>> + hwirq -= NUMBER_IRQS;
>> + /*
>> + * The hwirq numbering used in this driver is:
>> + * BASE (0-7) GPU1 (32-63) GPU2 (64-95).
>> + * This differ from the one used in the FIQ register:
>> + * GPU1 (0-31) GPU2 (32-63) BASE (64-71)
>> + */
>> + if (hwirq >= 32)
>> + return hwirq - 32;
>> +
>> + return hwirq + 64;
>> +}
>> +
>> static void armctrl_mask_irq(struct irq_data *d)
>> {
>> - writel_relaxed(HWIRQ_BIT(d->hwirq), intc.disable[HWIRQ_BANK(d->hwirq)]);
>> + if (d->hwirq >= NUMBER_IRQS)
>> + writel_relaxed(REG_FIQ_DISABLE, intc.base + REG_FIQ_CONTROL);
>> + else
>> + writel_relaxed(HWIRQ_BIT(d->hwirq),
>> + intc.disable[HWIRQ_BANK(d->hwirq)]);
>> }
>>
>> static void armctrl_unmask_irq(struct irq_data *d)
>> {
>> - writel_relaxed(HWIRQ_BIT(d->hwirq), intc.enable[HWIRQ_BANK(d->hwirq)]);
>> + if (d->hwirq >= NUMBER_IRQS)
>> + writel_relaxed(REG_FIQ_ENABLE | hwirq_to_fiq(d->hwirq),
>> + intc.base + REG_FIQ_CONTROL);
>> + else
>> + writel_relaxed(HWIRQ_BIT(d->hwirq),
>> + intc.enable[HWIRQ_BANK(d->hwirq)]);
>> }
> I found it nice for the 2836 controller to declare a new irqchip when
> both the mask/unmask hooks needed to be changed for that class of
> interrupt. However, it looks like these functions aren't going to be
> called regularly, so it doesn't matter much.
>
> As far as interaction with my 2836 series, it looks like the only thing
> downstream does is make the FIQ get handled on CPU1 instead of CPU0. I
> think we'll be fine fixing this up later.
>
> Reviewed-by: Eric Anholt <eric@anholt.net>

It seems that this has slipped through the cracks, at least it didn't
enter in the 4.3 merge window.

Noralf.