Re: [PATCH] irqchip/qcom-pdc: add support for v3.2 HW

["Maulik Shah (mkshah)" <quic_mkshah@xxxxxxxxxxx>]

Hi,

On 8/21/2023 1:00 PM, Neil Armstrong wrote:
> The PDC Hw version 3.2 and later doesn't have the enable registers
> anymore, get the HW version from registers and stop accessing those
> registers starting at this version.

Starting PDC v3.2, enable bit is moved from IRQ_ENABLE_BANK to the 
IRQ_i_CFG register.
we need to set enable bit to tell PDC HW whether IRQ is enabled / 
disabled in order to wake up from SoC sleep states.

> Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
>   drivers/irqchip/qcom-pdc.c | 64 ++++++++++++++++++++++++++++++++++++++--------
>   1 file changed, 53 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
> index d96916cf6a41..620efb9fcc96 100644
> --- a/drivers/irqchip/qcom-pdc.c
> +++ b/drivers/irqchip/qcom-pdc.c
> @@ -26,6 +26,13 @@
>   #define IRQ_ENABLE_BANK		0x10
>   #define IRQ_i_CFG		0x110
>   
> +#define PDC_VERSION		0x1000
> +
> +/* Notable PDC versions */
> +enum {
> +	PDC_VERSION_3_2	= 0x30200,
> +};
> +
>   struct pdc_pin_region {
>   	u32 pin_base;
>   	u32 parent_base;
> @@ -38,6 +45,7 @@ static DEFINE_RAW_SPINLOCK(pdc_lock);
>   static void __iomem *pdc_base;
>   static struct pdc_pin_region *pdc_region;
>   static int pdc_region_cnt;
> +static unsigned int pdc_version;
>   
>   static void pdc_reg_write(int reg, u32 i, u32 val)
>   {
> @@ -183,6 +191,25 @@ static struct irq_chip qcom_pdc_gic_chip = {
>   	.irq_set_affinity	= irq_chip_set_affinity_parent,
>   };
>   
> +static struct irq_chip qcom_pdc_gic_chip_3_2 = {
> +	.name			= "PDC",
> +	.irq_eoi		= irq_chip_eoi_parent,
> +	.irq_mask		= irq_chip_mask_parent,
> +	.irq_unmask		= irq_chip_unmask_parent,
> +	.irq_disable		= irq_chip_disable_parent,
> +	.irq_enable		= irq_chip_enable_parent,
> +	.irq_get_irqchip_state	= irq_chip_get_parent_state,
> +	.irq_set_irqchip_state	= irq_chip_set_parent_state,
> +	.irq_retrigger		= irq_chip_retrigger_hierarchy,
> +	.irq_set_type		= qcom_pdc_gic_set_type,
> +	.flags			= IRQCHIP_MASK_ON_SUSPEND |
> +				  IRQCHIP_SET_TYPE_MASKED |
> +				  IRQCHIP_SKIP_SET_WAKE |
> +				  IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
> +	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
> +	.irq_set_affinity	= irq_chip_set_affinity_parent,
> +};
> +
we should not need to have another irqchip defined for same as these 
remains same for old/new version.

Not sure if you have access to downstream change, or let me know i can 
post the same.
In downstream we do like...

The 3rd bit in IRQ_i_CFG in PDC v3.2 is for enable/disable,
The 0-2 bits are for the IRQ type in all PDC versions..

    #define IRQ_i_CFG_IRQ_ENABLE   BIT(3)
    #define IRQ_i_CFG_TYPE_MASK    0x7

and modify pdc_enable_intr()

       if (pdc_version < PDC_VERSION_3_2) {
               index = pin_out / 32;
               mask = pin_out % 32;
               enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
               __assign_bit(mask, &enable, on);
               pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
       } else {
               index = d->hwirq;
               enable = pdc_reg_read(IRQ_i_CFG, index);
               __assign_bit(IRQ_i_CFG_IRQ_ENABLE, &enable, on);
               pdc_reg_write(IRQ_i_CFG, index, enable);
       }

and qcom_pdc_gic_set_type(), add line to only take 0-2 bits from 
old_pdc_type as they are for type.

        old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq);
+       pdc_type |= (old_pdc_type & ~IRQ_i_CFG_TYPE_MASK);
> +		if (pdc_version < PDC_VERSION_3_2)
> +			pdc_enable_region(n);
>   	}

you will still need to clear enable bits in version 3.2.

Thanks,
Maulik