[PATCH v2 2/3] mailbox: exynos: Add support for Exynos850 mailbox

[Alexey Klimov]

On Wed Apr 8, 2026 at 2:08 PM BST, Alexey Klimov wrote:

[...]

> On Thu Apr 2, 2026 at 9:42 AM BST, Tudor Ambarus wrote:
>>>  static int exynos_mbox_send_data(struct mbox_chan *chan, void *data)
>>> @@ -57,7 +104,8 @@ static int exynos_mbox_send_data(struct mbox_chan *chan, void *data)
>>>  		return -EINVAL;
>>>  	}
>>>  
>>> -	writel(BIT(msg->chan_id), exynos_mbox->regs + EXYNOS_MBOX_INTGR1);
>>> +	writel(BIT(msg->chan_id) << exynos_mbox->data->irq_doorbell_shift,
>>> +	       exynos_mbox->regs + exynos_mbox->data->irq_doorbell_offset);
>>
>> Use FIELD_PREP from <linux/bitfield.h> please. You will use a mask instead of
>> a shift.
>>
>> I would rename irq_doorbell_offset to intgr. It aligns with the register name
>> from the datasheet. You won't need to prepend _offset to the name, we already
>> see it's an offset when doing the writel().
>
> Sure. Thanks. Let's use FIELD_PREP.

+       /* Ring the doorbell */
+       writel(BIT(msg->chan_id) << exynos_mbox->data->intgr_shift,
+              exynos_mbox->regs + exynos_mbox->data->intgr);

FIELD_PREP() wants a mask as a compile-time constant. Unless you want me to
add switch/case for different SoCs or I misunderstood something I don't see
how this is gonna fly.

Best regards,
Alexey