Re: [PATCH] spi: bcm2835: Implement shutdown callback

[Florian Fainelli]

On 5/29/20 10:58 AM, Lukas Wunner wrote:
> On Fri, May 29, 2020 at 10:48:11AM -0700, Florian Fainelli wrote:
>> On 5/29/20 10:47 AM, Lukas Wunner wrote:
>>> On Thu, May 28, 2020 at 12:06:05PM -0700, Florian Fainelli wrote:
>>>> Make sure we clear the FIFOs, stop the block, disable the clock and
>>>> release the DMA channel.
>>>
>>> To what end?  Why is this change necessary?  Sorry but this seems like
>>> an awfully terse commit message.
>>
>> To ensure clocks are disabled and to save power in low power modes used
>> on 7211 for instance.
> 
> Thanks for the explanation, that's an important tidbit.  I wasn't even
> aware that this SPI controller is used on SoCs beyond the Raspberry Pi
> ones.  Does the BCM7211 use shared interrupts for this controller?
> Does it have DMA DREQ attached?

For all practical purposes you can consider that 7211 is identical to a
2711, it does use shared interrupts for this controller and there is a
DRAM DREQ attached as well. Where they differ are on the display, video,
and memory controller MAC.
-- 
Florian