[2/6] dmaengine: sun6i: Add a quirk for additional mbus clock

[Vinod Koul <vkoul@kernel.org>]

On 16-03-19, 12:23, Jernej Škrabec wrote:
> Hi!
> 
> Dne sobota, 16. marec 2019 ob 12:07:53 CET je Vinod Koul napisal(a):
> > On 07-03-19, 17:58, Jernej Skrabec wrote:
> > > H6 DMA controller needs additional mbus clock to be enabled.
> > > 
> > > Add a quirk for it and handle it accordingly.
> > > 
> > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> > > ---
> > > 
> > >  drivers/dma/sun6i-dma.c | 23 ++++++++++++++++++++++-
> > >  1 file changed, 22 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> > > index 0cd13f17fc11..761555080325 100644
> > > --- a/drivers/dma/sun6i-dma.c
> > > +++ b/drivers/dma/sun6i-dma.c
> > > @@ -129,6 +129,7 @@ struct sun6i_dma_config {
> > > 
> > >  	u32 dst_burst_lengths;
> > >  	u32 src_addr_widths;
> > >  	u32 dst_addr_widths;
> > > 
> > > +	bool mbus_clk;
> > > 
> > >  };
> > >  
> > >  /*
> > > 
> > > @@ -182,6 +183,7 @@ struct sun6i_dma_dev {
> > > 
> > >  	struct dma_device	slave;
> > >  	void __iomem		*base;
> > >  	struct clk		*clk;
> > > 
> > > +	struct clk		*clk_mbus;
> > 
> > So rather than have mbus_clk and then a ptr, why not use the ptr and use
> > NULL value to check for..?
> > 
> 
> I'm not sure what you mean here. clk_mbus will hold a reference to a clock 
> retrieved by devm_clk_get() so it has to be "struct clk *".
> 
> What I'm missing here?

IIRC there were two variable one clk ptr and one an integer to mark
presence, you may be able to skip variable and use ptr..