Re: [PATCH v4 2/4] mmc: dw_mmc-rockchip: Add internal phase support

[Detlev Casanova <detlev.casanova@collabora.com>]

Hi Dragan,

On Friday, 23 August 2024 01:41:44 EDT Dragan Simic wrote:
> Hello Detlev,
> 
> Please see a comment below.
> 
> On 2024-08-22 23:15, Detlev Casanova wrote:
> > From: Shawn Lin <shawn.lin@rock-chips.com>
> > 
> > Some Rockchip devices put the phase settings into the dw_mmc
> > controller.
> > 
> > When the feature is present, the ciu-drive and ciu-sample clocks are
> > not used and the phase configuration is done directly through the mmc
> > controller.
> > 
> > Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> > Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
> > Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
> > ---
> > 
> >  drivers/mmc/host/dw_mmc-rockchip.c | 171 +++++++++++++++++++++++++++--
> >  1 file changed, 160 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/dw_mmc-rockchip.c
> > b/drivers/mmc/host/dw_mmc-rockchip.c
> > index b07190ba4b7a..2748f9bf2691 100644
> > --- a/drivers/mmc/host/dw_mmc-rockchip.c
> > +++ b/drivers/mmc/host/dw_mmc-rockchip.c
> > @@ -15,7 +15,17 @@
> > 
> >  #include "dw_mmc.h"
> >  #include "dw_mmc-pltfm.h"
> > 
> > -#define RK3288_CLKGEN_DIV	2
> > +#define RK3288_CLKGEN_DIV		2
> > +#define SDMMC_TIMING_CON0		0x130
> > +#define SDMMC_TIMING_CON1		0x134
> > +#define ROCKCHIP_MMC_DELAY_SEL		BIT(10)
> > +#define ROCKCHIP_MMC_DEGREE_MASK	0x3
> > +#define ROCKCHIP_MMC_DEGREE_OFFSET	1
> > +#define ROCKCHIP_MMC_DELAYNUM_OFFSET	2
> > +#define ROCKCHIP_MMC_DELAYNUM_MASK	(0xff <<
> > ROCKCHIP_MMC_DELAYNUM_OFFSET)
> > +#define ROCKCHIP_MMC_DELAY_ELEMENT_PSEC	60
> > +#define HIWORD_UPDATE(val, mask, shift) \
> > +		((val) << (shift) | (mask) << ((shift) + 16))
> > 
> >  static const unsigned int freqs[] = { 100000, 200000, 300000, 400000
> > 
> > };
> > 
> > @@ -24,8 +34,143 @@ struct dw_mci_rockchip_priv_data {
> > 
> >  	struct clk		*sample_clk;
> >  	int			default_sample_phase;
> >  	int			num_phases;
> > 
> > +	int			internal_phase;
> > 
> >  };
> 
> It might be good to declare internal_phase as "unsigned int
> internal_phase:1",
> i.e. as a bit field, which isn't going to save some memory in this
> particular
> case, but it would show additional attention to detail.

In that case, I would go with a bool instead of int, that makes things even 
clearer.