RE: [PATCH] phy: renesas: rcar-gen3-usb2: follow the hardware manual procedure

[Yoshihiro Shimoda]

Hi Simon-san,

Thank you for your review!

> From: Simon Horman, Sent: Monday, November 26, 2018 6:39 PM
> 
> On Wed, Nov 21, 2018 at 08:10:06AM +0000, Yoshihiro Shimoda wrote:
> > This patch modifies rcar_gen3_init_otg() procedure to follow Figure
> > 73.4 of "R-Car Series, 3rd Generation User's Manual: Hardware Rev.1.00".
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> >  This patch is based on the latest linux-phy / next branch
> > (commit id = 0eb86fa77f0f0c81631a030f10679a45c05df33a).
> >
> >  drivers/phy/renesas/phy-rcar-gen3-usb2.c | 17 +++++++++++------
> >  1 file changed, 11 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> > index d0f412c..a9e53e8 100644
> > --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> > +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> > @@ -307,16 +307,21 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
> >  	void __iomem *usb2_base = ch->base;
> >  	u32 val;
> >
> > +	rcar_gen3_set_linectrl(ch, 0, 1);
> > +	val = readl(usb2_base + USB2_LINECTRL1);
> > +	writel(val | USB2_LINECTRL1_DPRPD_EN | USB2_LINECTRL1_DMRPD_EN,
> > +	       usb2_base + USB2_LINECTRL1);
> 
> I am wondering if as well as the above
> USB2_LINECTRL1_DPRPD_EN should be set and
> USB2_LINECTRL1_DP_RPD should be cleared.

I assumed rcar_gen3_set_linectrl(ch, 0, 1); did
"USB2_LINECTRL1_DP_RPD should be cleared ".
But, the patch is not readable. So, I will fix this.

> > +
> >  	val = readl(usb2_base + USB2_VBCTRL);
> >  	writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
> > -	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTSTA);
> > -	rcar_gen3_control_otg_irq(ch, 1);
> >  	val = readl(usb2_base + USB2_ADPCTRL);
> >  	writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
> > -	val = readl(usb2_base + USB2_LINECTRL1);
> > -	rcar_gen3_set_linectrl(ch, 0, 0);
> > -	writel(val | USB2_LINECTRL1_DPRPD_EN | USB2_LINECTRL1_DMRPD_EN,
> > -	       usb2_base + USB2_LINECTRL1);
> > +
> > +	msleep(20);
> > +
> > +	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTSTA);
> 
> I wonder if it is appropriate to write 0xffffffff to USB2_OBINTSTA

Also, I'll fix this.

> and then USB2_OBINT_BITS to USB2_OBINTEN here.

I assumed the rcar_gen3_control_otg_irq() below did that.
However, since rcar_gen3_control_otg_irq() does read-modify-write the register,
it is not good as the initial routine because a boot loader wrote the register
with other value. So, I also fix this not to call rcar_gen3_control_otg_irq().

> > +
> > +	rcar_gen3_control_otg_irq(ch, 1);

Best regards,
Yoshihiro Shimoda

> >  	rcar_gen3_device_recognition(ch);
> >  }
> > --
> > 1.9.1
> >