Re: [PATCH v4 6/6] usb: musb: Add support for MediaTek musb controller

Min Guo
2019-01-22T01:45:15Z

Hi Bin,

On Mon, 2019-01-21 at 10:07 -0600, Bin Liu wrote:
> Hi Min,
>
> On Mon, Jan 21, 2019 at 08:22:31PM +0800, min.guo@mediatek.com wrote:
> > From: Min Guo <min.guo@mediatek.com>
> >
> > This adds support for MediaTek musb controller in
> > host, peripheral and otg mode.
> > There are some quirk of MediaTek musb controller, such as:
> > -W1C interrupt status registers
> > -Private data toggle registers
> > -No dedicated DMA interrupt line
> >
> > Signed-off-by: Min Guo <min.guo@mediatek.com>
> > Signed-off-by: Yonglong Wu <yonglong.wu@mediatek.com>
> > ---
> > changes in v4:
> > 1. no changes
> >
> > changes in v3:
> > suggested by Bin:
> > 1. Remove 'u8/u16 data' parameter in clearb/w() hooks
> > 2. Replace musb_readb/w() with musb_clearb/w() to clear interrupts status
> >
> > changes in v2:
> > suggested by Bin:
> > 1. Add summarize of MediaTek musb controller differences in the commit log
> > 2. Add "|| COMPILE_TEST" in Kconfig
> > 3. Move MediaTek's private toggle registers from musb_regs.h to mediatek.c
> > 4. Replace musb_readl() with musb_readw() to read 16bit toggle register
> > ---
> > drivers/usb/musb/Kconfig | 8 +-
> > drivers/usb/musb/Makefile | 1 +
> > drivers/usb/musb/mediatek.c | 624 ++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 632 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/usb/musb/mediatek.c
> >
>
> [snip]
>
> > +static irqreturn_t generic_interrupt(int irq, void *__hci)
> > +{
> > + unsigned long flags;
> > + irqreturn_t retval = IRQ_NONE;
> > + struct musb *musb = __hci;
> > +
> > + spin_lock_irqsave(&musb->lock, flags);
> > + musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB) &
> > + musb_readb(musb->mregs, MUSB_INTRUSBE);
> > + musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX)
> > + & musb_readw(musb->mregs, MUSB_INTRTXE);
> > + musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX)
> > + & musb_readw(musb->mregs, MUSB_INTRRXE);
>
> Based on my comment in 5/6, the above 3 musb_readb/w() can be changed to
>
> > + /* MediaTek controller interrupt status is W1C */
> > + musb_clearw(musb->mregs, MUSB_INTRRX);
> > + musb_clearw(musb->mregs, MUSB_INTRTX);
> > + musb_clearb(musb->mregs, MUSB_INTRUSB);
>
> musb->int_usb = musb_clearb(musb->mregs, MUSB_INTRUSB)
> musb->int_tx = musb_clearw(musb->mregs, MUSB_INTRTX);
> musb->int_rx = musb_clearw(musb->mregs, MUSB_INTRRX);

Okay.

> > +
> > + if (musb->int_usb || musb->int_tx || musb->int_rx)
> > + retval = musb_interrupt(musb);
> > +
> > + spin_unlock_irqrestore(&musb->lock, flags);
> > +
> > + return retval;
> > +}
> > +
>
> [snip]
>
> > +
> > +static u8 mtk_musb_clearb(void __iomem *addr, unsigned int offset)
> > +{
> > + u8 data;
> > +
> > + /* W1C */
> > + data = musb_readb(addr, offset);
> > + musb_writeb(addr, offset, data);
> > + return musb_readb(addr, offset);
>
> return data;

Okay.

> > +}
> > +
> > +static u16 mtk_musb_clearw(void __iomem *addr, unsigned int offset)
> > +{
> > + u16 data;
> > +
> > + /* W1C */
> > + data = musb_readw(addr, offset);
> > + musb_writew(addr, offset, data);
> > + return musb_readw(addr, offset);
>
> return data;

Okay.

>
> Regards,
> -Bin.