by Min Guo

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Subject: Re: [PATCH 4/4] usb: musb: Add support for MediaTek musb controller

Hi Bin,

On Thu, 2019-01-10 at 08:18 -0600, Bin Liu wrote:
> Hi Min,
>
> Please briefly summarize the controller differences in the commit log,
> such as
>
> - WIC interrupt registers;
> - data toggle bit;
> - no dedicated DMA interrupt line;
>
> so that we can quickly understand the core driver is modified
> accordingly to handle the differences.

Okay, tkanks.

> On Thu, Jan 10, 2019 at 03:24:22PM +0800, Min Guo wrote:
> > Hi Bin,
>
> [snip]
>
> > > > > > + musb_writeb(mbase, MUSB_INTRUSB,
> > > > > > + musb_readb(mbase, MUSB_INTRUSB));
> > > > >
> > > > > For this clearing register bit operation, please create platform hooks
> > > > > musb_clearb() and musb_clearw() in struct musb_platform_ops instead,
> > > > > then follow how musb_readb() pointer is assigned in
> > > > > musb_init_controller() to use the W1C version for mtk platform.
> > > >
> > > > I have tried implementing musb_readb(), musb_readw() interface with
> > > > interrupt status W1C function in struct musb_platform_ops. But this
> > > > interface will require a global variable to hold MAC basic address for
> > > > judgment, and then special handling of the interrupt state. A global
> > > > variable will make the driver work with only a single instance, so it
> > > > can't work on some MTK platforms which have two instances.
> > >
> > > I didn't mean to modify musb_read*(), but
> > >
> > > > How about creating musb_clearb/w() as following:
> > > > void (*clearb)(void __iomem *addr, unsigned offset, u8 data);
> > > > void (*clearw)(void __iomem *addr, unsigned offset, u16 data);
> > >
> > > this is what I was asking for, similar to what musb_readb/w() is
> > > implemented.
> >
> > I will prepare a patch for musb_clearb/w().
>
> This doesn't have to be a separate patch.

Okay.

> > > > > > + musb_writew(mbase, MUSB_INTRRX,
> > > > > > + musb_readw(mbase, MUSB_INTRRX));
> > > > > > + musb_writew(mbase, MUSB_INTRTX,
> > > > > > + musb_readw(mbase, MUSB_INTRTX));
> > > > > > + }
>
> [snip]
>
> > > > > > + /* MediaTek controller has private toggle register */
> > > > >
> > > > > only one toggle register for all endpoints? how does it handle
> > > > > difference toggle values for different endpoints?
> > > >
> > > > MediaTek controller has separate registers to describe TX/RX toggle.
> > >
> > > Is it one register per endpoint?
> >
> > MUSB_RXTOG/MUSB_TXTOG is common register, each bit reflects the toggle
> > state of an endpoint. bit[0] not used,bit[1~8] corresponds to ep[1~8]
> >
> > > >
> > > > > > + if (musb->ops->quirks & MUSB_MTK_QUIRKS) {
> > > > > > + u16 toggle;
> > > > > > + u8 epnum = qh->hw_ep->epnum;
> > > > > > +
> > > > > > + if (is_in)
> > > > > > + toggle = musb_readl(musb->mregs, MUSB_RXTOG);
> > >
> > > this line seems telling there is just *one* register for all endpoints.
> >
> > Yes, all endpoint share this register, endpoint and bit are one-to-one
> > correspondence.
>
> Okay, thanks. Sorry I missed the bit operation in the code below.
>
> >
> > > > >
> > > > > should use musb_readw() instead? MUSB_RXTOG seems to be 16bit.
> > > >
> > > > Ok
> > > >
> > > > > > + else
> > > > > > + toggle = musb_readl(musb->mregs, MUSB_TXTOG);
> > > > > > +
> > > > > > + csr = toggle & (1 << epnum);
>
> Regards,
> -Bin.

2019-01-11 05:40:52

by Min Guo

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Subject: Re: [PATCH 4/4] usb: musb: Add support for MediaTek musb controller

Hi Bin,

I have some questions about
musbhs_dma_controller_destroy/create_noirq().
1,Because of controller->irq=0 in noirq case, destroy_noirq can reuse
musbhs_dma_controller_destroy. Is it necessary to write a destroy_noirq
function?
2, How about creating a common function for create musb dma controller
as following:
static struct musb_dma_controller *dma_controller_alloc(struct musb
*musb, void __iomem *base)
then musbhs_dma_controller_create() and
musbhs_dma_controller_create_noirq() call it to alloc common resource.

On Tue, 2019-01-08 at 09:44 -0600, Bin Liu wrote:
> Hi,
>
> On Thu, Dec 27, 2018 at 03:34:26PM +0800, [email protected] wrote:
> > From: Min Guo <[email protected]>
> >
> > This adds support for MediaTek musb controller in
> > host, peripheral and otg mode
> >

> > diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c
> > index 824adcb..c545475 100644
> > --- a/drivers/usb/musb/musbhsdma.c
> > +++ b/drivers/usb/musb/musbhsdma.c

> >
> > void musbhs_dma_controller_destroy(struct dma_controller *c)
> > {
> > struct musb_dma_controller *controller = container_of(c,
> > struct musb_dma_controller, controller);
> > + struct musb *musb = controller->private_data;
> >
> > dma_controller_stop(controller);
> >
> > - if (controller->irq)
> > + if (!(musb->ops->quirks & MUSB_MTK_QUIRKS) && controller->irq)
> > free_irq(controller->irq, c);
> >
> > kfree(controller);
> > @@ -398,11 +402,15 @@ struct dma_controller *musbhs_dma_controller_create(struct musb *musb,
> > struct musb_dma_controller *controller;
> > struct device *dev = musb->controller;
> > struct platform_device *pdev = to_platform_device(dev);
> > - int irq = platform_get_irq_byname(pdev, "dma");
> > + int irq = -1;
> >
> > - if (irq <= 0) {
> > - dev_err(dev, "No DMA interrupt line!\n");
> > - return NULL;
> > + if (!(musb->ops->quirks & MUSB_MTK_QUIRKS)) {
> > + irq = platform_get_irq_byname(pdev, "dma");
> > +
> > + if (irq < 0) {
> > + dev_err(dev, "No DMA interrupt line!\n");
> > + return NULL;
> > + }
> > }
>
> Please create musbhs_dma_controller_destroy_noirq() for your platform to
> not use the quirk.
>
> >
> > controller = kzalloc(sizeof(*controller), GFP_KERNEL);
> > @@ -418,15 +426,17 @@ struct dma_controller *musbhs_dma_controller_create(struct musb *musb,
> > controller->controller.channel_program = dma_channel_program;
> > controller->controller.channel_abort = dma_channel_abort;
> >
> > - if (request_irq(irq, dma_controller_irq, 0,
> > + if (!(musb->ops->quirks & MUSB_MTK_QUIRKS)) {
> > + if (request_irq(irq, dma_controller_irq, 0,
> > dev_name(musb->controller), &controller->controller)) {
> > - dev_err(dev, "request_irq %d failed!\n", irq);
> > - musb_dma_controller_destroy(&controller->controller);
> > + dev_err(dev, "request_irq %d failed!\n", irq);
> > + musb_dma_controller_destroy(&controller->controller);
> >
> > - return NULL;
> > - }
> > + return NULL;
> > + }
> >
> > - controller->irq = irq;
> > + controller->irq = irq;
> > + }
> >
> > return &controller->controller;
> > }
>
> Same here, create musbhs_dma_controller_create_noirq(). Then use both
> new API for the mtk glue driver.

> Regards,
> -Bin.