Re: [PATCH v2] USB: Add MSM USB Device Controller driver

[Pavan Kondeti <pkondeti@codeaurora.org>]

Hi Igor,

On Wed, Nov 10, 2010 at 08:47:16AM +0200, Igor Grinberg wrote:
>  On 11/10/10 04:19, Pavan Kondeti wrote:
> > On Tue, Nov 09, 2010 at 05:36:28PM +0200, Igor Grinberg wrote:
> >>
> >> On 11/09/10 15:52, Matthieu CASTET wrote:
> >>> Hi,
> >>>
> >>> Pavankumar Kondeti a écrit :
> >>>
> >>>> diff --git a/drivers/usb/gadget/msm72k_udc.c b/drivers/usb/gadget/msm72k_udc.c
> >>>> new file mode 100644
> >>>> index 0000000..3fa4192
> >>>> --- /dev/null
> >>>> +++ b/drivers/usb/gadget/msm72k_udc.c
> >>>> +
> >>>> +static unsigned ulpi_read(struct usb_info *ui, unsigned reg)
> >>>> +{
> >>>> +       unsigned timeout = 100000;
> >>>> +
> >>>> +       /* initiate read operation */
> >>>> +       writel(ULPI_RUN | ULPI_READ | ULPI_ADDR(reg),
> >>>> +              USB_ULPI_VIEWPORT);
> >>>> +
> >>>> +       /* wait for completion */
> >>>> +       while ((readl(USB_ULPI_VIEWPORT) & ULPI_RUN) && (--timeout))
> >>>> +               ;
> >>>> +
> >>>> +       if (timeout == 0) {
> >>>> +               dev_err(&ui->pdev->dev, "ulpi_read: timeout %08x\n",
> >>>> +                               readl(USB_ULPI_VIEWPORT));
> >>>> +               return 0xffffffff;
> >>>> +       }
> >>>> +       return ULPI_DATA_READ(readl(USB_ULPI_VIEWPORT));
> >>>> +}
> >>>> +
> >>>> +static int ulpi_write(struct usb_info *ui, unsigned val, unsigned reg)
> >>>> +{
> >>>> +       unsigned timeout = 10000;
> >>>> +
> >>>> +       /* initiate write operation */
> >>>> +       writel(ULPI_RUN | ULPI_WRITE |
> >>>> +              ULPI_ADDR(reg) | ULPI_DATA(val),
> >>>> +              USB_ULPI_VIEWPORT);
> >>>> +
> >>>> +       /* wait for completion */
> >>>> +       while ((readl(USB_ULPI_VIEWPORT) & ULPI_RUN) && (--timeout))
> >>>> +               ;
> >>>> +
> >>>> +       if (timeout == 0) {
> >>>> +               dev_err(&ui->pdev->dev, "ulpi_write: timeout\n");
> >>>> +               return -1;
> >>>> +       }
> >>>> +
> >>>> +       return 0;
> >>>> +}
> >>>> +
> >>>> +static void ulpi_init(struct usb_info *ui)
> >>>> +{
> >>>> +       int *seq = ui->phy_init_seq;
> >>>> +
> >>>> +       if (!seq)
> >>>> +               return;
> >>>> +
> >>>> +       while (seq[0] >= 0) {
> >>>> +               dev_vdbg(&ui->pdev->dev, "ulpi: write 0x%02x to 0x%02x\n",
> >>>> +                               seq[0], seq[1]);
> >>>> +               ulpi_write(ui, seq[0], seq[1]);
> >>>> +               seq += 2;
> >>>> +       }
> >>>> +}
> >>>> +
> >>>
> >>> --- /dev/null
> >>> +++ b/drivers/usb/otg/msm72k_otg.c
> >>>
> >>> +
> >>> +#define ULPI_IO_TIMEOUT_USEC   (10 * 1000)
> >>> +static int ulpi_read(struct otg_transceiver *otg, u32 reg)
> >>> +{
> >>> +       int cnt = 0;
> >>> +
> >>> +       /* initiate read operation */
> >>> +       writel(ULPI_RUN | ULPI_READ | ULPI_ADDR(reg),
> >>> +              USB_ULPI_VIEWPORT);
> >>> +
> >>> +       /* wait for completion */
> >>> +       while (cnt < ULPI_IO_TIMEOUT_USEC) {
> >>> +               if (!(readl(USB_ULPI_VIEWPORT) & ULPI_RUN))
> >>> +                       break;
> >>> +               udelay(1);
> >>> +               cnt++;
> >>> +       }
> >>> +
> >>> +       if (cnt >= ULPI_IO_TIMEOUT_USEC) {
> >>> +               dev_err(otg->dev, "ulpi_read: timeout %08x\n",
> >>> +                       readl(USB_ULPI_VIEWPORT));
> >>> +               return -ETIMEDOUT;
> >>> +       }
> >>> +       return ULPI_DATA_READ(readl(USB_ULPI_VIEWPORT));
> >>> +}
> >>> +
> >>> +static int ulpi_write(struct otg_transceiver *otg, u32 val, u32 reg)
> >>> +{
> >>> +       int cnt = 0;
> >>> +
> >>> +       /* initiate write operation */
> >>> +       writel(ULPI_RUN | ULPI_WRITE |
> >>> +              ULPI_ADDR(reg) | ULPI_DATA(val),
> >>> +              USB_ULPI_VIEWPORT);
> >>> +
> >>> +       /* wait for completion */
> >>> +       while (cnt < ULPI_IO_TIMEOUT_USEC) {
> >>> +               if (!(readl(USB_ULPI_VIEWPORT) & ULPI_RUN))
> >>> +                       break;
> >>> +               udelay(1);
> >>> +               cnt++;
> >>> +       }
> >>> +
> >>> +       if (cnt >= ULPI_IO_TIMEOUT_USEC) {
> >>> +               dev_err(otg->dev, "ulpi_write: timeout\n");
> >>> +               return -ETIMEDOUT;
> >>> +       }
> >>> +       return 0;
> >>> +}
> >>> +
> >>> +static struct otg_io_access_ops msm_otg_io_ops = {
> >>> +       .read = ulpi_read,
> >>> +       .write = ulpi_write,
> >>> +};
> >>> +
> >>> +static void ulpi_init(struct msm_otg *motg)
> >>> +{
> >>> +       struct msm_otg_platform_data *pdata = motg->pdata;
> >>> +       int *seq = pdata->phy_init_seq;
> >>> +
> >>> +       if (!seq)
> >>> +               return;
> >>> +
> >>> +       while (seq[0] >= 0) {
> >>> +               dev_vdbg(motg->otg.dev, "ulpi: write 0x%02x to 0x%02x\n",
> >>> +                               seq[0], seq[1]);
> >>> +               ulpi_write(&motg->otg, seq[0], seq[1]);
> >>> +               seq += 2;
> >>> +       }
> >>> +}
> >>>
> >>>
> >>> can't you share the ulpi fonctions from udc and otg ?
> >> The best would be to use the usb/otg/ulpi.c driver for the ulpi access.
> >>
> > This driver will eventually use msm72k_otg.c transceiver.
> 
> Well, I mean, in addition to defining the struct otg_io_access_ops in some place,
> where both device and host drivers can share the same ops code, you can also
> use the ulpi generic driver as the protocol driver, instead of writing private code.

I have not looked at generic ULPI driver. I will see if we can re-use it in
our msm72k_otg.c.

> If the generic driver still lack some functionality, I can try to help you with this.
> 
Sure. Thanks for offering help.
-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.