Re: [PATCH 3/3 v2] musb: AM35x: Workaround for fifo read issue

[Venkatraman S <svenkatr@ti.com>]

Ajay Kumar Gupta <ajay.gupta@ti.com> wrote:
> AM35x supports only 32bit read operations so we need to have
> workaround for 8bit and 16bit read operations.
>
> Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
> ---
>  drivers/usb/musb/am3517.c    |   30 ++++++++++++++++++++++++++++++
>  drivers/usb/musb/musb_core.c |    2 ++
>  2 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/musb/am3517.c b/drivers/usb/musb/am3517.c
> index dd9e883..24bdc2e 100644
> --- a/drivers/usb/musb/am3517.c
> +++ b/drivers/usb/musb/am3517.c
> @@ -515,3 +515,33 @@ void musb_platform_restore_context(struct musb_context_registers
>        phy_on();
>  }
>  #endif
> +
> +/* AM35x supports only 32bit read operation */
> +void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> +{
> +       void __iomem *fifo = hw_ep->fifo;
> +       u32             val;
> +       int             i;
> +
> +       /* Read for 32bit-aligned destination address */
> +       if ((likely((0x03 & (unsigned long) dst) == 0)) && len >= 4) {
> +               readsl(fifo, dst, len >> 2);
> +               dst += (len & ~0x03);
> +               len &= 0x03;
> +       }
> +       /* Now read the rest 1 to 3 bytes or complete length if
check multiline comments style
> +        * unaligned address.
> +        */
> +       if (len > 4) {
> +               for (i = 0; i < (len >> 2); i++) {
> +                       val = musb_readl(fifo, 0);
> +                       memcpy(dst, &val, 4);
> +                       dst += 4;
> +               }
> +               len %= 4;
> +       }
> +       if (len > 0) {
> +               val = musb_readl(fifo, 0);
> +               memcpy(dst, &val, len);
> +       }
> +}
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index 705cc4a..bc2cf14 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -191,6 +191,7 @@ void musb_write_fifo(struct musb_hw_ep *hw_ep, u16 len, const u8 *src)
>        }
>  }
>
> +#if !defined(CONFIG_MACH_OMAP3517EVM)
>  /*
>  * Unload an endpoint's FIFO
>  */
> @@ -228,6 +229,7 @@ void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
>                readsb(fifo, dst, len);
>        }
>  }
> +#endif
>
>  #endif /* normal PIO */
>
> --
> 1.6.2.4
>
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