> PS: Aric, would you retest that patch, as I transformed "a bit" your original
> work, and confirm your "Signed-off-by" stills holds for that patch please ?
>
Well, for Aric's patch below, my comment is that this also holds true for
pxa27x, so the if (cpu_is_pxa3xx()) isn't really necessary. We have to
clear OPC on both pxa27x and pxa3xx for this.
For pxa3xx specific part, there should be another bit defined as:
#define UDCCSR0_ODFCLR (1 << 10)
which can be turned on to prevent inadvertent back-to-back setup packets.
> From c225a9dcca4523e9d769bd8a6b1e110b57c77521 Mon Sep 17 00:00:00 2001
> From: Aric Blumer <aric@xxxxxxxxxxxxxx>
> Date: Sat, 7 Mar 2009 18:36:07 +0100
> Subject: [PATCH] pxa27x_udc: compatibility with pxa320 SoC
>
> Got pxa27x_udc working on the pxa320 Nomad platform. The
> problem was that the pxa3xx UDC is not quite compatible with
> the pxa27x UDC in how it handles back-to-back control
> packets. The pxa27x probably drops them by default, but the
> pxa320 does not, and you have to detect it and set the OPC
> bit to clear the zero-length packet.
>
> Signed-off-by: Aric Blumer <aric@xxxxxxxxxxxxxx>
> Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
> ---
> drivers/usb/gadget/Kconfig | 2 +-
> drivers/usb/gadget/pxa27x_udc.c | 20 +++++++++++++++++++-
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
> index e55fef5..4e298b3 100644
> --- a/drivers/usb/gadget/Kconfig
> +++ b/drivers/usb/gadget/Kconfig
> @@ -253,7 +253,7 @@ config USB_PXA25X_SMALL
>
> config USB_GADGET_PXA27X
> boolean "PXA 27x"
> - depends on ARCH_PXA && PXA27x
> + depends on ARCH_PXA && (PXA27x || PXA3xx)
> help
> Intel's PXA 27x series XScale ARM v5TE processors include
> an integrated full speed USB 1.1 device controller.
> diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c
> index 990f40f..121dae6 100644
> --- a/drivers/usb/gadget/pxa27x_udc.c
> +++ b/drivers/usb/gadget/pxa27x_udc.c
> @@ -37,7 +37,10 @@
> #include <linux/usb.h>
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> +
> +#ifdef CONFIG_PXA2xx
> #include <mach/pxa2xx-regs.h> /* FIXME: for PSSR */
> +#endif
> #include <mach/udc.h>
>
> #include "pxa27x_udc.h"
> @@ -1729,6 +1732,17 @@ static void handle_ep0_ctrl_req(struct pxa_udc *udc,
>
> nuke(ep, -EPROTO);
>
> + /*
> + * In the PXA320 manual, in the section about Back-to-Back setup
> + * packets, it describes this situation. The solution is to set OPC to
> + * get rid of the status packet, and then continue with the setup
> + * packet.
> + */
> + if (cpu_is_pxa3xx()) {
> + if (!ep_is_empty(ep) && (ep_count_bytes_remain(ep) == 0))
> + udc_ep_writel(ep, UDCCSR, UDCCSR0_OPC);
> + }
> +
> /* read SETUP packet */
> for (i = 0; i < 2; i++) {
> if (unlikely(ep_is_empty(ep)))
> @@ -1802,6 +1816,8 @@ stall:
> * cleared by software.
> * - clearing UDCCSR0_OPC always flushes ep0. If in setup stage, never do it
> * before reading ep0.
> + * This is true only for PXA27x. This is not true anymore for PXA3xx family
> + * (check Back-to-Back setup packet in developers guide).
> * - irq can be called on a "packet complete" event (opc_irq=1), while
> * UDCCSR0_OPC is not yet raised (delta can be as big as 100ms
> * from experimentation).
> @@ -2356,8 +2372,10 @@ static int pxa_udc_resume(struct platform_device *_dev)
> * Software must configure the USB OTG pad, UDC, and UHC
> * to the state they were in before entering sleep mode.
> */
> +#ifdef CONFIG_PXA2xx
> if (cpu_is_pxa27x())
> PSSR |= PSSR_OTGPH;
> +#endif
>
> return 0;
> }
> @@ -2381,7 +2399,7 @@ static struct platform_driver udc_driver = {
>
> static int __init udc_init(void)
> {
> - if (!cpu_is_pxa27x())
> + if (!cpu_is_pxa27x() && !cpu_is_pxa3xx())
> return -ENODEV;
>
> printk(KERN_INFO "%s: version %s\n", driver_name, DRIVER_VERSION);
> --
> 1.5.6.5
>
> --
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--
Cheers
- eric
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