[U-Boot] [PATCH v2 05/13] usb: dwc3: change DWC3 core support code into a driver

Roger Quadros
2016-05-17T08:20:47Z

Hi Masahiro,

On 16/05/16 15:51, Masahiro Yamada wrote:
> Synopsys DWC3 IP generally works with an SoC-specific glue layer.
> DT binding for that is like this:
>
> usb3_glue {
> compatible = "foo,dwc3";
> ...
>
> usb3 {
> compatible = "snps,dwc3";
> ...
> };
> };
>
> The glue layer initializes some SoC-specific parts, then populates
> the child DWC3 core. To see how it works, refer to
>
> drivers/usb/dwc3/dwc3-exynos.c
> drivers/usb/dwc3/dwc3-keystone.c
> drivers/usb/dwc3/dwc3-omap.c
> drivers/usb/dwc3/dwc3-st.c
>
> of Linux Kernel.
>
> This commit implements a driver compatible with "snps,dwc3", allowing
> to use the same binding in U-Boot. The glue layer can be simply
> implemented based on Simple Bus Uclass.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Reviewed-by: Marek Vasut <marex@denx.de>
> ---
>
> Changes in v2: None
>
> drivers/usb/host/xhci-dwc3.c | 71 +++++++++++++++++++++++++++++++++++++++++++-

"snps,dwc3" compatible is for the dual-role controller that implements both
device and host controllers. So calling the driver xhci-dwc3.c is a bit misleading.

> 1 file changed, 70 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-dwc3.c b/drivers/usb/host/xhci-dwc3.c
> index 33961cd..c7c8324 100644
> --- a/drivers/usb/host/xhci-dwc3.c
> +++ b/drivers/usb/host/xhci-dwc3.c
> @@ -9,8 +9,13 @@
> */
>
> #include <common.h>
> -#include <asm/io.h>
> +#include <dm/device.h>
> +#include <mapmem.h>
> +#include <linux/io.h>
> #include <linux/usb/dwc3.h>
> +#include <linux/sizes.h>
> +
> +#include "xhci.h"
>
> void dwc3_set_mode(struct dwc3 *dwc3_reg, u32 mode)
> {
> @@ -97,3 +102,67 @@ void dwc3_set_fladj(struct dwc3 *dwc3_reg, u32 val)
> setbits_le32(&dwc3_reg->g_fladj, GFLADJ_30MHZ_REG_SEL |
> GFLADJ_30MHZ(val));
> }
> +
> +struct dwc3_priv {
> + struct xhci_ctrl ctrl; /* should be the first member */
> + void __iomem *regs;
> +};
> +
> +static int dwc3_probe(struct udevice *dev)
> +{
> + struct dwc3_priv *priv = dev_get_priv(dev);
> + struct xhci_hccr *hccr;
> + struct xhci_hcor *hcor;
> + fdt_addr_t base;
> + int ret;
> +
> + base = dev_get_addr(dev);
> + if (base == FDT_ADDR_T_NONE)
> + return -EINVAL;
> +
> + priv->regs = map_sysmem(base, SZ_32K);
> + if (!priv->regs)
> + return -ENOMEM;
> +
> + hccr = priv->regs;
> +
> + hcor = priv->regs + HC_LENGTH(xhci_readl(&hccr->cr_capbase));
> +
> + ret = dwc3_core_init(priv->regs + DWC3_REG_OFFSET);
> + if (ret) {
> + puts("XHCI: failed to initialize controller\n");
> + return ret;
> + }
> +
> + /* We are hard-coding DWC3 core to Host Mode */
> + dwc3_set_mode(priv->regs + DWC3_REG_OFFSET, DWC3_GCTL_PRTCAP_HOST);

Why are we hard-coding it to host mode? We need to take into account
the dr_mode DT property and the Kconfig options to decide which mode
we can operate in.

> +
> + return xhci_register(dev, hccr, hcor);
> +}
> +
> +static int dwc3_remove(struct udevice *dev)
> +{
> + struct dwc3_priv *priv = dev_get_priv(dev);
> +
> + xhci_deregister(dev);
> + unmap_sysmem(priv->regs);
> +
> + return 0;
> +}
> +
> +static const struct udevice_id of_dwc3_match[] = {
> + { .compatible = "snps,dwc3" },
> + { .compatible = "synopsys,dwc3" },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(dwc3) = {
> + .name = "dwc3",
> + .id = UCLASS_USB,
> + .of_match = of_dwc3_match,
> + .probe = dwc3_probe,
> + .remove = dwc3_remove,
> + .ops = &xhci_usb_ops,
> + .priv_auto_alloc_size = sizeof(struct dwc3_priv),
> + .flags = DM_FLAG_ALLOC_PRIV_DMA,
> +};
>

cheers,
-roger