Re: [PATCH v6 4/4] usb: xhci: Add reset controller support

[Matthias Brugger]

On 29/06/2020 18:37, Nicolas Saenz Julienne wrote:

Some atypical users of xhci might need to manually reset their xHCI
controller before starting the HCD setup. Check if a reset controller
device is available to the PCI bus and trigger a reset.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulie...@suse.de>

---
Changes since v5:
  - Take !CONFIG_IS_ENABLED(DM_RESET) into account

  drivers/usb/host/xhci-mem.c |  2 ++
  drivers/usb/host/xhci.c     | 33 +++++++++++++++++++++++++++++++++
  include/usb/xhci.h          |  2 ++
  3 files changed, 37 insertions(+)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index f446520528..108f4bd8cf 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -180,6 +180,8 @@ void xhci_cleanup(struct xhci_ctrl *ctrl)
        xhci_free_virt_devices(ctrl);
        free(ctrl->erst.entries);
        free(ctrl->dcbaa);
+       if (reset_valid(&ctrl->reset))
+               reset_free(&ctrl->reset);
        memset(ctrl, '\0', sizeof(struct xhci_ctrl));
  }

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

index ebd2954571..e252964d0d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -190,6 +190,35 @@ static int xhci_start(struct xhci_hcor *hcor)
        return ret;
  }

+/**

+ * Resets XHCI Hardware
+ *
+ * @param ctrl pointer to host controller
+ * @return 0 if OK, or a negative error code.
+ */
+static int xhci_reset_hw(struct xhci_ctrl *ctrl)
+{
+       int ret;
+
+       ret = reset_get_by_index(ctrl->dev, 0, &ctrl->reset);

That seems to break arm32 builds:
https://pastebin.com/eHBf7Xp0
https://gitlab.denx.de/u-boot/custodians/u-boot-raspberrypi/-/jobs/121247

Nicolas, can you have a look?

Thanks
Matthias

+       if (ret && ret != -ENOENT && ret != -ENOTSUPP) {
+               dev_err(ctrl->dev, "failed to get reset\n");
+               return ret;
+       }
+
+       if (reset_valid(&ctrl->reset)) {
+               ret = reset_assert(&ctrl->reset);
+               if (ret)
+                       return ret;
+
+               ret = reset_deassert(&ctrl->reset);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
  /**
   * Resets the XHCI Controller
   *
@@ -1508,6 +1537,10 @@ int xhci_register(struct udevice *dev, struct xhci_hccr 
*hccr,

ctrl->dev = dev; + ret = xhci_reset_hw(ctrl);

+       if (ret)
+               goto err;
+
        /*
         * XHCI needs to issue a Address device command to setup
         * proper device context structures, before it can interact
diff --git a/include/usb/xhci.h b/include/usb/xhci.h
index 1170c0ac69..7d34103fd5 100644
--- a/include/usb/xhci.h
+++ b/include/usb/xhci.h
@@ -16,6 +16,7 @@
  #ifndef HOST_XHCI_H_
  #define HOST_XHCI_H_

+#include <reset.h>

  #include <asm/types.h>
  #include <asm/cache.h>
  #include <asm/io.h>
@@ -1209,6 +1210,7 @@ struct xhci_ctrl {
  #if CONFIG_IS_ENABLED(DM_USB)
        struct udevice *dev;
  #endif
+       struct reset_ctl reset;
        struct xhci_hccr *hccr; /* R/O registers, not need for volatile */
        struct xhci_hcor *hcor;
        struct xhci_doorbell_array *dba;