bcm53xx: add early support for kernel 4.14

Don't switch to it by default yet as it requires more testing.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 137 insertions, 0 deletions

diff --git a/target/linux/bcm53xx/patches-4.14/180-usb-xhci-add-support-for-performing-fake-doorbell.patch b/target/linux/bcm53xx/patches-4.14/180-usb-xhci-add-support-for-performing-fake-doorbell.patch
new file mode 100644
index 0000000000..ec2df9125f
--- /dev/null
+++ b/target/linux/bcm53xx/patches-4.14/180-usb-xhci-add-support-for-performing-fake-doorbell.patch
@@ -0,0 +1,137 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Sat, 1 Oct 2016 22:54:48 +0200
+Subject: [PATCH] usb: xhci: add support for performing fake doorbell
+
+Broadcom's Northstar XHCI controllers seem to need a special start
+procedure to work correctly. There isn't any official documentation of
+this, the problem is that controller doesn't detect any connected
+devices with default setup. Moreover connecting USB device to controller
+that doesn't run properly can cause SoC's watchdog issues.
+
+A workaround that was successfully tested on multiple devices is to
+perform a fake doorbell. This patch adds code for doing this and enables
+it on BCM4708 family.
+---
+ drivers/usb/host/xhci-plat.c |  6 +++++
+ drivers/usb/host/xhci.c      | 63 +++++++++++++++++++++++++++++++++++++++++---
+ drivers/usb/host/xhci.h      |  1 +
+ 3 files changed, 67 insertions(+), 3 deletions(-)
+
+--- a/drivers/usb/host/xhci-plat.c
++++ b/drivers/usb/host/xhci-plat.c
+@@ -67,12 +67,18 @@ static int xhci_priv_resume_quirk(struct
+ 
+ static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
+ {
++	struct platform_device	*pdev = to_platform_device(dev);
++	struct device_node	*node = pdev->dev.of_node;
++
+ 	/*
+ 	 * As of now platform drivers don't provide MSI support so we ensure
+ 	 * here that the generic code does not try to make a pci_dev from our
+ 	 * dev struct in order to setup MSI
+ 	 */
+ 	xhci->quirks |= XHCI_PLAT;
++
++	if (node && of_machine_is_compatible("brcm,bcm4708"))
++		xhci->quirks |= XHCI_FAKE_DOORBELL;
+ }
+ 
+ /* called during probe() after chip reset completes */
+--- a/drivers/usb/host/xhci.c
++++ b/drivers/usb/host/xhci.c
+@@ -153,6 +153,49 @@ int xhci_start(struct xhci_hcd *xhci)
+ 	return ret;
+ }
+ 
++/**
++ * xhci_fake_doorbell - Perform a fake doorbell on a specified slot
++ *
++ * Some controllers require a fake doorbell to start correctly. Without that
++ * they simply don't detect any devices.
++ */
++static int xhci_fake_doorbell(struct xhci_hcd *xhci, int slot_id)
++{
++	u32 temp;
++
++	/* Alloc a virt device for that slot */
++	if (!xhci_alloc_virt_device(xhci, slot_id, NULL, GFP_NOIO)) {
++		xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
++		return -ENOMEM;
++	}
++
++	/* Ring fake doorbell for slot_id ep 0 */
++	xhci_ring_ep_doorbell(xhci, slot_id, 0, 0);
++	usleep_range(1000, 1500);
++
++	/* Read the status to check if HSE is set or not */
++	temp = readl(&xhci->op_regs->status);
++
++	/* Clear HSE if set */
++	if (temp & STS_FATAL) {
++		xhci_dbg(xhci, "HSE problem detected, status: 0x%08x\n", temp);
++		temp &= ~0x1fff;
++		temp |= STS_FATAL;
++		writel(temp, &xhci->op_regs->status);
++		usleep_range(1000, 1500);
++		readl(&xhci->op_regs->status);
++	}
++
++	/* Free virt device */
++	xhci_free_virt_device(xhci, slot_id);
++
++	/* We're done if controller is already running */
++	if (readl(&xhci->op_regs->command) & CMD_RUN)
++		return 0;
++
++	return xhci_start(xhci);
++}
++
+ /*
+  * Reset a halted HC.
+  *
+@@ -536,10 +579,20 @@ static int xhci_init(struct usb_hcd *hcd
+ 
+ static int xhci_run_finished(struct xhci_hcd *xhci)
+ {
+-	if (xhci_start(xhci)) {
+-		xhci_halt(xhci);
+-		return -ENODEV;
++	int err;
++
++	err = xhci_start(xhci);
++	if (err) {
++		err = -ENODEV;
++		goto err_halt;
+ 	}
++
++	if (xhci->quirks & XHCI_FAKE_DOORBELL) {
++		err = xhci_fake_doorbell(xhci, 1);
++		if (err)
++			goto err_halt;
++	}
++
+ 	xhci->shared_hcd->state = HC_STATE_RUNNING;
+ 	xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
+ 
+@@ -549,6 +602,10 @@ static int xhci_run_finished(struct xhci
+ 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+ 			"Finished xhci_run for USB3 roothub");
+ 	return 0;
++
++err_halt:
++	xhci_halt(xhci);
++	return err;
+ }
+ 
+ /*
+--- a/drivers/usb/host/xhci.h
++++ b/drivers/usb/host/xhci.h
+@@ -1830,6 +1830,7 @@ struct xhci_hcd {
+ #define XHCI_LIMIT_ENDPOINT_INTERVAL_7	(1 << 26)
+ /* Reserved. It was XHCI_U2_DISABLE_WAKE */
+ #define XHCI_ASMEDIA_MODIFY_FLOWCONTROL	(1 << 28)
++#define XHCI_FAKE_DOORBELL	(1 << 29)
+ 
+ 	unsigned int		num_active_eps;
+ 	unsigned int		limit_active_eps;