Add a new EHCI driver for Broadcom STB SoC's. A new EHCI driver
was created instead of adding support to the existing ehci platform
driver because of the code required to workaround bugs in the EHCI
controller.

Signed-off-by: Al Cooper <alcoop...@gmail.com>
---
 drivers/usb/host/ehci-brcm.c | 286 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 286 insertions(+)
 create mode 100644 drivers/usb/host/ehci-brcm.c

diff --git a/drivers/usb/host/ehci-brcm.c b/drivers/usb/host/ehci-brcm.c
new file mode 100644
index 000000000000..eb0ea030a4c8
--- /dev/null
+++ b/drivers/usb/host/ehci-brcm.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018, Broadcom */
+
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+
+#include "ehci.h"
+
+#define BRCM_DRIVER_DESC "EHCI Broadcom STB driver"
+
+#define hcd_to_ehci_priv(h) ((struct brcm_priv *)hcd_to_ehci(h)->priv)
+
+struct brcm_priv {
+       struct clk *clk;
+};
+
+static const char brcm_hcd_name[] = "ehci-brcm";
+
+static int (*org_hub_control)(struct usb_hcd *hcd,
+                       u16 typeReq, u16 wValue, u16 wIndex,
+                       char *buf, u16 wLength);
+
+/* ehci_brcm_wait_for_sof
+ * Wait for start of next microframe, then wait extra delay microseconds
+ */
+static inline void ehci_brcm_wait_for_sof(struct ehci_hcd *ehci, u32 delay)
+{
+       int frame_idx = ehci_readl(ehci, &ehci->regs->frame_index);
+
+       while (frame_idx == ehci_readl(ehci, &ehci->regs->frame_index))
+               ;
+       udelay(delay);
+}
+
+/*
+ * ehci_brcm_hub_control
+ * Intercept echi-hcd request to complete RESUME and align it to the start
+ * of the next microframe.
+ * If RESUME is complete too late in the microframe, host controller
+ * detects babble on suspended port and resets the port afterwards.
+ * This s/w workaround allows to avoid this problem.
+ * See SWLINUX-1909 for more details
+ */
+static int ehci_brcm_hub_control(
+       struct usb_hcd  *hcd,
+       u16             typeReq,
+       u16             wValue,
+       u16             wIndex,
+       char            *buf,
+       u16             wLength)
+{
+       struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+       int             ports = HCS_N_PORTS(ehci->hcs_params);
+       u32 __iomem     *status_reg = &ehci->regs->port_status[
+                               (wIndex & 0xff) - 1];
+       unsigned long flags;
+       int retval, irq_disabled = 0;
+
+       /*
+        * RESUME is cleared when GetPortStatus() is called 20ms after start
+        * of RESUME
+        */
+       if ((typeReq == GetPortStatus) &&
+           (wIndex && wIndex <= ports) &&
+           ehci->reset_done[wIndex-1] &&
+           time_after_eq(jiffies, ehci->reset_done[wIndex-1]) &&
+           (ehci_readl(ehci, status_reg) & PORT_RESUME)) {
+
+               /*
+                * to make sure we are not interrupted until RESUME bit
+                * is cleared, disable interrupts on current CPU
+                */
+               ehci_dbg(ehci, "SOF alignment workaround\n");
+               irq_disabled = 1;
+               local_irq_save(flags);
+               ehci_brcm_wait_for_sof(ehci, 5);
+       }
+       retval = (*org_hub_control)(hcd, typeReq, wValue, wIndex, buf, wLength);
+       if (irq_disabled)
+               local_irq_restore(flags);
+       return retval;
+}
+
+static int ehci_brcm_reset(struct usb_hcd *hcd)
+{
+       struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+       ehci->big_endian_mmio = 1;
+
+       ehci->caps = (struct ehci_caps *) hcd->regs;
+       ehci->regs = (struct ehci_regs *) (hcd->regs +
+               HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase)));
+
+       /* This fixes the lockup during reboot due to prior interrupts */
+       ehci_writel(ehci, CMD_RESET, &ehci->regs->command);
+       mdelay(10);
+
+       /*
+        * SWLINUX-1705: Avoid OUT packet underflows during high memory
+        *   bus usage
+        * port_status[0x0f] = Broadcom-proprietary USB_EHCI_INSNREG00 @ 0x90
+        */
+       ehci_writel(ehci, 0x00800040, &ehci->regs->port_status[0x10]);
+       ehci_writel(ehci, 0x00000001, &ehci->regs->port_status[0x12]);
+
+       return ehci_setup(hcd);
+}
+
+static struct hc_driver __read_mostly ehci_brcm_hc_driver;
+
+static const struct ehci_driver_overrides brcm_overrides __initconst = {
+
+       .reset =        ehci_brcm_reset,
+       .extra_priv_size = sizeof(struct brcm_priv),
+};
+
+static int ehci_brcm_probe(struct platform_device *pdev)
+{
+       struct usb_hcd *hcd;
+       struct resource *res_mem;
+       struct brcm_priv *priv;
+       int irq;
+       int err;
+
+       if (usb_disabled())
+               return -ENODEV;
+
+       err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+       if (err)
+               return err;
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "no irq provided");
+               return irq;
+       }
+
+       /* Hook the hub control routine to work around a bug */
+       if (org_hub_control == NULL)
+               org_hub_control = ehci_brcm_hc_driver.hub_control;
+       ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;
+
+       /* initialize hcd */
+       hcd = usb_create_hcd(&ehci_brcm_hc_driver,
+                       &pdev->dev, dev_name(&pdev->dev));
+       if (!hcd)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, hcd);
+       priv = hcd_to_ehci_priv(hcd);
+
+       priv->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(priv->clk)) {
+               dev_err(&pdev->dev, "Clock not found in Device Tree\n");
+               priv->clk = NULL;
+       }
+       err = clk_prepare_enable(priv->clk);
+       if (err)
+               goto err_hcd;
+
+       res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       hcd->regs = devm_ioremap_resource(&pdev->dev, res_mem);
+       if (IS_ERR(hcd->regs)) {
+               err = PTR_ERR(hcd->regs);
+               goto err_clk;
+       }
+       hcd->rsrc_start = res_mem->start;
+       hcd->rsrc_len = resource_size(res_mem);
+       err = usb_add_hcd(hcd, irq, IRQF_SHARED);
+       if (err)
+               goto err_clk;
+
+       device_wakeup_enable(hcd->self.controller);
+       device_enable_async_suspend(hcd->self.controller);
+       platform_set_drvdata(pdev, hcd);
+
+       return err;
+
+err_clk:
+       clk_disable_unprepare(priv->clk);
+err_hcd:
+       usb_put_hcd(hcd);
+
+       return err;
+}
+
+static int ehci_brcm_remove(struct platform_device *dev)
+{
+       struct usb_hcd *hcd = platform_get_drvdata(dev);
+       struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
+
+       usb_remove_hcd(hcd);
+       clk_disable_unprepare(priv->clk);
+       usb_put_hcd(hcd);
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ehci_brcm_suspend(struct device *dev)
+{
+       int ret;
+       struct usb_hcd *hcd = dev_get_drvdata(dev);
+       struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
+       bool do_wakeup = device_may_wakeup(dev);
+
+       ret = ehci_suspend(hcd, do_wakeup);
+       clk_disable_unprepare(priv->clk);
+       return ret;
+}
+
+static int ehci_brcm_resume(struct device *dev)
+{
+       struct usb_hcd *hcd = dev_get_drvdata(dev);
+       struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+       struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
+       int err;
+
+       err = clk_prepare_enable(priv->clk);
+       if (err)
+               return err;
+       /*
+        * SWLINUX-1705: Avoid OUT packet underflows during high memory
+        *   bus usage
+        * port_status[0x0f] = Broadcom-proprietary USB_EHCI_INSNREG00
+        * @ 0x90
+        */
+       ehci_writel(ehci, 0x00800040, &ehci->regs->port_status[0x10]);
+       ehci_writel(ehci, 0x00000001, &ehci->regs->port_status[0x12]);
+
+       ehci_resume(hcd, false);
+       return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(ehci_brcm_pm_ops, ehci_brcm_suspend,
+               ehci_brcm_resume);
+
+static const struct of_device_id brcm_ehci_of_match[] = {
+       { .compatible = "brcm,bcm7445-ehci", },
+       {}
+};
+
+static struct platform_driver ehci_brcm_driver = {
+       .probe          = ehci_brcm_probe,
+       .remove         = ehci_brcm_remove,
+       .shutdown       = usb_hcd_platform_shutdown,
+       .driver         = {
+               .owner  = THIS_MODULE,
+               .name   = "ehci-brcm",
+               .pm     = &ehci_brcm_pm_ops,
+               .of_match_table = brcm_ehci_of_match,
+       }
+};
+
+static int __init ehci_brcm_init(void)
+{
+       if (usb_disabled())
+               return -ENODEV;
+
+       pr_info("%s: " BRCM_DRIVER_DESC "\n", brcm_hcd_name);
+
+       ehci_init_driver(&ehci_brcm_hc_driver, &brcm_overrides);
+       return platform_driver_register(&ehci_brcm_driver);
+}
+module_init(ehci_brcm_init);
+
+static void __exit ehci_brcm_exit(void)
+{
+       platform_driver_unregister(&ehci_brcm_driver);
+}
+module_exit(ehci_brcm_exit);
+
+MODULE_ALIAS("platform:ehci-brcm");
+MODULE_DESCRIPTION(BRCM_DRIVER_DESC);
+MODULE_AUTHOR("Al Cooper");
+MODULE_LICENSE("GPL");
-- 
1.9.0.138.g2de3478

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