// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020, Broadcom */
#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/platform_device.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/iopoll.h>
#include "ehci.h"
#define hcd_to_ehci_priv(h) ((struct brcm_priv *)hcd_to_ehci(h)->priv)
struct brcm_priv {
struct clk *clk;
};
/*
* 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)
{
u32 frame_idx = ehci_readl(ehci, &ehci->regs->frame_index);
u32 val;
int res;
/* Wait for next microframe (every 125 usecs) */
res = readl_relaxed_poll_timeout(&ehci->regs->frame_index, val,
val != frame_idx, 1, 130);
if (res)
ehci_err(ehci, "Error waiting for SOF\n");
udelay(delay);
}
/*
* ehci_brcm_hub_control
* The EHCI controller has a bug where it can violate the SOF
* interval between the first two SOF's transmitted after resume
* if the resume occurs near the end of the microframe. This causees
* the controller to detect babble on the suspended port and
* will eventually cause the controller to reset the port.
* The fix is to Intercept the echi-hcd request to complete RESUME and
* align it to the start of the next microframe.
* 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;
unsigned long flags;
int retval, irq_disabled = 0;
u32 temp;
temp = (wIndex & 0xff) - 1;
if (temp >= HCS_N_PORTS_MAX) /* Avoid index-out-of-bounds warning */
temp = 0;
status_reg = &ehci->regs->port_status[temp];
/*
* 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 = ehci_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);
int len;
ehci->big_endian_mmio = 1;
ehci->caps = (void __iomem *)hcd->regs;
len = HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));
ehci->regs = (void __iomem *)(hcd->regs + len);
/* 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
*/
ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
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 device *dev = &pdev->dev;
struct resource *res_mem;
struct brcm_priv *priv;
struct usb_hcd *hcd;
int irq;
int err;
err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (err)
return err;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
/* Hook the hub control routine to work around a bug */
ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;
/* initialize hcd */
hcd = usb_create_hcd(&ehci_brcm_hc_driver, dev, dev_name(dev));
if (!hcd)
return -ENOMEM;
platform_set_drvdata(pdev, hcd);
priv = hcd_to_ehci_priv(hcd);
priv->clk = devm_clk_get_optional(dev, NULL);
if (IS_ERR(priv->clk)) {
err = PTR_ERR(priv->clk);
goto err_hcd;
}
err = clk_prepare_enable(priv->clk);
if (err)
goto err_hcd;
hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &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);
return 0;
err_clk:
clk_disable_unprepare(priv->clk);
err_hcd:
usb_put_hcd(hcd);
return err;
}
static void 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);
}
static int __maybe_unused 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);
if (ret)
return ret;
clk_disable_unprepare(priv->clk);
return 0;
}
static int __maybe_unused 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
*/
ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
ehci_resume(hcd, false);
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
return 0;
}
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,ehci-brcm-v2", },
{ .compatible = "brcm,bcm7445-ehci", },
{}
};
MODULE_DEVICE_TABLE(of, brcm_ehci_of_match);
static struct platform_driver ehci_brcm_driver = {
.probe = ehci_brcm_probe,
.remove_new = ehci_brcm_remove,
.shutdown = usb_hcd_platform_shutdown,
.driver = {
.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;
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("EHCI Broadcom STB driver");
MODULE_AUTHOR("Al Cooper");
MODULE_LICENSE("GPL");
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