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First of all the commite0082698b6("usb: dwc3: ulpi: conditionally resume ULPI PHY") introduced the Suspend USB2.0 HS/FS/LS PHY regression, as by design of the fix any attempt to read/write from/to the PHY control registers will completely disable the PHY suspension, which consequently will increase the USB bus power consumption. Secondly the fix won't work well for the very first attempt of the ULPI PHY control registers IO, because after disabling the USB2.0 PHY suspension functionality it will still take some time for the bus to resume from the sleep state if one has been reached before it. So the very first PHY register read/write operation will take more time than the busy-loop provides and the IO timeout error might be returned anyway. Here we suggest to fix the denoted problems in the following way. First of all let's not disable the Suspend USB2.0 HS/FS/LS PHY functionality so to make the controller and the USB2.0 bus more power efficient. Secondly instead of that we'll extend the PHY IO op wait procedure with 1 - 1.2 ms sleep if the PHY suspension is enabled (1ms should be enough as by LPM specification it is at most how long it takes for the USB2.0 bus to resume from L1 (Sleep) state). Finally in case if the USB2.0 PHY suspension functionality has been disabled on the DWC USB3 controller setup procedure we'll compensate the USB bus resume process latency by extending the busy-loop attempts counter. Fixes:e0082698b6("usb: dwc3: ulpi: conditionally resume ULPI PHY") Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20201210085008.13264-4-Sergey.Semin@baikalelectronics.ru Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
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*
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* Copyright (C) 2015 Intel Corporation
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*
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* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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*/
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#include <linux/delay.h>
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#include <linux/time64.h>
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#include <linux/ulpi/regs.h>
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#include "core.h"
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#include "io.h"
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#define DWC3_ULPI_ADDR(a) \
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((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
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DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
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DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
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#define DWC3_ULPI_BASE_DELAY DIV_ROUND_UP(NSEC_PER_SEC, 60000000L)
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static int dwc3_ulpi_busyloop(struct dwc3 *dwc, u8 addr, bool read)
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{
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unsigned long ns = 5L * DWC3_ULPI_BASE_DELAY;
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unsigned int count = 10000;
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u32 reg;
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if (addr >= ULPI_EXT_VENDOR_SPECIFIC)
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ns += DWC3_ULPI_BASE_DELAY;
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if (read)
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ns += DWC3_ULPI_BASE_DELAY;
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reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
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if (reg & DWC3_GUSB2PHYCFG_SUSPHY)
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usleep_range(1000, 1200);
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while (count--) {
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ndelay(ns);
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reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
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if (reg & DWC3_GUSB2PHYACC_DONE)
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return 0;
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cpu_relax();
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}
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return -ETIMEDOUT;
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}
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static int dwc3_ulpi_read(struct device *dev, u8 addr)
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{
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struct dwc3 *dwc = dev_get_drvdata(dev);
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u32 reg;
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int ret;
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reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
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dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
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ret = dwc3_ulpi_busyloop(dwc, addr, true);
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if (ret)
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return ret;
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reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
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return DWC3_GUSB2PHYACC_DATA(reg);
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}
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static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
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{
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struct dwc3 *dwc = dev_get_drvdata(dev);
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u32 reg;
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reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
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reg |= DWC3_GUSB2PHYACC_WRITE | val;
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dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
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return dwc3_ulpi_busyloop(dwc, addr, false);
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}
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static const struct ulpi_ops dwc3_ulpi_ops = {
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.read = dwc3_ulpi_read,
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.write = dwc3_ulpi_write,
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};
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int dwc3_ulpi_init(struct dwc3 *dwc)
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{
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/* Register the interface */
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dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
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if (IS_ERR(dwc->ulpi)) {
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dev_err(dwc->dev, "failed to register ULPI interface");
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return PTR_ERR(dwc->ulpi);
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}
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return 0;
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}
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void dwc3_ulpi_exit(struct dwc3 *dwc)
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{
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if (dwc->ulpi) {
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ulpi_unregister_interface(dwc->ulpi);
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dwc->ulpi = NULL;
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}
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}
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