From 91736d0619eb4083f33ae737b9d9763fc6b196ed Mon Sep 17 00:00:00 2001 From: Krishna Kurapati Date: Tue, 19 Dec 2023 09:45:59 +0530 Subject: usb: dwc3: core: set force_gen1 bit in USB31 devices if max speed is SS Currently for dwc3_usb31 controller, if maximum_speed is limited to super-speed in DT, then device mode is limited to SS, but host mode still works in SSP. The documentation for max-speed property is as follows: "Tells USB controllers we want to work up to a certain speed. Incase this isn't passed via DT, USB controllers should default to their maximum HW capability." It doesn't specify that the property is only for device mode. There are cases where we need to limit the host's maximum speed to SuperSpeed only. Use this property for host mode to contrain host's speed to SuperSpeed. Signed-off-by: Krishna Kurapati Acked-by: Thinh Nguyen Link: https://lore.kernel.org/r/20231219041559.15789-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/core.c | 12 ++++++++++++ drivers/usb/dwc3/core.h | 5 +++++ 2 files changed, 17 insertions(+) (limited to 'drivers') diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index f50b5575d588..4447ef2cbc0f 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1330,6 +1330,18 @@ static int dwc3_core_init(struct dwc3 *dwc) dwc3_config_threshold(dwc); + /* + * Modify this for all supported Super Speed ports when + * multiport support is added. + */ + if (hw_mode != DWC3_GHWPARAMS0_MODE_GADGET && + (DWC3_IP_IS(DWC31)) && + dwc->maximum_speed == USB_SPEED_SUPER) { + reg = dwc3_readl(dwc->regs, DWC3_LLUCTL); + reg |= DWC3_LLUCTL_FORCE_GEN1; + dwc3_writel(dwc->regs, DWC3_LLUCTL, reg); + } + return 0; err_power_off_phy: diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index efe6caf4d0e8..e120611a5174 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -172,6 +172,8 @@ #define DWC3_OEVTEN 0xcc0C #define DWC3_OSTS 0xcc10 +#define DWC3_LLUCTL 0xd024 + /* Bit fields */ /* Global SoC Bus Configuration INCRx Register 0 */ @@ -657,6 +659,9 @@ #define DWC3_OSTS_VBUSVLD BIT(1) #define DWC3_OSTS_CONIDSTS BIT(0) +/* Force Gen1 speed on Gen2 link */ +#define DWC3_LLUCTL_FORCE_GEN1 BIT(10) + /* Structures */ struct dwc3_trb; -- cgit v1.2.3