diff options
| author | Herve Codina <herve.codina@bootlin.com> | 2025-09-10 18:07:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-12 14:03:10 +0200 |
| commit | e77ee1d2a8fa0f3179d4ac7b7d35b555da6a8cea (patch) | |
| tree | 2128fcb69168ec8dcbcfbb71388c70bec64c32e5 /drivers/usb/dwc2 | |
| parent | usb: typec: tcpci: add wakeup support (diff) | |
| download | linux-e77ee1d2a8fa0f3179d4ac7b7d35b555da6a8cea.tar.gz linux-e77ee1d2a8fa0f3179d4ac7b7d35b555da6a8cea.zip | |
usb: dwc2: Add support for 'maximum-speed' property
The DWC2 IP can be properly integrated in a SoC to work at high-speed
USB speed but some board issues, EMC constraints or any other reasons
can lead to the need to limit this USB speed at board level.
The device-tree 'maximum-speed' property already exists for this purpose
but is not handled by the DWC2 driver.
Fill this lack adding support for 'maximum-speed' property and so allow
to limit the USB speed in device-tree (board description).
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/20250910160730.585303-1-herve.codina@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc2')
| -rw-r--r-- | drivers/usb/dwc2/params.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c index ea6bd537e337..091bfcfef753 100644 --- a/drivers/usb/dwc2/params.c +++ b/drivers/usb/dwc2/params.c @@ -1029,11 +1029,33 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg) return 0; } +static int dwc2_limit_speed(struct dwc2_hsotg *hsotg) +{ + enum usb_device_speed usb_speed; + + usb_speed = usb_get_maximum_speed(hsotg->dev); + switch (usb_speed) { + case USB_SPEED_LOW: + dev_err(hsotg->dev, "Maximum speed cannot be forced to low-speed\n"); + return -EINVAL; + case USB_SPEED_FULL: + if (hsotg->params.speed == DWC2_SPEED_PARAM_LOW) + break; + hsotg->params.speed = DWC2_SPEED_PARAM_FULL; + break; + default: + break; + } + + return 0; +} + typedef void (*set_params_cb)(struct dwc2_hsotg *data); int dwc2_init_params(struct dwc2_hsotg *hsotg) { set_params_cb set_params; + int ret; dwc2_set_default_params(hsotg); dwc2_get_device_properties(hsotg); @@ -1051,6 +1073,10 @@ int dwc2_init_params(struct dwc2_hsotg *hsotg) } } + ret = dwc2_limit_speed(hsotg); + if (ret) + return ret; + dwc2_check_params(hsotg); return 0; |