The USB "maximum-speed" property can now take the SSP signaling rate
generation and lane count with these new strings:
"super-speed-plus-gen2x2"
"super-speed-plus-gen2x1"
"super-speed-plus-gen1x2"
Introduce usb_get_maximum_ssp_rate() to parse for the corresponding
usb_ssp_rate enum. The original usb_get_maximum_speed() will return
USB_SPEED_SUPER_PLUS if it matches one of these new strings.
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
---
Changes in v6:
- Rebase on Greg's usb-testing branch
- Remove usb_get_ssp_num_lanes() and usb_get_ssp_phy_gen() and use
usb_get_ssp_rate() to return the corresponding usb_ssp_rate enum instead
- Update commit message
Changes in v5:
- Rebase on Felipe's testing/next branch
- Changed Signed-off-by email to match From: email header
Changes in v4:
- Create 2 functions to get the SSP gen and number of lanes from "maximum-speed" property
- Update usb_get_maximum_speed() to check new SSP strings with genXxY
- Update commit message and subject title to reflect the new changes
Changes in v3:
- Add new function to parse "maximum-speed" for lanes and transfer rate
- Remove separate functions getting num_lanes and transfer rate properties
Changes in v2:
- New commit
drivers/usb/common/common.c | 26 +++++++++++++++++++++++++-
include/linux/usb/ch9.h | 11 +++++++++++
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index 1433260d99b4..fc21cf2d36f6 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -69,6 +69,13 @@ static const char *const speed_names[] = {
[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
};
+static const char *const ssp_rate[] = {
+ [USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
+ [USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
+ [USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
+ [USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
+};
+
const char *usb_speed_string(enum usb_device_speed speed)
{
if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
@@ -86,12 +93,29 @@ enum usb_device_speed usb_get_maximum_speed(struct device *dev)
if (ret < 0)
return USB_SPEED_UNKNOWN;
- ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
+ ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
+ if (ret > 0)
+ return USB_SPEED_SUPER_PLUS;
+ ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
}
EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
+enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
+{
+ const char *maximum_speed;
+ int ret;
+
+ ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
+ if (ret < 0)
+ return USB_SSP_GEN_UNKNOWN;
+
+ ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
+ return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
+}
+EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
+
const char *usb_state_string(enum usb_device_state state)
{
static const char *const names[] = {
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 86c50907634e..abdd310c77f0 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -71,6 +71,17 @@ extern const char *usb_speed_string(enum usb_device_speed speed);
*/
extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
+/**
+ * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
+ * of a SuperSpeed Plus capable device.
+ * @dev: Pointer to the given USB controller device
+ *
+ * If the string from "maximum-speed" property is super-speed-plus-genXxY where
+ * 'X' is the generation number and 'Y' is the number of lanes, then this
+ * function returns the corresponding enum usb_ssp_rate.
+ */
+extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev);
+
/**
* usb_state_string - Returns human readable name for the state.
* @state: The state to return a human-readable name for. If it's not
--
2.28.0
