usb: dwc3: add u2exit lfps quirk

This patch adds u2exit lfps quirk, and some special platforms can configure
that if it is needed.

[ balbi@ti.com : added DeviceTree binding documentation ]

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 2b0c1f2..5fcd680 100644 (file)
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -18,6 +18,7 @@ Optional properties:
        Only really useful for FPGA builds.
  - snps,has-lpm-erratum: true when DWC3 was configured with LPM Erratum enabled
  - snps,lpm-nyet-threshold: LPM NYET threshold
+ - snps,u2exit_lfps_quirk: set if we want to enable u2exit lfps quirk
 
 This is usually a subnode to DWC3 glue to which it is connected.
 

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 6f9e5b8..33cbea5 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -473,6 +473,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
        else
                reg &= ~DWC3_GCTL_DISSCRAMBLE;
 
+       if (dwc->u2exit_lfps_quirk)
+               reg |= DWC3_GCTL_U2EXIT_LFPS;
+
        /*
         * WORKAROUND: DWC3 revisions <1.90a have a bug
         * where the device can fail to connect at SuperSpeed
@@ -729,6 +732,8 @@ static int dwc3_probe(struct platform_device *pdev)
 
                dwc->disable_scramble_quirk = of_property_read_bool(node,
                                "snps,disable_scramble_quirk");
+               dwc->u2exit_lfps_quirk = of_property_read_bool(node,
+                               "snps,u2exit_lfps_quirk");
        } else if (pdata) {
                dwc->maximum_speed = pdata->maximum_speed;
                dwc->has_lpm_erratum = pdata->has_lpm_erratum;
@@ -739,6 +744,7 @@ static int dwc3_probe(struct platform_device *pdev)
                dwc->dr_mode = pdata->dr_mode;
 
                dwc->disable_scramble_quirk = pdata->disable_scramble_quirk;
+               dwc->u2exit_lfps_quirk = pdata->u2exit_lfps_quirk;
        }
 
        /* default to superspeed if no maximum_speed passed */

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 34f1e08..f93145c 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -166,6 +166,7 @@
 #define DWC3_GCTL_SCALEDOWN(n)         ((n) << 4)
 #define DWC3_GCTL_SCALEDOWN_MASK       DWC3_GCTL_SCALEDOWN(3)
 #define DWC3_GCTL_DISSCRAMBLE          (1 << 3)
+#define DWC3_GCTL_U2EXIT_LFPS          (1 << 2)
 #define DWC3_GCTL_GBLHIBERNATIONEN     (1 << 1)
 #define DWC3_GCTL_DSBLCLKGTNG          (1 << 0)
 
@@ -679,6 +680,7 @@ struct dwc3_scratchpad_array {
  * @start_config_issued: true when StartConfig command has been issued
  * @three_stage_setup: set if we perform a three phase setup
  * @disable_scramble_quirk: set if we enable the disable scramble quirk
+ * @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
  */
 struct dwc3 {
        struct usb_ctrlrequest  *ctrl_req;
@@ -787,6 +789,7 @@ struct dwc3 {
        unsigned                three_stage_setup:1;
 
        unsigned                disable_scramble_quirk:1;
+       unsigned                u2exit_lfps_quirk:1;
 };
 
 /* -------------------------------------------------------------------------- */

diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index e128308..3f21591 100644 (file)
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -29,4 +29,5 @@ struct dwc3_platform_data {
 
        unsigned disable_scramble_quirk:1;
        unsigned has_lpm_erratum:1;
+       unsigned u2exit_lfps_quirk:1;
 };