usb: dwc3: add disable u2mac linestate check quirk

This patch adds a quirk to disable USB 2.0 MAC linestate check
during HS transmit. Refer the dwc3 databook, we can use it for
some special platforms if the linestate not reflect the expected
line state(J) during transmission.

When use this quirk, the controller implements a fixed 40-bit
TxEndDelay after the packet is given on UTMI and ignores the
linestate during the transmit of a token (during token-to-token
and token-to-data IPGAP).

On some rockchip platforms (e.g. rk3399), it requires to disable
the u2mac linestate check to decrease the SSPLIT token to SETUP
token inter-packet delay from 566ns to 466ns, and fix the issue
that FS/LS devices not recognized if inserted through USB 3.0 HUB.

Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: William Wu <william.wu@rock-chips.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index f658f394c2d3a11bd951509dab01d8fbbcc15763..52fb41046b342b8786b437a69527e43358a94c84 100644 (file)
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -45,6 +45,8 @@ Optional properties:
                        a free-running PHY clock.
  - snps,dis-del-phy-power-chg-quirk: when set core will change PHY power
                        from P0 to P1/P2/P3 without delay.
+ - snps,dis-tx-ipgap-linecheck-quirk: when set, disable u2mac linestate check
+                       during HS transmit.
  - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal
                        utmi_l1_suspend_n, false when asserts utmi_sleep_n
  - snps,hird-threshold: HIRD threshold

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 455d89a1cd6dbbb3e3f707bc42bada4a9569e5d7..9d5a67cc2645a63965304ada92deb81c0ceed78e 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -796,13 +796,19 @@ static int dwc3_core_init(struct dwc3 *dwc)
                dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
        }
 
-       /*
-        * Enable hardware control of sending remote wakeup in HS when
-        * the device is in the L1 state.
-        */
-       if (dwc->revision >= DWC3_REVISION_290A) {
+       if (dwc->revision >= DWC3_REVISION_250A) {
                reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
-               reg |= DWC3_GUCTL1_DEV_L1_EXIT_BY_HW;
+
+               /*
+                * Enable hardware control of sending remote wakeup
+                * in HS when the device is in the L1 state.
+                */
+               if (dwc->revision >= DWC3_REVISION_290A)
+                       reg |= DWC3_GUCTL1_DEV_L1_EXIT_BY_HW;
+
+               if (dwc->dis_tx_ipgap_linecheck_quirk)
+                       reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;
+
                dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
        }
 
@@ -1023,6 +1029,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
                                "snps,dis-u2-freeclk-exists-quirk");
        dwc->dis_del_phy_power_chg_quirk = device_property_read_bool(dev,
                                "snps,dis-del-phy-power-chg-quirk");
+       dwc->dis_tx_ipgap_linecheck_quirk = device_property_read_bool(dev,
+                               "snps,dis-tx-ipgap-linecheck-quirk");
 
        dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
                                "snps,tx_de_emphasis_quirk");

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 981c77f5628e105731b41756b798c988b6c6692d..6f6294dbea9dec04a2d9c9d49f8951439375366d 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -204,6 +204,7 @@
 #define DWC3_GCTL_DSBLCLKGTNG          BIT(0)
 
 /* Global User Control 1 Register */
+#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS     BIT(28)
 #define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW  BIT(24)
 
 /* Global USB2 PHY Configuration Register */
@@ -850,6 +851,8 @@ struct dwc3_scratchpad_array {
  *                     provide a free-running PHY clock.
  * @dis_del_phy_power_chg_quirk: set if we disable delay phy power
  *                     change quirk.
+ * @dis_tx_ipgap_linecheck_quirk: set if we disable u2mac linestate
+ *                     check during HS transmit.
  * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
  * @tx_de_emphasis: Tx de-emphasis value
  *     0       - -6dB de-emphasis
@@ -1004,6 +1007,7 @@ struct dwc3 {
        unsigned                dis_rxdet_inp3_quirk:1;
        unsigned                dis_u2_freeclk_exists_quirk:1;
        unsigned                dis_del_phy_power_chg_quirk:1;
+       unsigned                dis_tx_ipgap_linecheck_quirk:1;
 
        unsigned                tx_de_emphasis_quirk:1;
        unsigned                tx_de_emphasis:2;