usb: dwc3: add Tx de-emphasis quirk

This patch adds Tx de-emphasis quirk, and the Tx de-emphasis value is
configurable according to PIPE3 specification.

Value		Description
0		-6dB de-emphasis
1		-3.5dB de-emphasis
2		No de-emphasis
3		Reserved

It can be configured on DT or platform data.

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 1ecc333..b724b2e 100644 (file)
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -29,6 +29,9 @@ Optional properties:
  - snps,lfps_filter_quirk: when set core will filter LFPS reception.
  - snps,rx_detect_poll_quirk: when set core will disable a 400us delay to start
                        Polling LFPS after RX.Detect.
+ - snps,tx_de_emphasis_quirk: when set core will set Tx de-emphasis value.
+ - snps,tx_de_emphasis: the value driven to the PHY is controlled by the
+                       LTSSM during USB3 Compliance mode.
 
 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 aefb59d..c3dfb19 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -401,6 +401,9 @@ static void dwc3_phy_setup(struct dwc3 *dwc)
        if (dwc->rx_detect_poll_quirk)
                reg |= DWC3_GUSB3PIPECTL_RX_DETOPOLL;
 
+       if (dwc->tx_de_emphasis_quirk)
+               reg |= DWC3_GUSB3PIPECTL_TX_DEEPH(dwc->tx_de_emphasis);
+
        dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);
 
        mdelay(100);
@@ -720,6 +723,7 @@ static int dwc3_probe(struct platform_device *pdev)
        struct resource         *res;
        struct dwc3             *dwc;
        u8                      lpm_nyet_threshold;
+       u8                      tx_de_emphasis;
 
        int                     ret;
 
@@ -778,6 +782,9 @@ static int dwc3_probe(struct platform_device *pdev)
        /* default to highest possible threshold */
        lpm_nyet_threshold = 0xff;
 
+       /* default to -3.5dB de-emphasis */
+       tx_de_emphasis = 1;
+
        if (node) {
                dwc->maximum_speed = of_usb_get_maximum_speed(node);
                dwc->has_lpm_erratum = of_property_read_bool(node,
@@ -805,6 +812,11 @@ static int dwc3_probe(struct platform_device *pdev)
                                "snps,lfps_filter_quirk");
                dwc->rx_detect_poll_quirk = of_property_read_bool(node,
                                "snps,rx_detect_poll_quirk");
+
+               dwc->tx_de_emphasis_quirk = of_property_read_bool(node,
+                               "snps,tx_de_emphasis_quirk");
+               of_property_read_u8(node, "snps,tx_de_emphasis",
+                               &tx_de_emphasis);
        } else if (pdata) {
                dwc->maximum_speed = pdata->maximum_speed;
                dwc->has_lpm_erratum = pdata->has_lpm_erratum;
@@ -822,6 +834,10 @@ static int dwc3_probe(struct platform_device *pdev)
                dwc->del_phy_power_chg_quirk = pdata->del_phy_power_chg_quirk;
                dwc->lfps_filter_quirk = pdata->lfps_filter_quirk;
                dwc->rx_detect_poll_quirk = pdata->rx_detect_poll_quirk;
+
+               dwc->tx_de_emphasis_quirk = pdata->tx_de_emphasis_quirk;
+               if (pdata->tx_de_emphasis)
+                       tx_de_emphasis = pdata->tx_de_emphasis;
        }
 
        /* default to superspeed if no maximum_speed passed */
@@ -829,6 +845,7 @@ static int dwc3_probe(struct platform_device *pdev)
                dwc->maximum_speed = USB_SPEED_SUPER;
 
        dwc->lpm_nyet_threshold = lpm_nyet_threshold;
+       dwc->tx_de_emphasis = tx_de_emphasis;
 
        ret = dwc3_core_get_phy(dwc);
        if (ret)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 8953d73..cf9aaca 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -185,6 +185,8 @@
 #define DWC3_GUSB3PIPECTL_SUSPHY       (1 << 17)
 #define DWC3_GUSB3PIPECTL_LFPSFILT     (1 << 9)
 #define DWC3_GUSB3PIPECTL_RX_DETOPOLL  (1 << 8)
+#define DWC3_GUSB3PIPECTL_TX_DEEPH_MASK        DWC3_GUSB3PIPECTL_TX_DEEPH(3)
+#define DWC3_GUSB3PIPECTL_TX_DEEPH(n)  ((n) << 1)
 
 /* Global TX Fifo Size Register */
 #define DWC3_GTXFIFOSIZ_TXFDEF(n)      ((n) & 0xffff)
@@ -695,6 +697,12 @@ struct dwc3_scratchpad_array {
  * @del_phy_power_chg_quirk: set if we enable delay phy power change quirk
  * @lfps_filter_quirk: set if we enable LFPS filter quirk
  * @rx_detect_poll_quirk: set if we enable rx_detect to polling lfps quirk
+ * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
+ * @tx_de_emphasis: Tx de-emphasis value
+ *     0       - -6dB de-emphasis
+ *     1       - -3.5dB de-emphasis
+ *     2       - No de-emphasis
+ *     3       - Reserved
  */
 struct dwc3 {
        struct usb_ctrlrequest  *ctrl_req;
@@ -810,6 +818,9 @@ struct dwc3 {
        unsigned                del_phy_power_chg_quirk:1;
        unsigned                lfps_filter_quirk:1;
        unsigned                rx_detect_poll_quirk:1;
+
+       unsigned                tx_de_emphasis_quirk:1;
+       unsigned                tx_de_emphasis:2;
 };
 
 /* -------------------------------------------------------------------------- */

diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index 4a0f06b..e1ab900 100644 (file)
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -36,4 +36,7 @@ struct dwc3_platform_data {
        unsigned del_phy_power_chg_quirk:1;
        unsigned lfps_filter_quirk:1;
        unsigned rx_detect_poll_quirk:1;
+
+       unsigned tx_de_emphasis_quirk:1;
+       unsigned tx_de_emphasis:2;
 };