usb: dwc3: Add frame length adjustment quirk

Add adjust_frame_length_quirk for writing to fladj register
which adjusts (micro)frame length to value provided by
"snps,quirk-frame-length-adjustment" property thus avoiding
USB 2.0 devices to time-out over a longer run

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 064123e445664a5e23bb28ba48cfb1755ec7fb88..6270581fc7a9141460cdbb3cde27a4d04a539725 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -143,6 +143,32 @@ static int dwc3_soft_reset(struct dwc3 *dwc)
        return 0;
 }
 
+/*
+ * dwc3_frame_length_adjustment - Adjusts frame length if required
+ * @dwc3: Pointer to our controller context structure
+ * @fladj: Value of GFLADJ_30MHZ to adjust frame length
+ */
+static void dwc3_frame_length_adjustment(struct dwc3 *dwc, u32 fladj)
+{
+       u32 reg;
+       u32 dft;
+
+       if (dwc->revision < DWC3_REVISION_250A)
+               return;
+
+       if (fladj == 0)
+               return;
+
+       reg = dwc3_readl(dwc->regs, DWC3_GFLADJ);
+       dft = reg & DWC3_GFLADJ_30MHZ_MASK;
+       if (!dev_WARN_ONCE(dwc->dev, dft == fladj,
+           "request value same as default, ignoring\n")) {
+               reg &= ~DWC3_GFLADJ_30MHZ_MASK;
+               reg |= DWC3_GFLADJ_30MHZ_SDBND_SEL | fladj;
+               dwc3_writel(dwc->regs, DWC3_GFLADJ, reg);
+       }
+}
+
 /**
  * dwc3_free_one_event_buffer - Frees one event buffer
  * @dwc: Pointer to our controller context structure
@@ -779,6 +805,7 @@ static int dwc3_probe(struct platform_device *pdev)
        u8                      lpm_nyet_threshold;
        u8                      tx_de_emphasis;
        u8                      hird_threshold;
+       u32                     fladj = 0;
 
        int                     ret;
 
@@ -886,6 +913,9 @@ static int dwc3_probe(struct platform_device *pdev)
                                &tx_de_emphasis);
                of_property_read_string(node, "snps,hsphy_interface",
                                        &dwc->hsphy_interface);
+               of_property_read_u32(node,
+                                    "snps,quirk-frame-length-adjustment",
+                                    &fladj);
        } else if (pdata) {
                dwc->maximum_speed = pdata->maximum_speed;
                dwc->has_lpm_erratum = pdata->has_lpm_erratum;
@@ -915,6 +945,7 @@ static int dwc3_probe(struct platform_device *pdev)
                        tx_de_emphasis = pdata->tx_de_emphasis;
 
                dwc->hsphy_interface = pdata->hsphy_interface;
+               fladj = pdata->fladj_value;
        }
 
        /* default to superspeed if no maximum_speed passed */
@@ -971,6 +1002,9 @@ static int dwc3_probe(struct platform_device *pdev)
                goto err1;
        }
 
+       /* Adjust Frame Length */
+       dwc3_frame_length_adjustment(dwc, fladj);
+
        usb_phy_set_suspend(dwc->usb2_phy, 0);
        usb_phy_set_suspend(dwc->usb3_phy, 0);
        ret = phy_power_on(dwc->usb2_generic_phy);

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 0447788845856e57190561b1117253200c1050a6..91887455133addb04970ab7d4e067db5695df58e 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -124,6 +124,7 @@
 #define DWC3_GEVNTCOUNT(n)     (0xc40c + (n * 0x10))
 
 #define DWC3_GHWPARAMS8                0xc600
+#define DWC3_GFLADJ            0xc630
 
 /* Device Registers */
 #define DWC3_DCFG              0xc700
@@ -234,6 +235,10 @@
 /* Global HWPARAMS6 Register */
 #define DWC3_GHWPARAMS6_EN_FPGA                        (1 << 7)
 
+/* Global Frame Length Adjustment Register */
+#define DWC3_GFLADJ_30MHZ_SDBND_SEL            (1 << 7)
+#define DWC3_GFLADJ_30MHZ_MASK                 0x3f
+
 /* Device Configuration Register */
 #define DWC3_DCFG_DEVADDR(addr)        ((addr) << 3)
 #define DWC3_DCFG_DEVADDR_MASK DWC3_DCFG_DEVADDR(0x7f)

diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index d3614ecbb9ca284cf6304eee2291ec3ce03a7990..400b197d998519564c1c45902aae9dd0c17a2912 100644 (file)
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -46,5 +46,7 @@ struct dwc3_platform_data {
        unsigned tx_de_emphasis_quirk:1;
        unsigned tx_de_emphasis:2;
 
+       u32 fladj_value;
+
        const char *hsphy_interface;
 };