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Subject[PATCH 2/3][v3] drivers: usb: dwc3: Add frame length adjustment quirk
Date
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>
---
Changes for v3:
- removed unnecessary if(fladj) condition
- removed stray newline

drivers/usb/dwc3/core.c | 34 ++++++++++++++++++++++++++++++++++
drivers/usb/dwc3/core.h | 5 +++++
drivers/usb/dwc3/platform_data.h | 2 ++
3 files changed, 41 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 064123e..75a17bf 100644
--- 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)
+{
+ if (dwc->revision < DWC3_REVISION_250A)
+ return;
+
+ if (fladj == 0)
+ return;
+
+ u32 reg;
+ u32 dft;
+
+ 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 0447788..9188745 100644
--- 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 d3614ec..400b197 100644
--- 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;
};
--
2.1.0


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