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Diffstat (limited to 'src/soc/samsung/exynos5420/usb.c')
-rw-r--r--src/soc/samsung/exynos5420/usb.c43
1 files changed, 36 insertions, 7 deletions
diff --git a/src/soc/samsung/exynos5420/usb.c b/src/soc/samsung/exynos5420/usb.c
index 9313fea147..c7862232c6 100644
--- a/src/soc/samsung/exynos5420/usb.c
+++ b/src/soc/samsung/exynos5420/usb.c
@@ -58,12 +58,22 @@ static void setup_dwc3(struct exynos5_usb_drd_dwc3 *dwc3)
/* Set relevant registers to default values (clearing all reset bits) */
write32(&dwc3->usb3pipectl,
- 0x1 << 24 | 0x4 << 19 | 0x1 << 18 | 0x1 << 17 | 0x1 << 1 | 0);
+ 0x1 << 24 | /* activate PHY low power states */
+ 0x4 << 19 | /* low power delay value */
+ 0x1 << 18 | /* activate PHY low power delay */
+ 0x1 << 17 | /* enable SuperSpeed PHY suspend */
+ 0x1 << 1); /* default Tx deemphasis value */
/* Configure PHY clock turnaround for 8-bit UTMI+, disable suspend */
- write32(&dwc3->usb2phycfg, 0x9 << 10 | 0x1 << 8 | 0x1 << 6 | 0);
-
- write32(&dwc3->ctl, 0x5dc << 19 | 0x1 << 16 | 0x1 << 12 | 0);
+ write32(&dwc3->usb2phycfg,
+ 0x9 << 10 | /* PHY clock turnaround for 8-bit UTMI+ */
+ 0x1 << 8 | /* enable PHY sleep in L1 */
+ 0x1 << 6); /* enable PHY suspend */
+
+ write32(&dwc3->ctl,
+ 0x5dc << 19 | /* suspend clock scale for 24MHz */
+ 0x1 << 16 | /* retry SS three times (bugfix from U-Boot) */
+ 0x1 << 12); /* port capability HOST */
}
void setup_usb_drd0_dwc3()
@@ -89,13 +99,32 @@ static void setup_drd_phy(struct exynos5_usb_drd_phy *phy)
write32(&phy->utmi, 1 << 6);
write32(&phy->clkrst,
- 0x88 << 23 | 0x1 << 20 | 0x1 << 19 | 0x68 << 11 | 0x5 << 5 | 0x1 << 4 | 0x3 << 2 | 0x1 << 1 | 0x1 << 0 | 0);
+ 0x88 << 23 | /* spread spectrum refclk selector */
+ 0x1 << 20 | /* enable spread spectrum */
+ 0x1 << 19 | /* enable prescaler refclk */
+ 0x68 << 11 | /* multiplier for 24MHz refclk */
+ 0x5 << 5 | /* select 24MHz refclk (weird, from U-Boot) */
+ 0x1 << 4 | /* power supply in normal operating mode */
+ 0x3 << 2 | /* use external refclk (undocumented on 5420?)*/
+ 0x1 << 1 | /* force port reset */
+ 0x1 << 0); /* normal operating mode */
write32(&phy->param0,
- 0x9 << 26 | 0x3 << 22 | 0x1 << 20 | 0x1 << 18 | 0x3 << 13 | 0x3 << 9 | 0x3 << 6 | 0x4 << 3 | 0x4 << 0 | 0);
+ 0x9 << 26 | /* LOS level */
+ 0x3 << 22 | /* TX VREF tune */
+ 0x1 << 20 | /* TX rise tune */
+ 0x1 << 18 | /* TX res tune */
+ 0x3 << 13 | /* TX HS X Vtune */
+ 0x3 << 9 | /* TX FS/LS tune */
+ 0x3 << 6 | /* SQRX tune */
+ 0x4 << 3 | /* OTG tune */
+ 0x4 << 0); /* comp disc tune */
write32(&phy->param1,
- 0x7f << 19 | 0x7f << 12 | 0x20 << 6 | 0x1c << 0 | 0);
+ 0x7f << 19 | /* reserved */
+ 0x7f << 12 | /* Tx launch amplitude */
+ 0x20 << 6 | /* Tx deemphasis 6dB */
+ 0x1c << 0); /* Tx deemphasis 3.5dB (value from U-Boot) */
/* disable all test features */
write32(&phy->test, 0);