static int tegra186_utmi_enable_phy_sleepwalk()

in tegra/xusb-tegra186.c [315:458]

• 93 lines of code
• 7 McCabe index (conditional complexity)

static int tegra186_utmi_enable_phy_sleepwalk(struct tegra_xusb_lane *lane,
					      enum usb_device_speed speed)
{
	struct tegra_xusb_padctl *padctl = lane->pad->padctl;
	struct tegra186_xusb_padctl *priv = to_tegra186_xusb_padctl(padctl);
	unsigned int index = lane->index;
	u32 value;

	mutex_lock(&padctl->lock);

	/* ensure sleepwalk logic is disabled */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value &= ~MASTER_ENABLE;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* ensure sleepwalk logics are in low power mode */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value |= MASTER_CFG_SEL;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* set debounce time */
	value = ao_readl(priv, XUSB_AO_USB_DEBOUNCE_DEL);
	value &= ~UTMIP_LINE_DEB_CNT(~0);
	value |= UTMIP_LINE_DEB_CNT(1);
	ao_writel(priv, value, XUSB_AO_USB_DEBOUNCE_DEL);

	/* ensure fake events of sleepwalk logic are desiabled */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value &= ~(FAKE_USBOP_VAL | FAKE_USBON_VAL |
		FAKE_USBOP_EN | FAKE_USBON_EN);
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* ensure wake events of sleepwalk logic are not latched */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value &= ~LINE_WAKEUP_EN;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* disable wake event triggers of sleepwalk logic */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value &= ~WAKE_VAL(~0);
	value |= WAKE_VAL_NONE;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* power down the line state detectors of the pad */
	value = ao_readl(priv, XUSB_AO_UTMIP_PAD_CFG(index));
	value |= (USBOP_VAL_PD | USBON_VAL_PD);
	ao_writel(priv, value, XUSB_AO_UTMIP_PAD_CFG(index));

	/* save state per speed */
	value = ao_readl(priv, XUSB_AO_UTMIP_SAVED_STATE(index));
	value &= ~SPEED(~0);

	switch (speed) {
	case USB_SPEED_HIGH:
		value |= UTMI_HS;
		break;

	case USB_SPEED_FULL:
		value |= UTMI_FS;
		break;

	case USB_SPEED_LOW:
		value |= UTMI_LS;
		break;

	default:
		value |= UTMI_RST;
		break;
	}

	ao_writel(priv, value, XUSB_AO_UTMIP_SAVED_STATE(index));

	/* enable the trigger of the sleepwalk logic */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value |= LINEVAL_WALK_EN;
	value &= ~WAKE_WALK_EN;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* reset the walk pointer and clear the alarm of the sleepwalk logic,
	 * as well as capture the configuration of the USB2.0 pad
	 */
	value = ao_readl(priv, XUSB_AO_UTMIP_TRIGGERS(index));
	value |= (CLR_WALK_PTR | CLR_WAKE_ALARM | CAP_CFG);
	ao_writel(priv, value, XUSB_AO_UTMIP_TRIGGERS(index));

	/* setup the pull-ups and pull-downs of the signals during the four
	 * stages of sleepwalk.
	 * if device is connected, program sleepwalk logic to maintain a J and
	 * keep driving K upon seeing remote wake.
	 */
	value = USBOP_RPD_A | USBOP_RPD_B | USBOP_RPD_C | USBOP_RPD_D;
	value |= USBON_RPD_A | USBON_RPD_B | USBON_RPD_C | USBON_RPD_D;

	switch (speed) {
	case USB_SPEED_HIGH:
	case USB_SPEED_FULL:
		/* J state: D+/D- = high/low, K state: D+/D- = low/high */
		value |= HIGHZ_A;
		value |= AP_A;
		value |= AN_B | AN_C | AN_D;
		break;

	case USB_SPEED_LOW:
		/* J state: D+/D- = low/high, K state: D+/D- = high/low */
		value |= HIGHZ_A;
		value |= AN_A;
		value |= AP_B | AP_C | AP_D;
		break;

	default:
		value |= HIGHZ_A | HIGHZ_B | HIGHZ_C | HIGHZ_D;
		break;
	}

	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK(index));

	/* power up the line state detectors of the pad */
	value = ao_readl(priv, XUSB_AO_UTMIP_PAD_CFG(index));
	value &= ~(USBOP_VAL_PD | USBON_VAL_PD);
	ao_writel(priv, value, XUSB_AO_UTMIP_PAD_CFG(index));

	usleep_range(150, 200);

	/* switch the electric control of the USB2.0 pad to XUSB_AO */
	value = ao_readl(priv, XUSB_AO_UTMIP_PAD_CFG(index));
	value |= FSLS_USE_XUSB_AO | TRK_CTRL_USE_XUSB_AO | RPD_CTRL_USE_XUSB_AO |
		 RPU_USE_XUSB_AO | VREG_USE_XUSB_AO;
	ao_writel(priv, value, XUSB_AO_UTMIP_PAD_CFG(index));

	/* set the wake signaling trigger events */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value &= ~WAKE_VAL(~0);
	value |= WAKE_VAL_ANY;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	/* enable the wake detection */
	value = ao_readl(priv, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));
	value |= MASTER_ENABLE | LINE_WAKEUP_EN;
	ao_writel(priv, value, XUSB_AO_UTMIP_SLEEPWALK_CFG(index));

	mutex_unlock(&padctl->lock);

	return 0;
}