Re: [Patch V3 07/18] phy: tegra: xusb: Add set_mode support for utmi phy on Tegra186
From: Thierry Reding <hidden>
Date: 2020-01-28 17:45:13
Also in:
linux-tegra, linux-usb, lkml
On Mon, Dec 30, 2019 at 04:39:44PM +0530, Nagarjuna Kristam wrote:
Add support for set_mode on utmi phy. This allow XUSB host/device mode drivers to configure the hardware to corresponding modes.
"utmi" -> "UTMI" in the subject and the commit message.
quoted hunk ↗ jump to hunk
Signed-off-by: Nagarjuna Kristam <redacted> --- V2-V3: - No changes in this version --- drivers/phy/tegra/xusb-tegra186.c | 109 ++++++++++++++++++++++++++++++-------- 1 file changed, 87 insertions(+), 22 deletions(-)diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c index 84c2739..9a45160 100644 --- a/drivers/phy/tegra/xusb-tegra186.c +++ b/drivers/phy/tegra/xusb-tegra186.c@@ -301,6 +301,92 @@ static void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy) tegra186_utmi_bias_pad_power_off(padctl); } +static int tegra186_xusb_padctl_vbus_override(struct tegra_xusb_padctl *padctl, + bool status) +{ + u32 value; + + dev_dbg(padctl->dev, "%s vbus override\n", status ? "set" : "clear"); + + value = padctl_readl(padctl, USB2_VBUS_ID); + + if (status) { + value |= VBUS_OVERRIDE; + value &= ~ID_OVERRIDE(~0); + value |= ID_OVERRIDE_FLOATING; + } else { + value &= ~VBUS_OVERRIDE; + } + + padctl_writel(padctl, value, USB2_VBUS_ID); + + return 0; +} + +static int tegra186_xusb_padctl_id_override(struct tegra_xusb_padctl *padctl, + bool status) +{ + u32 value; + + dev_dbg(padctl->dev, "%s id override\n", status ? "set" : "clear"); + + value = padctl_readl(padctl, USB2_VBUS_ID); + + if (status) { + if (value & VBUS_OVERRIDE) { + value &= ~VBUS_OVERRIDE; + padctl_writel(padctl, value, USB2_VBUS_ID); + usleep_range(1000, 2000); + + value = padctl_readl(padctl, USB2_VBUS_ID); + } + + value &= ~ID_OVERRIDE(~0); + value |= ID_OVERRIDE_GROUNDED; + } else { + value &= ~ID_OVERRIDE(~0); + value |= ID_OVERRIDE_FLOATING; + } + + padctl_writel(padctl, value, USB2_VBUS_ID); + + return 0; +} + +static int tegra186_utmi_phy_set_mode(struct phy *phy, enum phy_mode mode, + int submode) +{ + struct tegra_xusb_lane *lane = phy_get_drvdata(phy); + struct tegra_xusb_padctl *padctl = lane->pad->padctl; + struct tegra_xusb_usb2_port *port = tegra_xusb_find_usb2_port(padctl, + lane->index); + int err = 0; + + mutex_lock(&padctl->lock); + + dev_dbg(&port->base.dev, "%s: mode %d", __func__, mode); + + if (mode == PHY_MODE_USB_OTG) { + if (submode == USB_ROLE_HOST) { + tegra186_xusb_padctl_id_override(padctl, true); + + err = regulator_enable(port->supply); + } else if (submode == USB_ROLE_DEVICE) { + tegra186_xusb_padctl_vbus_override(padctl, true); + } else if (submode == USB_ROLE_NONE) { + if (regulator_is_enabled(port->supply))
I vaguely recall that we discussed this before, but I don't recall. Why do we need to check that the regulator is enabled? Regulators are reference-counted, so as long as the reference count is balanced, there should be no need to check for this. If there's really no way to avoid this check, perhaps add a comment that points out exactly why this is needed? With that fixed: Acked-by: Thierry Reding <redacted>
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