Re: [PATCH v2 1/2] phy: tegra: xusb: add utmi pad power on/down ops

From: JC Kuo
Date: Mon Sep 05 2022 - 22:44:21 EST


Hi Vinod,
Before the device or host is being attached, we can keep most of the
transceivers powered down (PD=1/PD_DR=1) to minimize power consumption. At this
stage, in .phy_power_on(), we enable only the single-ended receiver (PD_ZI=0)
for detecting connection. Upon detecting device's or host's connection, host or
controller driver will invoke tegra_phy_xusb_utmi_pad_power_on() to power on all
of the transceivers (PD=0/PD_DR=0) to equip full link functionality.

Thanks,
JC


On 9/4/22 22:45, Vinod Koul wrote:
> On 16-08-22, 16:23, Jim Lin wrote:
>> Add utmi_pad_power_on/down ops for each SOC instead of exporting
>> tegra_phy_xusb_utmi_pad_power_on/down directly for Tegra186 chip.
>
> Can you please help me understand why do we need to utmi power_on/down
> exported and cant be handled thry phy-ops..
>
>>
>> Signed-off-by: BH Hsieh <bhsieh@xxxxxxxxxx>
>> Signed-off-by: Jim Lin <jilin@xxxxxxxxxx>
>> ---
>> v2: update copyright year
>>
>> drivers/phy/tegra/xusb-tegra186.c | 19 ++++++++++++-------
>> drivers/phy/tegra/xusb.c | 22 +++++++++++++++++++++-
>> drivers/phy/tegra/xusb.h | 4 +++-
>> include/linux/phy/tegra/xusb.h | 4 +++-
>> 4 files changed, 39 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c
>> index ae3915ed9fef..5abdf81aa143 100644
>> --- a/drivers/phy/tegra/xusb-tegra186.c
>> +++ b/drivers/phy/tegra/xusb-tegra186.c
>> @@ -1,6 +1,6 @@
>> // SPDX-License-Identifier: GPL-2.0
>> /*
>> - * Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
>> + * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
>> */
>>
>> #include <linux/delay.h>
>> @@ -638,7 +638,7 @@ static void tegra186_utmi_bias_pad_power_off(struct tegra_xusb_padctl *padctl)
>> mutex_unlock(&padctl->lock);
>> }
>>
>> -static void tegra_phy_xusb_utmi_pad_power_on(struct phy *phy)
>> +static void tegra186_utmi_pad_power_on(struct phy *phy)
>> {
>> struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
>> struct tegra_xusb_padctl *padctl = lane->pad->padctl;
>> @@ -656,6 +656,8 @@ static void tegra_phy_xusb_utmi_pad_power_on(struct phy *phy)
>> return;
>> }
>>
>> + dev_dbg(dev, "power on UTMI pad %u\n", index);
>> +
>> tegra186_utmi_bias_pad_power_on(padctl);
>>
>> udelay(2);
>> @@ -669,7 +671,7 @@ static void tegra_phy_xusb_utmi_pad_power_on(struct phy *phy)
>> padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL1(index));
>> }
>>
>> -static void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy)
>> +static void tegra186_utmi_pad_power_down(struct phy *phy)
>> {
>> struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
>> struct tegra_xusb_padctl *padctl = lane->pad->padctl;
>> @@ -679,6 +681,8 @@ static void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy)
>> if (!phy)
>> return;
>>
>> + dev_dbg(padctl->dev, "power down UTMI pad %u\n", index);
>> +
>> value = padctl_readl(padctl, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
>> value |= USB2_OTG_PD;
>> padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
>> @@ -849,15 +853,14 @@ static int tegra186_utmi_phy_power_on(struct phy *phy)
>> value |= RPD_CTRL(priv->calib.rpd_ctrl);
>> padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL1(index));
>>
>> - /* TODO: pad power saving */
>> - tegra_phy_xusb_utmi_pad_power_on(phy);
>> + tegra186_utmi_pad_power_on(phy);
>> +
>> return 0;
>> }
>>
>> static int tegra186_utmi_phy_power_off(struct phy *phy)
>> {
>> - /* TODO: pad power saving */
>> - tegra_phy_xusb_utmi_pad_power_down(phy);
>> + tegra186_utmi_pad_power_down(phy);
>>
>> return 0;
>> }
>> @@ -1486,6 +1489,8 @@ static const struct tegra_xusb_padctl_ops tegra186_xusb_padctl_ops = {
>> .suspend_noirq = tegra186_xusb_padctl_suspend_noirq,
>> .resume_noirq = tegra186_xusb_padctl_resume_noirq,
>> .vbus_override = tegra186_xusb_padctl_vbus_override,
>> + .utmi_pad_power_on = tegra186_utmi_pad_power_on,
>> + .utmi_pad_power_down = tegra186_utmi_pad_power_down,
>> };
>>
>> #if IS_ENABLED(CONFIG_ARCH_TEGRA_186_SOC)
>> diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
>> index 963de5913e50..49873718d54a 100644
>> --- a/drivers/phy/tegra/xusb.c
>> +++ b/drivers/phy/tegra/xusb.c
>> @@ -1,6 +1,6 @@
>> // SPDX-License-Identifier: GPL-2.0-only
>> /*
>> - * Copyright (c) 2014-2020, NVIDIA CORPORATION. All rights reserved.
>> + * Copyright (c) 2014-2022, NVIDIA CORPORATION. All rights reserved.
>> */
>>
>> #include <linux/delay.h>
>> @@ -1458,6 +1458,26 @@ int tegra_phy_xusb_utmi_port_reset(struct phy *phy)
>> }
>> EXPORT_SYMBOL_GPL(tegra_phy_xusb_utmi_port_reset);
>>
>> +void tegra_phy_xusb_utmi_pad_power_on(struct phy *phy)
>> +{
>> + struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
>> + struct tegra_xusb_padctl *padctl = lane->pad->padctl;
>> +
>> + if (padctl->soc->ops->utmi_pad_power_on)
>> + padctl->soc->ops->utmi_pad_power_on(phy);
>> +}
>> +EXPORT_SYMBOL_GPL(tegra_phy_xusb_utmi_pad_power_on);
>> +
>> +void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy)
>> +{
>> + struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
>> + struct tegra_xusb_padctl *padctl = lane->pad->padctl;
>> +
>> + if (padctl->soc->ops->utmi_pad_power_down)
>> + padctl->soc->ops->utmi_pad_power_down(phy);
>> +}
>> +EXPORT_SYMBOL_GPL(tegra_phy_xusb_utmi_pad_power_down);
>> +
>> int tegra_xusb_padctl_get_usb3_companion(struct tegra_xusb_padctl *padctl,
>> unsigned int port)
>> {
>> diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
>> index 034f7a2c28d6..8cfbbdbd6e0c 100644
>> --- a/drivers/phy/tegra/xusb.h
>> +++ b/drivers/phy/tegra/xusb.h
>> @@ -1,6 +1,6 @@
>> /* SPDX-License-Identifier: GPL-2.0-only */
>> /*
>> - * Copyright (c) 2014-2020, NVIDIA CORPORATION. All rights reserved.
>> + * Copyright (c) 2014-2022, NVIDIA CORPORATION. All rights reserved.
>> * Copyright (c) 2015, Google Inc.
>> */
>>
>> @@ -412,6 +412,8 @@ struct tegra_xusb_padctl_ops {
>> unsigned int index, bool enable);
>> int (*vbus_override)(struct tegra_xusb_padctl *padctl, bool set);
>> int (*utmi_port_reset)(struct phy *phy);
>> + void (*utmi_pad_power_on)(struct phy *phy);
>> + void (*utmi_pad_power_down)(struct phy *phy);
>> };
>>
>> struct tegra_xusb_padctl_soc {
>> diff --git a/include/linux/phy/tegra/xusb.h b/include/linux/phy/tegra/xusb.h
>> index 3a35e74cdc61..70998e6dd6fd 100644
>> --- a/include/linux/phy/tegra/xusb.h
>> +++ b/include/linux/phy/tegra/xusb.h
>> @@ -1,6 +1,6 @@
>> /* SPDX-License-Identifier: GPL-2.0-only */
>> /*
>> - * Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
>> + * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
>> */
>>
>> #ifndef PHY_TEGRA_XUSB_H
>> @@ -21,6 +21,8 @@ int tegra_xusb_padctl_usb3_set_lfps_detect(struct tegra_xusb_padctl *padctl,
>> unsigned int port, bool enable);
>> int tegra_xusb_padctl_set_vbus_override(struct tegra_xusb_padctl *padctl,
>> bool val);
>> +void tegra_phy_xusb_utmi_pad_power_on(struct phy *phy);
>> +void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy);
>> int tegra_phy_xusb_utmi_port_reset(struct phy *phy);
>> int tegra_xusb_padctl_get_usb3_companion(struct tegra_xusb_padctl *padctl,
>> unsigned int port);
>> --
>> 2.17.1
>