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Message-ID: <d50ca4c0-8954-4e4c-9ce9-2c40ebacf8b0@linaro.org>
Date: Thu, 29 Feb 2024 16:47:46 +0100
From: Neil Armstrong <neil.armstrong@...aro.org>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>,
Konrad Dybcio <konrad.dybcio@...aro.org>, Vinod Koul <vkoul@...nel.org>,
Kishon Vijay Abraham I <kishon@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>, linux-arm-msm@...r.kernel.org,
linux-phy@...ts.infradead.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFT 4/7] phy: qcom: qmp-combo: register a typec mux to
change the QPHY_MODE
On 29/02/2024 16:25, Dmitry Baryshkov wrote:
> On Thu, 29 Feb 2024 at 15:08, Neil Armstrong <neil.armstrong@...aro.org> wrote:
>>
>> Register a typec mux in order to change the PHY mode on the Type-C
>> mux events depending on the mode and the svid when in Altmode setup.
>>
>> The DisplayPort phy should be left enabled if is still powered on
>> by the DRM DisplayPort controller, so bail out until the DisplayPort
>> PHY is not powered off.
>>
>> The Type-C Mode/SVID only changes on plug/unplug, and USB SAFE states
>> will be set in between of USB-Only, Combo and DisplayPort Only so
>> this will leave enough time to the DRM DisplayPort controller to
>> turn of the DisplayPort PHY.
>
> I think this is not fully correct. Please correct me if I'm wrong, but
> it is possible to switch between USB / USB+DP / DP-only at runtime.
> See the Status Update and Configure commands.
Yes, but the current implementation is still valid because we need to
have the DP powered-off before changing the PHY mode.
I never encountered such setup and I have no idea how to test this.
>
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@...aro.org>
>> ---
>> drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 122 ++++++++++++++++++++++++++++--
>> 1 file changed, 117 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> index ac5d528fd7a1..b5fb6cbcf867 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> @@ -19,6 +19,7 @@
>> #include <linux/reset.h>
>> #include <linux/slab.h>
>> #include <linux/usb/typec.h>
>> +#include <linux/usb/typec_dp.h>
>> #include <linux/usb/typec_mux.h>
>>
>> #include <drm/bridge/aux-bridge.h>
>> @@ -1515,6 +1516,10 @@ struct qmp_combo {
>>
>> struct typec_switch_dev *sw;
>> enum typec_orientation orientation;
>> +
>> + struct typec_mux_dev *mux;
>> + unsigned long mux_mode;
>> + unsigned int svid;
>> };
>>
>> static void qmp_v3_dp_aux_init(struct qmp_combo *qmp);
>> @@ -3295,17 +3300,111 @@ static int qmp_combo_typec_switch_set(struct typec_switch_dev *sw,
>> return 0;
>> }
>>
>> -static void qmp_combo_typec_unregister(void *data)
>> +static int qmp_combo_typec_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
>> +{
>> + struct qmp_combo *qmp = typec_mux_get_drvdata(mux);
>> + const struct qmp_phy_cfg *cfg = qmp->cfg;
>> + enum qphy_mode new_mode;
>> + unsigned int svid;
>> +
>> + if (state->mode == qmp->mode)
>> + return 0;
>> +
>> + mutex_lock(&qmp->phy_mutex);
>> +
>> + if (state->alt)
>> + svid = state->alt->svid;
>> + else
>> + svid = 0; // No SVID
>> +
>> + if (svid) {
>
> We should check svid against USB_TYPEC_DP_SID. Otherwise the driver
> will mishandle the USB_SID_PD states.
Ack will do
>
>> + switch (state->mode) {
>> + /* DP Only */
>> + case TYPEC_DP_STATE_C:
>> + case TYPEC_DP_STATE_E:
>> + new_mode = QPHY_MODE_DP_ONLY;
>> + break;
>> +
>> + /* DP + USB */
>> + case TYPEC_DP_STATE_D:
>> + case TYPEC_DP_STATE_F:
>> + /* Safe fallback...*/
>> + default:
>> + new_mode = QPHY_MODE_COMBO;
>> + break;
>> + }
>> + } else {
>> + /* Only switch to USB_ONLY when we know we only have USB3 */
>> + if (qmp->mux_mode == TYPEC_MODE_USB3)
>> + new_mode = QPHY_MODE_USB_ONLY;
>> + else
>> + new_mode = QPHY_MODE_COMBO;
>> + }
>> +
>> + if (new_mode == qmp->init_mode) {
>> + dev_dbg(qmp->dev, "typec_mux_set: same phy mode, bail out\n");
>> + qmp->mode = state->mode;
>> + goto out;
>> + }
>> +
>> + if (qmp->init_mode != QPHY_MODE_USB_ONLY && qmp->dp_powered_on) {
>> + dev_dbg(qmp->dev, "typec_mux_set: DP is still powered on, delaying switch\n");
>> + goto out;
>> + }
>> +
>> + dev_dbg(qmp->dev, "typec_mux_set: switching from phy mode %d to %d\n",
>> + qmp->init_mode, new_mode);
>> +
>> + qmp->mux_mode = state->mode;
>> + qmp->init_mode = new_mode;
>> +
>> + if (qmp->init_count) {
>> + if (qmp->usb_init_count)
>> + qmp_combo_usb_power_off(qmp->usb_phy);
>> + if (qmp->dp_init_count)
>> + writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
>> + qmp_combo_com_exit(qmp, true);
>> +
>> + /* Now everything's powered down, power up the right PHYs */
>> +
>> + qmp_combo_com_init(qmp, true);
>> + if (qmp->init_mode == QPHY_MODE_DP_ONLY && qmp->usb_init_count) {
>> + qmp->usb_init_count--;
>> + } else if (qmp->init_mode != QPHY_MODE_DP_ONLY) {
>> + qmp_combo_usb_power_on(qmp->usb_phy);
>> + if (!qmp->usb_init_count)
>> + qmp->usb_init_count++;
>> + }
>> + if (qmp->init_mode != QPHY_MODE_USB_ONLY && qmp->dp_init_count)
>> + cfg->dp_aux_init(qmp);
>> + }
>> +
>> +out:
>> + mutex_unlock(&qmp->phy_mutex);
>> +
>> + return 0;
>> +}
>> +
>> +static void qmp_combo_typec_switch_unregister(void *data)
>> {
>> struct qmp_combo *qmp = data;
>>
>> typec_switch_unregister(qmp->sw);
>> }
>>
>> -static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
>> +static void qmp_combo_typec_mux_unregister(void *data)
>> +{
>> + struct qmp_combo *qmp = data;
>> +
>> + typec_mux_unregister(qmp->mux);
>> +}
>> +
>> +static int qmp_combo_typec_register(struct qmp_combo *qmp)
>> {
>> struct typec_switch_desc sw_desc = {};
>> + struct typec_mux_desc mux_desc = { };
>> struct device *dev = qmp->dev;
>> + int ret;
>>
>> sw_desc.drvdata = qmp;
>> sw_desc.fwnode = dev->fwnode;
>> @@ -3316,10 +3415,23 @@ static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
>> return PTR_ERR(qmp->sw);
>> }
>>
>> - return devm_add_action_or_reset(dev, qmp_combo_typec_unregister, qmp);
>> + ret = devm_add_action_or_reset(dev, qmp_combo_typec_switch_unregister, qmp);
>> + if (ret)
>> + return ret;
>> +
>> + mux_desc.drvdata = qmp;
>> + mux_desc.fwnode = dev->fwnode;
>> + mux_desc.set = qmp_combo_typec_mux_set;
>> + qmp->mux = typec_mux_register(dev, &mux_desc);
>> + if (IS_ERR(qmp->mux)) {
>> + dev_err(dev, "Unable to register typec mux: %pe\n", qmp->mux);
>> + return PTR_ERR(qmp->mux);
>> + }
>> +
>> + return devm_add_action_or_reset(dev, qmp_combo_typec_mux_unregister, qmp);
>> }
>> #else
>> -static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
>> +static int qmp_combo_typec_register(struct qmp_combo *qmp)
>> {
>> return 0;
>> }
>> @@ -3532,7 +3644,7 @@ static int qmp_combo_probe(struct platform_device *pdev)
>> if (ret)
>> return ret;
>>
>> - ret = qmp_combo_typec_switch_register(qmp);
>> + ret = qmp_combo_typec_register(qmp);
>> if (ret)
>> return ret;
>>
>>
>> --
>> 2.34.1
>>
>>
>
>
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