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Message-ID: <ece3e721-6e67-b2a9-4544-14e41a9b8589@linaro.org>
Date:   Thu, 27 Apr 2023 15:18:44 +0200
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Reply-To: neil.armstrong@linaro.org
Subject: Re: [PATCH 4/7] phy: qcom-qmp-combo: Introduce orientation switching
Content-Language: en-US
To:     Bjorn Andersson <quic_bjorande@quicinc.com>,
        Vinod Koul <vkoul@kernel.org>,
        Kishon Vijay Abraham I <kishon@kernel.org>,
        Johan Hovold <johan@kernel.org>
Cc:     Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230425034010.3789376-1-quic_bjorande@quicinc.com>
 <20230425034010.3789376-5-quic_bjorande@quicinc.com>
From:   Neil Armstrong <neil.armstrong@linaro.org>
Organization: Linaro Developer Services
In-Reply-To: <20230425034010.3789376-5-quic_bjorande@quicinc.com>
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Precedence: bulk

Hi,

On 25/04/2023 05:40, Bjorn Andersson wrote:
> The data lanes of the QMP PHY is swapped in order to handle changing
> orientation of the USB Type-C cable. Register a typec_switch device to
> allow a TCPM to configure the orientation.
> 
> The newly introduced orientation variable is adjusted based on the
> request, and the initialized components are brought down and up again.
> To keep track of what parts needs to be cycled new variables to keep
> track of the individual init_count is introduced.
> 
> Both the USB and the DisplayPort altmode signals are properly switched.
> For DisplayPort the controller will after the TCPM having established
> orientation power on the PHY, so this is not done implicitly, but for
> USB the PHY typically is kept initialized across the switch, and must
> therefor then be reinitialized.

   therefore
> 
> This is based on initial work by Wesley Cheng.
> 
> Link: https://lore.kernel.org/r/20201009082843.28503-3-wcheng@codeaurora.org/
> Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 92 ++++++++++++++++++++---
>   1 file changed, 83 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> index 6748f31da7a3..5d6d6ef3944b 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> @@ -20,6 +20,7 @@
>   #include <linux/reset.h>
>   #include <linux/slab.h>
>   #include <linux/usb/typec.h>
> +#include <linux/usb/typec_mux.h>
>   
>   #include <dt-bindings/phy/phy-qcom-qmp.h>
>   
> @@ -1320,15 +1321,18 @@ struct qmp_combo {
>   
>   	struct phy *usb_phy;
>   	enum phy_mode mode;
> +	unsigned int usb_init_count;
>   
>   	struct phy *dp_phy;
>   	unsigned int dp_aux_cfg;
>   	struct phy_configure_opts_dp dp_opts;
> +	unsigned int dp_init_count;
>   
>   	struct clk_fixed_rate pipe_clk_fixed;
>   	struct clk_hw dp_link_hw;
>   	struct clk_hw dp_pixel_hw;
>   
> +	struct typec_switch_dev *sw;
>   	enum typec_orientation orientation;
>   };
>   
> @@ -2458,14 +2462,14 @@ static int qmp_combo_dp_calibrate(struct phy *phy)
>   	return 0;
>   }
>   
> -static int qmp_combo_com_init(struct qmp_combo *qmp)
> +static int qmp_combo_com_init(struct qmp_combo *qmp, bool force)
>   {
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>   	void __iomem *com = qmp->com;
>   	int ret;
>   	u32 val;
>   
> -	if (qmp->init_count++)
> +	if (!force && qmp->init_count++)
>   		return 0;
>   
>   	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> @@ -2526,11 +2530,11 @@ static int qmp_combo_com_init(struct qmp_combo *qmp)
>   	return ret;
>   }
>   
> -static int qmp_combo_com_exit(struct qmp_combo *qmp)
> +static int qmp_combo_com_exit(struct qmp_combo *qmp, bool force)
>   {
>   	const struct qmp_phy_cfg *cfg = qmp->cfg;
>   
> -	if (--qmp->init_count)
> +	if (!force && --qmp->init_count)
>   		return 0;
>   
>   	reset_control_bulk_assert(cfg->num_resets, qmp->resets);
> @@ -2550,12 +2554,14 @@ static int qmp_combo_dp_init(struct phy *phy)
>   
>   	mutex_lock(&qmp->phy_mutex);
>   
> -	ret = qmp_combo_com_init(qmp);
> +	ret = qmp_combo_com_init(qmp, false);
>   	if (ret)
>   		goto out_unlock;
>   
>   	cfg->dp_aux_init(qmp);
>   
> +	qmp->dp_init_count++;
> +
>   out_unlock:
>   	mutex_unlock(&qmp->phy_mutex);
>   	return ret;
> @@ -2567,8 +2573,9 @@ static int qmp_combo_dp_exit(struct phy *phy)
>   
>   	mutex_lock(&qmp->phy_mutex);
>   
> -	qmp_combo_com_exit(qmp);
> +	qmp_combo_com_exit(qmp, false);
>   
> +	qmp->dp_init_count--;
>   	mutex_unlock(&qmp->phy_mutex);
>   
>   	return 0;
> @@ -2688,16 +2695,18 @@ static int qmp_combo_usb_init(struct phy *phy)
>   	int ret;
>   
>   	mutex_lock(&qmp->phy_mutex);
> -	ret = qmp_combo_com_init(qmp);
> +	ret = qmp_combo_com_init(qmp, false);
>   	if (ret)
>   		goto out_unlock;
>   
>   	ret = qmp_combo_usb_power_on(phy);
>   	if (ret) {
> -		qmp_combo_com_exit(qmp);
> +		qmp_combo_com_exit(qmp, false);
>   		goto out_unlock;
>   	}
>   
> +	qmp->usb_init_count++;
> +
>   out_unlock:
>   	mutex_unlock(&qmp->phy_mutex);
>   	return ret;
> @@ -2713,10 +2722,12 @@ static int qmp_combo_usb_exit(struct phy *phy)
>   	if (ret)
>   		goto out_unlock;
>   
> -	ret = qmp_combo_com_exit(qmp);
> +	ret = qmp_combo_com_exit(qmp, false);
>   	if (ret)
>   		goto out_unlock;
>   
> +	qmp->usb_init_count--;
> +
>   out_unlock:
>   	mutex_unlock(&qmp->phy_mutex);
>   	return ret;
> @@ -3351,6 +3362,65 @@ static struct phy *qmp_combo_phy_xlate(struct device *dev, struct of_phandle_arg
>   	return ERR_PTR(-EINVAL);
>   }
>   
> +#if IS_ENABLED(CONFIG_TYPEC)
> +static int qmp_combo_typec_switch_set(struct typec_switch_dev *sw,
> +				      enum typec_orientation orientation)
> +{
> +	struct qmp_combo *qmp = typec_switch_get_drvdata(sw);
> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +
> +	if (orientation == qmp->orientation || orientation == TYPEC_ORIENTATION_NONE)
> +		return 0;
> +
> +	mutex_lock(&qmp->phy_mutex);
> +	qmp->orientation = orientation;
> +
> +	if (qmp->init_count) {
> +		if (qmp->usb_init_count)
> +			qmp_combo_usb_power_off(qmp->usb_phy);
> +		qmp_combo_com_exit(qmp, true);
> +
> +		qmp_combo_com_init(qmp, true);
> +		if (qmp->usb_init_count)
> +			qmp_combo_usb_power_on(qmp->usb_phy);
> +		if (qmp->dp_init_count)
> +			cfg->dp_aux_init(qmp);
> +	}
> +	mutex_unlock(&qmp->phy_mutex);
> +
> +	return 0;
> +}
> +
> +static void qmp_combo_typec_unregister(void *data)
> +{
> +	struct qmp_combo *qmp = data;
> +
> +	typec_switch_unregister(qmp->sw);
> +}
> +
> +static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
> +{
> +	struct typec_switch_desc sw_desc = {};
> +	struct device *dev = qmp->dev;
> +
> +	sw_desc.drvdata = qmp;
> +	sw_desc.fwnode = dev->fwnode;
> +	sw_desc.set = qmp_combo_typec_switch_set;
> +	qmp->sw = typec_switch_register(dev, &sw_desc);
> +	if (IS_ERR(qmp->sw)) {
> +		dev_err(dev, "Unable to register typec switch: %pe\n", qmp->sw);
> +		return PTR_ERR(qmp->sw);
> +	}
> +
> +	return devm_add_action_or_reset(dev, qmp_combo_typec_unregister, qmp);
> +}
> +#else
> +static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
> +{
> +	return 0;
> +}
> +#endif
> +
>   static int qmp_combo_probe(struct platform_device *pdev)
>   {
>   	struct qmp_combo *qmp;
> @@ -3385,6 +3455,10 @@ static int qmp_combo_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> +	ret = qmp_combo_typec_switch_register(qmp);
> +	if (ret)
> +		return ret;
> +
>   	/* Check for legacy binding with child nodes. */
>   	usb_np = of_get_child_by_name(dev->of_node, "usb3-phy");
>   	if (usb_np) {

Thanks for taking care of this, with the commit typo fix:

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>