linux-kernel - Re: [PATCH v6 2/2] phy: qualcomm: Add Synopsys High-Speed USB PHY driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f106782b6d8e26ebf851f00563c68948@codeaurora.org>
Date:   Thu, 20 Dec 2018 09:33:43 +0530
From:   mgautam@...eaurora.org
To:     Shawn Guo <shawn.guo@...aro.org>
Cc:     Kishon Vijay Abraham I <kishon@...com>,
        Rob Herring <robh+dt@...nel.org>,
        Sriharsha Allenki <sallenki@...eaurora.org>,
        Anu Ramanathan <anur@...eaurora.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Vinod Koul <vkoul@...nel.org>,
        Jack Pham <jackp@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm-owner@...r.kernel.org
Subject: Re: [PATCH v6 2/2] phy: qualcomm: Add Synopsys High-Speed USB PHY
 driver

Hi Shawn,

On 2018-12-20 06:31, Shawn Guo wrote:
> It adds Synopsys 28nm Femto High-Speed USB PHY driver support, which
> is usually paired with Synopsys DWC3 USB controllers on Qualcomm SoCs.
> 
> Signed-off-by: Shawn Guo <shawn.guo@...aro.org>
> ---
....

> +
> +/* PHY register and bit definitions */
> +#define PHY_CTRL_COMMON0		0x078
> +#define SIDDQ				BIT(2)
> +#define PHY_IRQ_CMD			0x0d0
> +#define PHY_INTR_MASK0			0x0d4
> +#define PHY_INTR_CLEAR0			0x0dc
> +#define DPDM_MASK			0x1e
> +#define DP_1_0				BIT(4)
> +#define DP_0_1				BIT(3)
> +#define DM_1_0				BIT(2)
> +#define DM_0_1				BIT(1)

Can we rename these to something more readable? e.g.:
#define DP_FALL_INT_EN    BIT(4)
#define DP_RISE_INT_EN    BIT(3)
...

> +
> +enum hsphy_voltage {
> +	VOL_NONE,
> +	VOL_MIN,
> +	VOL_MAX,
> +	VOL_NUM,
> +};
> +
> +enum hsphy_vreg {
> +	VDD,
> +	VDDA_1P8,
> +	VDDA_3P3,
> +	VREG_NUM,
> +};
> +
> +struct hsphy_init_seq {
> +	int offset;
> +	int val;
> +	int delay;
> +};
> +
> +struct hsphy_data {
> +	const struct hsphy_init_seq *init_seq;
> +	unsigned int init_seq_num;
> +};
> +
> +struct hsphy_priv {
nit-pick - indentation for following structure members?

> +	void __iomem *base;
> +	struct clk_bulk_data *clks;
> +	int num_clks;
> +	struct reset_control *phy_reset;
> +	struct reset_control *por_reset;
> +	struct regulator_bulk_data vregs[VREG_NUM];
> +	unsigned int voltages[VREG_NUM][VOL_NUM];
> +	const struct hsphy_data *data;
> +	bool cable_connected;

You can get cable-connected state from "enum phy_mode mode" which
is present in this driver.
E.g. cable_connected is false if mode is neither HOST nor DEVICE.


> +	struct extcon_dev *vbus_edev;
> +	struct notifier_block vbus_notify;

extcons not needed if you use "mode" for the same purpose.


> +	enum phy_mode mode;
> +};
> +


> +
> +static int qcom_snps_hsphy_vbus_notifier(struct notifier_block *nb,
> +					 unsigned long event, void *ptr)
> +{
> +	struct hsphy_priv *priv = container_of(nb, struct hsphy_priv,
> +						    vbus_notify);
> +	priv->cable_connected = !!event;
> +	return 0;
> +}
> +
> +static int qcom_snps_hsphy_power_on(struct phy *phy)

Can you instead merge this power_on function with phy_init?

> +{
> +	struct hsphy_priv *priv = phy_get_drvdata(phy);
> +	int ret;
> +
> +	if (priv->cable_connected) {

Why distinguish between cable connected vs not-connected?


> +		ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
> +		if (ret)
> +			return ret;
> +		qcom_snps_hsphy_disable_hv_interrupts(priv);
> +	} else {
> +		ret = qcom_snps_hsphy_enable_regulators(priv);
> +		if (ret)
> +			return ret;
> +		ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
> +		if (ret)
> +			return ret;
> +		qcom_snps_hsphy_exit_retention(priv);
> +	}
> +
> +	return 0;
> +}
> +
> +static int qcom_snps_hsphy_power_off(struct phy *phy)
> +{
> +	struct hsphy_priv *priv = phy_get_drvdata(phy);
> +
> +	if (priv->cable_connected) {
> +		qcom_snps_hsphy_enable_hv_interrupts(priv);
> +		clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
> +	} else {
> +		qcom_snps_hsphy_enter_retention(priv);
> +		clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
> +		qcom_snps_hsphy_disable_regulators(priv);
> +	}
> +
> +	return 0;
> +}
> +



..
> +static const struct phy_ops qcom_snps_hsphy_ops = {
> +	.init = qcom_snps_hsphy_init,
> +	.power_on = qcom_snps_hsphy_power_on,
> +	.power_off = qcom_snps_hsphy_power_off,
> +	.set_mode = qcom_snps_hsphy_set_mode,

.phy_exit()?
I believe that is needed as dwc3 core driver performs
phy_exit/phy_init across pm_suspend/resume.


> +	.owner = THIS_MODULE,
> +};
> +