Re: [PATCH] phy: xilinx: phy-zynqmp: dynamic clock support for power-save
From: Vinod Koul
Date: Tue Sep 20 2022 - 02:41:53 EST
On 09-09-22, 18:34, Piyush Mehta wrote:
> Enabling clock for all the lanes, consuming power even PHY is active or
> not.
Pls consider revision to:
Enabling clock for all the lanes consumes power even PHY is active or
idle..
>
> To resolve the above issue and power saving,made clock enabled/disabled
> based on active PHYs on call of phy_init/phy_exit.
To resolve this, enable/disable clocks in phy_init/phy_exit
> By default clock is disabled for all the lanes. Whenever phy_init called
> from USB, SATA, SGMII, or display driver, it enabled the required clock
> for requested lane. On phy_exit cycle, it disabled clock for the active
> PHYs.
>
> During the suspend/resume cycle, each USB/ SATA/ SGMII/ display driver
> called phy_exit/phy_init individually. it disabled clock on exit, and
> enabled on initialization for the active PHYs.
>
> Active PHY configuration depends on the peripheral DT node status,
> like USB DT node status 'okay' then driver enabled clock for the USB
> configured lane.
>
> Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxx>
> ---
> drivers/phy/xilinx/phy-zynqmp.c | 59 ++++++++-------------------------
> 1 file changed, 14 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
> index 9be9535ad7ab..912c4defdf8d 100644
> --- a/drivers/phy/xilinx/phy-zynqmp.c
> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> @@ -572,6 +572,10 @@ static int xpsgtr_phy_init(struct phy *phy)
>
> mutex_lock(>r_dev->gtr_mutex);
>
> + /* Configure and enable the clock when peripheral phy_init call */
when peripheral invokes phy_init
> + if (clk_prepare_enable(gtr_dev->clk[gtr_phy->lane]))
> + goto out;
> +
> /* Skip initialization if not required. */
> if (!xpsgtr_phy_init_required(gtr_phy))
> goto out;
> @@ -616,9 +620,13 @@ static int xpsgtr_phy_init(struct phy *phy)
> static int xpsgtr_phy_exit(struct phy *phy)
> {
> struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
> + struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>
> gtr_phy->skip_phy_init = false;
>
> + /* Ensure that disable clock only, which configure for lane */
> + clk_disable_unprepare(gtr_dev->clk[gtr_phy->lane]);
> +
> return 0;
> }
>
> @@ -824,15 +832,11 @@ static struct phy *xpsgtr_xlate(struct device *dev,
> static int __maybe_unused xpsgtr_suspend(struct device *dev)
> {
> struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
> - unsigned int i;
>
> /* Save the snapshot ICM_CFG registers. */
> gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
> gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
>
> - for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
> - clk_disable_unprepare(gtr_dev->clk[i]);
> -
> return 0;
> }
>
> @@ -842,13 +846,6 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
> unsigned int icm_cfg0, icm_cfg1;
> unsigned int i;
> bool skip_phy_init;
> - int err;
> -
> - for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) {
> - err = clk_prepare_enable(gtr_dev->clk[i]);
> - if (err)
> - goto err_clk_put;
> - }
hold on, why is this being removed from suspend/resume?
>
> icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
> icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
> @@ -869,12 +866,6 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
> gtr_dev->phys[i].skip_phy_init = skip_phy_init;
>
> return 0;
> -
> -err_clk_put:
> - while (i--)
> - clk_disable_unprepare(gtr_dev->clk[i]);
> -
> - return err;
> }
>
> static const struct dev_pm_ops xpsgtr_pm_ops = {
> @@ -888,7 +879,6 @@ static const struct dev_pm_ops xpsgtr_pm_ops = {
> static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
> {
> unsigned int refclk;
> - int ret;
>
> for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->refclk_sscs); ++refclk) {
> unsigned long rate;
> @@ -899,19 +889,14 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
> snprintf(name, sizeof(name), "ref%u", refclk);
> clk = devm_clk_get_optional(gtr_dev->dev, name);
> if (IS_ERR(clk)) {
> - ret = dev_err_probe(gtr_dev->dev, PTR_ERR(clk),
> - "Failed to get reference clock %u\n",
> - refclk);
> - goto err_clk_put;
> + return dev_err_probe(gtr_dev->dev, PTR_ERR(clk),
> + "Failed to get ref clock %u\n",
> + refclk);
> }
>
> if (!clk)
> continue;
>
> - ret = clk_prepare_enable(clk);
> - if (ret)
> - goto err_clk_put;
> -
> gtr_dev->clk[refclk] = clk;
>
> /*
> @@ -931,18 +916,11 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
> dev_err(gtr_dev->dev,
> "Invalid rate %lu for reference clock %u\n",
> rate, refclk);
> - ret = -EINVAL;
> - goto err_clk_put;
> + return -EINVAL;
> }
> }
>
> return 0;
> -
> -err_clk_put:
> - while (refclk--)
> - clk_disable_unprepare(gtr_dev->clk[refclk]);
> -
> - return ret;
> }
>
> static int xpsgtr_probe(struct platform_device *pdev)
> @@ -951,7 +929,6 @@ static int xpsgtr_probe(struct platform_device *pdev)
> struct xpsgtr_dev *gtr_dev;
> struct phy_provider *provider;
> unsigned int port;
> - unsigned int i;
> int ret;
>
> gtr_dev = devm_kzalloc(&pdev->dev, sizeof(*gtr_dev), GFP_KERNEL);
> @@ -991,8 +968,7 @@ static int xpsgtr_probe(struct platform_device *pdev)
> phy = devm_phy_create(&pdev->dev, np, &xpsgtr_phyops);
> if (IS_ERR(phy)) {
> dev_err(&pdev->dev, "failed to create PHY\n");
> - ret = PTR_ERR(phy);
> - goto err_clk_put;
> + return PTR_ERR(phy);
> }
>
> gtr_phy->phy = phy;
> @@ -1003,16 +979,9 @@ static int xpsgtr_probe(struct platform_device *pdev)
> provider = devm_of_phy_provider_register(&pdev->dev, xpsgtr_xlate);
> if (IS_ERR(provider)) {
> dev_err(&pdev->dev, "registering provider failed\n");
> - ret = PTR_ERR(provider);
> - goto err_clk_put;
> + return PTR_ERR(provider);
> }
> return 0;
> -
> -err_clk_put:
> - for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
> - clk_disable_unprepare(gtr_dev->clk[i]);
> -
> - return ret;
> }
>
> static const struct of_device_id xpsgtr_of_match[] = {
> --
> 2.25.1
--
~Vinod