phy: xilinx: phy-zynqmp: dynamic clock support for power-save

Enabling clock for all the lanes consumes power even PHY is active or
inactive. 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, or display driver, etc. 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/ display driver called
phy_exit/phy_init individually. It disabled clock on exit, and enabled
on initialization for the active PHYs.

Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
Link: https://lore.kernel.org/r/20230613140250.3018947-3-piyush.mehta@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index aada181..b0c2045 100644 (file)
--- 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(&gtr_dev->gtr_mutex);
 
+       /* Configure and enable the clock when peripheral phy_init call */
+       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 @@ out:
 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 xpsgtr_runtime_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 xpsgtr_runtime_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;
-       }
 
        icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
        icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
@@ -869,12 +866,6 @@ static int xpsgtr_runtime_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 DEFINE_RUNTIME_DEV_PM_OPS(xpsgtr_pm_ops, xpsgtr_runtime_suspend,
@@ -886,7 +877,6 @@ static DEFINE_RUNTIME_DEV_PM_OPS(xpsgtr_pm_ops, xpsgtr_runtime_suspend,
 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;
@@ -897,19 +887,14 @@ 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;
 
                /*
@@ -929,18 +914,11 @@ 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)
@@ -949,7 +927,6 @@ 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);
@@ -989,8 +966,7 @@ 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;
@@ -1001,8 +977,7 @@ 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);
        }
 
        pm_runtime_set_active(gtr_dev->dev);
@@ -1011,16 +986,10 @@ static int xpsgtr_probe(struct platform_device *pdev)
        ret = pm_runtime_resume_and_get(gtr_dev->dev);
        if (ret < 0) {
                pm_runtime_disable(gtr_dev->dev);
-               goto err_clk_put;
+               return ret;
        }
 
        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 int xpsgtr_remove(struct platform_device *pdev)