scsi: ufs: ti-j721e: Add suspend-resume support

Restore the ctrl register to resume the TI UFS wrapper.

Signed-off-by: Thomas Richard (TI.com) <thomas.richard@bootlin.com>
Link: https://patch.msgid.link/20251106-scsi-ufs-ti-j721e-suspend-resume-support-v1-1-6f395f51219e@bootlin.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/host/ti-j721e-ufs.c b/drivers/ufs/host/ti-j721e-ufs.c
index 21214e5d5896447431b251d7f5783585532a835a..43781593b5c1ae42e899e5510db8bf46e9383439 100644 (file)
--- a/drivers/ufs/host/ti-j721e-ufs.c
+++ b/drivers/ufs/host/ti-j721e-ufs.c
@@ -15,18 +15,26 @@
 #define TI_UFS_SS_RST_N_PCS    BIT(0)
 #define TI_UFS_SS_CLK_26MHZ    BIT(4)
 
+struct ti_j721e_ufs {
+       void __iomem *regbase;
+       u32 reg;
+};
+
 static int ti_j721e_ufs_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
+       struct ti_j721e_ufs *ufs;
        unsigned long clk_rate;
-       void __iomem *regbase;
        struct clk *clk;
-       u32 reg = 0;
        int ret;
 
-       regbase = devm_platform_ioremap_resource(pdev, 0);
-       if (IS_ERR(regbase))
-               return PTR_ERR(regbase);
+       ufs = devm_kzalloc(dev, sizeof(*ufs), GFP_KERNEL);
+       if (!ufs)
+               return -ENOMEM;
+
+       ufs->regbase = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(ufs->regbase))
+               return PTR_ERR(ufs->regbase);
 
        pm_runtime_enable(dev);
        ret = pm_runtime_resume_and_get(dev);
@@ -42,12 +50,14 @@ static int ti_j721e_ufs_probe(struct platform_device *pdev)
        }
        clk_rate = clk_get_rate(clk);
        if (clk_rate == 26000000)
-               reg |= TI_UFS_SS_CLK_26MHZ;
+               ufs->reg |= TI_UFS_SS_CLK_26MHZ;
        devm_clk_put(dev, clk);
 
        /*  Take UFS slave device out of reset */
-       reg |= TI_UFS_SS_RST_N_PCS;
-       writel(reg, regbase + TI_UFS_SS_CTRL);
+       ufs->reg |= TI_UFS_SS_RST_N_PCS;
+       writel(ufs->reg, ufs->regbase + TI_UFS_SS_CTRL);
+
+       dev_set_drvdata(dev, ufs);
 
        ret = of_platform_populate(pdev->dev.of_node, NULL, NULL,
                                   dev);
@@ -72,6 +82,16 @@ static void ti_j721e_ufs_remove(struct platform_device *pdev)
        pm_runtime_disable(&pdev->dev);
 }
 
+static int ti_j721e_ufs_resume(struct device *dev)
+{
+       struct ti_j721e_ufs *ufs = dev_get_drvdata(dev);
+
+       writel(ufs->reg, ufs->regbase + TI_UFS_SS_CTRL);
+       return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ti_j721e_ufs_pm_ops, NULL, ti_j721e_ufs_resume);
+
 static const struct of_device_id ti_j721e_ufs_of_match[] = {
        {
                .compatible = "ti,j721e-ufs",
@@ -87,6 +107,7 @@ static struct platform_driver ti_j721e_ufs_driver = {
        .driver = {
                .name   = "ti-j721e-ufs",
                .of_match_table = ti_j721e_ufs_of_match,
+               .pm = pm_sleep_ptr(&ti_j721e_ufs_pm_ops),
        },
 };
 module_platform_driver(ti_j721e_ufs_driver);