1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
4 //
5
6 #include <linux/clk.h>
7 #include <linux/io.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/of_platform.h>
11 #include <linux/platform_device.h>
12 #include <linux/pm_runtime.h>
13
14 #define TI_UFS_SS_CTRL 0x4
15 #define TI_UFS_SS_RST_N_PCS BIT(0)
16 #define TI_UFS_SS_CLK_26MHZ BIT(4)
17
18 struct ti_j721e_ufs {
19 void __iomem *regbase;
20 u32 reg;
21 };
22
ti_j721e_ufs_probe(struct platform_device * pdev)23 static int ti_j721e_ufs_probe(struct platform_device *pdev)
24 {
25 struct device *dev = &pdev->dev;
26 struct ti_j721e_ufs *ufs;
27 unsigned long clk_rate;
28 struct clk *clk;
29 int ret;
30
31 ufs = devm_kzalloc(dev, sizeof(*ufs), GFP_KERNEL);
32 if (!ufs)
33 return -ENOMEM;
34
35 ufs->regbase = devm_platform_ioremap_resource(pdev, 0);
36 if (IS_ERR(ufs->regbase))
37 return PTR_ERR(ufs->regbase);
38
39 pm_runtime_enable(dev);
40 ret = pm_runtime_resume_and_get(dev);
41 if (ret < 0)
42 goto disable_pm;
43
44 /* Select MPHY refclk frequency */
45 clk = devm_clk_get(dev, NULL);
46 if (IS_ERR(clk)) {
47 ret = PTR_ERR(clk);
48 dev_err(dev, "Cannot claim MPHY clock.\n");
49 goto clk_err;
50 }
51 clk_rate = clk_get_rate(clk);
52 if (clk_rate == 26000000)
53 ufs->reg |= TI_UFS_SS_CLK_26MHZ;
54 devm_clk_put(dev, clk);
55
56 /* Take UFS slave device out of reset */
57 ufs->reg |= TI_UFS_SS_RST_N_PCS;
58 writel(ufs->reg, ufs->regbase + TI_UFS_SS_CTRL);
59
60 dev_set_drvdata(dev, ufs);
61
62 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL,
63 dev);
64 if (ret) {
65 dev_err(dev, "failed to populate child nodes %d\n", ret);
66 goto clk_err;
67 }
68
69 return ret;
70
71 clk_err:
72 pm_runtime_put_sync(dev);
73 disable_pm:
74 pm_runtime_disable(dev);
75 return ret;
76 }
77
ti_j721e_ufs_remove(struct platform_device * pdev)78 static void ti_j721e_ufs_remove(struct platform_device *pdev)
79 {
80 of_platform_depopulate(&pdev->dev);
81 pm_runtime_put_sync(&pdev->dev);
82 pm_runtime_disable(&pdev->dev);
83 }
84
ti_j721e_ufs_resume(struct device * dev)85 static int ti_j721e_ufs_resume(struct device *dev)
86 {
87 struct ti_j721e_ufs *ufs = dev_get_drvdata(dev);
88
89 writel(ufs->reg, ufs->regbase + TI_UFS_SS_CTRL);
90 return 0;
91 }
92
93 static DEFINE_SIMPLE_DEV_PM_OPS(ti_j721e_ufs_pm_ops, NULL, ti_j721e_ufs_resume);
94
95 static const struct of_device_id ti_j721e_ufs_of_match[] = {
96 {
97 .compatible = "ti,j721e-ufs",
98 },
99 { },
100 };
101
102 MODULE_DEVICE_TABLE(of, ti_j721e_ufs_of_match);
103
104 static struct platform_driver ti_j721e_ufs_driver = {
105 .probe = ti_j721e_ufs_probe,
106 .remove = ti_j721e_ufs_remove,
107 .driver = {
108 .name = "ti-j721e-ufs",
109 .of_match_table = ti_j721e_ufs_of_match,
110 .pm = pm_sleep_ptr(&ti_j721e_ufs_pm_ops),
111 },
112 };
113 module_platform_driver(ti_j721e_ufs_driver);
114
115 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
116 MODULE_DESCRIPTION("TI UFS host controller glue driver");
117 MODULE_LICENSE("GPL v2");
118