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
ti_j721e_ufs_probe(struct platform_device * pdev)18 static int ti_j721e_ufs_probe(struct platform_device *pdev)
19 {
20 struct device *dev = &pdev->dev;
21 unsigned long clk_rate;
22 void __iomem *regbase;
23 struct clk *clk;
24 u32 reg = 0;
25 int ret;
26
27 regbase = devm_platform_ioremap_resource(pdev, 0);
28 if (IS_ERR(regbase))
29 return PTR_ERR(regbase);
30
31 pm_runtime_enable(dev);
32 ret = pm_runtime_get_sync(dev);
33 if (ret < 0) {
34 pm_runtime_put_noidle(dev);
35 goto disable_pm;
36 }
37
38 /* Select MPHY refclk frequency */
39 clk = devm_clk_get(dev, NULL);
40 if (IS_ERR(clk)) {
41 ret = PTR_ERR(clk);
42 dev_err(dev, "Cannot claim MPHY clock.\n");
43 goto clk_err;
44 }
45 clk_rate = clk_get_rate(clk);
46 if (clk_rate == 26000000)
47 reg |= TI_UFS_SS_CLK_26MHZ;
48 devm_clk_put(dev, clk);
49
50 /* Take UFS slave device out of reset */
51 reg |= TI_UFS_SS_RST_N_PCS;
52 writel(reg, regbase + TI_UFS_SS_CTRL);
53
54 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL,
55 dev);
56 if (ret) {
57 dev_err(dev, "failed to populate child nodes %d\n", ret);
58 goto clk_err;
59 }
60
61 return ret;
62
63 clk_err:
64 pm_runtime_put_sync(dev);
65 disable_pm:
66 pm_runtime_disable(dev);
67 return ret;
68 }
69
ti_j721e_ufs_remove(struct platform_device * pdev)70 static int ti_j721e_ufs_remove(struct platform_device *pdev)
71 {
72 of_platform_depopulate(&pdev->dev);
73 pm_runtime_put_sync(&pdev->dev);
74 pm_runtime_disable(&pdev->dev);
75
76 return 0;
77 }
78
79 static const struct of_device_id ti_j721e_ufs_of_match[] = {
80 {
81 .compatible = "ti,j721e-ufs",
82 },
83 { },
84 };
85
86 static struct platform_driver ti_j721e_ufs_driver = {
87 .probe = ti_j721e_ufs_probe,
88 .remove = ti_j721e_ufs_remove,
89 .driver = {
90 .name = "ti-j721e-ufs",
91 .of_match_table = ti_j721e_ufs_of_match,
92 },
93 };
94 module_platform_driver(ti_j721e_ufs_driver);
95
96 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
97 MODULE_DESCRIPTION("TI UFS host controller glue driver");
98 MODULE_LICENSE("GPL v2");
99
