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