ti-j721e-ufs.c

  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
 18struct ti_j721e_ufs {
 19	void __iomem *regbase;
 20	u32 reg;
 21};
 22
 23static 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
 71clk_err:
 72	pm_runtime_put_sync(dev);
 73disable_pm:
 74	pm_runtime_disable(dev);
 75	return ret;
 76}
 77
 78static 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
 85static 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
 93static DEFINE_SIMPLE_DEV_PM_OPS(ti_j721e_ufs_pm_ops, NULL, ti_j721e_ufs_resume);
 94
 95static const struct of_device_id ti_j721e_ufs_of_match[] = {
 96	{
 97		.compatible = "ti,j721e-ufs",
 98	},
 99	{ },
100};
101
102MODULE_DEVICE_TABLE(of, ti_j721e_ufs_of_match);
103
104static 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};
113module_platform_driver(ti_j721e_ufs_driver);
114
115MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
116MODULE_DESCRIPTION("TI UFS host controller glue driver");
117MODULE_LICENSE("GPL v2");