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 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_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 61 clk_err: 62 pm_runtime_put_sync(dev); 63 disable_pm: 64 pm_runtime_disable(dev); 65 return ret; 66 } 67 68 static int 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 return 0; 75 } 76 77 static const struct of_device_id ti_j721e_ufs_of_match[] = { 78 { 79 .compatible = "ti,j721e-ufs", 80 }, 81 { }, 82 }; 83 84 MODULE_DEVICE_TABLE(of, ti_j721e_ufs_of_match); 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