1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Broadcom Northstar USB 2.0 PHY Driver 4 * 5 * Copyright (C) 2016 Rafał Miłecki <zajec5@gmail.com> 6 */ 7 8 #include <linux/bcma/bcma.h> 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/err.h> 12 #include <linux/mfd/syscon.h> 13 #include <linux/module.h> 14 #include <linux/of_address.h> 15 #include <linux/of_platform.h> 16 #include <linux/phy/phy.h> 17 #include <linux/platform_device.h> 18 #include <linux/regmap.h> 19 #include <linux/slab.h> 20 21 struct bcm_ns_usb2 { 22 struct device *dev; 23 struct clk *ref_clk; 24 struct phy *phy; 25 struct regmap *clkset; 26 void __iomem *base; 27 }; 28 29 static int bcm_ns_usb2_phy_init(struct phy *phy) 30 { 31 struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy); 32 struct device *dev = usb2->dev; 33 u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv; 34 int err = 0; 35 36 err = clk_prepare_enable(usb2->ref_clk); 37 if (err < 0) { 38 dev_err(dev, "Failed to prepare ref clock: %d\n", err); 39 goto err_out; 40 } 41 42 ref_clk_rate = clk_get_rate(usb2->ref_clk); 43 if (!ref_clk_rate) { 44 dev_err(dev, "Failed to get ref clock rate\n"); 45 err = -EINVAL; 46 goto err_clk_off; 47 } 48 49 usb2ctl = readl(usb2->base); 50 51 if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) { 52 usb_pll_pdiv = usb2ctl; 53 usb_pll_pdiv &= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK; 54 usb_pll_pdiv >>= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_SHIFT; 55 } else { 56 usb_pll_pdiv = 1 << 3; 57 } 58 59 /* Calculate ndiv based on a solid 1920 MHz that is for USB2 PHY */ 60 usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate; 61 62 /* Unlock DMU PLL settings with some magic value */ 63 regmap_write(usb2->clkset, 0, 0x0000ea68); 64 65 /* Write USB 2.0 PLL control setting */ 66 usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK; 67 usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT; 68 69 writel(usb2ctl, usb2->base); 70 71 /* Lock DMU PLL settings */ 72 regmap_write(usb2->clkset, 0, 0x00000000); 73 74 err_clk_off: 75 clk_disable_unprepare(usb2->ref_clk); 76 err_out: 77 return err; 78 } 79 80 static const struct phy_ops ops = { 81 .init = bcm_ns_usb2_phy_init, 82 .owner = THIS_MODULE, 83 }; 84 85 static int bcm_ns_usb2_probe(struct platform_device *pdev) 86 { 87 struct device *dev = &pdev->dev; 88 struct bcm_ns_usb2 *usb2; 89 struct phy_provider *phy_provider; 90 91 usb2 = devm_kzalloc(&pdev->dev, sizeof(*usb2), GFP_KERNEL); 92 if (!usb2) 93 return -ENOMEM; 94 usb2->dev = dev; 95 96 usb2->base = devm_platform_ioremap_resource(pdev, 0); 97 if (IS_ERR(usb2->base)) { 98 dev_err(dev, "Failed to map control reg\n"); 99 return PTR_ERR(usb2->base); 100 } 101 102 usb2->clkset = syscon_regmap_lookup_by_phandle(dev->of_node, 103 "brcm,syscon-clkset"); 104 if (IS_ERR(usb2->clkset)) { 105 dev_err(dev, "Failed to lookup clkset regmap\n"); 106 return PTR_ERR(usb2->clkset); 107 } 108 109 usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk"); 110 if (IS_ERR(usb2->ref_clk)) { 111 dev_err_probe(dev, PTR_ERR(usb2->ref_clk), "failed to get ref clk\n"); 112 return PTR_ERR(usb2->ref_clk); 113 } 114 115 usb2->phy = devm_phy_create(dev, NULL, &ops); 116 if (IS_ERR(usb2->phy)) 117 return PTR_ERR(usb2->phy); 118 119 phy_set_drvdata(usb2->phy, usb2); 120 platform_set_drvdata(pdev, usb2); 121 122 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 123 return PTR_ERR_OR_ZERO(phy_provider); 124 } 125 126 static const struct of_device_id bcm_ns_usb2_id_table[] = { 127 { .compatible = "brcm,ns-usb2-phy", }, 128 {}, 129 }; 130 MODULE_DEVICE_TABLE(of, bcm_ns_usb2_id_table); 131 132 static struct platform_driver bcm_ns_usb2_driver = { 133 .probe = bcm_ns_usb2_probe, 134 .driver = { 135 .name = "bcm_ns_usb2", 136 .of_match_table = bcm_ns_usb2_id_table, 137 }, 138 }; 139 module_platform_driver(bcm_ns_usb2_driver); 140 141 MODULE_DESCRIPTION("Broadcom Northstar USB 2.0 PHY Driver"); 142 MODULE_LICENSE("GPL v2"); 143