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 /* Deprecated binding */ 29 void __iomem *dmu; 30 }; 31 32 static int bcm_ns_usb2_phy_init(struct phy *phy) 33 { 34 struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy); 35 struct device *dev = usb2->dev; 36 u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv; 37 int err = 0; 38 39 err = clk_prepare_enable(usb2->ref_clk); 40 if (err < 0) { 41 dev_err(dev, "Failed to prepare ref clock: %d\n", err); 42 goto err_out; 43 } 44 45 ref_clk_rate = clk_get_rate(usb2->ref_clk); 46 if (!ref_clk_rate) { 47 dev_err(dev, "Failed to get ref clock rate\n"); 48 err = -EINVAL; 49 goto err_clk_off; 50 } 51 52 if (usb2->base) 53 usb2ctl = readl(usb2->base); 54 else 55 usb2ctl = readl(usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL); 56 57 if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) { 58 usb_pll_pdiv = usb2ctl; 59 usb_pll_pdiv &= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK; 60 usb_pll_pdiv >>= BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_SHIFT; 61 } else { 62 usb_pll_pdiv = 1 << 3; 63 } 64 65 /* Calculate ndiv based on a solid 1920 MHz that is for USB2 PHY */ 66 usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate; 67 68 /* Unlock DMU PLL settings with some magic value */ 69 if (usb2->clkset) 70 regmap_write(usb2->clkset, 0, 0x0000ea68); 71 else 72 writel(0x0000ea68, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY); 73 74 /* Write USB 2.0 PLL control setting */ 75 usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK; 76 usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT; 77 if (usb2->base) 78 writel(usb2ctl, usb2->base); 79 else 80 writel(usb2ctl, usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL); 81 82 /* Lock DMU PLL settings */ 83 if (usb2->clkset) 84 regmap_write(usb2->clkset, 0, 0x00000000); 85 else 86 writel(0x00000000, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY); 87 88 err_clk_off: 89 clk_disable_unprepare(usb2->ref_clk); 90 err_out: 91 return err; 92 } 93 94 static const struct phy_ops ops = { 95 .init = bcm_ns_usb2_phy_init, 96 .owner = THIS_MODULE, 97 }; 98 99 static int bcm_ns_usb2_probe(struct platform_device *pdev) 100 { 101 struct device *dev = &pdev->dev; 102 struct bcm_ns_usb2 *usb2; 103 struct phy_provider *phy_provider; 104 105 usb2 = devm_kzalloc(&pdev->dev, sizeof(*usb2), GFP_KERNEL); 106 if (!usb2) 107 return -ENOMEM; 108 usb2->dev = dev; 109 110 if (of_property_present(dev->of_node, "brcm,syscon-clkset")) { 111 usb2->base = devm_platform_ioremap_resource(pdev, 0); 112 if (IS_ERR(usb2->base)) { 113 dev_err(dev, "Failed to map control reg\n"); 114 return PTR_ERR(usb2->base); 115 } 116 117 usb2->clkset = syscon_regmap_lookup_by_phandle(dev->of_node, 118 "brcm,syscon-clkset"); 119 if (IS_ERR(usb2->clkset)) { 120 dev_err(dev, "Failed to lookup clkset regmap\n"); 121 return PTR_ERR(usb2->clkset); 122 } 123 } else { 124 usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu"); 125 if (IS_ERR(usb2->dmu)) { 126 dev_err(dev, "Failed to map DMU regs\n"); 127 return PTR_ERR(usb2->dmu); 128 } 129 130 dev_warn(dev, "using deprecated DT binding\n"); 131 } 132 133 usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk"); 134 if (IS_ERR(usb2->ref_clk)) { 135 dev_err_probe(dev, PTR_ERR(usb2->ref_clk), "failed to get ref clk\n"); 136 return PTR_ERR(usb2->ref_clk); 137 } 138 139 usb2->phy = devm_phy_create(dev, NULL, &ops); 140 if (IS_ERR(usb2->phy)) 141 return PTR_ERR(usb2->phy); 142 143 phy_set_drvdata(usb2->phy, usb2); 144 platform_set_drvdata(pdev, usb2); 145 146 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 147 return PTR_ERR_OR_ZERO(phy_provider); 148 } 149 150 static const struct of_device_id bcm_ns_usb2_id_table[] = { 151 { .compatible = "brcm,ns-usb2-phy", }, 152 {}, 153 }; 154 MODULE_DEVICE_TABLE(of, bcm_ns_usb2_id_table); 155 156 static struct platform_driver bcm_ns_usb2_driver = { 157 .probe = bcm_ns_usb2_probe, 158 .driver = { 159 .name = "bcm_ns_usb2", 160 .of_match_table = bcm_ns_usb2_id_table, 161 }, 162 }; 163 module_platform_driver(bcm_ns_usb2_driver); 164 165 MODULE_DESCRIPTION("Broadcom Northstar USB 2.0 PHY Driver"); 166 MODULE_LICENSE("GPL v2"); 167