1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2014 STMicroelectronics 4 * 5 * STMicroelectronics Generic PHY driver for STiH407 USB2. 6 * 7 * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> 8 */ 9 #include <linux/platform_device.h> 10 #include <linux/io.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/of_platform.h> 15 #include <linux/clk.h> 16 #include <linux/regmap.h> 17 #include <linux/reset.h> 18 #include <linux/mfd/syscon.h> 19 #include <linux/phy/phy.h> 20 21 #define PHYPARAM_REG 1 22 #define PHYCTRL_REG 2 23 24 /* Default PHY_SEL and REFCLKSEL configuration */ 25 #define STIH407_USB_PICOPHY_CTRL_PORT_CONF 0x6 26 #define STIH407_USB_PICOPHY_CTRL_PORT_MASK 0x1f 27 28 /* ports parameters overriding */ 29 #define STIH407_USB_PICOPHY_PARAM_DEF 0x39a4dc 30 #define STIH407_USB_PICOPHY_PARAM_MASK 0xffffffff 31 32 struct stih407_usb2_picophy { 33 struct phy *phy; 34 struct regmap *regmap; 35 struct device *dev; 36 struct reset_control *rstc; 37 struct reset_control *rstport; 38 int ctrl; 39 int param; 40 }; 41 42 static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev) 43 { 44 reset_control_deassert(phy_dev->rstc); 45 46 return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl, 47 STIH407_USB_PICOPHY_CTRL_PORT_MASK, 48 STIH407_USB_PICOPHY_CTRL_PORT_CONF); 49 } 50 51 static int stih407_usb2_init_port(struct phy *phy) 52 { 53 int ret; 54 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy); 55 56 stih407_usb2_pico_ctrl(phy_dev); 57 58 ret = regmap_update_bits(phy_dev->regmap, 59 phy_dev->param, 60 STIH407_USB_PICOPHY_PARAM_MASK, 61 STIH407_USB_PICOPHY_PARAM_DEF); 62 if (ret) 63 return ret; 64 65 return reset_control_deassert(phy_dev->rstport); 66 } 67 68 static int stih407_usb2_exit_port(struct phy *phy) 69 { 70 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy); 71 72 /* 73 * Only port reset is asserted, phy global reset is kept untouched 74 * as other ports may still be active. When all ports are in reset 75 * state, assumption is made that power will be cut off on the phy, in 76 * case of suspend for instance. Theoretically, asserting individual 77 * reset (like here) or global reset should be equivalent. 78 */ 79 return reset_control_assert(phy_dev->rstport); 80 } 81 82 static const struct phy_ops stih407_usb2_picophy_data = { 83 .init = stih407_usb2_init_port, 84 .exit = stih407_usb2_exit_port, 85 .owner = THIS_MODULE, 86 }; 87 88 static int stih407_usb2_picophy_probe(struct platform_device *pdev) 89 { 90 struct stih407_usb2_picophy *phy_dev; 91 struct device *dev = &pdev->dev; 92 struct device_node *np = dev->of_node; 93 struct phy_provider *phy_provider; 94 struct phy *phy; 95 int ret; 96 97 phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL); 98 if (!phy_dev) 99 return -ENOMEM; 100 101 phy_dev->dev = dev; 102 dev_set_drvdata(dev, phy_dev); 103 104 phy_dev->rstc = devm_reset_control_get_shared(dev, "global"); 105 if (IS_ERR(phy_dev->rstc)) { 106 dev_err(dev, "failed to ctrl picoPHY reset\n"); 107 return PTR_ERR(phy_dev->rstc); 108 } 109 110 phy_dev->rstport = devm_reset_control_get_exclusive(dev, "port"); 111 if (IS_ERR(phy_dev->rstport)) { 112 dev_err(dev, "failed to ctrl picoPHY reset\n"); 113 return PTR_ERR(phy_dev->rstport); 114 } 115 116 /* Reset port by default: only deassert it in phy init */ 117 reset_control_assert(phy_dev->rstport); 118 119 phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); 120 if (IS_ERR(phy_dev->regmap)) { 121 dev_err(dev, "No syscfg phandle specified\n"); 122 return PTR_ERR(phy_dev->regmap); 123 } 124 125 ret = of_property_read_u32_index(np, "st,syscfg", PHYPARAM_REG, 126 &phy_dev->param); 127 if (ret) { 128 dev_err(dev, "can't get phyparam offset (%d)\n", ret); 129 return ret; 130 } 131 132 ret = of_property_read_u32_index(np, "st,syscfg", PHYCTRL_REG, 133 &phy_dev->ctrl); 134 if (ret) { 135 dev_err(dev, "can't get phyctrl offset (%d)\n", ret); 136 return ret; 137 } 138 139 phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data); 140 if (IS_ERR(phy)) { 141 dev_err(dev, "failed to create Display Port PHY\n"); 142 return PTR_ERR(phy); 143 } 144 145 phy_dev->phy = phy; 146 phy_set_drvdata(phy, phy_dev); 147 148 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); 149 if (IS_ERR(phy_provider)) 150 return PTR_ERR(phy_provider); 151 152 dev_info(dev, "STiH407 USB Generic picoPHY driver probed!"); 153 154 return 0; 155 } 156 157 static const struct of_device_id stih407_usb2_picophy_of_match[] = { 158 { .compatible = "st,stih407-usb2-phy" }, 159 { /*sentinel */ }, 160 }; 161 162 MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match); 163 164 static struct platform_driver stih407_usb2_picophy_driver = { 165 .probe = stih407_usb2_picophy_probe, 166 .driver = { 167 .name = "stih407-usb-genphy", 168 .of_match_table = stih407_usb2_picophy_of_match, 169 } 170 }; 171 172 module_platform_driver(stih407_usb2_picophy_driver); 173 174 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>"); 175 MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407"); 176 MODULE_LICENSE("GPL v2"); 177