phy/st/phy-stih407-usb.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2014 STMicroelectronics
0004  *
0005  * STMicroelectronics Generic PHY driver for STiH407 USB2.
0006  *
0007  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
0008  */
0009 #include <linux/platform_device.h>
0010 #include <linux/io.h>
0011 #include <linux/kernel.h>
0012 #include <linux/module.h>
0013 #include <linux/of.h>
0014 #include <linux/of_platform.h>
0015 #include <linux/clk.h>
0016 #include <linux/regmap.h>
0017 #include <linux/reset.h>
0018 #include <linux/mfd/syscon.h>
0019 #include <linux/phy/phy.h>
0020
0021 #define PHYPARAM_REG    1
0022 #define PHYCTRL_REG 2
0023
0024 /* Default PHY_SEL and REFCLKSEL configuration */
0025 #define STIH407_USB_PICOPHY_CTRL_PORT_CONF  0x6
0026 #define STIH407_USB_PICOPHY_CTRL_PORT_MASK  0x1f
0027
0028 /* ports parameters overriding */
0029 #define STIH407_USB_PICOPHY_PARAM_DEF       0x39a4dc
0030 #define STIH407_USB_PICOPHY_PARAM_MASK      0xffffffff
0031
0032 struct stih407_usb2_picophy {
0033     struct phy *phy;
0034     struct regmap *regmap;
0035     struct device *dev;
0036     struct reset_control *rstc;
0037     struct reset_control *rstport;
0038     int ctrl;
0039     int param;
0040 };
0041
0042 static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
0043 {
0044     reset_control_deassert(phy_dev->rstc);
0045
0046     return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
0047                   STIH407_USB_PICOPHY_CTRL_PORT_MASK,
0048                   STIH407_USB_PICOPHY_CTRL_PORT_CONF);
0049 }
0050
0051 static int stih407_usb2_init_port(struct phy *phy)
0052 {
0053     int ret;
0054     struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
0055
0056     stih407_usb2_pico_ctrl(phy_dev);
0057
0058     ret = regmap_update_bits(phy_dev->regmap,
0059                  phy_dev->param,
0060                  STIH407_USB_PICOPHY_PARAM_MASK,
0061                  STIH407_USB_PICOPHY_PARAM_DEF);
0062     if (ret)
0063         return ret;
0064
0065     return reset_control_deassert(phy_dev->rstport);
0066 }
0067
0068 static int stih407_usb2_exit_port(struct phy *phy)
0069 {
0070     struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
0071
0072     /*
0073      * Only port reset is asserted, phy global reset is kept untouched
0074      * as other ports may still be active. When all ports are in reset
0075      * state, assumption is made that power will be cut off on the phy, in
0076      * case of suspend for instance. Theoretically, asserting individual
0077      * reset (like here) or global reset should be equivalent.
0078      */
0079     return reset_control_assert(phy_dev->rstport);
0080 }
0081
0082 static const struct phy_ops stih407_usb2_picophy_data = {
0083     .init = stih407_usb2_init_port,
0084     .exit = stih407_usb2_exit_port,
0085     .owner = THIS_MODULE,
0086 };
0087
0088 static int stih407_usb2_picophy_probe(struct platform_device *pdev)
0089 {
0090     struct stih407_usb2_picophy *phy_dev;
0091     struct device *dev = &pdev->dev;
0092     struct device_node *np = dev->of_node;
0093     struct phy_provider *phy_provider;
0094     struct phy *phy;
0095     int ret;
0096
0097     phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
0098     if (!phy_dev)
0099         return -ENOMEM;
0100
0101     phy_dev->dev = dev;
0102     dev_set_drvdata(dev, phy_dev);
0103
0104     phy_dev->rstc = devm_reset_control_get_shared(dev, "global");
0105     if (IS_ERR(phy_dev->rstc)) {
0106         dev_err(dev, "failed to ctrl picoPHY reset\n");
0107         return PTR_ERR(phy_dev->rstc);
0108     }
0109
0110     phy_dev->rstport = devm_reset_control_get_exclusive(dev, "port");
0111     if (IS_ERR(phy_dev->rstport)) {
0112         dev_err(dev, "failed to ctrl picoPHY reset\n");
0113         return PTR_ERR(phy_dev->rstport);
0114     }
0115
0116     /* Reset port by default: only deassert it in phy init */
0117     reset_control_assert(phy_dev->rstport);
0118
0119     phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
0120     if (IS_ERR(phy_dev->regmap)) {
0121         dev_err(dev, "No syscfg phandle specified\n");
0122         return PTR_ERR(phy_dev->regmap);
0123     }
0124
0125     ret = of_property_read_u32_index(np, "st,syscfg", PHYPARAM_REG,
0126                     &phy_dev->param);
0127     if (ret) {
0128         dev_err(dev, "can't get phyparam offset (%d)\n", ret);
0129         return ret;
0130     }
0131
0132     ret = of_property_read_u32_index(np, "st,syscfg", PHYCTRL_REG,
0133                     &phy_dev->ctrl);
0134     if (ret) {
0135         dev_err(dev, "can't get phyctrl offset (%d)\n", ret);
0136         return ret;
0137     }
0138
0139     phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data);
0140     if (IS_ERR(phy)) {
0141         dev_err(dev, "failed to create Display Port PHY\n");
0142         return PTR_ERR(phy);
0143     }
0144
0145     phy_dev->phy = phy;
0146     phy_set_drvdata(phy, phy_dev);
0147
0148     phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
0149     if (IS_ERR(phy_provider))
0150         return PTR_ERR(phy_provider);
0151
0152     dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
0153
0154     return 0;
0155 }
0156
0157 static const struct of_device_id stih407_usb2_picophy_of_match[] = {
0158     { .compatible = "st,stih407-usb2-phy" },
0159     { /*sentinel */ },
0160 };
0161
0162 MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
0163
0164 static struct platform_driver stih407_usb2_picophy_driver = {
0165     .probe = stih407_usb2_picophy_probe,
0166     .driver = {
0167            .name = "stih407-usb-genphy",
0168            .of_match_table = stih407_usb2_picophy_of_match,
0169            }
0170 };
0171
0172 module_platform_driver(stih407_usb2_picophy_driver);
0173
0174 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
0175 MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
0176 MODULE_LICENSE("GPL v2");