drivers/phy/st/phy-stih407-usb.c

   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");