drivers/phy/phy-stih407-usb.c

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