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 /* Default PHY_SEL and REFCLKSEL configuration */
  26 #define STIH407_USB_PICOPHY_CTRL_PORT_CONF      0x6
  27 #define STIH407_USB_PICOPHY_CTRL_PORT_MASK      0x1f
  28
  29 /* ports parameters overriding */
  30 #define STIH407_USB_PICOPHY_PARAM_DEF           0x39a4dc
  31 #define STIH407_USB_PICOPHY_PARAM_MASK          0xffffffff
  32
  33 struct stih407_usb2_picophy {
  34         struct phy *phy;
  35         struct regmap *regmap;
  36         struct device *dev;
  37         struct reset_control *rstc;
  38         struct reset_control *rstport;
  39         int ctrl;
  40         int param;
  41 };
  42
  43 static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
  44 {
  45         reset_control_deassert(phy_dev->rstc);
  46
  47         return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
  48                                   STIH407_USB_PICOPHY_CTRL_PORT_MASK,
  49                                   STIH407_USB_PICOPHY_CTRL_PORT_CONF);
  50 }
  51
  52 static int stih407_usb2_init_port(struct phy *phy)
  53 {
  54         int ret;
  55         struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
  56
  57         stih407_usb2_pico_ctrl(phy_dev);
  58
  59         ret = regmap_update_bits(phy_dev->regmap,
  60                                  phy_dev->param,
  61                                  STIH407_USB_PICOPHY_PARAM_MASK,
  62                                  STIH407_USB_PICOPHY_PARAM_DEF);
  63         if (ret)
  64                 return ret;
  65
  66         return reset_control_deassert(phy_dev->rstport);
  67 }
  68
  69 static int stih407_usb2_exit_port(struct phy *phy)
  70 {
  71         struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
  72
  73         /*
  74          * Only port reset is asserted, phy global reset is kept untouched
  75          * as other ports may still be active. When all ports are in reset
  76          * state, assumption is made that power will be cut off on the phy, in
  77          * case of suspend for instance. Theoretically, asserting individual
  78          * reset (like here) or global reset should be equivalent.
  79          */
  80         return reset_control_assert(phy_dev->rstport);
  81 }
  82
  83 static const struct phy_ops stih407_usb2_picophy_data = {
  84         .init = stih407_usb2_init_port,
  85         .exit = stih407_usb2_exit_port,
  86         .owner = THIS_MODULE,
  87 };
  88
  89 static int stih407_usb2_picophy_probe(struct platform_device *pdev)
  90 {
  91         struct stih407_usb2_picophy *phy_dev;
  92         struct device *dev = &pdev->dev;
  93         struct device_node *np = dev->of_node;
  94         struct phy_provider *phy_provider;
  95         struct phy *phy;
  96         struct resource *res;
  97
  98         phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
  99         if (!phy_dev)
 100                 return -ENOMEM;
 101
 102         phy_dev->dev = dev;
 103         dev_set_drvdata(dev, phy_dev);
 104
 105         phy_dev->rstc = devm_reset_control_get(dev, "global");
 106         if (IS_ERR(phy_dev->rstc)) {
 107                 dev_err(dev, "failed to ctrl picoPHY reset\n");
 108                 return PTR_ERR(phy_dev->rstc);
 109         }
 110
 111         phy_dev->rstport = devm_reset_control_get(dev, "port");
 112         if (IS_ERR(phy_dev->rstport)) {
 113                 dev_err(dev, "failed to ctrl picoPHY reset\n");
 114                 return PTR_ERR(phy_dev->rstport);
 115         }
 116
 117         /* Reset port by default: only deassert it in phy init */
 118         reset_control_assert(phy_dev->rstport);
 119
 120         phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 121         if (IS_ERR(phy_dev->regmap)) {
 122                 dev_err(dev, "No syscfg phandle specified\n");
 123                 return PTR_ERR(phy_dev->regmap);
 124         }
 125
 126         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
 127         if (!res) {
 128                 dev_err(dev, "No ctrl reg found\n");
 129                 return -ENXIO;
 130         }
 131         phy_dev->ctrl = res->start;
 132
 133         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "param");
 134         if (!res) {
 135                 dev_err(dev, "No param reg found\n");
 136                 return -ENXIO;
 137         }
 138         phy_dev->param = res->start;
 139
 140         phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data, NULL);
 141         if (IS_ERR(phy)) {
 142                 dev_err(dev, "failed to create Display Port PHY\n");
 143                 return PTR_ERR(phy);
 144         }
 145
 146         phy_dev->phy = phy;
 147         phy_set_drvdata(phy, phy_dev);
 148
 149         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 150         if (IS_ERR(phy_provider))
 151                 return PTR_ERR(phy_provider);
 152
 153         dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
 154
 155         return 0;
 156 }
 157
 158 static const struct of_device_id stih407_usb2_picophy_of_match[] = {
 159         { .compatible = "st,stih407-usb2-phy" },
 160         { /*sentinel */ },
 161 };
 162
 163 MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
 164
 165 static struct platform_driver stih407_usb2_picophy_driver = {
 166         .probe = stih407_usb2_picophy_probe,
 167         .driver = {
 168                    .name = "stih407-usb-genphy",
 169                    .of_match_table = stih407_usb2_picophy_of_match,
 170                    }
 171 };
 172
 173 module_platform_driver(stih407_usb2_picophy_driver);
 174
 175 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
 176 MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
 177 MODULE_LICENSE("GPL v2");