LXR linux/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
  36struct 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
  46static 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
  55static 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
  72static 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
  86static 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
  92static 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
 161static const struct of_device_id stih407_usb2_picophy_of_match[] = {
 162        { .compatible = "st,stih407-usb2-phy" },
 163        { /*sentinel */ },
 164};
 165
 166MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
 167
 168static 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
 176module_platform_driver(stih407_usb2_picophy_driver);
 177
 178MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
 179MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
 180MODULE_LICENSE("GPL v2");
 181