LXR linux/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
  32struct 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
  42static 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
  51static 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
  68static 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
  82static 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
  88static 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
 157static const struct of_device_id stih407_usb2_picophy_of_match[] = {
 158        { .compatible = "st,stih407-usb2-phy" },
 159        { /*sentinel */ },
 160};
 161
 162MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
 163
 164static 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
 172module_platform_driver(stih407_usb2_picophy_driver);
 173
 174MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
 175MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
 176MODULE_LICENSE("GPL v2");
 177