drivers/phy/phy-lgm-usb.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Intel LGM USB PHY driver
   4  *
   5  * Copyright (C) 2020 Intel Corporation.
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/delay.h>
  10 #include <linux/iopoll.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regulator/consumer.h>
  15 #include <linux/reset.h>
  16 #include <linux/usb/phy.h>
  17 #include <linux/workqueue.h>
  18
  19 #define CTRL1_OFFSET            0x14
  20 #define SRAM_EXT_LD_DONE        BIT(25)
  21 #define SRAM_INIT_DONE          BIT(26)
  22
  23 #define TCPC_OFFSET             0x1014
  24 #define TCPC_MUX_CTL            GENMASK(1, 0)
  25 #define MUX_NC                  0
  26 #define MUX_USB                 1
  27 #define MUX_DP                  2
  28 #define MUX_USBDP               3
  29 #define TCPC_FLIPPED            BIT(2)
  30 #define TCPC_LOW_POWER_EN       BIT(3)
  31 #define TCPC_VALID              BIT(4)
  32 #define TCPC_CONN               \
  33         (TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_USB))
  34 #define TCPC_DISCONN            \
  35         (TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_NC) | TCPC_LOW_POWER_EN)
  36
  37 static const char *const PHY_RESETS[] = { "phy31", "phy", };
  38 static const char *const CTL_RESETS[] = { "apb", "ctrl", };
  39
  40 struct tca_apb {
  41         struct reset_control *resets[ARRAY_SIZE(PHY_RESETS)];
  42         struct regulator *vbus;
  43         struct work_struct wk;
  44         struct usb_phy phy;
  45
  46         bool regulator_enabled;
  47         bool phy_initialized;
  48         bool connected;
  49 };
  50
  51 static int get_flipped(struct tca_apb *ta, bool *flipped)
  52 {
  53         union extcon_property_value property;
  54         int ret;
  55
  56         ret = extcon_get_property(ta->phy.edev, EXTCON_USB_HOST,
  57                                   EXTCON_PROP_USB_TYPEC_POLARITY, &property);
  58         if (ret) {
  59                 dev_err(ta->phy.dev, "no polarity property from extcon\n");
  60                 return ret;
  61         }
  62
  63         *flipped = property.intval;
  64
  65         return 0;
  66 }
  67
  68 static int phy_init(struct usb_phy *phy)
  69 {
  70         struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
  71         void __iomem *ctrl1 = phy->io_priv + CTRL1_OFFSET;
  72         int val, ret, i;
  73
  74         if (ta->phy_initialized)
  75                 return 0;
  76
  77         for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
  78                 reset_control_deassert(ta->resets[i]);
  79
  80         ret = readl_poll_timeout(ctrl1, val, val & SRAM_INIT_DONE, 10, 10 * 1000);
  81         if (ret) {
  82                 dev_err(ta->phy.dev, "SRAM init failed, 0x%x\n", val);
  83                 return ret;
  84         }
  85
  86         writel(readl(ctrl1) | SRAM_EXT_LD_DONE, ctrl1);
  87
  88         ta->phy_initialized = true;
  89         if (!ta->phy.edev) {
  90                 writel(TCPC_CONN, ta->phy.io_priv + TCPC_OFFSET);
  91                 return phy->set_vbus(phy, true);
  92         }
  93
  94         schedule_work(&ta->wk);
  95
  96         return ret;
  97 }
  98
  99 static void phy_shutdown(struct usb_phy *phy)
 100 {
 101         struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
 102         int i;
 103
 104         if (!ta->phy_initialized)
 105                 return;
 106
 107         ta->phy_initialized = false;
 108         flush_work(&ta->wk);
 109         ta->phy.set_vbus(&ta->phy, false);
 110
 111         ta->connected = false;
 112         writel(TCPC_DISCONN, ta->phy.io_priv + TCPC_OFFSET);
 113
 114         for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
 115                 reset_control_assert(ta->resets[i]);
 116 }
 117
 118 static int phy_set_vbus(struct usb_phy *phy, int on)
 119 {
 120         struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
 121         int ret;
 122
 123         if (!!on == ta->regulator_enabled)
 124                 return 0;
 125
 126         if (on)
 127                 ret = regulator_enable(ta->vbus);
 128         else
 129                 ret = regulator_disable(ta->vbus);
 130
 131         if (!ret)
 132                 ta->regulator_enabled = on;
 133
 134         dev_dbg(ta->phy.dev, "set vbus: %d\n", on);
 135         return ret;
 136 }
 137
 138 static void tca_work(struct work_struct *work)
 139 {
 140         struct tca_apb *ta = container_of(work, struct tca_apb, wk);
 141         bool connected;
 142         bool flipped = false;
 143         u32 val;
 144         int ret;
 145
 146         ret = get_flipped(ta, &flipped);
 147         if (ret)
 148                 return;
 149
 150         connected = extcon_get_state(ta->phy.edev, EXTCON_USB_HOST);
 151         if (connected == ta->connected)
 152                 return;
 153
 154         ta->connected = connected;
 155         if (connected) {
 156                 val = TCPC_CONN;
 157                 if (flipped)
 158                         val |= TCPC_FLIPPED;
 159                 dev_dbg(ta->phy.dev, "connected%s\n", flipped ? " flipped" : "");
 160         } else {
 161                 val = TCPC_DISCONN;
 162                 dev_dbg(ta->phy.dev, "disconnected\n");
 163         }
 164
 165         writel(val, ta->phy.io_priv + TCPC_OFFSET);
 166
 167         ret = ta->phy.set_vbus(&ta->phy, connected);
 168         if (ret)
 169                 dev_err(ta->phy.dev, "failed to set VBUS\n");
 170 }
 171
 172 static int id_notifier(struct notifier_block *nb, unsigned long event, void *ptr)
 173 {
 174         struct tca_apb *ta = container_of(nb, struct tca_apb, phy.id_nb);
 175
 176         if (ta->phy_initialized)
 177                 schedule_work(&ta->wk);
 178
 179         return NOTIFY_DONE;
 180 }
 181
 182 static int vbus_notifier(struct notifier_block *nb, unsigned long evnt, void *ptr)
 183 {
 184         return NOTIFY_DONE;
 185 }
 186
 187 static int phy_probe(struct platform_device *pdev)
 188 {
 189         struct reset_control *resets[ARRAY_SIZE(CTL_RESETS)];
 190         struct device *dev = &pdev->dev;
 191         struct usb_phy *phy;
 192         struct tca_apb *ta;
 193         int i;
 194
 195         ta = devm_kzalloc(dev, sizeof(*ta), GFP_KERNEL);
 196         if (!ta)
 197                 return -ENOMEM;
 198
 199         platform_set_drvdata(pdev, ta);
 200         INIT_WORK(&ta->wk, tca_work);
 201
 202         phy = &ta->phy;
 203         phy->dev = dev;
 204         phy->label = dev_name(dev);
 205         phy->type = USB_PHY_TYPE_USB3;
 206         phy->init = phy_init;
 207         phy->shutdown = phy_shutdown;
 208         phy->set_vbus = phy_set_vbus;
 209         phy->id_nb.notifier_call = id_notifier;
 210         phy->vbus_nb.notifier_call = vbus_notifier;
 211
 212         phy->io_priv = devm_platform_ioremap_resource(pdev, 0);
 213         if (IS_ERR(phy->io_priv))
 214                 return PTR_ERR(phy->io_priv);
 215
 216         ta->vbus = devm_regulator_get(dev, "vbus");
 217         if (IS_ERR(ta->vbus))
 218                 return PTR_ERR(ta->vbus);
 219
 220         for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) {
 221                 resets[i] = devm_reset_control_get_exclusive(dev, CTL_RESETS[i]);
 222                 if (IS_ERR(resets[i])) {
 223                         dev_err(dev, "%s reset not found\n", CTL_RESETS[i]);
 224                         return PTR_ERR(resets[i]);
 225                 }
 226         }
 227
 228         for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) {
 229                 ta->resets[i] = devm_reset_control_get_exclusive(dev, PHY_RESETS[i]);
 230                 if (IS_ERR(ta->resets[i])) {
 231                         dev_err(dev, "%s reset not found\n", PHY_RESETS[i]);
 232                         return PTR_ERR(ta->resets[i]);
 233                 }
 234         }
 235
 236         for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
 237                 reset_control_assert(resets[i]);
 238
 239         for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
 240                 reset_control_assert(ta->resets[i]);
 241         /*
 242          * Out-of-band reset of the controller after PHY reset will cause
 243          * controller malfunctioning, so we should use in-band controller
 244          * reset only and leave the controller de-asserted here.
 245          */
 246         for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
 247                 reset_control_deassert(resets[i]);
 248
 249         /* Need to wait at least 20us after de-assert the controller */
 250         usleep_range(20, 100);
 251
 252         return usb_add_phy_dev(phy);
 253 }
 254
 255 static int phy_remove(struct platform_device *pdev)
 256 {
 257         struct tca_apb *ta = platform_get_drvdata(pdev);
 258
 259         usb_remove_phy(&ta->phy);
 260
 261         return 0;
 262 }
 263
 264 static const struct of_device_id intel_usb_phy_dt_ids[] = {
 265         { .compatible = "intel,lgm-usb-phy" },
 266         { }
 267 };
 268 MODULE_DEVICE_TABLE(of, intel_usb_phy_dt_ids);
 269
 270 static struct platform_driver lgm_phy_driver = {
 271         .driver = {
 272                 .name = "lgm-usb-phy",
 273                 .of_match_table = intel_usb_phy_dt_ids,
 274         },
 275         .probe = phy_probe,
 276         .remove = phy_remove,
 277 };
 278
 279 module_platform_driver(lgm_phy_driver);
 280
 281 MODULE_DESCRIPTION("Intel LGM USB PHY driver");
 282 MODULE_AUTHOR("Li Yin <yin1.li@intel.com>");
 283 MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@linux.intel.com>");
 284 MODULE_LICENSE("GPL v2");