Ramuthevar Vadivel Murugan | 1cce8f7 | 2020-08-28 10:23:12 +0800 | [diff] [blame] | 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"); |