drivers/usb/dwc3/dwc3-st.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /**
   3  * dwc3-st.c Support for dwc3 platform devices on ST Microelectronics platforms
   4  *
   5  * This is a small driver for the dwc3 to provide the glue logic
   6  * to configure the controller. Tested on STi platforms.
   7  *
   8  * Copyright (C) 2014 Stmicroelectronics
   9  *
  10  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  11  * Contributors: Aymen Bouattay <aymen.bouattay@st.com>
  12  *               Peter Griffin <peter.griffin@linaro.org>
  13  *
  14  * Inspired by dwc3-omap.c and dwc3-exynos.c.
  15  */
  16
  17 #include <linux/delay.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/io.h>
  20 #include <linux/ioport.h>
  21 #include <linux/kernel.h>
  22 #include <linux/mfd/syscon.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/of_platform.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28 #include <linux/regmap.h>
  29 #include <linux/reset.h>
  30 #include <linux/pinctrl/consumer.h>
  31 #include <linux/usb/of.h>
  32
  33 #include "core.h"
  34 #include "io.h"
  35
  36 /* glue registers */
  37 #define CLKRST_CTRL             0x00
  38 #define AUX_CLK_EN              BIT(0)
  39 #define SW_PIPEW_RESET_N        BIT(4)
  40 #define EXT_CFG_RESET_N         BIT(8)
  41 /*
  42  * 1'b0 : The host controller complies with the xHCI revision 0.96
  43  * 1'b1 : The host controller complies with the xHCI revision 1.0
  44  */
  45 #define XHCI_REVISION           BIT(12)
  46
  47 #define USB2_VBUS_MNGMNT_SEL1   0x2C
  48 /*
  49  * For all fields in USB2_VBUS_MNGMNT_SEL1
  50  * 2’b00 : Override value from Reg 0x30 is selected
  51  * 2’b01 : utmiotg_<signal_name> from usb3_top is selected
  52  * 2’b10 : pipew_<signal_name> from PIPEW instance is selected
  53  * 2’b11 : value is 1'b0
  54  */
  55 #define USB2_VBUS_REG30         0x0
  56 #define USB2_VBUS_UTMIOTG       0x1
  57 #define USB2_VBUS_PIPEW         0x2
  58 #define USB2_VBUS_ZERO          0x3
  59
  60 #define SEL_OVERRIDE_VBUSVALID(n)       (n << 0)
  61 #define SEL_OVERRIDE_POWERPRESENT(n)    (n << 4)
  62 #define SEL_OVERRIDE_BVALID(n)          (n << 8)
  63
  64 /* Static DRD configuration */
  65 #define USB3_CONTROL_MASK               0xf77
  66
  67 #define USB3_DEVICE_NOT_HOST            BIT(0)
  68 #define USB3_FORCE_VBUSVALID            BIT(1)
  69 #define USB3_DELAY_VBUSVALID            BIT(2)
  70 #define USB3_SEL_FORCE_OPMODE           BIT(4)
  71 #define USB3_FORCE_OPMODE(n)            (n << 5)
  72 #define USB3_SEL_FORCE_DPPULLDOWN2      BIT(8)
  73 #define USB3_FORCE_DPPULLDOWN2          BIT(9)
  74 #define USB3_SEL_FORCE_DMPULLDOWN2      BIT(10)
  75 #define USB3_FORCE_DMPULLDOWN2          BIT(11)
  76
  77 /**
  78  * struct st_dwc3 - dwc3-st driver private structure
  79  * @dev:                device pointer
  80  * @glue_base:          ioaddr for the glue registers
  81  * @regmap:             regmap pointer for getting syscfg
  82  * @syscfg_reg_off:     usb syscfg control offset
  83  * @dr_mode:            drd static host/device config
  84  * @rstc_pwrdn:         rest controller for powerdown signal
  85  * @rstc_rst:           reset controller for softreset signal
  86  */
  87
  88 struct st_dwc3 {
  89         struct device *dev;
  90         void __iomem *glue_base;
  91         struct regmap *regmap;
  92         int syscfg_reg_off;
  93         enum usb_dr_mode dr_mode;
  94         struct reset_control *rstc_pwrdn;
  95         struct reset_control *rstc_rst;
  96 };
  97
  98 static inline u32 st_dwc3_readl(void __iomem *base, u32 offset)
  99 {
 100         return readl_relaxed(base + offset);
 101 }
 102
 103 static inline void st_dwc3_writel(void __iomem *base, u32 offset, u32 value)
 104 {
 105         writel_relaxed(value, base + offset);
 106 }
 107
 108 /**
 109  * st_dwc3_drd_init: program the port
 110  * @dwc3_data: driver private structure
 111  * Description: this function is to program the port as either host or device
 112  * according to the static configuration passed from devicetree.
 113  * OTG and dual role are not yet supported!
 114  */
 115 static int st_dwc3_drd_init(struct st_dwc3 *dwc3_data)
 116 {
 117         u32 val;
 118         int err;
 119
 120         err = regmap_read(dwc3_data->regmap, dwc3_data->syscfg_reg_off, &val);
 121         if (err)
 122                 return err;
 123
 124         val &= USB3_CONTROL_MASK;
 125
 126         switch (dwc3_data->dr_mode) {
 127         case USB_DR_MODE_PERIPHERAL:
 128
 129                 val &= ~(USB3_DELAY_VBUSVALID
 130                         | USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
 131                         | USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
 132                         | USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
 133
 134                 /*
 135                  * USB3_PORT2_FORCE_VBUSVALID When '1' and when
 136                  * USB3_PORT2_DEVICE_NOT_HOST = 1, forces VBUSVLDEXT2 input
 137                  * of the pico PHY to 1.
 138                  */
 139
 140                 val |= USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID;
 141                 break;
 142
 143         case USB_DR_MODE_HOST:
 144
 145                 val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
 146                         | USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
 147                         | USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
 148                         | USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
 149
 150                 /*
 151                  * USB3_DELAY_VBUSVALID is ANDed with USB_C_VBUSVALID. Thus,
 152                  * when set to ‘0‘, it can delay the arrival of VBUSVALID
 153                  * information to VBUSVLDEXT2 input of the pico PHY.
 154                  * We don't want to do that so we set the bit to '1'.
 155                  */
 156
 157                 val |= USB3_DELAY_VBUSVALID;
 158                 break;
 159
 160         default:
 161                 dev_err(dwc3_data->dev, "Unsupported mode of operation %d\n",
 162                         dwc3_data->dr_mode);
 163                 return -EINVAL;
 164         }
 165
 166         return regmap_write(dwc3_data->regmap, dwc3_data->syscfg_reg_off, val);
 167 }
 168
 169 /**
 170  * st_dwc3_init: init the controller via glue logic
 171  * @dwc3_data: driver private structure
 172  */
 173 static void st_dwc3_init(struct st_dwc3 *dwc3_data)
 174 {
 175         u32 reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
 176
 177         reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
 178         reg &= ~SW_PIPEW_RESET_N;
 179         st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
 180
 181         /* configure mux for vbus, powerpresent and bvalid signals */
 182         reg = st_dwc3_readl(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1);
 183
 184         reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
 185                 SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
 186                 SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
 187
 188         st_dwc3_writel(dwc3_data->glue_base, USB2_VBUS_MNGMNT_SEL1, reg);
 189
 190         reg = st_dwc3_readl(dwc3_data->glue_base, CLKRST_CTRL);
 191         reg |= SW_PIPEW_RESET_N;
 192         st_dwc3_writel(dwc3_data->glue_base, CLKRST_CTRL, reg);
 193 }
 194
 195 static int st_dwc3_probe(struct platform_device *pdev)
 196 {
 197         struct st_dwc3 *dwc3_data;
 198         struct resource *res;
 199         struct device *dev = &pdev->dev;
 200         struct device_node *node = dev->of_node, *child;
 201         struct platform_device *child_pdev;
 202         struct regmap *regmap;
 203         int ret;
 204
 205         dwc3_data = devm_kzalloc(dev, sizeof(*dwc3_data), GFP_KERNEL);
 206         if (!dwc3_data)
 207                 return -ENOMEM;
 208
 209         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg-glue");
 210         dwc3_data->glue_base = devm_ioremap_resource(dev, res);
 211         if (IS_ERR(dwc3_data->glue_base))
 212                 return PTR_ERR(dwc3_data->glue_base);
 213
 214         regmap = syscon_regmap_lookup_by_phandle(node, "st,syscfg");
 215         if (IS_ERR(regmap))
 216                 return PTR_ERR(regmap);
 217
 218         dwc3_data->dev = dev;
 219         dwc3_data->regmap = regmap;
 220
 221         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
 222         if (!res) {
 223                 ret = -ENXIO;
 224                 goto undo_platform_dev_alloc;
 225         }
 226
 227         dwc3_data->syscfg_reg_off = res->start;
 228
 229         dev_vdbg(&pdev->dev, "glue-logic addr 0x%pK, syscfg-reg offset 0x%x\n",
 230                  dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
 231
 232         dwc3_data->rstc_pwrdn =
 233                 devm_reset_control_get_exclusive(dev, "powerdown");
 234         if (IS_ERR(dwc3_data->rstc_pwrdn)) {
 235                 dev_err(&pdev->dev, "could not get power controller\n");
 236                 ret = PTR_ERR(dwc3_data->rstc_pwrdn);
 237                 goto undo_platform_dev_alloc;
 238         }
 239
 240         /* Manage PowerDown */
 241         reset_control_deassert(dwc3_data->rstc_pwrdn);
 242
 243         dwc3_data->rstc_rst =
 244                 devm_reset_control_get_shared(dev, "softreset");
 245         if (IS_ERR(dwc3_data->rstc_rst)) {
 246                 dev_err(&pdev->dev, "could not get reset controller\n");
 247                 ret = PTR_ERR(dwc3_data->rstc_rst);
 248                 goto undo_powerdown;
 249         }
 250
 251         /* Manage SoftReset */
 252         reset_control_deassert(dwc3_data->rstc_rst);
 253
 254         child = of_get_child_by_name(node, "dwc3");
 255         if (!child) {
 256                 dev_err(&pdev->dev, "failed to find dwc3 core node\n");
 257                 ret = -ENODEV;
 258                 goto undo_softreset;
 259         }
 260
 261         /* Allocate and initialize the core */
 262         ret = of_platform_populate(node, NULL, NULL, dev);
 263         if (ret) {
 264                 dev_err(dev, "failed to add dwc3 core\n");
 265                 goto undo_softreset;
 266         }
 267
 268         child_pdev = of_find_device_by_node(child);
 269         if (!child_pdev) {
 270                 dev_err(dev, "failed to find dwc3 core device\n");
 271                 ret = -ENODEV;
 272                 goto undo_softreset;
 273         }
 274
 275         dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
 276
 277         /*
 278          * Configure the USB port as device or host according to the static
 279          * configuration passed from DT.
 280          * DRD is the only mode currently supported so this will be enhanced
 281          * as soon as OTG is available.
 282          */
 283         ret = st_dwc3_drd_init(dwc3_data);
 284         if (ret) {
 285                 dev_err(dev, "drd initialisation failed\n");
 286                 goto undo_softreset;
 287         }
 288
 289         /* ST glue logic init */
 290         st_dwc3_init(dwc3_data);
 291
 292         platform_set_drvdata(pdev, dwc3_data);
 293         return 0;
 294
 295 undo_softreset:
 296         reset_control_assert(dwc3_data->rstc_rst);
 297 undo_powerdown:
 298         reset_control_assert(dwc3_data->rstc_pwrdn);
 299 undo_platform_dev_alloc:
 300         platform_device_put(pdev);
 301         return ret;
 302 }
 303
 304 static int st_dwc3_remove(struct platform_device *pdev)
 305 {
 306         struct st_dwc3 *dwc3_data = platform_get_drvdata(pdev);
 307
 308         of_platform_depopulate(&pdev->dev);
 309
 310         reset_control_assert(dwc3_data->rstc_pwrdn);
 311         reset_control_assert(dwc3_data->rstc_rst);
 312
 313         return 0;
 314 }
 315
 316 #ifdef CONFIG_PM_SLEEP
 317 static int st_dwc3_suspend(struct device *dev)
 318 {
 319         struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
 320
 321         reset_control_assert(dwc3_data->rstc_pwrdn);
 322         reset_control_assert(dwc3_data->rstc_rst);
 323
 324         pinctrl_pm_select_sleep_state(dev);
 325
 326         return 0;
 327 }
 328
 329 static int st_dwc3_resume(struct device *dev)
 330 {
 331         struct st_dwc3 *dwc3_data = dev_get_drvdata(dev);
 332         int ret;
 333
 334         pinctrl_pm_select_default_state(dev);
 335
 336         reset_control_deassert(dwc3_data->rstc_pwrdn);
 337         reset_control_deassert(dwc3_data->rstc_rst);
 338
 339         ret = st_dwc3_drd_init(dwc3_data);
 340         if (ret) {
 341                 dev_err(dev, "drd initialisation failed\n");
 342                 return ret;
 343         }
 344
 345         /* ST glue logic init */
 346         st_dwc3_init(dwc3_data);
 347
 348         return 0;
 349 }
 350 #endif /* CONFIG_PM_SLEEP */
 351
 352 static SIMPLE_DEV_PM_OPS(st_dwc3_dev_pm_ops, st_dwc3_suspend, st_dwc3_resume);
 353
 354 static const struct of_device_id st_dwc3_match[] = {
 355         { .compatible = "st,stih407-dwc3" },
 356         { /* sentinel */ },
 357 };
 358
 359 MODULE_DEVICE_TABLE(of, st_dwc3_match);
 360
 361 static struct platform_driver st_dwc3_driver = {
 362         .probe = st_dwc3_probe,
 363         .remove = st_dwc3_remove,
 364         .driver = {
 365                 .name = "usb-st-dwc3",
 366                 .of_match_table = st_dwc3_match,
 367                 .pm = &st_dwc3_dev_pm_ops,
 368         },
 369 };
 370
 371 module_platform_driver(st_dwc3_driver);
 372
 373 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
 374 MODULE_DESCRIPTION("DesignWare USB3 STi Glue Layer");
 375 MODULE_LICENSE("GPL v2");