linux/drivers/phy/st/phy-stm32-usbphyc.c
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   1// SPDX-Licence-Identifier: GPL-2.0
   2/*
   3 * STMicroelectronics STM32 USB PHY Controller driver
   4 *
   5 * Copyright (C) 2018 STMicroelectronics
   6 * Author(s): Amelie Delaunay <amelie.delaunay@st.com>.
   7 */
   8#include <linux/bitfield.h>
   9#include <linux/clk.h>
  10#include <linux/delay.h>
  11#include <linux/io.h>
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/of_platform.h>
  15#include <linux/phy/phy.h>
  16#include <linux/reset.h>
  17
  18#define STM32_USBPHYC_PLL       0x0
  19#define STM32_USBPHYC_MISC      0x8
  20#define STM32_USBPHYC_VERSION   0x3F4
  21
  22/* STM32_USBPHYC_PLL bit fields */
  23#define PLLNDIV                 GENMASK(6, 0)
  24#define PLLFRACIN               GENMASK(25, 10)
  25#define PLLEN                   BIT(26)
  26#define PLLSTRB                 BIT(27)
  27#define PLLSTRBYP               BIT(28)
  28#define PLLFRACCTL              BIT(29)
  29#define PLLDITHEN0              BIT(30)
  30#define PLLDITHEN1              BIT(31)
  31
  32/* STM32_USBPHYC_MISC bit fields */
  33#define SWITHOST                BIT(0)
  34
  35/* STM32_USBPHYC_VERSION bit fields */
  36#define MINREV                  GENMASK(3, 0)
  37#define MAJREV                  GENMASK(7, 4)
  38
  39static const char * const supplies_names[] = {
  40        "vdda1v1",      /* 1V1 */
  41        "vdda1v8",      /* 1V8 */
  42};
  43
  44#define NUM_SUPPLIES            ARRAY_SIZE(supplies_names)
  45
  46#define PLL_LOCK_TIME_US        100
  47#define PLL_PWR_DOWN_TIME_US    5
  48#define PLL_FVCO_MHZ            2880
  49#define PLL_INFF_MIN_RATE_HZ    19200000
  50#define PLL_INFF_MAX_RATE_HZ    38400000
  51#define HZ_PER_MHZ              1000000L
  52
  53struct pll_params {
  54        u8 ndiv;
  55        u16 frac;
  56};
  57
  58struct stm32_usbphyc_phy {
  59        struct phy *phy;
  60        struct stm32_usbphyc *usbphyc;
  61        struct regulator_bulk_data supplies[NUM_SUPPLIES];
  62        u32 index;
  63        bool active;
  64};
  65
  66struct stm32_usbphyc {
  67        struct device *dev;
  68        void __iomem *base;
  69        struct clk *clk;
  70        struct reset_control *rst;
  71        struct stm32_usbphyc_phy **phys;
  72        int nphys;
  73        int switch_setup;
  74        bool pll_enabled;
  75};
  76
  77static inline void stm32_usbphyc_set_bits(void __iomem *reg, u32 bits)
  78{
  79        writel_relaxed(readl_relaxed(reg) | bits, reg);
  80}
  81
  82static inline void stm32_usbphyc_clr_bits(void __iomem *reg, u32 bits)
  83{
  84        writel_relaxed(readl_relaxed(reg) & ~bits, reg);
  85}
  86
  87static void stm32_usbphyc_get_pll_params(u32 clk_rate, struct pll_params *pll_params)
  88{
  89        unsigned long long fvco, ndiv, frac;
  90
  91        /*    _
  92         *   | FVCO = INFF*2*(NDIV + FRACT/2^16) when DITHER_DISABLE[1] = 1
  93         *   | FVCO = 2880MHz
  94         *  <
  95         *   | NDIV = integer part of input bits to set the LDF
  96         *   |_FRACT = fractional part of input bits to set the LDF
  97         *  =>  PLLNDIV = integer part of (FVCO / (INFF*2))
  98         *  =>  PLLFRACIN = fractional part of(FVCO / INFF*2) * 2^16
  99         * <=>  PLLFRACIN = ((FVCO / (INFF*2)) - PLLNDIV) * 2^16
 100         */
 101        fvco = (unsigned long long)PLL_FVCO_MHZ * HZ_PER_MHZ;
 102
 103        ndiv = fvco;
 104        do_div(ndiv, (clk_rate * 2));
 105        pll_params->ndiv = (u8)ndiv;
 106
 107        frac = fvco * (1 << 16);
 108        do_div(frac, (clk_rate * 2));
 109        frac = frac - (ndiv * (1 << 16));
 110        pll_params->frac = (u16)frac;
 111}
 112
 113static int stm32_usbphyc_pll_init(struct stm32_usbphyc *usbphyc)
 114{
 115        struct pll_params pll_params;
 116        u32 clk_rate = clk_get_rate(usbphyc->clk);
 117        u32 ndiv, frac;
 118        u32 usbphyc_pll;
 119
 120        if ((clk_rate < PLL_INFF_MIN_RATE_HZ) ||
 121            (clk_rate > PLL_INFF_MAX_RATE_HZ)) {
 122                dev_err(usbphyc->dev, "input clk freq (%dHz) out of range\n",
 123                        clk_rate);
 124                return -EINVAL;
 125        }
 126
 127        stm32_usbphyc_get_pll_params(clk_rate, &pll_params);
 128        ndiv = FIELD_PREP(PLLNDIV, pll_params.ndiv);
 129        frac = FIELD_PREP(PLLFRACIN, pll_params.frac);
 130
 131        usbphyc_pll = PLLDITHEN1 | PLLDITHEN0 | PLLSTRBYP | ndiv;
 132
 133        if (pll_params.frac)
 134                usbphyc_pll |= PLLFRACCTL | frac;
 135
 136        writel_relaxed(usbphyc_pll, usbphyc->base + STM32_USBPHYC_PLL);
 137
 138        dev_dbg(usbphyc->dev, "input clk freq=%dHz, ndiv=%lu, frac=%lu\n",
 139                clk_rate, FIELD_GET(PLLNDIV, usbphyc_pll),
 140                FIELD_GET(PLLFRACIN, usbphyc_pll));
 141
 142        return 0;
 143}
 144
 145static bool stm32_usbphyc_has_one_phy_active(struct stm32_usbphyc *usbphyc)
 146{
 147        int i;
 148
 149        for (i = 0; i < usbphyc->nphys; i++)
 150                if (usbphyc->phys[i]->active)
 151                        return true;
 152
 153        return false;
 154}
 155
 156static int stm32_usbphyc_pll_enable(struct stm32_usbphyc *usbphyc)
 157{
 158        void __iomem *pll_reg = usbphyc->base + STM32_USBPHYC_PLL;
 159        bool pllen = (readl_relaxed(pll_reg) & PLLEN);
 160        int ret;
 161
 162        /* Check if one phy port has already configured the pll */
 163        if (pllen && stm32_usbphyc_has_one_phy_active(usbphyc))
 164                return 0;
 165
 166        if (pllen) {
 167                stm32_usbphyc_clr_bits(pll_reg, PLLEN);
 168                /* Wait for minimum width of powerdown pulse (ENABLE = Low) */
 169                udelay(PLL_PWR_DOWN_TIME_US);
 170        }
 171
 172        ret = stm32_usbphyc_pll_init(usbphyc);
 173        if (ret)
 174                return ret;
 175
 176        stm32_usbphyc_set_bits(pll_reg, PLLEN);
 177
 178        /* Wait for maximum lock time */
 179        udelay(PLL_LOCK_TIME_US);
 180
 181        if (!(readl_relaxed(pll_reg) & PLLEN)) {
 182                dev_err(usbphyc->dev, "PLLEN not set\n");
 183                return -EIO;
 184        }
 185
 186        return 0;
 187}
 188
 189static int stm32_usbphyc_pll_disable(struct stm32_usbphyc *usbphyc)
 190{
 191        void __iomem *pll_reg = usbphyc->base + STM32_USBPHYC_PLL;
 192
 193        /* Check if other phy port active */
 194        if (stm32_usbphyc_has_one_phy_active(usbphyc))
 195                return 0;
 196
 197        stm32_usbphyc_clr_bits(pll_reg, PLLEN);
 198        /* Wait for minimum width of powerdown pulse (ENABLE = Low) */
 199        udelay(PLL_PWR_DOWN_TIME_US);
 200
 201        if (readl_relaxed(pll_reg) & PLLEN) {
 202                dev_err(usbphyc->dev, "PLL not reset\n");
 203                return -EIO;
 204        }
 205
 206        return 0;
 207}
 208
 209static int stm32_usbphyc_phy_init(struct phy *phy)
 210{
 211        struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
 212        struct stm32_usbphyc *usbphyc = usbphyc_phy->usbphyc;
 213        int ret;
 214
 215        ret = stm32_usbphyc_pll_enable(usbphyc);
 216        if (ret)
 217                return ret;
 218
 219        usbphyc_phy->active = true;
 220
 221        return 0;
 222}
 223
 224static int stm32_usbphyc_phy_exit(struct phy *phy)
 225{
 226        struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
 227        struct stm32_usbphyc *usbphyc = usbphyc_phy->usbphyc;
 228
 229        usbphyc_phy->active = false;
 230
 231        return stm32_usbphyc_pll_disable(usbphyc);
 232}
 233
 234static int stm32_usbphyc_phy_power_on(struct phy *phy)
 235{
 236        struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
 237
 238        return regulator_bulk_enable(NUM_SUPPLIES, usbphyc_phy->supplies);
 239}
 240
 241static int stm32_usbphyc_phy_power_off(struct phy *phy)
 242{
 243        struct stm32_usbphyc_phy *usbphyc_phy = phy_get_drvdata(phy);
 244
 245        return regulator_bulk_disable(NUM_SUPPLIES, usbphyc_phy->supplies);
 246}
 247
 248static const struct phy_ops stm32_usbphyc_phy_ops = {
 249        .init = stm32_usbphyc_phy_init,
 250        .exit = stm32_usbphyc_phy_exit,
 251        .power_on = stm32_usbphyc_phy_power_on,
 252        .power_off = stm32_usbphyc_phy_power_off,
 253        .owner = THIS_MODULE,
 254};
 255
 256static void stm32_usbphyc_switch_setup(struct stm32_usbphyc *usbphyc,
 257                                       u32 utmi_switch)
 258{
 259        if (!utmi_switch)
 260                stm32_usbphyc_clr_bits(usbphyc->base + STM32_USBPHYC_MISC,
 261                                       SWITHOST);
 262        else
 263                stm32_usbphyc_set_bits(usbphyc->base + STM32_USBPHYC_MISC,
 264                                       SWITHOST);
 265        usbphyc->switch_setup = utmi_switch;
 266}
 267
 268static struct phy *stm32_usbphyc_of_xlate(struct device *dev,
 269                                          struct of_phandle_args *args)
 270{
 271        struct stm32_usbphyc *usbphyc = dev_get_drvdata(dev);
 272        struct stm32_usbphyc_phy *usbphyc_phy = NULL;
 273        struct device_node *phynode = args->np;
 274
 275        int port = 0;
 276
 277        for (port = 0; port < usbphyc->nphys; port++) {
 278                if (phynode == usbphyc->phys[port]->phy->dev.of_node) {
 279                        usbphyc_phy = usbphyc->phys[port];
 280                        break;
 281                }
 282        }
 283        if (!usbphyc_phy) {
 284                dev_err(dev, "failed to find phy\n");
 285                return ERR_PTR(-EINVAL);
 286        }
 287
 288        if (((usbphyc_phy->index == 0) && (args->args_count != 0)) ||
 289            ((usbphyc_phy->index == 1) && (args->args_count != 1))) {
 290                dev_err(dev, "invalid number of cells for phy port%d\n",
 291                        usbphyc_phy->index);
 292                return ERR_PTR(-EINVAL);
 293        }
 294
 295        /* Configure the UTMI switch for PHY port#2 */
 296        if (usbphyc_phy->index == 1) {
 297                if (usbphyc->switch_setup < 0) {
 298                        stm32_usbphyc_switch_setup(usbphyc, args->args[0]);
 299                } else {
 300                        if (args->args[0] != usbphyc->switch_setup) {
 301                                dev_err(dev, "phy port1 already used\n");
 302                                return ERR_PTR(-EBUSY);
 303                        }
 304                }
 305        }
 306
 307        return usbphyc_phy->phy;
 308}
 309
 310static int stm32_usbphyc_probe(struct platform_device *pdev)
 311{
 312        struct stm32_usbphyc *usbphyc;
 313        struct device *dev = &pdev->dev;
 314        struct device_node *child, *np = dev->of_node;
 315        struct resource *res;
 316        struct phy_provider *phy_provider;
 317        u32 version;
 318        int ret, port = 0;
 319
 320        usbphyc = devm_kzalloc(dev, sizeof(*usbphyc), GFP_KERNEL);
 321        if (!usbphyc)
 322                return -ENOMEM;
 323        usbphyc->dev = dev;
 324        dev_set_drvdata(dev, usbphyc);
 325
 326        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 327        usbphyc->base = devm_ioremap_resource(dev, res);
 328        if (IS_ERR(usbphyc->base))
 329                return PTR_ERR(usbphyc->base);
 330
 331        usbphyc->clk = devm_clk_get(dev, 0);
 332        if (IS_ERR(usbphyc->clk)) {
 333                ret = PTR_ERR(usbphyc->clk);
 334                dev_err(dev, "clk get failed: %d\n", ret);
 335                return ret;
 336        }
 337
 338        ret = clk_prepare_enable(usbphyc->clk);
 339        if (ret) {
 340                dev_err(dev, "clk enable failed: %d\n", ret);
 341                return ret;
 342        }
 343
 344        usbphyc->rst = devm_reset_control_get(dev, 0);
 345        if (!IS_ERR(usbphyc->rst)) {
 346                reset_control_assert(usbphyc->rst);
 347                udelay(2);
 348                reset_control_deassert(usbphyc->rst);
 349        }
 350
 351        usbphyc->switch_setup = -EINVAL;
 352        usbphyc->nphys = of_get_child_count(np);
 353        usbphyc->phys = devm_kcalloc(dev, usbphyc->nphys,
 354                                     sizeof(*usbphyc->phys), GFP_KERNEL);
 355        if (!usbphyc->phys) {
 356                ret = -ENOMEM;
 357                goto clk_disable;
 358        }
 359
 360        for_each_child_of_node(np, child) {
 361                struct stm32_usbphyc_phy *usbphyc_phy;
 362                struct phy *phy;
 363                u32 index;
 364                int i;
 365
 366                phy = devm_phy_create(dev, child, &stm32_usbphyc_phy_ops);
 367                if (IS_ERR(phy)) {
 368                        ret = PTR_ERR(phy);
 369                        if (ret != -EPROBE_DEFER)
 370                                dev_err(dev,
 371                                        "failed to create phy%d: %d\n", i, ret);
 372                        goto put_child;
 373                }
 374
 375                usbphyc_phy = devm_kzalloc(dev, sizeof(*usbphyc_phy),
 376                                           GFP_KERNEL);
 377                if (!usbphyc_phy) {
 378                        ret = -ENOMEM;
 379                        goto put_child;
 380                }
 381
 382                for (i = 0; i < NUM_SUPPLIES; i++)
 383                        usbphyc_phy->supplies[i].supply = supplies_names[i];
 384
 385                ret = devm_regulator_bulk_get(&phy->dev, NUM_SUPPLIES,
 386                                              usbphyc_phy->supplies);
 387                if (ret) {
 388                        if (ret != -EPROBE_DEFER)
 389                                dev_err(&phy->dev,
 390                                        "failed to get regulators: %d\n", ret);
 391                        goto put_child;
 392                }
 393
 394                ret = of_property_read_u32(child, "reg", &index);
 395                if (ret || index > usbphyc->nphys) {
 396                        dev_err(&phy->dev, "invalid reg property: %d\n", ret);
 397                        goto put_child;
 398                }
 399
 400                usbphyc->phys[port] = usbphyc_phy;
 401                phy_set_bus_width(phy, 8);
 402                phy_set_drvdata(phy, usbphyc_phy);
 403
 404                usbphyc->phys[port]->phy = phy;
 405                usbphyc->phys[port]->usbphyc = usbphyc;
 406                usbphyc->phys[port]->index = index;
 407                usbphyc->phys[port]->active = false;
 408
 409                port++;
 410        }
 411
 412        phy_provider = devm_of_phy_provider_register(dev,
 413                                                     stm32_usbphyc_of_xlate);
 414        if (IS_ERR(phy_provider)) {
 415                ret = PTR_ERR(phy_provider);
 416                dev_err(dev, "failed to register phy provider: %d\n", ret);
 417                goto clk_disable;
 418        }
 419
 420        version = readl_relaxed(usbphyc->base + STM32_USBPHYC_VERSION);
 421        dev_info(dev, "registered rev:%lu.%lu\n",
 422                 FIELD_GET(MAJREV, version), FIELD_GET(MINREV, version));
 423
 424        return 0;
 425
 426put_child:
 427        of_node_put(child);
 428clk_disable:
 429        clk_disable_unprepare(usbphyc->clk);
 430
 431        return ret;
 432}
 433
 434static int stm32_usbphyc_remove(struct platform_device *pdev)
 435{
 436        struct stm32_usbphyc *usbphyc = dev_get_drvdata(&pdev->dev);
 437
 438        clk_disable_unprepare(usbphyc->clk);
 439
 440        return 0;
 441}
 442
 443static const struct of_device_id stm32_usbphyc_of_match[] = {
 444        { .compatible = "st,stm32mp1-usbphyc", },
 445        { },
 446};
 447MODULE_DEVICE_TABLE(of, stm32_usbphyc_of_match);
 448
 449static struct platform_driver stm32_usbphyc_driver = {
 450        .probe = stm32_usbphyc_probe,
 451        .remove = stm32_usbphyc_remove,
 452        .driver = {
 453                .of_match_table = stm32_usbphyc_of_match,
 454                .name = "stm32-usbphyc",
 455        }
 456};
 457module_platform_driver(stm32_usbphyc_driver);
 458
 459MODULE_DESCRIPTION("STMicroelectronics STM32 USBPHYC driver");
 460MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
 461MODULE_LICENSE("GPL v2");
 462