drivers/usb/phy/phy-samsung-usb3.c

   1 /* linux/drivers/usb/phy/phy-samsung-usb3.c
   2  *
   3  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Author: Vivek Gautam <gautam.vivek@samsung.com>
   7  *
   8  * Samsung USB 3.0 PHY transceiver; talks to DWC3 controller.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/clk.h>
  23 #include <linux/delay.h>
  24 #include <linux/err.h>
  25 #include <linux/io.h>
  26 #include <linux/of.h>
  27 #include <linux/usb/samsung_usb_phy.h>
  28 #include <linux/platform_data/samsung-usbphy.h>
  29
  30 #include "phy-samsung-usb.h"
  31
  32 /*
  33  * Sets the phy clk as EXTREFCLK (XXTI) which is internal clock from clock core.
  34  */
  35 static u32 samsung_usb3phy_set_refclk(struct samsung_usbphy *sphy)
  36 {
  37         u32 reg;
  38         u32 refclk;
  39
  40         refclk = sphy->ref_clk_freq;
  41
  42         reg = PHYCLKRST_REFCLKSEL_EXT_REFCLK |
  43                 PHYCLKRST_FSEL(refclk);
  44
  45         switch (refclk) {
  46         case FSEL_CLKSEL_50M:
  47                 reg |= (PHYCLKRST_MPLL_MULTIPLIER_50M_REF |
  48                         PHYCLKRST_SSC_REFCLKSEL(0x00));
  49                 break;
  50         case FSEL_CLKSEL_20M:
  51                 reg |= (PHYCLKRST_MPLL_MULTIPLIER_20MHZ_REF |
  52                         PHYCLKRST_SSC_REFCLKSEL(0x00));
  53                 break;
  54         case FSEL_CLKSEL_19200K:
  55                 reg |= (PHYCLKRST_MPLL_MULTIPLIER_19200KHZ_REF |
  56                         PHYCLKRST_SSC_REFCLKSEL(0x88));
  57                 break;
  58         case FSEL_CLKSEL_24M:
  59         default:
  60                 reg |= (PHYCLKRST_MPLL_MULTIPLIER_24MHZ_REF |
  61                         PHYCLKRST_SSC_REFCLKSEL(0x88));
  62                 break;
  63         }
  64
  65         return reg;
  66 }
  67
  68 static void samsung_exynos5_usb3phy_enable(struct samsung_usbphy *sphy)
  69 {
  70         void __iomem *regs = sphy->regs;
  71         u32 phyparam0;
  72         u32 phyparam1;
  73         u32 linksystem;
  74         u32 phybatchg;
  75         u32 phytest;
  76         u32 phyclkrst;
  77
  78         /* Reset USB 3.0 PHY */
  79         writel(0x0, regs + EXYNOS5_DRD_PHYREG0);
  80
  81         phyparam0 = readl(regs + EXYNOS5_DRD_PHYPARAM0);
  82         /* Select PHY CLK source */
  83         phyparam0 &= ~PHYPARAM0_REF_USE_PAD;
  84         /* Set Loss-of-Signal Detector sensitivity */
  85         phyparam0 &= ~PHYPARAM0_REF_LOSLEVEL_MASK;
  86         phyparam0 |= PHYPARAM0_REF_LOSLEVEL;
  87         writel(phyparam0, regs + EXYNOS5_DRD_PHYPARAM0);
  88
  89         writel(0x0, regs + EXYNOS5_DRD_PHYRESUME);
  90
  91         /*
  92          * Setting the Frame length Adj value[6:1] to default 0x20
  93          * See xHCI 1.0 spec, 5.2.4
  94          */
  95         linksystem = LINKSYSTEM_XHCI_VERSION_CONTROL |
  96                         LINKSYSTEM_FLADJ(0x20);
  97         writel(linksystem, regs + EXYNOS5_DRD_LINKSYSTEM);
  98
  99         phyparam1 = readl(regs + EXYNOS5_DRD_PHYPARAM1);
 100         /* Set Tx De-Emphasis level */
 101         phyparam1 &= ~PHYPARAM1_PCS_TXDEEMPH_MASK;
 102         phyparam1 |= PHYPARAM1_PCS_TXDEEMPH;
 103         writel(phyparam1, regs + EXYNOS5_DRD_PHYPARAM1);
 104
 105         phybatchg = readl(regs + EXYNOS5_DRD_PHYBATCHG);
 106         phybatchg |= PHYBATCHG_UTMI_CLKSEL;
 107         writel(phybatchg, regs + EXYNOS5_DRD_PHYBATCHG);
 108
 109         /* PHYTEST POWERDOWN Control */
 110         phytest = readl(regs + EXYNOS5_DRD_PHYTEST);
 111         phytest &= ~(PHYTEST_POWERDOWN_SSP |
 112                         PHYTEST_POWERDOWN_HSP);
 113         writel(phytest, regs + EXYNOS5_DRD_PHYTEST);
 114
 115         /* UTMI Power Control */
 116         writel(PHYUTMI_OTGDISABLE, regs + EXYNOS5_DRD_PHYUTMI);
 117
 118         phyclkrst = samsung_usb3phy_set_refclk(sphy);
 119
 120         phyclkrst |= PHYCLKRST_PORTRESET |
 121                         /* Digital power supply in normal operating mode */
 122                         PHYCLKRST_RETENABLEN |
 123                         /* Enable ref clock for SS function */
 124                         PHYCLKRST_REF_SSP_EN |
 125                         /* Enable spread spectrum */
 126                         PHYCLKRST_SSC_EN |
 127                         /* Power down HS Bias and PLL blocks in suspend mode */
 128                         PHYCLKRST_COMMONONN;
 129
 130         writel(phyclkrst, regs + EXYNOS5_DRD_PHYCLKRST);
 131
 132         udelay(10);
 133
 134         phyclkrst &= ~(PHYCLKRST_PORTRESET);
 135         writel(phyclkrst, regs + EXYNOS5_DRD_PHYCLKRST);
 136 }
 137
 138 static void samsung_exynos5_usb3phy_disable(struct samsung_usbphy *sphy)
 139 {
 140         u32 phyutmi;
 141         u32 phyclkrst;
 142         u32 phytest;
 143         void __iomem *regs = sphy->regs;
 144
 145         phyutmi = PHYUTMI_OTGDISABLE |
 146                         PHYUTMI_FORCESUSPEND |
 147                         PHYUTMI_FORCESLEEP;
 148         writel(phyutmi, regs + EXYNOS5_DRD_PHYUTMI);
 149
 150         /* Resetting the PHYCLKRST enable bits to reduce leakage current */
 151         phyclkrst = readl(regs + EXYNOS5_DRD_PHYCLKRST);
 152         phyclkrst &= ~(PHYCLKRST_REF_SSP_EN |
 153                         PHYCLKRST_SSC_EN |
 154                         PHYCLKRST_COMMONONN);
 155         writel(phyclkrst, regs + EXYNOS5_DRD_PHYCLKRST);
 156
 157         /* Control PHYTEST to remove leakage current */
 158         phytest = readl(regs + EXYNOS5_DRD_PHYTEST);
 159         phytest |= (PHYTEST_POWERDOWN_SSP |
 160                         PHYTEST_POWERDOWN_HSP);
 161         writel(phytest, regs + EXYNOS5_DRD_PHYTEST);
 162 }
 163
 164 static int samsung_usb3phy_init(struct usb_phy *phy)
 165 {
 166         struct samsung_usbphy *sphy;
 167         unsigned long flags;
 168         int ret = 0;
 169
 170         sphy = phy_to_sphy(phy);
 171
 172         /* Enable the phy clock */
 173         ret = clk_prepare_enable(sphy->clk);
 174         if (ret) {
 175                 dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
 176                 return ret;
 177         }
 178
 179         spin_lock_irqsave(&sphy->lock, flags);
 180
 181         /* setting default phy-type for USB 3.0 */
 182         samsung_usbphy_set_type(&sphy->phy, USB_PHY_TYPE_DEVICE);
 183
 184         /* Disable phy isolation */
 185         if (sphy->drv_data->set_isolation)
 186                 sphy->drv_data->set_isolation(sphy, false);
 187
 188         /* Initialize usb phy registers */
 189         sphy->drv_data->phy_enable(sphy);
 190
 191         spin_unlock_irqrestore(&sphy->lock, flags);
 192
 193         /* Disable the phy clock */
 194         clk_disable_unprepare(sphy->clk);
 195
 196         return ret;
 197 }
 198
 199 /*
 200  * The function passed to the usb driver for phy shutdown
 201  */
 202 static void samsung_usb3phy_shutdown(struct usb_phy *phy)
 203 {
 204         struct samsung_usbphy *sphy;
 205         unsigned long flags;
 206
 207         sphy = phy_to_sphy(phy);
 208
 209         if (clk_prepare_enable(sphy->clk)) {
 210                 dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
 211                 return;
 212         }
 213
 214         spin_lock_irqsave(&sphy->lock, flags);
 215
 216         /* setting default phy-type for USB 3.0 */
 217         samsung_usbphy_set_type(&sphy->phy, USB_PHY_TYPE_DEVICE);
 218
 219         /* De-initialize usb phy registers */
 220         sphy->drv_data->phy_disable(sphy);
 221
 222         /* Enable phy isolation */
 223         if (sphy->drv_data->set_isolation)
 224                 sphy->drv_data->set_isolation(sphy, true);
 225
 226         spin_unlock_irqrestore(&sphy->lock, flags);
 227
 228         clk_disable_unprepare(sphy->clk);
 229 }
 230
 231 static int samsung_usb3phy_probe(struct platform_device *pdev)
 232 {
 233         struct samsung_usbphy *sphy;
 234         struct samsung_usbphy_data *pdata = pdev->dev.platform_data;
 235         struct device *dev = &pdev->dev;
 236         struct resource *phy_mem;
 237         void __iomem    *phy_base;
 238         struct clk *clk;
 239         int ret;
 240
 241         phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 242         phy_base = devm_ioremap_resource(dev, phy_mem);
 243         if (IS_ERR(phy_base))
 244                 return PTR_ERR(phy_base);
 245
 246         sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
 247         if (!sphy)
 248                 return -ENOMEM;
 249
 250         clk = devm_clk_get(dev, "usbdrd30");
 251         if (IS_ERR(clk)) {
 252                 dev_err(dev, "Failed to get device clock\n");
 253                 return PTR_ERR(clk);
 254         }
 255
 256         sphy->dev = dev;
 257
 258         if (dev->of_node) {
 259                 ret = samsung_usbphy_parse_dt(sphy);
 260                 if (ret < 0)
 261                         return ret;
 262         } else {
 263                 if (!pdata) {
 264                         dev_err(dev, "no platform data specified\n");
 265                         return -EINVAL;
 266                 }
 267         }
 268
 269         sphy->plat              = pdata;
 270         sphy->regs              = phy_base;
 271         sphy->clk               = clk;
 272         sphy->phy.dev           = sphy->dev;
 273         sphy->phy.label         = "samsung-usb3phy";
 274         sphy->phy.init          = samsung_usb3phy_init;
 275         sphy->phy.shutdown      = samsung_usb3phy_shutdown;
 276         sphy->drv_data          = samsung_usbphy_get_driver_data(pdev);
 277
 278         sphy->ref_clk_freq = samsung_usbphy_get_refclk_freq(sphy);
 279         if (sphy->ref_clk_freq < 0)
 280                 return -EINVAL;
 281
 282         spin_lock_init(&sphy->lock);
 283
 284         platform_set_drvdata(pdev, sphy);
 285
 286         return usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB3);
 287 }
 288
 289 static int samsung_usb3phy_remove(struct platform_device *pdev)
 290 {
 291         struct samsung_usbphy *sphy = platform_get_drvdata(pdev);
 292
 293         usb_remove_phy(&sphy->phy);
 294
 295         if (sphy->pmuregs)
 296                 iounmap(sphy->pmuregs);
 297         if (sphy->sysreg)
 298                 iounmap(sphy->sysreg);
 299
 300         return 0;
 301 }
 302
 303 static struct samsung_usbphy_drvdata usb3phy_exynos5 = {
 304         .cpu_type               = TYPE_EXYNOS5250,
 305         .devphy_en_mask         = EXYNOS_USBPHY_ENABLE,
 306         .rate_to_clksel         = samsung_usbphy_rate_to_clksel_4x12,
 307         .set_isolation          = samsung_usbphy_set_isolation_4210,
 308         .phy_enable             = samsung_exynos5_usb3phy_enable,
 309         .phy_disable            = samsung_exynos5_usb3phy_disable,
 310 };
 311
 312 #ifdef CONFIG_OF
 313 static const struct of_device_id samsung_usbphy_dt_match[] = {
 314         {
 315                 .compatible = "samsung,exynos5250-usb3phy",
 316                 .data = &usb3phy_exynos5
 317         },
 318         {},
 319 };
 320 MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
 321 #endif
 322
 323 static struct platform_device_id samsung_usbphy_driver_ids[] = {
 324         {
 325                 .name           = "exynos5250-usb3phy",
 326                 .driver_data    = (unsigned long)&usb3phy_exynos5,
 327         },
 328         {},
 329 };
 330
 331 MODULE_DEVICE_TABLE(platform, samsung_usbphy_driver_ids);
 332
 333 static struct platform_driver samsung_usb3phy_driver = {
 334         .probe          = samsung_usb3phy_probe,
 335         .remove         = samsung_usb3phy_remove,
 336         .id_table       = samsung_usbphy_driver_ids,
 337         .driver         = {
 338                 .name   = "samsung-usb3phy",
 339                 .owner  = THIS_MODULE,
 340                 .of_match_table = of_match_ptr(samsung_usbphy_dt_match),
 341         },
 342 };
 343
 344 module_platform_driver(samsung_usb3phy_driver);
 345
 346 MODULE_DESCRIPTION("Samsung USB 3.0 phy controller");
 347 MODULE_AUTHOR("Vivek Gautam <gautam.vivek@samsung.com>");
 348 MODULE_LICENSE("GPL");
 349 MODULE_ALIAS("platform:samsung-usb3phy");