drivers/phy/mediatek/phy-mtk-xfi-tphy.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MediaTek 10GE SerDes XFI T-PHY driver
   4  *
   5  * Copyright (c) 2024 Daniel Golle <daniel@makrotopia.org>
   6  *                    Bc-bocun Chen <bc-bocun.chen@mediatek.com>
   7  * based on mtk_usxgmii.c and mtk_sgmii.c found in MediaTek's SDK (GPL-2.0)
   8  * Copyright (c) 2022 MediaTek Inc.
   9  * Author: Henry Yen <henry.yen@mediatek.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/device.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/of.h>
  16 #include <linux/io.h>
  17 #include <linux/clk.h>
  18 #include <linux/reset.h>
  19 #include <linux/phy.h>
  20 #include <linux/phy/phy.h>
  21
  22 #include "phy-mtk-io.h"
  23
  24 #define MTK_XFI_TPHY_NUM_CLOCKS         2
  25
  26 #define REG_DIG_GLB_70                  0x0070
  27 #define  XTP_PCS_RX_EQ_IN_PROGRESS(x)   FIELD_PREP(GENMASK(25, 24), (x))
  28 #define  XTP_PCS_MODE_MASK              GENMASK(17, 16)
  29 #define  XTP_PCS_MODE(x)                FIELD_PREP(GENMASK(17, 16), (x))
  30 #define  XTP_PCS_RST_B                  BIT(15)
  31 #define  XTP_FRC_PCS_RST_B              BIT(14)
  32 #define  XTP_PCS_PWD_SYNC_MASK          GENMASK(13, 12)
  33 #define  XTP_PCS_PWD_SYNC(x)            FIELD_PREP(XTP_PCS_PWD_SYNC_MASK, (x))
  34 #define  XTP_PCS_PWD_ASYNC_MASK         GENMASK(11, 10)
  35 #define  XTP_PCS_PWD_ASYNC(x)           FIELD_PREP(XTP_PCS_PWD_ASYNC_MASK, (x))
  36 #define  XTP_FRC_PCS_PWD_ASYNC          BIT(8)
  37 #define  XTP_PCS_UPDT                   BIT(4)
  38 #define  XTP_PCS_IN_FR_RG               BIT(0)
  39
  40 #define REG_DIG_GLB_F4                  0x00f4
  41 #define  XFI_DPHY_PCS_SEL               BIT(0)
  42 #define   XFI_DPHY_PCS_SEL_SGMII        FIELD_PREP(XFI_DPHY_PCS_SEL, 1)
  43 #define   XFI_DPHY_PCS_SEL_USXGMII      FIELD_PREP(XFI_DPHY_PCS_SEL, 0)
  44 #define  XFI_DPHY_AD_SGDT_FRC_EN        BIT(5)
  45
  46 #define REG_DIG_LN_TRX_40               0x3040
  47 #define  XTP_LN_FRC_TX_DATA_EN          BIT(29)
  48 #define  XTP_LN_TX_DATA_EN              BIT(28)
  49
  50 #define REG_DIG_LN_TRX_B0               0x30b0
  51 #define  XTP_LN_FRC_TX_MACCK_EN         BIT(5)
  52 #define  XTP_LN_TX_MACCK_EN             BIT(4)
  53
  54 #define REG_ANA_GLB_D0                  0x90d0
  55 #define  XTP_GLB_USXGMII_SEL_MASK       GENMASK(3, 1)
  56 #define  XTP_GLB_USXGMII_SEL(x)         FIELD_PREP(GENMASK(3, 1), (x))
  57 #define  XTP_GLB_USXGMII_EN             BIT(0)
  58
  59 /**
  60  * struct mtk_xfi_tphy - run-time data of the XFI phy instance
  61  * @base: IO memory area to access phy registers.
  62  * @dev: Kernel device used to output prefixed debug info.
  63  * @reset: Reset control corresponding to the phy instance.
  64  * @clocks: All clocks required for the phy to operate.
  65  * @da_war: Enables work-around for 10GBase-R mode.
  66  */
  67 struct mtk_xfi_tphy {
  68         void __iomem            *base;
  69         struct device           *dev;
  70         struct reset_control    *reset;
  71         struct clk_bulk_data    clocks[MTK_XFI_TPHY_NUM_CLOCKS];
  72         bool                    da_war;
  73 };
  74
  75 /**
  76  * mtk_xfi_tphy_setup() - Setup phy for specified interface mode.
  77  * @xfi_tphy: XFI phy instance.
  78  * @interface: Ethernet interface mode
  79  *
  80  * The setup function is the condensed result of combining the 5 functions which
  81  * setup the phy in MediaTek's GPL licensed public SDK sources. They can be found
  82  * in mtk_sgmii.c[1] as well as mtk_usxgmii.c[2].
  83  *
  84  * Many magic values have been replaced by register and bit definitions, however,
  85  * that has not been possible in all cases. While the vendor driver uses a
  86  * sequence of 32-bit writes, here we try to only modify the actually required
  87  * bits.
  88  *
  89  * [1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/b72d6cba92bf9e29fb035c03052fa1e86664a25b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_sgmii.c
  90  *
  91  * [2]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/dec96a1d9b82cdcda4a56453fd0b453d4cab4b85/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  92  */
  93 static void mtk_xfi_tphy_setup(struct mtk_xfi_tphy *xfi_tphy,
  94                                phy_interface_t interface)
  95 {
  96         bool is_1g, is_2p5g, is_5g, is_10g, da_war, use_lynxi_pcs;
  97
  98         /* shorthands for specific clock speeds depending on interface mode */
  99         is_1g = interface == PHY_INTERFACE_MODE_1000BASEX ||
 100                 interface == PHY_INTERFACE_MODE_SGMII;
 101         is_2p5g = interface == PHY_INTERFACE_MODE_2500BASEX;
 102         is_5g = interface == PHY_INTERFACE_MODE_5GBASER;
 103         is_10g = interface == PHY_INTERFACE_MODE_10GBASER ||
 104                  interface == PHY_INTERFACE_MODE_USXGMII;
 105
 106         /* Is overriding 10GBase-R tuning value required? */
 107         da_war = xfi_tphy->da_war && (interface == PHY_INTERFACE_MODE_10GBASER);
 108
 109         /* configure input mux to either
 110          *  - USXGMII PCS (64b/66b coding) for 5G/10G
 111          *  - LynxI PCS (8b/10b coding) for 1G/2.5G
 112          */
 113         use_lynxi_pcs = is_1g || is_2p5g;
 114
 115         dev_dbg(xfi_tphy->dev, "setting up for mode %s\n", phy_modes(interface));
 116
 117         /* Setup PLL setting */
 118         mtk_phy_update_bits(xfi_tphy->base + 0x9024, 0x100000, is_10g ? 0x0 : 0x100000);
 119         mtk_phy_update_bits(xfi_tphy->base + 0x2020, 0x202000, is_5g ? 0x202000 : 0x0);
 120         mtk_phy_update_bits(xfi_tphy->base + 0x2030, 0x500, is_1g ? 0x0 : 0x500);
 121         mtk_phy_update_bits(xfi_tphy->base + 0x2034, 0xa00, is_1g ? 0x0 : 0xa00);
 122         mtk_phy_update_bits(xfi_tphy->base + 0x2040, 0x340000, is_1g ? 0x200000 : 0x140000);
 123
 124         /* Setup RXFE BW setting */
 125         mtk_phy_update_bits(xfi_tphy->base + 0x50f0, 0xc10, is_1g ? 0x410 : is_5g ? 0x800 : 0x400);
 126         mtk_phy_update_bits(xfi_tphy->base + 0x50e0, 0x4000, is_5g ? 0x0 : 0x4000);
 127
 128         /* Setup RX CDR setting */
 129         mtk_phy_update_bits(xfi_tphy->base + 0x506c, 0x30000, is_5g ? 0x0 : 0x30000);
 130         mtk_phy_update_bits(xfi_tphy->base + 0x5070, 0x670000, is_5g ? 0x620000 : 0x50000);
 131         mtk_phy_update_bits(xfi_tphy->base + 0x5074, 0x180000, is_5g ? 0x180000 : 0x0);
 132         mtk_phy_update_bits(xfi_tphy->base + 0x5078, 0xf000400, is_5g ? 0x8000000 :
 133                                                                         0x7000400);
 134         mtk_phy_update_bits(xfi_tphy->base + 0x507c, 0x5000500, is_5g ? 0x4000400 :
 135                                                                         0x1000100);
 136         mtk_phy_update_bits(xfi_tphy->base + 0x5080, 0x1410, is_1g ? 0x400 : is_5g ? 0x1010 : 0x0);
 137         mtk_phy_update_bits(xfi_tphy->base + 0x5084, 0x30300, is_1g ? 0x30300 :
 138                                                               is_5g ? 0x30100 :
 139                                                                       0x100);
 140         mtk_phy_update_bits(xfi_tphy->base + 0x5088, 0x60200, is_1g ? 0x20200 :
 141                                                               is_5g ? 0x40000 :
 142                                                                       0x20000);
 143
 144         /* Setting RXFE adaptation range setting */
 145         mtk_phy_update_bits(xfi_tphy->base + 0x50e4, 0xc0000, is_5g ? 0x0 : 0xc0000);
 146         mtk_phy_update_bits(xfi_tphy->base + 0x50e8, 0x40000, is_5g ? 0x0 : 0x40000);
 147         mtk_phy_update_bits(xfi_tphy->base + 0x50ec, 0xa00, is_1g ? 0x200 : 0x800);
 148         mtk_phy_update_bits(xfi_tphy->base + 0x50a8, 0xee0000, is_5g ? 0x800000 :
 149                                                                        0x6e0000);
 150         mtk_phy_update_bits(xfi_tphy->base + 0x6004, 0x190000, is_5g ? 0x0 : 0x190000);
 151
 152         if (is_10g)
 153                 writel(0x01423342, xfi_tphy->base + 0x00f8);
 154         else if (is_5g)
 155                 writel(0x00a132a1, xfi_tphy->base + 0x00f8);
 156         else if (is_2p5g)
 157                 writel(0x009c329c, xfi_tphy->base + 0x00f8);
 158         else
 159                 writel(0x00fa32fa, xfi_tphy->base + 0x00f8);
 160
 161         /* Force SGDT_OUT off and select PCS */
 162         mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_F4,
 163                             XFI_DPHY_AD_SGDT_FRC_EN | XFI_DPHY_PCS_SEL,
 164                             XFI_DPHY_AD_SGDT_FRC_EN |
 165                             (use_lynxi_pcs ? XFI_DPHY_PCS_SEL_SGMII :
 166                                              XFI_DPHY_PCS_SEL_USXGMII));
 167
 168         /* Force GLB_CKDET_OUT */
 169         mtk_phy_set_bits(xfi_tphy->base + 0x0030, 0xc00);
 170
 171         /* Force AEQ on */
 172         writel(XTP_PCS_RX_EQ_IN_PROGRESS(2) | XTP_PCS_PWD_SYNC(2) | XTP_PCS_PWD_ASYNC(2),
 173                xfi_tphy->base + REG_DIG_GLB_70);
 174
 175         usleep_range(1, 5);
 176         writel(XTP_LN_FRC_TX_DATA_EN, xfi_tphy->base + REG_DIG_LN_TRX_40);
 177
 178         /* Setup TX DA default value */
 179         mtk_phy_update_bits(xfi_tphy->base + 0x30b0, 0x30, 0x20);
 180         writel(0x00008a01, xfi_tphy->base + 0x3028);
 181         writel(0x0000a884, xfi_tphy->base + 0x302c);
 182         writel(0x00083002, xfi_tphy->base + 0x3024);
 183
 184         /* Setup RG default value */
 185         if (use_lynxi_pcs) {
 186                 writel(0x00011110, xfi_tphy->base + 0x3010);
 187                 writel(0x40704000, xfi_tphy->base + 0x3048);
 188         } else {
 189                 writel(0x00022220, xfi_tphy->base + 0x3010);
 190                 writel(0x0f020a01, xfi_tphy->base + 0x5064);
 191                 writel(0x06100600, xfi_tphy->base + 0x50b4);
 192                 if (interface == PHY_INTERFACE_MODE_USXGMII)
 193                         writel(0x40704000, xfi_tphy->base + 0x3048);
 194                 else
 195                         writel(0x47684100, xfi_tphy->base + 0x3048);
 196         }
 197
 198         if (is_1g)
 199                 writel(0x0000c000, xfi_tphy->base + 0x3064);
 200
 201         /* Setup RX EQ initial value */
 202         mtk_phy_update_bits(xfi_tphy->base + 0x3050, 0xa8000000,
 203                             (interface != PHY_INTERFACE_MODE_10GBASER) ? 0xa8000000 : 0x0);
 204         mtk_phy_update_bits(xfi_tphy->base + 0x3054, 0xaa,
 205                             (interface != PHY_INTERFACE_MODE_10GBASER) ? 0xaa : 0x0);
 206
 207         if (!use_lynxi_pcs)
 208                 writel(0x00000f00, xfi_tphy->base + 0x306c);
 209         else if (is_2p5g)
 210                 writel(0x22000f00, xfi_tphy->base + 0x306c);
 211         else
 212                 writel(0x20200f00, xfi_tphy->base + 0x306c);
 213
 214         mtk_phy_update_bits(xfi_tphy->base + 0xa008, 0x10000, da_war ? 0x10000 : 0x0);
 215
 216         mtk_phy_update_bits(xfi_tphy->base + 0xa060, 0x50000, use_lynxi_pcs ? 0x50000 : 0x40000);
 217
 218         /* Setup PHYA speed */
 219         mtk_phy_update_bits(xfi_tphy->base + REG_ANA_GLB_D0,
 220                             XTP_GLB_USXGMII_SEL_MASK | XTP_GLB_USXGMII_EN,
 221                             is_10g ?  XTP_GLB_USXGMII_SEL(0) :
 222                             is_5g ?   XTP_GLB_USXGMII_SEL(1) :
 223                             is_2p5g ? XTP_GLB_USXGMII_SEL(2) :
 224                                       XTP_GLB_USXGMII_SEL(3));
 225         mtk_phy_set_bits(xfi_tphy->base + REG_ANA_GLB_D0, XTP_GLB_USXGMII_EN);
 226
 227         /* Release reset */
 228         mtk_phy_set_bits(xfi_tphy->base + REG_DIG_GLB_70,
 229                          XTP_PCS_RST_B | XTP_FRC_PCS_RST_B);
 230         usleep_range(150, 500);
 231
 232         /* Switch to P0 */
 233         mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
 234                             XTP_PCS_IN_FR_RG |
 235                             XTP_FRC_PCS_PWD_ASYNC |
 236                             XTP_PCS_PWD_ASYNC_MASK |
 237                             XTP_PCS_PWD_SYNC_MASK |
 238                             XTP_PCS_UPDT,
 239                             XTP_PCS_IN_FR_RG |
 240                             XTP_FRC_PCS_PWD_ASYNC |
 241                             XTP_PCS_UPDT);
 242         usleep_range(1, 5);
 243
 244         mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_70, XTP_PCS_UPDT);
 245         usleep_range(15, 50);
 246
 247         if (use_lynxi_pcs) {
 248                 /* Switch to Gen2 */
 249                 mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
 250                                     XTP_PCS_MODE_MASK | XTP_PCS_UPDT,
 251                                     XTP_PCS_MODE(1) | XTP_PCS_UPDT);
 252         } else {
 253                 /* Switch to Gen3 */
 254                 mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
 255                                     XTP_PCS_MODE_MASK | XTP_PCS_UPDT,
 256                                     XTP_PCS_MODE(2) | XTP_PCS_UPDT);
 257         }
 258         usleep_range(1, 5);
 259
 260         mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_70, XTP_PCS_UPDT);
 261
 262         usleep_range(100, 500);
 263
 264         /* Enable MAC CK */
 265         mtk_phy_set_bits(xfi_tphy->base + REG_DIG_LN_TRX_B0, XTP_LN_TX_MACCK_EN);
 266         mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_F4, XFI_DPHY_AD_SGDT_FRC_EN);
 267
 268         /* Enable TX data */
 269         mtk_phy_set_bits(xfi_tphy->base + REG_DIG_LN_TRX_40,
 270                          XTP_LN_FRC_TX_DATA_EN | XTP_LN_TX_DATA_EN);
 271         usleep_range(400, 1000);
 272 }
 273
 274 /**
 275  * mtk_xfi_tphy_set_mode() - Setup phy for specified interface mode.
 276  *
 277  * @phy: Phy instance.
 278  * @mode: Only PHY_MODE_ETHERNET is supported.
 279  * @submode: An Ethernet interface mode.
 280  *
 281  * Validate selected mode and call function mtk_xfi_tphy_setup().
 282  *
 283  * Return:
 284  * * %0 - OK
 285  * * %-EINVAL - invalid mode
 286  */
 287 static int mtk_xfi_tphy_set_mode(struct phy *phy, enum phy_mode mode, int
 288                                  submode)
 289 {
 290         struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);
 291
 292         if (mode != PHY_MODE_ETHERNET)
 293                 return -EINVAL;
 294
 295         switch (submode) {
 296         case PHY_INTERFACE_MODE_1000BASEX:
 297         case PHY_INTERFACE_MODE_2500BASEX:
 298         case PHY_INTERFACE_MODE_SGMII:
 299         case PHY_INTERFACE_MODE_5GBASER:
 300         case PHY_INTERFACE_MODE_10GBASER:
 301         case PHY_INTERFACE_MODE_USXGMII:
 302                 mtk_xfi_tphy_setup(xfi_tphy, submode);
 303                 return 0;
 304         default:
 305                 return -EINVAL;
 306         }
 307 }
 308
 309 /**
 310  * mtk_xfi_tphy_reset() - Reset the phy.
 311  *
 312  * @phy: Phy instance.
 313  *
 314  * Reset the phy using the external reset controller.
 315  *
 316  * Return:
 317  * %0 - OK
 318  */
 319 static int mtk_xfi_tphy_reset(struct phy *phy)
 320 {
 321         struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);
 322
 323         reset_control_assert(xfi_tphy->reset);
 324         usleep_range(100, 500);
 325         reset_control_deassert(xfi_tphy->reset);
 326         usleep_range(1, 10);
 327
 328         return 0;
 329 }
 330
 331 /**
 332  * mtk_xfi_tphy_power_on() - Power-on the phy.
 333  *
 334  * @phy: Phy instance.
 335  *
 336  * Prepare and enable all clocks required for the phy to operate.
 337  *
 338  * Return:
 339  * See clk_bulk_prepare_enable().
 340  */
 341 static int mtk_xfi_tphy_power_on(struct phy *phy)
 342 {
 343         struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);
 344
 345         return clk_bulk_prepare_enable(MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);
 346 }
 347
 348 /**
 349  * mtk_xfi_tphy_power_off() - Power-off the phy.
 350  *
 351  * @phy: Phy instance.
 352  *
 353  * Disable and unprepare all clocks previously enabled.
 354  *
 355  * Return:
 356  * See clk_bulk_prepare_disable().
 357  */
 358 static int mtk_xfi_tphy_power_off(struct phy *phy)
 359 {
 360         struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);
 361
 362         clk_bulk_disable_unprepare(MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);
 363
 364         return 0;
 365 }
 366
 367 static const struct phy_ops mtk_xfi_tphy_ops = {
 368         .power_on       = mtk_xfi_tphy_power_on,
 369         .power_off      = mtk_xfi_tphy_power_off,
 370         .set_mode       = mtk_xfi_tphy_set_mode,
 371         .reset          = mtk_xfi_tphy_reset,
 372         .owner          = THIS_MODULE,
 373 };
 374
 375 /**
 376  * mtk_xfi_tphy_probe() - Probe phy instance from Device Tree.
 377  * @pdev: Matching platform device.
 378  *
 379  * The probe function gets IO resource, clocks, reset controller and
 380  * whether the DA work-around for 10GBase-R is required from Device Tree and
 381  * allocates memory for holding that information in a struct mtk_xfi_tphy.
 382  *
 383  * Return:
 384  * * %0       - OK
 385  * * %-ENODEV - Missing associated Device Tree node (should never happen).
 386  * * %-ENOMEM - Out of memory.
 387  * * Any error value which devm_platform_ioremap_resource(),
 388  *   devm_clk_bulk_get(), devm_reset_control_get_exclusive(),
 389  *   devm_phy_create() or devm_of_phy_provider_register() may return.
 390  */
 391 static int mtk_xfi_tphy_probe(struct platform_device *pdev)
 392 {
 393         struct device_node *np = pdev->dev.of_node;
 394         struct phy_provider *phy_provider;
 395         struct mtk_xfi_tphy *xfi_tphy;
 396         struct phy *phy;
 397         int ret;
 398
 399         if (!np)
 400                 return -ENODEV;
 401
 402         xfi_tphy = devm_kzalloc(&pdev->dev, sizeof(*xfi_tphy), GFP_KERNEL);
 403         if (!xfi_tphy)
 404                 return -ENOMEM;
 405
 406         xfi_tphy->base = devm_platform_ioremap_resource(pdev, 0);
 407         if (IS_ERR(xfi_tphy->base))
 408                 return PTR_ERR(xfi_tphy->base);
 409
 410         xfi_tphy->dev = &pdev->dev;
 411         xfi_tphy->clocks[0].id = "topxtal";
 412         xfi_tphy->clocks[1].id = "xfipll";
 413         ret = devm_clk_bulk_get(&pdev->dev, MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);
 414         if (ret)
 415                 return ret;
 416
 417         xfi_tphy->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 418         if (IS_ERR(xfi_tphy->reset))
 419                 return PTR_ERR(xfi_tphy->reset);
 420
 421         xfi_tphy->da_war = of_property_read_bool(np, "mediatek,usxgmii-performance-errata");
 422
 423         phy = devm_phy_create(&pdev->dev, NULL, &mtk_xfi_tphy_ops);
 424         if (IS_ERR(phy))
 425                 return PTR_ERR(phy);
 426
 427         phy_set_drvdata(phy, xfi_tphy);
 428         phy_provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
 429
 430         return PTR_ERR_OR_ZERO(phy_provider);
 431 }
 432
 433 static const struct of_device_id mtk_xfi_tphy_match[] = {
 434         { .compatible = "mediatek,mt7988-xfi-tphy", },
 435         { /* sentinel */ }
 436 };
 437 MODULE_DEVICE_TABLE(of, mtk_xfi_tphy_match);
 438
 439 static struct platform_driver mtk_xfi_tphy_driver = {
 440         .probe = mtk_xfi_tphy_probe,
 441         .driver = {
 442                 .name = "mtk-xfi-tphy",
 443                 .of_match_table = mtk_xfi_tphy_match,
 444         },
 445 };
 446 module_platform_driver(mtk_xfi_tphy_driver);
 447
 448 MODULE_DESCRIPTION("MediaTek 10GE SerDes XFI T-PHY driver");
 449 MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>");
 450 MODULE_AUTHOR("Bc-bocun Chen <bc-bocun.chen@mediatek.com>");
 451 MODULE_LICENSE("GPL");