drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c

   1 /**
   2  * dwmac-sti.c - STMicroelectronics DWMAC Specific Glue layer
   3  *
   4  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
   5  * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
   6  *
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/stmmac.h>
  18 #include <linux/phy.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/regmap.h>
  21 #include <linux/clk.h>
  22 #include <linux/of.h>
  23 #include <linux/of_net.h>
  24
  25 /**
  26  *                      STi GMAC glue logic.
  27  *                      --------------------
  28  *
  29  *               _
  30  *              |  \
  31  *      --------|0  \ ETH_SEL_INTERNAL_NOTEXT_PHYCLK
  32  * phyclk       |    |___________________________________________
  33  *              |    |  |                       (phyclk-in)
  34  *      --------|1  /   |
  35  * int-clk      |_ /    |
  36  *                      |        _
  37  *                      |       |  \
  38  *                      |_______|1  \ ETH_SEL_TX_RETIME_CLK
  39  *                              |    |___________________________
  40  *                              |    |          (tx-retime-clk)
  41  *                       _______|0  /
  42  *                      |       |_ /
  43  *               _      |
  44  *              |  \    |
  45  *      --------|0  \   |
  46  * clk_125      |    |__|
  47  *              |    |  ETH_SEL_TXCLK_NOT_CLK125
  48  *      --------|1  /
  49  * txclk        |_ /
  50  *
  51  *
  52  * ETH_SEL_INTERNAL_NOTEXT_PHYCLK is valid only for RMII where PHY can
  53  * generate 50MHz clock or MAC can generate it.
  54  * This bit is configured by "st,ext-phyclk" property.
  55  *
  56  * ETH_SEL_TXCLK_NOT_CLK125 is only valid for gigabit modes, where the 125Mhz
  57  * clock either comes from clk-125 pin or txclk pin. This configuration is
  58  * totally driven by the board wiring. This bit is configured by
  59  * "st,tx-retime-src" property.
  60  *
  61  * TXCLK configuration is different for different phy interface modes
  62  * and changes according to link speed in modes like RGMII.
  63  *
  64  * Below table summarizes the clock requirement and clock sources for
  65  * supported phy interface modes with link speeds.
  66  * ________________________________________________
  67  *|  PHY_MODE   | 1000 Mbit Link | 100 Mbit Link   |
  68  * ------------------------------------------------
  69  *|     MII     |       n/a      |      25Mhz      |
  70  *|             |                |      txclk      |
  71  * ------------------------------------------------
  72  *|     GMII    |     125Mhz     |      25Mhz      |
  73  *|             |  clk-125/txclk |      txclk      |
  74  * ------------------------------------------------
  75  *|     RGMII   |     125Mhz     |      25Mhz      |
  76  *|             |  clk-125/txclk |      clkgen     |
  77  * ------------------------------------------------
  78  *|     RMII    |       n/a      |      25Mhz      |
  79  *|             |                |clkgen/phyclk-in |
  80  * ------------------------------------------------
  81  *
  82  * TX lines are always retimed with a clk, which can vary depending
  83  * on the board configuration. Below is the table of these bits
  84  * in eth configuration register depending on source of retime clk.
  85  *
  86  *---------------------------------------------------------------
  87  * src   | tx_rt_clk    | int_not_ext_phyclk    | txclk_n_clk125|
  88  *---------------------------------------------------------------
  89  * txclk |      0       |       n/a             |       1       |
  90  *---------------------------------------------------------------
  91  * ck_125|      0       |       n/a             |       0       |
  92  *---------------------------------------------------------------
  93  * phyclk|      1       |       0               |       n/a     |
  94  *---------------------------------------------------------------
  95  * clkgen|      1       |       1               |       n/a     |
  96  *---------------------------------------------------------------
  97  */
  98
  99  /* Register definition */
 100
 101  /* 3 bits [8:6]
 102   *  [6:6]      ETH_SEL_TXCLK_NOT_CLK125
 103   *  [7:7]      ETH_SEL_INTERNAL_NOTEXT_PHYCLK
 104   *  [8:8]      ETH_SEL_TX_RETIME_CLK
 105   *
 106   */
 107
 108 #define TX_RETIME_SRC_MASK              GENMASK(8, 6)
 109 #define ETH_SEL_TX_RETIME_CLK           BIT(8)
 110 #define ETH_SEL_INTERNAL_NOTEXT_PHYCLK  BIT(7)
 111 #define ETH_SEL_TXCLK_NOT_CLK125        BIT(6)
 112
 113 #define ENMII_MASK                      GENMASK(5, 5)
 114 #define ENMII                           BIT(5)
 115
 116 /**
 117  * 3 bits [4:2]
 118  *      000-GMII/MII
 119  *      001-RGMII
 120  *      010-SGMII
 121  *      100-RMII
 122 */
 123 #define MII_PHY_SEL_MASK                GENMASK(4, 2)
 124 #define ETH_PHY_SEL_RMII                BIT(4)
 125 #define ETH_PHY_SEL_SGMII               BIT(3)
 126 #define ETH_PHY_SEL_RGMII               BIT(2)
 127 #define ETH_PHY_SEL_GMII                0x0
 128 #define ETH_PHY_SEL_MII                 0x0
 129
 130 #define IS_PHY_IF_MODE_RGMII(iface)     (iface == PHY_INTERFACE_MODE_RGMII || \
 131                         iface == PHY_INTERFACE_MODE_RGMII_ID || \
 132                         iface == PHY_INTERFACE_MODE_RGMII_RXID || \
 133                         iface == PHY_INTERFACE_MODE_RGMII_TXID)
 134
 135 #define IS_PHY_IF_MODE_GBIT(iface)      (IS_PHY_IF_MODE_RGMII(iface) || \
 136                         iface == PHY_INTERFACE_MODE_GMII)
 137
 138 struct sti_dwmac {
 139         int interface;
 140         bool ext_phyclk;
 141         bool is_tx_retime_src_clk_125;
 142         struct clk *clk;
 143         int reg;
 144         struct device *dev;
 145         struct regmap *regmap;
 146 };
 147
 148 static u32 phy_intf_sels[] = {
 149         [PHY_INTERFACE_MODE_MII] = ETH_PHY_SEL_MII,
 150         [PHY_INTERFACE_MODE_GMII] = ETH_PHY_SEL_GMII,
 151         [PHY_INTERFACE_MODE_RGMII] = ETH_PHY_SEL_RGMII,
 152         [PHY_INTERFACE_MODE_RGMII_ID] = ETH_PHY_SEL_RGMII,
 153         [PHY_INTERFACE_MODE_SGMII] = ETH_PHY_SEL_SGMII,
 154         [PHY_INTERFACE_MODE_RMII] = ETH_PHY_SEL_RMII,
 155 };
 156
 157 enum {
 158         TX_RETIME_SRC_NA = 0,
 159         TX_RETIME_SRC_TXCLK = 1,
 160         TX_RETIME_SRC_CLK_125,
 161         TX_RETIME_SRC_PHYCLK,
 162         TX_RETIME_SRC_CLKGEN,
 163 };
 164
 165 static const char *const tx_retime_srcs[] = {
 166         [TX_RETIME_SRC_NA] = "",
 167         [TX_RETIME_SRC_TXCLK] = "txclk",
 168         [TX_RETIME_SRC_CLK_125] = "clk_125",
 169         [TX_RETIME_SRC_PHYCLK] = "phyclk",
 170         [TX_RETIME_SRC_CLKGEN] = "clkgen",
 171 };
 172
 173 static u32 tx_retime_val[] = {
 174         [TX_RETIME_SRC_TXCLK] = ETH_SEL_TXCLK_NOT_CLK125,
 175         [TX_RETIME_SRC_CLK_125] = 0x0,
 176         [TX_RETIME_SRC_PHYCLK] = ETH_SEL_TX_RETIME_CLK,
 177         [TX_RETIME_SRC_CLKGEN] = ETH_SEL_TX_RETIME_CLK |
 178             ETH_SEL_INTERNAL_NOTEXT_PHYCLK,
 179 };
 180
 181 static void setup_retime_src(struct sti_dwmac *dwmac, u32 spd)
 182 {
 183         u32 src = 0, freq = 0;
 184
 185         if (spd == SPEED_100) {
 186                 if (dwmac->interface == PHY_INTERFACE_MODE_MII ||
 187                     dwmac->interface == PHY_INTERFACE_MODE_GMII) {
 188                         src = TX_RETIME_SRC_TXCLK;
 189                 } else if (dwmac->interface == PHY_INTERFACE_MODE_RMII) {
 190                         if (dwmac->ext_phyclk) {
 191                                 src = TX_RETIME_SRC_PHYCLK;
 192                         } else {
 193                                 src = TX_RETIME_SRC_CLKGEN;
 194                                 freq = 50000000;
 195                         }
 196
 197                 } else if (IS_PHY_IF_MODE_RGMII(dwmac->interface)) {
 198                         src = TX_RETIME_SRC_CLKGEN;
 199                         freq = 25000000;
 200                 }
 201
 202                 if (src == TX_RETIME_SRC_CLKGEN && dwmac->clk)
 203                         clk_set_rate(dwmac->clk, freq);
 204
 205         } else if (spd == SPEED_1000) {
 206                 if (dwmac->is_tx_retime_src_clk_125)
 207                         src = TX_RETIME_SRC_CLK_125;
 208                 else
 209                         src = TX_RETIME_SRC_TXCLK;
 210         }
 211
 212         regmap_update_bits(dwmac->regmap, dwmac->reg,
 213                            TX_RETIME_SRC_MASK, tx_retime_val[src]);
 214 }
 215
 216 static void sti_dwmac_exit(struct platform_device *pdev, void *priv)
 217 {
 218         struct sti_dwmac *dwmac = priv;
 219
 220         if (dwmac->clk)
 221                 clk_disable_unprepare(dwmac->clk);
 222 }
 223
 224 static void sti_fix_mac_speed(void *priv, unsigned int spd)
 225 {
 226         struct sti_dwmac *dwmac = priv;
 227
 228         setup_retime_src(dwmac, spd);
 229
 230         return;
 231 }
 232
 233 static int sti_dwmac_parse_data(struct sti_dwmac *dwmac,
 234                                 struct platform_device *pdev)
 235 {
 236         struct resource *res;
 237         struct device *dev = &pdev->dev;
 238         struct device_node *np = dev->of_node;
 239         struct regmap *regmap;
 240         int err;
 241
 242         if (!np)
 243                 return -EINVAL;
 244
 245         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sti-ethconf");
 246         if (!res)
 247                 return -ENODATA;
 248
 249         regmap = syscon_regmap_lookup_by_phandle(np, "st,syscon");
 250         if (IS_ERR(regmap))
 251                 return PTR_ERR(regmap);
 252
 253         dwmac->dev = dev;
 254         dwmac->interface = of_get_phy_mode(np);
 255         dwmac->regmap = regmap;
 256         dwmac->reg = res->start;
 257         dwmac->ext_phyclk = of_property_read_bool(np, "st,ext-phyclk");
 258         dwmac->is_tx_retime_src_clk_125 = false;
 259
 260         if (IS_PHY_IF_MODE_GBIT(dwmac->interface)) {
 261                 const char *rs;
 262
 263                 err = of_property_read_string(np, "st,tx-retime-src", &rs);
 264                 if (err < 0) {
 265                         dev_err(dev, "st,tx-retime-src not specified\n");
 266                         return err;
 267                 }
 268
 269                 if (!strcasecmp(rs, "clk_125"))
 270                         dwmac->is_tx_retime_src_clk_125 = true;
 271         }
 272
 273         dwmac->clk = devm_clk_get(dev, "sti-ethclk");
 274
 275         if (IS_ERR(dwmac->clk))
 276                 dwmac->clk = NULL;
 277
 278         return 0;
 279 }
 280
 281 static int sti_dwmac_init(struct platform_device *pdev, void *priv)
 282 {
 283         struct sti_dwmac *dwmac = priv;
 284         struct regmap *regmap = dwmac->regmap;
 285         int iface = dwmac->interface;
 286         u32 reg = dwmac->reg;
 287         u32 val, spd;
 288
 289         if (dwmac->clk)
 290                 clk_prepare_enable(dwmac->clk);
 291
 292         regmap_update_bits(regmap, reg, MII_PHY_SEL_MASK, phy_intf_sels[iface]);
 293
 294         val = (iface == PHY_INTERFACE_MODE_REVMII) ? 0 : ENMII;
 295         regmap_update_bits(regmap, reg, ENMII_MASK, val);
 296
 297         if (IS_PHY_IF_MODE_GBIT(iface))
 298                 spd = SPEED_1000;
 299         else
 300                 spd = SPEED_100;
 301
 302         setup_retime_src(dwmac, spd);
 303
 304         return 0;
 305 }
 306
 307 static void *sti_dwmac_setup(struct platform_device *pdev)
 308 {
 309         struct sti_dwmac *dwmac;
 310         int ret;
 311
 312         dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
 313         if (!dwmac)
 314                 return ERR_PTR(-ENOMEM);
 315
 316         ret = sti_dwmac_parse_data(dwmac, pdev);
 317         if (ret) {
 318                 dev_err(&pdev->dev, "Unable to parse OF data\n");
 319                 return ERR_PTR(ret);
 320         }
 321
 322         return dwmac;
 323 }
 324
 325 const struct stmmac_of_data sti_gmac_data = {
 326         .fix_mac_speed = sti_fix_mac_speed,
 327         .setup = sti_dwmac_setup,
 328         .init = sti_dwmac_init,
 329         .exit = sti_dwmac_exit,
 330 };