drivers/net/mdio/mdio-mux-meson-g12a.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2019 Baylibre, SAS.
   3  * Author: Jerome Brunet <jbrunet@baylibre.com>
   4  */
   5
   6 #include <linux/bitfield.h>
   7 #include <linux/clk.h>
   8 #include <linux/clk-provider.h>
   9 #include <linux/device.h>
  10 #include <linux/io.h>
  11 #include <linux/iopoll.h>
  12 #include <linux/mdio-mux.h>
  13 #include <linux/module.h>
  14 #include <linux/phy.h>
  15 #include <linux/platform_device.h>
  16
  17 #define ETH_PLL_STS             0x40
  18 #define ETH_PLL_CTL0            0x44
  19 #define  PLL_CTL0_LOCK_DIG      BIT(30)
  20 #define  PLL_CTL0_RST           BIT(29)
  21 #define  PLL_CTL0_EN            BIT(28)
  22 #define  PLL_CTL0_SEL           BIT(23)
  23 #define  PLL_CTL0_N             GENMASK(14, 10)
  24 #define  PLL_CTL0_M             GENMASK(8, 0)
  25 #define  PLL_LOCK_TIMEOUT       1000000
  26 #define  PLL_MUX_NUM_PARENT     2
  27 #define ETH_PLL_CTL1            0x48
  28 #define ETH_PLL_CTL2            0x4c
  29 #define ETH_PLL_CTL3            0x50
  30 #define ETH_PLL_CTL4            0x54
  31 #define ETH_PLL_CTL5            0x58
  32 #define ETH_PLL_CTL6            0x5c
  33 #define ETH_PLL_CTL7            0x60
  34
  35 #define ETH_PHY_CNTL0           0x80
  36 #define   EPHY_G12A_ID          0x33010180
  37 #define ETH_PHY_CNTL1           0x84
  38 #define  PHY_CNTL1_ST_MODE      GENMASK(2, 0)
  39 #define  PHY_CNTL1_ST_PHYADD    GENMASK(7, 3)
  40 #define   EPHY_DFLT_ADD         8
  41 #define  PHY_CNTL1_MII_MODE     GENMASK(15, 14)
  42 #define   EPHY_MODE_RMII        0x1
  43 #define  PHY_CNTL1_CLK_EN       BIT(16)
  44 #define  PHY_CNTL1_CLKFREQ      BIT(17)
  45 #define  PHY_CNTL1_PHY_ENB      BIT(18)
  46 #define ETH_PHY_CNTL2           0x88
  47 #define  PHY_CNTL2_USE_INTERNAL BIT(5)
  48 #define  PHY_CNTL2_SMI_SRC_MAC  BIT(6)
  49 #define  PHY_CNTL2_RX_CLK_EPHY  BIT(9)
  50
  51 #define MESON_G12A_MDIO_EXTERNAL_ID 0
  52 #define MESON_G12A_MDIO_INTERNAL_ID 1
  53
  54 struct g12a_mdio_mux {
  55         bool pll_is_enabled;
  56         void __iomem *regs;
  57         void *mux_handle;
  58         struct clk *pclk;
  59         struct clk *pll;
  60 };
  61
  62 struct g12a_ephy_pll {
  63         void __iomem *base;
  64         struct clk_hw hw;
  65 };
  66
  67 #define g12a_ephy_pll_to_dev(_hw)                       \
  68         container_of(_hw, struct g12a_ephy_pll, hw)
  69
  70 static unsigned long g12a_ephy_pll_recalc_rate(struct clk_hw *hw,
  71                                                unsigned long parent_rate)
  72 {
  73         struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
  74         u32 val, m, n;
  75
  76         val = readl(pll->base + ETH_PLL_CTL0);
  77         m = FIELD_GET(PLL_CTL0_M, val);
  78         n = FIELD_GET(PLL_CTL0_N, val);
  79
  80         return parent_rate * m / n;
  81 }
  82
  83 static int g12a_ephy_pll_enable(struct clk_hw *hw)
  84 {
  85         struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
  86         u32 val = readl(pll->base + ETH_PLL_CTL0);
  87
  88         /* Apply both enable an reset */
  89         val |= PLL_CTL0_RST | PLL_CTL0_EN;
  90         writel(val, pll->base + ETH_PLL_CTL0);
  91
  92         /* Clear the reset to let PLL lock */
  93         val &= ~PLL_CTL0_RST;
  94         writel(val, pll->base + ETH_PLL_CTL0);
  95
  96         /* Poll on the digital lock instead of the usual analog lock
  97          * This is done because bit 31 is unreliable on some SoC. Bit
  98          * 31 may indicate that the PLL is not lock even though the clock
  99          * is actually running
 100          */
 101         return readl_poll_timeout(pll->base + ETH_PLL_CTL0, val,
 102                                   val & PLL_CTL0_LOCK_DIG, 0, PLL_LOCK_TIMEOUT);
 103 }
 104
 105 static void g12a_ephy_pll_disable(struct clk_hw *hw)
 106 {
 107         struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
 108         u32 val;
 109
 110         val = readl(pll->base + ETH_PLL_CTL0);
 111         val &= ~PLL_CTL0_EN;
 112         val |= PLL_CTL0_RST;
 113         writel(val, pll->base + ETH_PLL_CTL0);
 114 }
 115
 116 static int g12a_ephy_pll_is_enabled(struct clk_hw *hw)
 117 {
 118         struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
 119         unsigned int val;
 120
 121         val = readl(pll->base + ETH_PLL_CTL0);
 122
 123         return (val & PLL_CTL0_LOCK_DIG) ? 1 : 0;
 124 }
 125
 126 static int g12a_ephy_pll_init(struct clk_hw *hw)
 127 {
 128         struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
 129
 130         /* Apply PLL HW settings */
 131         writel(0x29c0040a, pll->base + ETH_PLL_CTL0);
 132         writel(0x927e0000, pll->base + ETH_PLL_CTL1);
 133         writel(0xac5f49e5, pll->base + ETH_PLL_CTL2);
 134         writel(0x00000000, pll->base + ETH_PLL_CTL3);
 135         writel(0x00000000, pll->base + ETH_PLL_CTL4);
 136         writel(0x20200000, pll->base + ETH_PLL_CTL5);
 137         writel(0x0000c002, pll->base + ETH_PLL_CTL6);
 138         writel(0x00000023, pll->base + ETH_PLL_CTL7);
 139
 140         return 0;
 141 }
 142
 143 static const struct clk_ops g12a_ephy_pll_ops = {
 144         .recalc_rate    = g12a_ephy_pll_recalc_rate,
 145         .is_enabled     = g12a_ephy_pll_is_enabled,
 146         .enable         = g12a_ephy_pll_enable,
 147         .disable        = g12a_ephy_pll_disable,
 148         .init           = g12a_ephy_pll_init,
 149 };
 150
 151 static int g12a_enable_internal_mdio(struct g12a_mdio_mux *priv)
 152 {
 153         int ret;
 154
 155         /* Enable the phy clock */
 156         if (!priv->pll_is_enabled) {
 157                 ret = clk_prepare_enable(priv->pll);
 158                 if (ret)
 159                         return ret;
 160         }
 161
 162         priv->pll_is_enabled = true;
 163
 164         /* Initialize ephy control */
 165         writel(EPHY_G12A_ID, priv->regs + ETH_PHY_CNTL0);
 166         writel(FIELD_PREP(PHY_CNTL1_ST_MODE, 3) |
 167                FIELD_PREP(PHY_CNTL1_ST_PHYADD, EPHY_DFLT_ADD) |
 168                FIELD_PREP(PHY_CNTL1_MII_MODE, EPHY_MODE_RMII) |
 169                PHY_CNTL1_CLK_EN |
 170                PHY_CNTL1_CLKFREQ |
 171                PHY_CNTL1_PHY_ENB,
 172                priv->regs + ETH_PHY_CNTL1);
 173         writel(PHY_CNTL2_USE_INTERNAL |
 174                PHY_CNTL2_SMI_SRC_MAC |
 175                PHY_CNTL2_RX_CLK_EPHY,
 176                priv->regs + ETH_PHY_CNTL2);
 177
 178         return 0;
 179 }
 180
 181 static int g12a_enable_external_mdio(struct g12a_mdio_mux *priv)
 182 {
 183         /* Reset the mdio bus mux */
 184         writel_relaxed(0x0, priv->regs + ETH_PHY_CNTL2);
 185
 186         /* Disable the phy clock if enabled */
 187         if (priv->pll_is_enabled) {
 188                 clk_disable_unprepare(priv->pll);
 189                 priv->pll_is_enabled = false;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static int g12a_mdio_switch_fn(int current_child, int desired_child,
 196                                void *data)
 197 {
 198         struct g12a_mdio_mux *priv = dev_get_drvdata(data);
 199
 200         if (current_child == desired_child)
 201                 return 0;
 202
 203         switch (desired_child) {
 204         case MESON_G12A_MDIO_EXTERNAL_ID:
 205                 return g12a_enable_external_mdio(priv);
 206         case MESON_G12A_MDIO_INTERNAL_ID:
 207                 return g12a_enable_internal_mdio(priv);
 208         default:
 209                 return -EINVAL;
 210         }
 211 }
 212
 213 static const struct of_device_id g12a_mdio_mux_match[] = {
 214         { .compatible = "amlogic,g12a-mdio-mux", },
 215         {},
 216 };
 217 MODULE_DEVICE_TABLE(of, g12a_mdio_mux_match);
 218
 219 static int g12a_ephy_glue_clk_register(struct device *dev)
 220 {
 221         struct g12a_mdio_mux *priv = dev_get_drvdata(dev);
 222         const char *parent_names[PLL_MUX_NUM_PARENT];
 223         struct clk_init_data init;
 224         struct g12a_ephy_pll *pll;
 225         struct clk_mux *mux;
 226         struct clk *clk;
 227         char *name;
 228         int i;
 229
 230         /* get the mux parents */
 231         for (i = 0; i < PLL_MUX_NUM_PARENT; i++) {
 232                 char in_name[8];
 233
 234                 snprintf(in_name, sizeof(in_name), "clkin%d", i);
 235                 clk = devm_clk_get(dev, in_name);
 236                 if (IS_ERR(clk)) {
 237                         if (PTR_ERR(clk) != -EPROBE_DEFER)
 238                                 dev_err(dev, "Missing clock %s\n", in_name);
 239                         return PTR_ERR(clk);
 240                 }
 241
 242                 parent_names[i] = __clk_get_name(clk);
 243         }
 244
 245         /* create the input mux */
 246         mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
 247         if (!mux)
 248                 return -ENOMEM;
 249
 250         name = kasprintf(GFP_KERNEL, "%s#mux", dev_name(dev));
 251         if (!name)
 252                 return -ENOMEM;
 253
 254         init.name = name;
 255         init.ops = &clk_mux_ro_ops;
 256         init.flags = 0;
 257         init.parent_names = parent_names;
 258         init.num_parents = PLL_MUX_NUM_PARENT;
 259
 260         mux->reg = priv->regs + ETH_PLL_CTL0;
 261         mux->shift = __ffs(PLL_CTL0_SEL);
 262         mux->mask = PLL_CTL0_SEL >> mux->shift;
 263         mux->hw.init = &init;
 264
 265         clk = devm_clk_register(dev, &mux->hw);
 266         kfree(name);
 267         if (IS_ERR(clk)) {
 268                 dev_err(dev, "failed to register input mux\n");
 269                 return PTR_ERR(clk);
 270         }
 271
 272         /* create the pll */
 273         pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
 274         if (!pll)
 275                 return -ENOMEM;
 276
 277         name = kasprintf(GFP_KERNEL, "%s#pll", dev_name(dev));
 278         if (!name)
 279                 return -ENOMEM;
 280
 281         init.name = name;
 282         init.ops = &g12a_ephy_pll_ops;
 283         init.flags = 0;
 284         parent_names[0] = __clk_get_name(clk);
 285         init.parent_names = parent_names;
 286         init.num_parents = 1;
 287
 288         pll->base = priv->regs;
 289         pll->hw.init = &init;
 290
 291         clk = devm_clk_register(dev, &pll->hw);
 292         kfree(name);
 293         if (IS_ERR(clk)) {
 294                 dev_err(dev, "failed to register input mux\n");
 295                 return PTR_ERR(clk);
 296         }
 297
 298         priv->pll = clk;
 299
 300         return 0;
 301 }
 302
 303 static int g12a_mdio_mux_probe(struct platform_device *pdev)
 304 {
 305         struct device *dev = &pdev->dev;
 306         struct g12a_mdio_mux *priv;
 307         int ret;
 308
 309         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 310         if (!priv)
 311                 return -ENOMEM;
 312
 313         platform_set_drvdata(pdev, priv);
 314
 315         priv->regs = devm_platform_ioremap_resource(pdev, 0);
 316         if (IS_ERR(priv->regs))
 317                 return PTR_ERR(priv->regs);
 318
 319         priv->pclk = devm_clk_get(dev, "pclk");
 320         if (IS_ERR(priv->pclk)) {
 321                 ret = PTR_ERR(priv->pclk);
 322                 if (ret != -EPROBE_DEFER)
 323                         dev_err(dev, "failed to get peripheral clock\n");
 324                 return ret;
 325         }
 326
 327         /* Make sure the device registers are clocked */
 328         ret = clk_prepare_enable(priv->pclk);
 329         if (ret) {
 330                 dev_err(dev, "failed to enable peripheral clock");
 331                 return ret;
 332         }
 333
 334         /* Register PLL in CCF */
 335         ret = g12a_ephy_glue_clk_register(dev);
 336         if (ret)
 337                 goto err;
 338
 339         ret = mdio_mux_init(dev, dev->of_node, g12a_mdio_switch_fn,
 340                             &priv->mux_handle, dev, NULL);
 341         if (ret) {
 342                 if (ret != -EPROBE_DEFER)
 343                         dev_err(dev, "mdio multiplexer init failed: %d", ret);
 344                 goto err;
 345         }
 346
 347         return 0;
 348
 349 err:
 350         clk_disable_unprepare(priv->pclk);
 351         return ret;
 352 }
 353
 354 static int g12a_mdio_mux_remove(struct platform_device *pdev)
 355 {
 356         struct g12a_mdio_mux *priv = platform_get_drvdata(pdev);
 357
 358         mdio_mux_uninit(priv->mux_handle);
 359
 360         if (priv->pll_is_enabled)
 361                 clk_disable_unprepare(priv->pll);
 362
 363         clk_disable_unprepare(priv->pclk);
 364
 365         return 0;
 366 }
 367
 368 static struct platform_driver g12a_mdio_mux_driver = {
 369         .probe          = g12a_mdio_mux_probe,
 370         .remove         = g12a_mdio_mux_remove,
 371         .driver         = {
 372                 .name   = "g12a-mdio_mux",
 373                 .of_match_table = g12a_mdio_mux_match,
 374         },
 375 };
 376 module_platform_driver(g12a_mdio_mux_driver);
 377
 378 MODULE_DESCRIPTION("Amlogic G12a MDIO multiplexer driver");
 379 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
 380 MODULE_LICENSE("GPL v2");