drivers/phy/socionext/phy-uniphier-ahci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * phy-uniphier-ahci.c - PHY driver for UniPhier AHCI controller
   4  * Copyright 2016-2020, Socionext Inc.
   5  * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/bitops.h>
  10 #include <linux/clk.h>
  11 #include <linux/iopoll.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/phy/phy.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/reset.h>
  18
  19 struct uniphier_ahciphy_priv {
  20         struct device *dev;
  21         void __iomem  *base;
  22         struct clk *clk, *clk_parent;
  23         struct reset_control *rst, *rst_parent;
  24         const struct uniphier_ahciphy_soc_data *data;
  25 };
  26
  27 struct uniphier_ahciphy_soc_data {
  28         int (*init)(struct uniphier_ahciphy_priv *priv);
  29         int (*power_on)(struct uniphier_ahciphy_priv *priv);
  30         int (*power_off)(struct uniphier_ahciphy_priv *priv);
  31         bool is_ready_high;
  32         bool is_phy_clk;
  33 };
  34
  35 /* for PXs2/PXs3 */
  36 #define CKCTRL                          0x0
  37 #define CKCTRL_P0_READY                 BIT(15)
  38 #define CKCTRL_P0_RESET                 BIT(10)
  39 #define CKCTRL_REF_SSP_EN               BIT(9)
  40 #define TXCTRL0                         0x4
  41 #define TXCTRL0_AMP_G3_MASK             GENMASK(22, 16)
  42 #define TXCTRL0_AMP_G2_MASK             GENMASK(14, 8)
  43 #define TXCTRL0_AMP_G1_MASK             GENMASK(6, 0)
  44 #define TXCTRL1                         0x8
  45 #define TXCTRL1_DEEMPH_G3_MASK          GENMASK(21, 16)
  46 #define TXCTRL1_DEEMPH_G2_MASK          GENMASK(13, 8)
  47 #define TXCTRL1_DEEMPH_G1_MASK          GENMASK(5, 0)
  48 #define RXCTRL                          0xc
  49 #define RXCTRL_LOS_LVL_MASK             GENMASK(20, 16)
  50 #define RXCTRL_LOS_BIAS_MASK            GENMASK(10, 8)
  51 #define RXCTRL_RX_EQ_MASK               GENMASK(2, 0)
  52
  53 static void uniphier_ahciphy_pxs2_enable(struct uniphier_ahciphy_priv *priv,
  54                                          bool enable)
  55 {
  56         u32 val;
  57
  58         val = readl(priv->base + CKCTRL);
  59
  60         if (enable) {
  61                 val |= CKCTRL_REF_SSP_EN;
  62                 writel(val, priv->base + CKCTRL);
  63                 val &= ~CKCTRL_P0_RESET;
  64                 writel(val, priv->base + CKCTRL);
  65         } else {
  66                 val |= CKCTRL_P0_RESET;
  67                 writel(val, priv->base + CKCTRL);
  68                 val &= ~CKCTRL_REF_SSP_EN;
  69                 writel(val, priv->base + CKCTRL);
  70         }
  71 }
  72
  73 static int uniphier_ahciphy_pxs2_power_on(struct uniphier_ahciphy_priv *priv)
  74 {
  75         int ret;
  76         u32 val;
  77
  78         uniphier_ahciphy_pxs2_enable(priv, true);
  79
  80         /* wait until PLL is ready */
  81         if (priv->data->is_ready_high)
  82                 ret = readl_poll_timeout(priv->base + CKCTRL, val,
  83                                          (val & CKCTRL_P0_READY), 200, 400);
  84         else
  85                 ret = readl_poll_timeout(priv->base + CKCTRL, val,
  86                                          !(val & CKCTRL_P0_READY), 200, 400);
  87         if (ret) {
  88                 dev_err(priv->dev, "Failed to check whether PHY PLL is ready\n");
  89                 uniphier_ahciphy_pxs2_enable(priv, false);
  90         }
  91
  92         return ret;
  93 }
  94
  95 static int uniphier_ahciphy_pxs2_power_off(struct uniphier_ahciphy_priv *priv)
  96 {
  97         uniphier_ahciphy_pxs2_enable(priv, false);
  98
  99         return 0;
 100 }
 101
 102 static int uniphier_ahciphy_pxs3_init(struct uniphier_ahciphy_priv *priv)
 103 {
 104         int i;
 105         u32 val;
 106
 107         /* setup port parameter */
 108         val = readl(priv->base + TXCTRL0);
 109         val &= ~TXCTRL0_AMP_G3_MASK;
 110         val |= FIELD_PREP(TXCTRL0_AMP_G3_MASK, 0x73);
 111         val &= ~TXCTRL0_AMP_G2_MASK;
 112         val |= FIELD_PREP(TXCTRL0_AMP_G2_MASK, 0x46);
 113         val &= ~TXCTRL0_AMP_G1_MASK;
 114         val |= FIELD_PREP(TXCTRL0_AMP_G1_MASK, 0x42);
 115         writel(val, priv->base + TXCTRL0);
 116
 117         val = readl(priv->base + TXCTRL1);
 118         val &= ~TXCTRL1_DEEMPH_G3_MASK;
 119         val |= FIELD_PREP(TXCTRL1_DEEMPH_G3_MASK, 0x23);
 120         val &= ~TXCTRL1_DEEMPH_G2_MASK;
 121         val |= FIELD_PREP(TXCTRL1_DEEMPH_G2_MASK, 0x05);
 122         val &= ~TXCTRL1_DEEMPH_G1_MASK;
 123         val |= FIELD_PREP(TXCTRL1_DEEMPH_G1_MASK, 0x05);
 124
 125         val = readl(priv->base + RXCTRL);
 126         val &= ~RXCTRL_LOS_LVL_MASK;
 127         val |= FIELD_PREP(RXCTRL_LOS_LVL_MASK, 0x9);
 128         val &= ~RXCTRL_LOS_BIAS_MASK;
 129         val |= FIELD_PREP(RXCTRL_LOS_BIAS_MASK, 0x2);
 130         val &= ~RXCTRL_RX_EQ_MASK;
 131         val |= FIELD_PREP(RXCTRL_RX_EQ_MASK, 0x1);
 132
 133         /* dummy read 25 times to make a wait time for the phy to stabilize */
 134         for (i = 0; i < 25; i++)
 135                 readl(priv->base + CKCTRL);
 136
 137         return 0;
 138 }
 139
 140 static int uniphier_ahciphy_init(struct phy *phy)
 141 {
 142         struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
 143         int ret;
 144
 145         ret = clk_prepare_enable(priv->clk_parent);
 146         if (ret)
 147                 return ret;
 148
 149         ret = reset_control_deassert(priv->rst_parent);
 150         if (ret)
 151                 goto out_clk_disable;
 152
 153         if (priv->data->init) {
 154                 ret = priv->data->init(priv);
 155                 if (ret)
 156                         goto out_rst_assert;
 157         }
 158
 159         return 0;
 160
 161 out_rst_assert:
 162         reset_control_assert(priv->rst_parent);
 163 out_clk_disable:
 164         clk_disable_unprepare(priv->clk_parent);
 165
 166         return ret;
 167 }
 168
 169 static int uniphier_ahciphy_exit(struct phy *phy)
 170 {
 171         struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
 172
 173         reset_control_assert(priv->rst_parent);
 174         clk_disable_unprepare(priv->clk_parent);
 175
 176         return 0;
 177 }
 178
 179 static int uniphier_ahciphy_power_on(struct phy *phy)
 180 {
 181         struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
 182         int ret = 0;
 183
 184         ret = clk_prepare_enable(priv->clk);
 185         if (ret)
 186                 return ret;
 187
 188         ret = reset_control_deassert(priv->rst);
 189         if (ret)
 190                 goto out_clk_disable;
 191
 192         if (priv->data->power_on) {
 193                 ret = priv->data->power_on(priv);
 194                 if (ret)
 195                         goto out_reset_assert;
 196         }
 197
 198         return 0;
 199
 200 out_reset_assert:
 201         reset_control_assert(priv->rst);
 202 out_clk_disable:
 203         clk_disable_unprepare(priv->clk);
 204
 205         return ret;
 206 }
 207
 208 static int uniphier_ahciphy_power_off(struct phy *phy)
 209 {
 210         struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
 211         int ret = 0;
 212
 213         if (priv->data->power_off)
 214                 ret = priv->data->power_off(priv);
 215
 216         reset_control_assert(priv->rst);
 217         clk_disable_unprepare(priv->clk);
 218
 219         return ret;
 220 }
 221
 222 static const struct phy_ops uniphier_ahciphy_ops = {
 223         .init  = uniphier_ahciphy_init,
 224         .exit  = uniphier_ahciphy_exit,
 225         .power_on  = uniphier_ahciphy_power_on,
 226         .power_off = uniphier_ahciphy_power_off,
 227         .owner = THIS_MODULE,
 228 };
 229
 230 static int uniphier_ahciphy_probe(struct platform_device *pdev)
 231 {
 232         struct device *dev = &pdev->dev;
 233         struct uniphier_ahciphy_priv *priv;
 234         struct phy *phy;
 235         struct phy_provider *phy_provider;
 236
 237         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 238         if (!priv)
 239                 return -ENOMEM;
 240
 241         priv->dev = dev;
 242         priv->data = of_device_get_match_data(dev);
 243         if (WARN_ON(!priv->data))
 244                 return -EINVAL;
 245
 246         priv->base = devm_platform_ioremap_resource(pdev, 0);
 247         if (IS_ERR(priv->base))
 248                 return PTR_ERR(priv->base);
 249
 250         priv->clk_parent = devm_clk_get(dev, "link");
 251         if (IS_ERR(priv->clk_parent))
 252                 return PTR_ERR(priv->clk_parent);
 253
 254         if (priv->data->is_phy_clk) {
 255                 priv->clk = devm_clk_get(dev, "phy");
 256                 if (IS_ERR(priv->clk))
 257                         return PTR_ERR(priv->clk);
 258         }
 259
 260         priv->rst_parent = devm_reset_control_get_shared(dev, "link");
 261         if (IS_ERR(priv->rst_parent))
 262                 return PTR_ERR(priv->rst_parent);
 263
 264         priv->rst = devm_reset_control_get_shared(dev, "phy");
 265         if (IS_ERR(priv->rst))
 266                 return PTR_ERR(priv->rst);
 267
 268         phy = devm_phy_create(dev, dev->of_node, &uniphier_ahciphy_ops);
 269         if (IS_ERR(phy)) {
 270                 dev_err(dev, "failed to create phy\n");
 271                 return PTR_ERR(phy);
 272         }
 273
 274         phy_set_drvdata(phy, priv);
 275         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 276         if (IS_ERR(phy_provider))
 277                 return PTR_ERR(phy_provider);
 278
 279         return 0;
 280 }
 281
 282 static const struct uniphier_ahciphy_soc_data uniphier_pxs2_data = {
 283         .power_on  = uniphier_ahciphy_pxs2_power_on,
 284         .power_off = uniphier_ahciphy_pxs2_power_off,
 285         .is_ready_high = false,
 286         .is_phy_clk = false,
 287 };
 288
 289 static const struct uniphier_ahciphy_soc_data uniphier_pxs3_data = {
 290         .init      = uniphier_ahciphy_pxs3_init,
 291         .power_on  = uniphier_ahciphy_pxs2_power_on,
 292         .power_off = uniphier_ahciphy_pxs2_power_off,
 293         .is_ready_high = true,
 294         .is_phy_clk = true,
 295 };
 296
 297 static const struct of_device_id uniphier_ahciphy_match[] = {
 298         {
 299                 .compatible = "socionext,uniphier-pxs2-ahci-phy",
 300                 .data = &uniphier_pxs2_data,
 301         },
 302         {
 303                 .compatible = "socionext,uniphier-pxs3-ahci-phy",
 304                 .data = &uniphier_pxs3_data,
 305         },
 306         { /* Sentinel */ },
 307 };
 308 MODULE_DEVICE_TABLE(of, uniphier_ahciphy_match);
 309
 310 static struct platform_driver uniphier_ahciphy_driver = {
 311         .probe = uniphier_ahciphy_probe,
 312         .driver = {
 313                 .name = "uniphier-ahci-phy",
 314                 .of_match_table = uniphier_ahciphy_match,
 315         },
 316 };
 317 module_platform_driver(uniphier_ahciphy_driver);
 318
 319 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
 320 MODULE_DESCRIPTION("UniPhier PHY driver for AHCI controller");
 321 MODULE_LICENSE("GPL v2");