drivers/phy/phy-rockchip-emmc.c

   1 /*
   2  * Rockchip emmc PHY driver
   3  *
   4  * Copyright (C) 2016 Shawn Lin <shawn.lin@rock-chips.com>
   5  * Copyright (C) 2016 ROCKCHIP, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/delay.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/phy/phy.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25
  26 /*
  27  * The higher 16-bit of this register is used for write protection
  28  * only if BIT(x + 16) set to 1 the BIT(x) can be written.
  29  */
  30 #define HIWORD_UPDATE(val, mask, shift) \
  31                 ((val) << (shift) | (mask) << ((shift) + 16))
  32
  33 /* Register definition */
  34 #define GRF_EMMCPHY_CON0        0x0
  35 #define GRF_EMMCPHY_CON1        0x4
  36 #define GRF_EMMCPHY_CON2        0x8
  37 #define GRF_EMMCPHY_CON3        0xc
  38 #define GRF_EMMCPHY_CON4        0x10
  39 #define GRF_EMMCPHY_CON5        0x14
  40 #define GRF_EMMCPHY_CON6        0x18
  41 #define GRF_EMMCPHY_STATUS      0x20
  42
  43 #define PHYCTRL_PDB_MASK        0x1
  44 #define PHYCTRL_PDB_SHIFT       0x0
  45 #define PHYCTRL_PDB_PWR_ON      0x1
  46 #define PHYCTRL_PDB_PWR_OFF     0x0
  47 #define PHYCTRL_ENDLL_MASK      0x1
  48 #define PHYCTRL_ENDLL_SHIFT     0x1
  49 #define PHYCTRL_ENDLL_ENABLE    0x1
  50 #define PHYCTRL_ENDLL_DISABLE   0x0
  51 #define PHYCTRL_CALDONE_MASK    0x1
  52 #define PHYCTRL_CALDONE_SHIFT   0x6
  53 #define PHYCTRL_CALDONE_DONE    0x1
  54 #define PHYCTRL_CALDONE_GOING   0x0
  55 #define PHYCTRL_DLLRDY_MASK     0x1
  56 #define PHYCTRL_DLLRDY_SHIFT    0x5
  57 #define PHYCTRL_DLLRDY_DONE     0x1
  58 #define PHYCTRL_DLLRDY_GOING    0x0
  59
  60 struct rockchip_emmc_phy {
  61         unsigned int    reg_offset;
  62         struct regmap   *reg_base;
  63 };
  64
  65 static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy,
  66                                    bool on_off)
  67 {
  68         unsigned int caldone;
  69         unsigned int dllrdy;
  70
  71         /*
  72          * Keep phyctrl_pdb and phyctrl_endll low to allow
  73          * initialization of CALIO state M/C DFFs
  74          */
  75         regmap_write(rk_phy->reg_base,
  76                      rk_phy->reg_offset + GRF_EMMCPHY_CON6,
  77                      HIWORD_UPDATE(PHYCTRL_PDB_PWR_OFF,
  78                                    PHYCTRL_PDB_MASK,
  79                                    PHYCTRL_PDB_SHIFT));
  80         regmap_write(rk_phy->reg_base,
  81                      rk_phy->reg_offset + GRF_EMMCPHY_CON6,
  82                      HIWORD_UPDATE(PHYCTRL_ENDLL_DISABLE,
  83                                    PHYCTRL_ENDLL_MASK,
  84                                    PHYCTRL_ENDLL_SHIFT));
  85
  86         /* Already finish power_off above */
  87         if (on_off == PHYCTRL_PDB_PWR_OFF)
  88                 return 0;
  89
  90         /*
  91          * According to the user manual, calpad calibration
  92          * cycle takes more than 2us without the minimal recommended
  93          * value, so we may need a little margin here
  94          */
  95         udelay(3);
  96         regmap_write(rk_phy->reg_base,
  97                      rk_phy->reg_offset + GRF_EMMCPHY_CON6,
  98                      HIWORD_UPDATE(PHYCTRL_PDB_PWR_ON,
  99                                    PHYCTRL_PDB_MASK,
 100                                    PHYCTRL_PDB_SHIFT));
 101
 102         /*
 103          * According to the user manual, it asks driver to
 104          * wait 5us for calpad busy trimming
 105          */
 106         udelay(5);
 107         regmap_read(rk_phy->reg_base,
 108                     rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
 109                     &caldone);
 110         caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
 111         if (caldone != PHYCTRL_CALDONE_DONE) {
 112                 pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
 113                 return -ETIMEDOUT;
 114         }
 115
 116         regmap_write(rk_phy->reg_base,
 117                      rk_phy->reg_offset + GRF_EMMCPHY_CON6,
 118                      HIWORD_UPDATE(PHYCTRL_ENDLL_ENABLE,
 119                                    PHYCTRL_ENDLL_MASK,
 120                                    PHYCTRL_ENDLL_SHIFT));
 121         /*
 122          * After enable analog DLL circuits, we need extra 10.2us
 123          * for dll to be ready for work.
 124          */
 125         udelay(11);
 126         regmap_read(rk_phy->reg_base,
 127                     rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
 128                     &dllrdy);
 129         dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK;
 130         if (dllrdy != PHYCTRL_DLLRDY_DONE) {
 131                 pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n");
 132                 return -ETIMEDOUT;
 133         }
 134
 135         return 0;
 136 }
 137
 138 static int rockchip_emmc_phy_power_off(struct phy *phy)
 139 {
 140         struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
 141         int ret = 0;
 142
 143         /* Power down emmc phy analog blocks */
 144         ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_OFF);
 145         if (ret)
 146                 return ret;
 147
 148         return 0;
 149 }
 150
 151 static int rockchip_emmc_phy_power_on(struct phy *phy)
 152 {
 153         struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
 154         int ret = 0;
 155
 156         /* Power up emmc phy analog blocks */
 157         ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON);
 158         if (ret)
 159                 return ret;
 160
 161         return 0;
 162 }
 163
 164 static const struct phy_ops ops = {
 165         .power_on       = rockchip_emmc_phy_power_on,
 166         .power_off      = rockchip_emmc_phy_power_off,
 167         .owner          = THIS_MODULE,
 168 };
 169
 170 static int rockchip_emmc_phy_probe(struct platform_device *pdev)
 171 {
 172         struct device *dev = &pdev->dev;
 173         struct rockchip_emmc_phy *rk_phy;
 174         struct phy *generic_phy;
 175         struct phy_provider *phy_provider;
 176         struct regmap *grf;
 177         unsigned int reg_offset;
 178
 179         grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
 180         if (IS_ERR(grf)) {
 181                 dev_err(dev, "Missing rockchip,grf property\n");
 182                 return PTR_ERR(grf);
 183         }
 184
 185         rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL);
 186         if (!rk_phy)
 187                 return -ENOMEM;
 188
 189         if (of_property_read_u32(dev->of_node, "reg", &reg_offset)) {
 190                 dev_err(dev, "missing reg property in node %s\n",
 191                         dev->of_node->name);
 192                 return -EINVAL;
 193         }
 194
 195         rk_phy->reg_offset = reg_offset;
 196         rk_phy->reg_base = grf;
 197
 198         generic_phy = devm_phy_create(dev, dev->of_node, &ops);
 199         if (IS_ERR(generic_phy)) {
 200                 dev_err(dev, "failed to create PHY\n");
 201                 return PTR_ERR(generic_phy);
 202         }
 203
 204         phy_set_drvdata(generic_phy, rk_phy);
 205         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 206
 207         return PTR_ERR_OR_ZERO(phy_provider);
 208 }
 209
 210 static const struct of_device_id rockchip_emmc_phy_dt_ids[] = {
 211         { .compatible = "rockchip,rk3399-emmc-phy" },
 212         {}
 213 };
 214
 215 MODULE_DEVICE_TABLE(of, rockchip_emmc_phy_dt_ids);
 216
 217 static struct platform_driver rockchip_emmc_driver = {
 218         .probe          = rockchip_emmc_phy_probe,
 219         .driver         = {
 220                 .name   = "rockchip-emmc-phy",
 221                 .of_match_table = rockchip_emmc_phy_dt_ids,
 222         },
 223 };
 224
 225 module_platform_driver(rockchip_emmc_driver);
 226
 227 MODULE_AUTHOR("Shawn Lin <shawn.lin@rock-chips.com>");
 228 MODULE_DESCRIPTION("Rockchip EMMC PHY driver");
 229 MODULE_LICENSE("GPL v2");