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

   1 /*
   2  * dwmac-sunxi.c - Allwinner sunxi DWMAC specific glue layer
   3  *
   4  * Copyright (C) 2013 Chen-Yu Tsai
   5  *
   6  * Chen-Yu Tsai  <wens@csie.org>
   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  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/stmmac.h>
  20 #include <linux/clk.h>
  21 #include <linux/module.h>
  22 #include <linux/phy.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/of_net.h>
  25 #include <linux/regulator/consumer.h>
  26
  27 #include "stmmac_platform.h"
  28
  29 struct sunxi_priv_data {
  30         int interface;
  31         int clk_enabled;
  32         struct clk *tx_clk;
  33         struct regulator *regulator;
  34 };
  35
  36 static void *sun7i_gmac_setup(struct platform_device *pdev)
  37 {
  38         struct sunxi_priv_data *gmac;
  39         struct device *dev = &pdev->dev;
  40
  41         gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
  42         if (!gmac)
  43                 return ERR_PTR(-ENOMEM);
  44
  45         gmac->interface = of_get_phy_mode(dev->of_node);
  46
  47         gmac->tx_clk = devm_clk_get(dev, "allwinner_gmac_tx");
  48         if (IS_ERR(gmac->tx_clk)) {
  49                 dev_err(dev, "could not get tx clock\n");
  50                 return gmac->tx_clk;
  51         }
  52
  53         /* Optional regulator for PHY */
  54         gmac->regulator = devm_regulator_get_optional(dev, "phy");
  55         if (IS_ERR(gmac->regulator)) {
  56                 if (PTR_ERR(gmac->regulator) == -EPROBE_DEFER)
  57                         return ERR_PTR(-EPROBE_DEFER);
  58                 dev_info(dev, "no regulator found\n");
  59                 gmac->regulator = NULL;
  60         }
  61
  62         return gmac;
  63 }
  64
  65 #define SUN7I_GMAC_GMII_RGMII_RATE      125000000
  66 #define SUN7I_GMAC_MII_RATE             25000000
  67
  68 static int sun7i_gmac_init(struct platform_device *pdev, void *priv)
  69 {
  70         struct sunxi_priv_data *gmac = priv;
  71         int ret;
  72
  73         if (gmac->regulator) {
  74                 ret = regulator_enable(gmac->regulator);
  75                 if (ret)
  76                         return ret;
  77         }
  78
  79         /* Set GMAC interface port mode
  80          *
  81          * The GMAC TX clock lines are configured by setting the clock
  82          * rate, which then uses the auto-reparenting feature of the
  83          * clock driver, and enabling/disabling the clock.
  84          */
  85         if (gmac->interface == PHY_INTERFACE_MODE_RGMII) {
  86                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
  87                 clk_prepare_enable(gmac->tx_clk);
  88                 gmac->clk_enabled = 1;
  89         } else {
  90                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
  91                 clk_prepare(gmac->tx_clk);
  92         }
  93
  94         return 0;
  95 }
  96
  97 static void sun7i_gmac_exit(struct platform_device *pdev, void *priv)
  98 {
  99         struct sunxi_priv_data *gmac = priv;
 100
 101         if (gmac->clk_enabled) {
 102                 clk_disable(gmac->tx_clk);
 103                 gmac->clk_enabled = 0;
 104         }
 105         clk_unprepare(gmac->tx_clk);
 106
 107         if (gmac->regulator)
 108                 regulator_disable(gmac->regulator);
 109 }
 110
 111 static void sun7i_fix_speed(void *priv, unsigned int speed)
 112 {
 113         struct sunxi_priv_data *gmac = priv;
 114
 115         /* only GMII mode requires us to reconfigure the clock lines */
 116         if (gmac->interface != PHY_INTERFACE_MODE_GMII)
 117                 return;
 118
 119         if (gmac->clk_enabled) {
 120                 clk_disable(gmac->tx_clk);
 121                 gmac->clk_enabled = 0;
 122         }
 123         clk_unprepare(gmac->tx_clk);
 124
 125         if (speed == 1000) {
 126                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
 127                 clk_prepare_enable(gmac->tx_clk);
 128                 gmac->clk_enabled = 1;
 129         } else {
 130                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
 131                 clk_prepare(gmac->tx_clk);
 132         }
 133 }
 134
 135 /* of_data specifying hardware features and callbacks.
 136  * hardware features were copied from Allwinner drivers. */
 137 static const struct stmmac_of_data sun7i_gmac_data = {
 138         .has_gmac = 1,
 139         .tx_coe = 1,
 140         .fix_mac_speed = sun7i_fix_speed,
 141         .setup = sun7i_gmac_setup,
 142         .init = sun7i_gmac_init,
 143         .exit = sun7i_gmac_exit,
 144 };
 145
 146 static const struct of_device_id sun7i_dwmac_match[] = {
 147         { .compatible = "allwinner,sun7i-a20-gmac", .data = &sun7i_gmac_data},
 148         { }
 149 };
 150 MODULE_DEVICE_TABLE(of, sun7i_dwmac_match);
 151
 152 static struct platform_driver sun7i_dwmac_driver = {
 153         .probe  = stmmac_pltfr_probe,
 154         .remove = stmmac_pltfr_remove,
 155         .driver = {
 156                 .name           = "sun7i-dwmac",
 157                 .pm             = &stmmac_pltfr_pm_ops,
 158                 .of_match_table = sun7i_dwmac_match,
 159         },
 160 };
 161 module_platform_driver(sun7i_dwmac_driver);
 162
 163 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
 164 MODULE_DESCRIPTION("Allwinner sunxi DWMAC specific glue layer");
 165 MODULE_LICENSE("GPL");