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/phy.h>
  22 #include <linux/of_net.h>
  23 #include <linux/regulator/consumer.h>
  24
  25 struct sunxi_priv_data {
  26         int interface;
  27         int clk_enabled;
  28         struct clk *tx_clk;
  29         struct regulator *regulator;
  30 };
  31
  32 static void *sun7i_gmac_setup(struct platform_device *pdev)
  33 {
  34         struct sunxi_priv_data *gmac;
  35         struct device *dev = &pdev->dev;
  36
  37         gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
  38         if (!gmac)
  39                 return ERR_PTR(-ENOMEM);
  40
  41         gmac->interface = of_get_phy_mode(dev->of_node);
  42
  43         gmac->tx_clk = devm_clk_get(dev, "allwinner_gmac_tx");
  44         if (IS_ERR(gmac->tx_clk)) {
  45                 dev_err(dev, "could not get tx clock\n");
  46                 return gmac->tx_clk;
  47         }
  48
  49         /* Optional regulator for PHY */
  50         gmac->regulator = devm_regulator_get_optional(dev, "phy");
  51         if (IS_ERR(gmac->regulator)) {
  52                 if (PTR_ERR(gmac->regulator) == -EPROBE_DEFER)
  53                         return ERR_PTR(-EPROBE_DEFER);
  54                 dev_info(dev, "no regulator found\n");
  55                 gmac->regulator = NULL;
  56         }
  57
  58         return gmac;
  59 }
  60
  61 #define SUN7I_GMAC_GMII_RGMII_RATE      125000000
  62 #define SUN7I_GMAC_MII_RATE             25000000
  63
  64 static int sun7i_gmac_init(struct platform_device *pdev, void *priv)
  65 {
  66         struct sunxi_priv_data *gmac = priv;
  67         int ret;
  68
  69         if (gmac->regulator) {
  70                 ret = regulator_enable(gmac->regulator);
  71                 if (ret)
  72                         return ret;
  73         }
  74
  75         /* Set GMAC interface port mode
  76          *
  77          * The GMAC TX clock lines are configured by setting the clock
  78          * rate, which then uses the auto-reparenting feature of the
  79          * clock driver, and enabling/disabling the clock.
  80          */
  81         if (gmac->interface == PHY_INTERFACE_MODE_RGMII) {
  82                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
  83                 clk_prepare_enable(gmac->tx_clk);
  84                 gmac->clk_enabled = 1;
  85         } else {
  86                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
  87                 clk_prepare(gmac->tx_clk);
  88         }
  89
  90         return 0;
  91 }
  92
  93 static void sun7i_gmac_exit(struct platform_device *pdev, void *priv)
  94 {
  95         struct sunxi_priv_data *gmac = priv;
  96
  97         if (gmac->clk_enabled) {
  98                 clk_disable(gmac->tx_clk);
  99                 gmac->clk_enabled = 0;
 100         }
 101         clk_unprepare(gmac->tx_clk);
 102
 103         if (gmac->regulator)
 104                 regulator_disable(gmac->regulator);
 105 }
 106
 107 static void sun7i_fix_speed(void *priv, unsigned int speed)
 108 {
 109         struct sunxi_priv_data *gmac = priv;
 110
 111         /* only GMII mode requires us to reconfigure the clock lines */
 112         if (gmac->interface != PHY_INTERFACE_MODE_GMII)
 113                 return;
 114
 115         if (gmac->clk_enabled) {
 116                 clk_disable(gmac->tx_clk);
 117                 gmac->clk_enabled = 0;
 118         }
 119         clk_unprepare(gmac->tx_clk);
 120
 121         if (speed == 1000) {
 122                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
 123                 clk_prepare_enable(gmac->tx_clk);
 124                 gmac->clk_enabled = 1;
 125         } else {
 126                 clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
 127                 clk_prepare(gmac->tx_clk);
 128         }
 129 }
 130
 131 /* of_data specifying hardware features and callbacks.
 132  * hardware features were copied from Allwinner drivers. */
 133 const struct stmmac_of_data sun7i_gmac_data = {
 134         .has_gmac = 1,
 135         .tx_coe = 1,
 136         .fix_mac_speed = sun7i_fix_speed,
 137         .setup = sun7i_gmac_setup,
 138         .init = sun7i_gmac_init,
 139         .exit = sun7i_gmac_exit,
 140 };