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 #define SUN7I_GMAC_GMII_RGMII_RATE	125000000
37 #define SUN7I_GMAC_MII_RATE		25000000
38 
39 static int sun7i_gmac_init(struct platform_device *pdev, void *priv)
40 {
41 	struct sunxi_priv_data *gmac = priv;
42 	int ret;
43 
44 	if (gmac->regulator) {
45 		ret = regulator_enable(gmac->regulator);
46 		if (ret)
47 			return ret;
48 	}
49 
50 	/* Set GMAC interface port mode
51 	 *
52 	 * The GMAC TX clock lines are configured by setting the clock
53 	 * rate, which then uses the auto-reparenting feature of the
54 	 * clock driver, and enabling/disabling the clock.
55 	 */
56 	if (gmac->interface == PHY_INTERFACE_MODE_RGMII) {
57 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
58 		clk_prepare_enable(gmac->tx_clk);
59 		gmac->clk_enabled = 1;
60 	} else {
61 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
62 		ret = clk_prepare(gmac->tx_clk);
63 		if (ret)
64 			return ret;
65 	}
66 
67 	return 0;
68 }
69 
70 static void sun7i_gmac_exit(struct platform_device *pdev, void *priv)
71 {
72 	struct sunxi_priv_data *gmac = priv;
73 
74 	if (gmac->clk_enabled) {
75 		clk_disable(gmac->tx_clk);
76 		gmac->clk_enabled = 0;
77 	}
78 	clk_unprepare(gmac->tx_clk);
79 
80 	if (gmac->regulator)
81 		regulator_disable(gmac->regulator);
82 }
83 
84 static void sun7i_fix_speed(void *priv, unsigned int speed)
85 {
86 	struct sunxi_priv_data *gmac = priv;
87 
88 	/* only GMII mode requires us to reconfigure the clock lines */
89 	if (gmac->interface != PHY_INTERFACE_MODE_GMII)
90 		return;
91 
92 	if (gmac->clk_enabled) {
93 		clk_disable(gmac->tx_clk);
94 		gmac->clk_enabled = 0;
95 	}
96 	clk_unprepare(gmac->tx_clk);
97 
98 	if (speed == 1000) {
99 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
100 		clk_prepare_enable(gmac->tx_clk);
101 		gmac->clk_enabled = 1;
102 	} else {
103 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
104 		clk_prepare(gmac->tx_clk);
105 	}
106 }
107 
108 static int sun7i_gmac_probe(struct platform_device *pdev)
109 {
110 	struct plat_stmmacenet_data *plat_dat;
111 	struct stmmac_resources stmmac_res;
112 	struct sunxi_priv_data *gmac;
113 	struct device *dev = &pdev->dev;
114 	int ret;
115 
116 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
117 	if (ret)
118 		return ret;
119 
120 	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
121 	if (IS_ERR(plat_dat))
122 		return PTR_ERR(plat_dat);
123 
124 	gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
125 	if (!gmac) {
126 		ret = -ENOMEM;
127 		goto err_remove_config_dt;
128 	}
129 
130 	gmac->interface = of_get_phy_mode(dev->of_node);
131 
132 	gmac->tx_clk = devm_clk_get(dev, "allwinner_gmac_tx");
133 	if (IS_ERR(gmac->tx_clk)) {
134 		dev_err(dev, "could not get tx clock\n");
135 		ret = PTR_ERR(gmac->tx_clk);
136 		goto err_remove_config_dt;
137 	}
138 
139 	/* Optional regulator for PHY */
140 	gmac->regulator = devm_regulator_get_optional(dev, "phy");
141 	if (IS_ERR(gmac->regulator)) {
142 		if (PTR_ERR(gmac->regulator) == -EPROBE_DEFER) {
143 			ret = -EPROBE_DEFER;
144 			goto err_remove_config_dt;
145 		}
146 		dev_info(dev, "no regulator found\n");
147 		gmac->regulator = NULL;
148 	}
149 
150 	/* platform data specifying hardware features and callbacks.
151 	 * hardware features were copied from Allwinner drivers. */
152 	plat_dat->tx_coe = 1;
153 	plat_dat->has_gmac = true;
154 	plat_dat->bsp_priv = gmac;
155 	plat_dat->init = sun7i_gmac_init;
156 	plat_dat->exit = sun7i_gmac_exit;
157 	plat_dat->fix_mac_speed = sun7i_fix_speed;
158 
159 	ret = sun7i_gmac_init(pdev, plat_dat->bsp_priv);
160 	if (ret)
161 		goto err_remove_config_dt;
162 
163 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
164 	if (ret)
165 		goto err_gmac_exit;
166 
167 	return 0;
168 
169 err_gmac_exit:
170 	sun7i_gmac_exit(pdev, plat_dat->bsp_priv);
171 err_remove_config_dt:
172 	stmmac_remove_config_dt(pdev, plat_dat);
173 
174 	return ret;
175 }
176 
177 static const struct of_device_id sun7i_dwmac_match[] = {
178 	{ .compatible = "allwinner,sun7i-a20-gmac" },
179 	{ }
180 };
181 MODULE_DEVICE_TABLE(of, sun7i_dwmac_match);
182 
183 static struct platform_driver sun7i_dwmac_driver = {
184 	.probe  = sun7i_gmac_probe,
185 	.remove = stmmac_pltfr_remove,
186 	.driver = {
187 		.name           = "sun7i-dwmac",
188 		.pm		= &stmmac_pltfr_pm_ops,
189 		.of_match_table = sun7i_dwmac_match,
190 	},
191 };
192 module_platform_driver(sun7i_dwmac_driver);
193 
194 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
195 MODULE_DESCRIPTION("Allwinner sunxi DWMAC specific glue layer");
196 MODULE_LICENSE("GPL");
197