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