xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac-sunxi.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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 #include "stmmac_platform.h"
26 
27 struct sunxi_priv_data {
28 	int interface;
29 	int clk_enabled;
30 	struct clk *tx_clk;
31 	struct regulator *regulator;
32 };
33 
34 static void *sun7i_gmac_setup(struct platform_device *pdev)
35 {
36 	struct sunxi_priv_data *gmac;
37 	struct device *dev = &pdev->dev;
38 
39 	gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
40 	if (!gmac)
41 		return ERR_PTR(-ENOMEM);
42 
43 	gmac->interface = of_get_phy_mode(dev->of_node);
44 
45 	gmac->tx_clk = devm_clk_get(dev, "allwinner_gmac_tx");
46 	if (IS_ERR(gmac->tx_clk)) {
47 		dev_err(dev, "could not get tx clock\n");
48 		return gmac->tx_clk;
49 	}
50 
51 	/* Optional regulator for PHY */
52 	gmac->regulator = devm_regulator_get_optional(dev, "phy");
53 	if (IS_ERR(gmac->regulator)) {
54 		if (PTR_ERR(gmac->regulator) == -EPROBE_DEFER)
55 			return ERR_PTR(-EPROBE_DEFER);
56 		dev_info(dev, "no regulator found\n");
57 		gmac->regulator = NULL;
58 	}
59 
60 	return gmac;
61 }
62 
63 #define SUN7I_GMAC_GMII_RGMII_RATE	125000000
64 #define SUN7I_GMAC_MII_RATE		25000000
65 
66 static int sun7i_gmac_init(struct platform_device *pdev, void *priv)
67 {
68 	struct sunxi_priv_data *gmac = priv;
69 	int ret;
70 
71 	if (gmac->regulator) {
72 		ret = regulator_enable(gmac->regulator);
73 		if (ret)
74 			return ret;
75 	}
76 
77 	/* Set GMAC interface port mode
78 	 *
79 	 * The GMAC TX clock lines are configured by setting the clock
80 	 * rate, which then uses the auto-reparenting feature of the
81 	 * clock driver, and enabling/disabling the clock.
82 	 */
83 	if (gmac->interface == PHY_INTERFACE_MODE_RGMII) {
84 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
85 		clk_prepare_enable(gmac->tx_clk);
86 		gmac->clk_enabled = 1;
87 	} else {
88 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
89 		clk_prepare(gmac->tx_clk);
90 	}
91 
92 	return 0;
93 }
94 
95 static void sun7i_gmac_exit(struct platform_device *pdev, void *priv)
96 {
97 	struct sunxi_priv_data *gmac = priv;
98 
99 	if (gmac->clk_enabled) {
100 		clk_disable(gmac->tx_clk);
101 		gmac->clk_enabled = 0;
102 	}
103 	clk_unprepare(gmac->tx_clk);
104 
105 	if (gmac->regulator)
106 		regulator_disable(gmac->regulator);
107 }
108 
109 static void sun7i_fix_speed(void *priv, unsigned int speed)
110 {
111 	struct sunxi_priv_data *gmac = priv;
112 
113 	/* only GMII mode requires us to reconfigure the clock lines */
114 	if (gmac->interface != PHY_INTERFACE_MODE_GMII)
115 		return;
116 
117 	if (gmac->clk_enabled) {
118 		clk_disable(gmac->tx_clk);
119 		gmac->clk_enabled = 0;
120 	}
121 	clk_unprepare(gmac->tx_clk);
122 
123 	if (speed == 1000) {
124 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_GMII_RGMII_RATE);
125 		clk_prepare_enable(gmac->tx_clk);
126 		gmac->clk_enabled = 1;
127 	} else {
128 		clk_set_rate(gmac->tx_clk, SUN7I_GMAC_MII_RATE);
129 		clk_prepare(gmac->tx_clk);
130 	}
131 }
132 
133 /* of_data specifying hardware features and callbacks.
134  * hardware features were copied from Allwinner drivers. */
135 const struct stmmac_of_data sun7i_gmac_data = {
136 	.has_gmac = 1,
137 	.tx_coe = 1,
138 	.fix_mac_speed = sun7i_fix_speed,
139 	.setup = sun7i_gmac_setup,
140 	.init = sun7i_gmac_init,
141 	.exit = sun7i_gmac_exit,
142 };
143