1 /**
2  * emac-rockchip.c - Rockchip EMAC specific glue layer
3  *
4  * Copyright (C) 2014 Romain Perier <romain.perier@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/etherdevice.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of_net.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/regulator/consumer.h>
24 
25 #include "emac.h"
26 
27 #define DRV_NAME        "rockchip_emac"
28 #define DRV_VERSION     "1.1"
29 
30 struct emac_rockchip_soc_data {
31 	unsigned int grf_offset;
32 	unsigned int grf_mode_offset;
33 	unsigned int grf_speed_offset;
34 	bool need_div_macclk;
35 };
36 
37 struct rockchip_priv_data {
38 	struct arc_emac_priv emac;
39 	struct regmap *grf;
40 	const struct emac_rockchip_soc_data *soc_data;
41 	struct regulator *regulator;
42 	struct clk *refclk;
43 	struct clk *macclk;
44 };
45 
46 static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
47 {
48 	struct rockchip_priv_data *emac = priv;
49 	u32 speed_offset = emac->soc_data->grf_speed_offset;
50 	u32 data;
51 	int err = 0;
52 
53 	switch(speed) {
54 	case 10:
55 		data = (1 << (speed_offset + 16)) | (0 << speed_offset);
56 		break;
57 	case 100:
58 		data = (1 << (speed_offset + 16)) | (1 << speed_offset);
59 		break;
60 	default:
61 		pr_err("speed %u not supported\n", speed);
62 		return;
63 	}
64 
65 	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
66 	if (err)
67 		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
68 }
69 
70 static const struct emac_rockchip_soc_data emac_rk3036_emac_data = {
71 	.grf_offset = 0x140,   .grf_mode_offset = 8,
72 	.grf_speed_offset = 9, .need_div_macclk = 1,
73 };
74 
75 static const struct emac_rockchip_soc_data emac_rk3066_emac_data = {
76 	.grf_offset = 0x154,   .grf_mode_offset = 0,
77 	.grf_speed_offset = 1, .need_div_macclk = 0,
78 };
79 
80 static const struct emac_rockchip_soc_data emac_rk3188_emac_data = {
81 	.grf_offset = 0x0a4,   .grf_mode_offset = 0,
82 	.grf_speed_offset = 1, .need_div_macclk = 0,
83 };
84 
85 static const struct of_device_id emac_rockchip_dt_ids[] = {
86 	{ .compatible = "rockchip,rk3036-emac", .data = &emac_rk3036_emac_data },
87 	{ .compatible = "rockchip,rk3066-emac", .data = &emac_rk3066_emac_data },
88 	{ .compatible = "rockchip,rk3188-emac", .data = &emac_rk3188_emac_data },
89 	{ /* Sentinel */ }
90 };
91 
92 MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
93 
94 static int emac_rockchip_probe(struct platform_device *pdev)
95 {
96 	struct device *dev = &pdev->dev;
97 	struct net_device *ndev;
98 	struct rockchip_priv_data *priv;
99 	const struct of_device_id *match;
100 	u32 data;
101 	int err, interface;
102 
103 	if (!pdev->dev.of_node)
104 		return -ENODEV;
105 
106 	ndev = alloc_etherdev(sizeof(struct rockchip_priv_data));
107 	if (!ndev)
108 		return -ENOMEM;
109 	platform_set_drvdata(pdev, ndev);
110 	SET_NETDEV_DEV(ndev, dev);
111 
112 	priv = netdev_priv(ndev);
113 	priv->emac.drv_name = DRV_NAME;
114 	priv->emac.drv_version = DRV_VERSION;
115 	priv->emac.set_mac_speed = emac_rockchip_set_mac_speed;
116 
117 	interface = of_get_phy_mode(dev->of_node);
118 
119 	/* RK3036/RK3066/RK3188 SoCs only support RMII */
120 	if (interface != PHY_INTERFACE_MODE_RMII) {
121 		dev_err(dev, "unsupported phy interface mode %d\n", interface);
122 		err = -ENOTSUPP;
123 		goto out_netdev;
124 	}
125 
126 	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
127 	if (IS_ERR(priv->grf)) {
128 		dev_err(dev, "failed to retrieve global register file (%ld)\n", PTR_ERR(priv->grf));
129 		err = PTR_ERR(priv->grf);
130 		goto out_netdev;
131 	}
132 
133 	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
134 	priv->soc_data = match->data;
135 
136 	priv->emac.clk = devm_clk_get(dev, "hclk");
137 	if (IS_ERR(priv->emac.clk)) {
138 		dev_err(dev, "failed to retrieve host clock (%ld)\n", PTR_ERR(priv->emac.clk));
139 		err = PTR_ERR(priv->emac.clk);
140 		goto out_netdev;
141 	}
142 
143 	priv->refclk = devm_clk_get(dev, "macref");
144 	if (IS_ERR(priv->refclk)) {
145 		dev_err(dev, "failed to retrieve reference clock (%ld)\n", PTR_ERR(priv->refclk));
146 		err = PTR_ERR(priv->refclk);
147 		goto out_netdev;
148 	}
149 
150 	err = clk_prepare_enable(priv->refclk);
151 	if (err) {
152 		dev_err(dev, "failed to enable reference clock (%d)\n", err);
153 		goto out_netdev;
154 	}
155 
156 	/* Optional regulator for PHY */
157 	priv->regulator = devm_regulator_get_optional(dev, "phy");
158 	if (IS_ERR(priv->regulator)) {
159 		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER)
160 			return -EPROBE_DEFER;
161 		dev_err(dev, "no regulator found\n");
162 		priv->regulator = NULL;
163 	}
164 
165 	if (priv->regulator) {
166 		err = regulator_enable(priv->regulator);
167 		if (err) {
168 			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
169 			goto out_clk_disable;
170 		}
171 	}
172 
173 	/* Set speed 100M */
174 	data = (1 << (priv->soc_data->grf_speed_offset + 16)) |
175 	       (1 << priv->soc_data->grf_speed_offset);
176 	/* Set RMII mode */
177 	data |= (1 << (priv->soc_data->grf_mode_offset + 16)) |
178 		(0 << priv->soc_data->grf_mode_offset);
179 
180 	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
181 	if (err) {
182 		dev_err(dev, "unable to apply initial settings to grf (%d)\n", err);
183 		goto out_regulator_disable;
184 	}
185 
186 	/* RMII interface needs always a rate of 50MHz */
187 	err = clk_set_rate(priv->refclk, 50000000);
188 	if (err)
189 		dev_err(dev, "failed to change reference clock rate (%d)\n", err);
190 
191 	if (priv->soc_data->need_div_macclk) {
192 		priv->macclk = devm_clk_get(dev, "macclk");
193 		if (IS_ERR(priv->macclk)) {
194 			dev_err(dev, "failed to retrieve mac clock (%ld)\n", PTR_ERR(priv->macclk));
195 			err = PTR_ERR(priv->macclk);
196 			goto out_regulator_disable;
197 		}
198 
199 		err = clk_prepare_enable(priv->macclk);
200 		if (err) {
201 			dev_err(dev, "failed to enable mac clock (%d)\n", err);
202 			goto out_regulator_disable;
203 		}
204 
205 		/* RMII TX/RX needs always a rate of 25MHz */
206 		err = clk_set_rate(priv->macclk, 25000000);
207 		if (err)
208 			dev_err(dev, "failed to change mac clock rate (%d)\n", err);
209 	}
210 
211 	err = arc_emac_probe(ndev, interface);
212 	if (err) {
213 		dev_err(dev, "failed to probe arc emac (%d)\n", err);
214 		goto out_regulator_disable;
215 	}
216 
217 	return 0;
218 
219 out_regulator_disable:
220 	if (priv->regulator)
221 		regulator_disable(priv->regulator);
222 out_clk_disable:
223 	clk_disable_unprepare(priv->refclk);
224 out_netdev:
225 	free_netdev(ndev);
226 	return err;
227 }
228 
229 static int emac_rockchip_remove(struct platform_device *pdev)
230 {
231 	struct net_device *ndev = platform_get_drvdata(pdev);
232 	struct rockchip_priv_data *priv = netdev_priv(ndev);
233 	int err;
234 
235 	err = arc_emac_remove(ndev);
236 
237 	clk_disable_unprepare(priv->refclk);
238 
239 	if (priv->regulator)
240 		regulator_disable(priv->regulator);
241 
242 	free_netdev(ndev);
243 	return err;
244 }
245 
246 static struct platform_driver emac_rockchip_driver = {
247 	.probe = emac_rockchip_probe,
248 	.remove = emac_rockchip_remove,
249 	.driver = {
250 		.name = DRV_NAME,
251 		.of_match_table  = emac_rockchip_dt_ids,
252 	},
253 };
254 
255 module_platform_driver(emac_rockchip_driver);
256 
257 MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
258 MODULE_DESCRIPTION("Rockchip EMAC platform driver");
259 MODULE_LICENSE("GPL");
260