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 	{
87 		.compatible = "rockchip,rk3036-emac",
88 		.data = &emac_rk3036_emac_data,
89 	},
90 	{
91 		.compatible = "rockchip,rk3066-emac",
92 		.data = &emac_rk3066_emac_data,
93 	},
94 	{
95 		.compatible = "rockchip,rk3188-emac",
96 		.data = &emac_rk3188_emac_data,
97 	},
98 	{ /* Sentinel */ }
99 };
100 
101 MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
102 
103 static int emac_rockchip_probe(struct platform_device *pdev)
104 {
105 	struct device *dev = &pdev->dev;
106 	struct net_device *ndev;
107 	struct rockchip_priv_data *priv;
108 	const struct of_device_id *match;
109 	u32 data;
110 	int err, interface;
111 
112 	if (!pdev->dev.of_node)
113 		return -ENODEV;
114 
115 	ndev = alloc_etherdev(sizeof(struct rockchip_priv_data));
116 	if (!ndev)
117 		return -ENOMEM;
118 	platform_set_drvdata(pdev, ndev);
119 	SET_NETDEV_DEV(ndev, dev);
120 
121 	priv = netdev_priv(ndev);
122 	priv->emac.drv_name = DRV_NAME;
123 	priv->emac.drv_version = DRV_VERSION;
124 	priv->emac.set_mac_speed = emac_rockchip_set_mac_speed;
125 
126 	interface = of_get_phy_mode(dev->of_node);
127 
128 	/* RK3036/RK3066/RK3188 SoCs only support RMII */
129 	if (interface != PHY_INTERFACE_MODE_RMII) {
130 		dev_err(dev, "unsupported phy interface mode %d\n", interface);
131 		err = -ENOTSUPP;
132 		goto out_netdev;
133 	}
134 
135 	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
136 						    "rockchip,grf");
137 	if (IS_ERR(priv->grf)) {
138 		dev_err(dev, "failed to retrieve global register file (%ld)\n",
139 			PTR_ERR(priv->grf));
140 		err = PTR_ERR(priv->grf);
141 		goto out_netdev;
142 	}
143 
144 	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
145 	priv->soc_data = match->data;
146 
147 	priv->emac.clk = devm_clk_get(dev, "hclk");
148 	if (IS_ERR(priv->emac.clk)) {
149 		dev_err(dev, "failed to retrieve host clock (%ld)\n",
150 			PTR_ERR(priv->emac.clk));
151 		err = PTR_ERR(priv->emac.clk);
152 		goto out_netdev;
153 	}
154 
155 	priv->refclk = devm_clk_get(dev, "macref");
156 	if (IS_ERR(priv->refclk)) {
157 		dev_err(dev, "failed to retrieve reference clock (%ld)\n",
158 			PTR_ERR(priv->refclk));
159 		err = PTR_ERR(priv->refclk);
160 		goto out_netdev;
161 	}
162 
163 	err = clk_prepare_enable(priv->refclk);
164 	if (err) {
165 		dev_err(dev, "failed to enable reference clock (%d)\n", err);
166 		goto out_netdev;
167 	}
168 
169 	/* Optional regulator for PHY */
170 	priv->regulator = devm_regulator_get_optional(dev, "phy");
171 	if (IS_ERR(priv->regulator)) {
172 		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER)
173 			return -EPROBE_DEFER;
174 		dev_err(dev, "no regulator found\n");
175 		priv->regulator = NULL;
176 	}
177 
178 	if (priv->regulator) {
179 		err = regulator_enable(priv->regulator);
180 		if (err) {
181 			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
182 			goto out_clk_disable;
183 		}
184 	}
185 
186 	/* Set speed 100M */
187 	data = (1 << (priv->soc_data->grf_speed_offset + 16)) |
188 	       (1 << priv->soc_data->grf_speed_offset);
189 	/* Set RMII mode */
190 	data |= (1 << (priv->soc_data->grf_mode_offset + 16)) |
191 		(0 << priv->soc_data->grf_mode_offset);
192 
193 	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
194 	if (err) {
195 		dev_err(dev, "unable to apply initial settings to grf (%d)\n",
196 			err);
197 		goto out_regulator_disable;
198 	}
199 
200 	/* RMII interface needs always a rate of 50MHz */
201 	err = clk_set_rate(priv->refclk, 50000000);
202 	if (err)
203 		dev_err(dev,
204 			"failed to change reference clock rate (%d)\n", err);
205 
206 	if (priv->soc_data->need_div_macclk) {
207 		priv->macclk = devm_clk_get(dev, "macclk");
208 		if (IS_ERR(priv->macclk)) {
209 			dev_err(dev, "failed to retrieve mac clock (%ld)\n",
210 				PTR_ERR(priv->macclk));
211 			err = PTR_ERR(priv->macclk);
212 			goto out_regulator_disable;
213 		}
214 
215 		err = clk_prepare_enable(priv->macclk);
216 		if (err) {
217 			dev_err(dev, "failed to enable mac clock (%d)\n", err);
218 			goto out_regulator_disable;
219 		}
220 
221 		/* RMII TX/RX needs always a rate of 25MHz */
222 		err = clk_set_rate(priv->macclk, 25000000);
223 		if (err)
224 			dev_err(dev,
225 				"failed to change mac clock rate (%d)\n", err);
226 	}
227 
228 	err = arc_emac_probe(ndev, interface);
229 	if (err) {
230 		dev_err(dev, "failed to probe arc emac (%d)\n", err);
231 		goto out_regulator_disable;
232 	}
233 
234 	return 0;
235 
236 out_regulator_disable:
237 	if (priv->regulator)
238 		regulator_disable(priv->regulator);
239 out_clk_disable:
240 	clk_disable_unprepare(priv->refclk);
241 out_netdev:
242 	free_netdev(ndev);
243 	return err;
244 }
245 
246 static int emac_rockchip_remove(struct platform_device *pdev)
247 {
248 	struct net_device *ndev = platform_get_drvdata(pdev);
249 	struct rockchip_priv_data *priv = netdev_priv(ndev);
250 	int err;
251 
252 	err = arc_emac_remove(ndev);
253 
254 	clk_disable_unprepare(priv->refclk);
255 
256 	if (priv->regulator)
257 		regulator_disable(priv->regulator);
258 
259 	free_netdev(ndev);
260 	return err;
261 }
262 
263 static struct platform_driver emac_rockchip_driver = {
264 	.probe = emac_rockchip_probe,
265 	.remove = emac_rockchip_remove,
266 	.driver = {
267 		.name = DRV_NAME,
268 		.of_match_table  = emac_rockchip_dt_ids,
269 	},
270 };
271 
272 module_platform_driver(emac_rockchip_driver);
273 
274 MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
275 MODULE_DESCRIPTION("Rockchip EMAC platform driver");
276 MODULE_LICENSE("GPL");
277