1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /**
3  * emac-rockchip.c - Rockchip EMAC specific glue layer
4  *
5  * Copyright (C) 2014 Romain Perier <romain.perier@gmail.com>
6  */
7 
8 #include <linux/etherdevice.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/of_net.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/consumer.h>
15 
16 #include "emac.h"
17 
18 #define DRV_NAME        "rockchip_emac"
19 #define DRV_VERSION     "1.1"
20 
21 struct emac_rockchip_soc_data {
22 	unsigned int grf_offset;
23 	unsigned int grf_mode_offset;
24 	unsigned int grf_speed_offset;
25 	bool need_div_macclk;
26 };
27 
28 struct rockchip_priv_data {
29 	struct arc_emac_priv emac;
30 	struct regmap *grf;
31 	const struct emac_rockchip_soc_data *soc_data;
32 	struct regulator *regulator;
33 	struct clk *refclk;
34 	struct clk *macclk;
35 };
36 
37 static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
38 {
39 	struct rockchip_priv_data *emac = priv;
40 	u32 speed_offset = emac->soc_data->grf_speed_offset;
41 	u32 data;
42 	int err = 0;
43 
44 	switch (speed) {
45 	case 10:
46 		data = (1 << (speed_offset + 16)) | (0 << speed_offset);
47 		break;
48 	case 100:
49 		data = (1 << (speed_offset + 16)) | (1 << speed_offset);
50 		break;
51 	default:
52 		pr_err("speed %u not supported\n", speed);
53 		return;
54 	}
55 
56 	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
57 	if (err)
58 		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
59 }
60 
61 static const struct emac_rockchip_soc_data emac_rk3036_emac_data = {
62 	.grf_offset = 0x140,   .grf_mode_offset = 8,
63 	.grf_speed_offset = 9, .need_div_macclk = 1,
64 };
65 
66 static const struct emac_rockchip_soc_data emac_rk3066_emac_data = {
67 	.grf_offset = 0x154,   .grf_mode_offset = 0,
68 	.grf_speed_offset = 1, .need_div_macclk = 0,
69 };
70 
71 static const struct emac_rockchip_soc_data emac_rk3188_emac_data = {
72 	.grf_offset = 0x0a4,   .grf_mode_offset = 0,
73 	.grf_speed_offset = 1, .need_div_macclk = 0,
74 };
75 
76 static const struct of_device_id emac_rockchip_dt_ids[] = {
77 	{
78 		.compatible = "rockchip,rk3036-emac",
79 		.data = &emac_rk3036_emac_data,
80 	},
81 	{
82 		.compatible = "rockchip,rk3066-emac",
83 		.data = &emac_rk3066_emac_data,
84 	},
85 	{
86 		.compatible = "rockchip,rk3188-emac",
87 		.data = &emac_rk3188_emac_data,
88 	},
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,
127 						    "rockchip,grf");
128 	if (IS_ERR(priv->grf)) {
129 		dev_err(dev, "failed to retrieve global register file (%ld)\n",
130 			PTR_ERR(priv->grf));
131 		err = PTR_ERR(priv->grf);
132 		goto out_netdev;
133 	}
134 
135 	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
136 	priv->soc_data = match->data;
137 
138 	priv->emac.clk = devm_clk_get(dev, "hclk");
139 	if (IS_ERR(priv->emac.clk)) {
140 		dev_err(dev, "failed to retrieve host clock (%ld)\n",
141 			PTR_ERR(priv->emac.clk));
142 		err = PTR_ERR(priv->emac.clk);
143 		goto out_netdev;
144 	}
145 
146 	priv->refclk = devm_clk_get(dev, "macref");
147 	if (IS_ERR(priv->refclk)) {
148 		dev_err(dev, "failed to retrieve reference clock (%ld)\n",
149 			PTR_ERR(priv->refclk));
150 		err = PTR_ERR(priv->refclk);
151 		goto out_netdev;
152 	}
153 
154 	err = clk_prepare_enable(priv->refclk);
155 	if (err) {
156 		dev_err(dev, "failed to enable reference clock (%d)\n", err);
157 		goto out_netdev;
158 	}
159 
160 	/* Optional regulator for PHY */
161 	priv->regulator = devm_regulator_get_optional(dev, "phy");
162 	if (IS_ERR(priv->regulator)) {
163 		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER) {
164 			err = -EPROBE_DEFER;
165 			goto out_clk_disable;
166 		}
167 		dev_err(dev, "no regulator found\n");
168 		priv->regulator = NULL;
169 	}
170 
171 	if (priv->regulator) {
172 		err = regulator_enable(priv->regulator);
173 		if (err) {
174 			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
175 			goto out_clk_disable;
176 		}
177 	}
178 
179 	/* Set speed 100M */
180 	data = (1 << (priv->soc_data->grf_speed_offset + 16)) |
181 	       (1 << priv->soc_data->grf_speed_offset);
182 	/* Set RMII mode */
183 	data |= (1 << (priv->soc_data->grf_mode_offset + 16)) |
184 		(0 << priv->soc_data->grf_mode_offset);
185 
186 	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
187 	if (err) {
188 		dev_err(dev, "unable to apply initial settings to grf (%d)\n",
189 			err);
190 		goto out_regulator_disable;
191 	}
192 
193 	/* RMII interface needs always a rate of 50MHz */
194 	err = clk_set_rate(priv->refclk, 50000000);
195 	if (err) {
196 		dev_err(dev,
197 			"failed to change reference clock rate (%d)\n", err);
198 		goto out_regulator_disable;
199 	}
200 
201 	if (priv->soc_data->need_div_macclk) {
202 		priv->macclk = devm_clk_get(dev, "macclk");
203 		if (IS_ERR(priv->macclk)) {
204 			dev_err(dev, "failed to retrieve mac clock (%ld)\n",
205 				PTR_ERR(priv->macclk));
206 			err = PTR_ERR(priv->macclk);
207 			goto out_regulator_disable;
208 		}
209 
210 		err = clk_prepare_enable(priv->macclk);
211 		if (err) {
212 			dev_err(dev, "failed to enable mac clock (%d)\n", err);
213 			goto out_regulator_disable;
214 		}
215 
216 		/* RMII TX/RX needs always a rate of 25MHz */
217 		err = clk_set_rate(priv->macclk, 25000000);
218 		if (err) {
219 			dev_err(dev,
220 				"failed to change mac clock rate (%d)\n", err);
221 			goto out_clk_disable_macclk;
222 		}
223 	}
224 
225 	err = arc_emac_probe(ndev, interface);
226 	if (err) {
227 		dev_err(dev, "failed to probe arc emac (%d)\n", err);
228 		goto out_clk_disable_macclk;
229 	}
230 
231 	return 0;
232 
233 out_clk_disable_macclk:
234 	if (priv->soc_data->need_div_macclk)
235 		clk_disable_unprepare(priv->macclk);
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