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 
20 struct emac_rockchip_soc_data {
21 	unsigned int grf_offset;
22 	unsigned int grf_mode_offset;
23 	unsigned int grf_speed_offset;
24 	bool need_div_macclk;
25 };
26 
27 struct rockchip_priv_data {
28 	struct arc_emac_priv emac;
29 	struct regmap *grf;
30 	const struct emac_rockchip_soc_data *soc_data;
31 	struct regulator *regulator;
32 	struct clk *refclk;
33 	struct clk *macclk;
34 };
35 
36 static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
37 {
38 	struct rockchip_priv_data *emac = priv;
39 	u32 speed_offset = emac->soc_data->grf_speed_offset;
40 	u32 data;
41 	int err = 0;
42 
43 	switch (speed) {
44 	case 10:
45 		data = (1 << (speed_offset + 16)) | (0 << speed_offset);
46 		break;
47 	case 100:
48 		data = (1 << (speed_offset + 16)) | (1 << speed_offset);
49 		break;
50 	default:
51 		pr_err("speed %u not supported\n", speed);
52 		return;
53 	}
54 
55 	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
56 	if (err)
57 		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
58 }
59 
60 static const struct emac_rockchip_soc_data emac_rk3036_emac_data = {
61 	.grf_offset = 0x140,   .grf_mode_offset = 8,
62 	.grf_speed_offset = 9, .need_div_macclk = 1,
63 };
64 
65 static const struct emac_rockchip_soc_data emac_rk3066_emac_data = {
66 	.grf_offset = 0x154,   .grf_mode_offset = 0,
67 	.grf_speed_offset = 1, .need_div_macclk = 0,
68 };
69 
70 static const struct emac_rockchip_soc_data emac_rk3188_emac_data = {
71 	.grf_offset = 0x0a4,   .grf_mode_offset = 0,
72 	.grf_speed_offset = 1, .need_div_macclk = 0,
73 };
74 
75 static const struct of_device_id emac_rockchip_dt_ids[] = {
76 	{
77 		.compatible = "rockchip,rk3036-emac",
78 		.data = &emac_rk3036_emac_data,
79 	},
80 	{
81 		.compatible = "rockchip,rk3066-emac",
82 		.data = &emac_rk3066_emac_data,
83 	},
84 	{
85 		.compatible = "rockchip,rk3188-emac",
86 		.data = &emac_rk3188_emac_data,
87 	},
88 	{ /* Sentinel */ }
89 };
90 
91 MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
92 
93 static int emac_rockchip_probe(struct platform_device *pdev)
94 {
95 	struct device *dev = &pdev->dev;
96 	struct net_device *ndev;
97 	struct rockchip_priv_data *priv;
98 	const struct of_device_id *match;
99 	phy_interface_t interface;
100 	u32 data;
101 	int err;
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.set_mac_speed = emac_rockchip_set_mac_speed;
115 
116 	err = of_get_phy_mode(dev->of_node, &interface);
117 	if (err)
118 		goto out_netdev;
119 
120 	/* RK3036/RK3066/RK3188 SoCs only support RMII */
121 	if (interface != PHY_INTERFACE_MODE_RMII) {
122 		dev_err(dev, "unsupported phy interface mode %d\n", interface);
123 		err = -ENOTSUPP;
124 		goto out_netdev;
125 	}
126 
127 	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
128 						    "rockchip,grf");
129 	if (IS_ERR(priv->grf)) {
130 		dev_err(dev, "failed to retrieve global register file (%ld)\n",
131 			PTR_ERR(priv->grf));
132 		err = PTR_ERR(priv->grf);
133 		goto out_netdev;
134 	}
135 
136 	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
137 	priv->soc_data = match->data;
138 
139 	priv->emac.clk = devm_clk_get(dev, "hclk");
140 	if (IS_ERR(priv->emac.clk)) {
141 		dev_err(dev, "failed to retrieve host clock (%ld)\n",
142 			PTR_ERR(priv->emac.clk));
143 		err = PTR_ERR(priv->emac.clk);
144 		goto out_netdev;
145 	}
146 
147 	priv->refclk = devm_clk_get(dev, "macref");
148 	if (IS_ERR(priv->refclk)) {
149 		dev_err(dev, "failed to retrieve reference clock (%ld)\n",
150 			PTR_ERR(priv->refclk));
151 		err = PTR_ERR(priv->refclk);
152 		goto out_netdev;
153 	}
154 
155 	err = clk_prepare_enable(priv->refclk);
156 	if (err) {
157 		dev_err(dev, "failed to enable reference clock (%d)\n", err);
158 		goto out_netdev;
159 	}
160 
161 	/* Optional regulator for PHY */
162 	priv->regulator = devm_regulator_get_optional(dev, "phy");
163 	if (IS_ERR(priv->regulator)) {
164 		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER) {
165 			err = -EPROBE_DEFER;
166 			goto out_clk_disable;
167 		}
168 		dev_err(dev, "no regulator found\n");
169 		priv->regulator = NULL;
170 	}
171 
172 	if (priv->regulator) {
173 		err = regulator_enable(priv->regulator);
174 		if (err) {
175 			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
176 			goto out_clk_disable;
177 		}
178 	}
179 
180 	/* Set speed 100M */
181 	data = (1 << (priv->soc_data->grf_speed_offset + 16)) |
182 	       (1 << priv->soc_data->grf_speed_offset);
183 	/* Set RMII mode */
184 	data |= (1 << (priv->soc_data->grf_mode_offset + 16)) |
185 		(0 << priv->soc_data->grf_mode_offset);
186 
187 	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
188 	if (err) {
189 		dev_err(dev, "unable to apply initial settings to grf (%d)\n",
190 			err);
191 		goto out_regulator_disable;
192 	}
193 
194 	/* RMII interface needs always a rate of 50MHz */
195 	err = clk_set_rate(priv->refclk, 50000000);
196 	if (err) {
197 		dev_err(dev,
198 			"failed to change reference clock rate (%d)\n", err);
199 		goto out_regulator_disable;
200 	}
201 
202 	if (priv->soc_data->need_div_macclk) {
203 		priv->macclk = devm_clk_get(dev, "macclk");
204 		if (IS_ERR(priv->macclk)) {
205 			dev_err(dev, "failed to retrieve mac clock (%ld)\n",
206 				PTR_ERR(priv->macclk));
207 			err = PTR_ERR(priv->macclk);
208 			goto out_regulator_disable;
209 		}
210 
211 		err = clk_prepare_enable(priv->macclk);
212 		if (err) {
213 			dev_err(dev, "failed to enable mac clock (%d)\n", err);
214 			goto out_regulator_disable;
215 		}
216 
217 		/* RMII TX/RX needs always a rate of 25MHz */
218 		err = clk_set_rate(priv->macclk, 25000000);
219 		if (err) {
220 			dev_err(dev,
221 				"failed to change mac clock rate (%d)\n", err);
222 			goto out_clk_disable_macclk;
223 		}
224 	}
225 
226 	err = arc_emac_probe(ndev, interface);
227 	if (err) {
228 		dev_err(dev, "failed to probe arc emac (%d)\n", err);
229 		goto out_clk_disable_macclk;
230 	}
231 
232 	return 0;
233 
234 out_clk_disable_macclk:
235 	if (priv->soc_data->need_div_macclk)
236 		clk_disable_unprepare(priv->macclk);
237 out_regulator_disable:
238 	if (priv->regulator)
239 		regulator_disable(priv->regulator);
240 out_clk_disable:
241 	clk_disable_unprepare(priv->refclk);
242 out_netdev:
243 	free_netdev(ndev);
244 	return err;
245 }
246 
247 static int emac_rockchip_remove(struct platform_device *pdev)
248 {
249 	struct net_device *ndev = platform_get_drvdata(pdev);
250 	struct rockchip_priv_data *priv = netdev_priv(ndev);
251 	int err;
252 
253 	err = arc_emac_remove(ndev);
254 
255 	clk_disable_unprepare(priv->refclk);
256 
257 	if (priv->regulator)
258 		regulator_disable(priv->regulator);
259 
260 	if (priv->soc_data->need_div_macclk)
261 		clk_disable_unprepare(priv->macclk);
262 
263 	free_netdev(ndev);
264 	return err;
265 }
266 
267 static struct platform_driver emac_rockchip_driver = {
268 	.probe = emac_rockchip_probe,
269 	.remove = emac_rockchip_remove,
270 	.driver = {
271 		.name = DRV_NAME,
272 		.of_match_table  = emac_rockchip_dt_ids,
273 	},
274 };
275 
276 module_platform_driver(emac_rockchip_driver);
277 
278 MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
279 MODULE_DESCRIPTION("Rockchip EMAC platform driver");
280 MODULE_LICENSE("GPL");
281