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     "1.0"
29
30#define GRF_MODE_MII		(1UL << 0)
31#define GRF_MODE_RMII		(0UL << 0)
32#define GRF_SPEED_10M		(0UL << 1)
33#define GRF_SPEED_100M		(1UL << 1)
34#define GRF_SPEED_ENABLE_BIT	(1UL << 17)
35#define GRF_MODE_ENABLE_BIT	(1UL << 16)
36
37struct emac_rockchip_soc_data {
38	int grf_offset;
39};
40
41struct rockchip_priv_data {
42	struct arc_emac_priv emac;
43	struct regmap *grf;
44	const struct emac_rockchip_soc_data *soc_data;
45	struct regulator *regulator;
46	struct clk *refclk;
47};
48
49static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
50{
51	struct rockchip_priv_data *emac = priv;
52	u32 data;
53	int err = 0;
54
55	/* write-enable bits */
56	data = GRF_SPEED_ENABLE_BIT;
57
58	switch(speed) {
59	case 10:
60		data |= GRF_SPEED_10M;
61		break;
62	case 100:
63		data |= GRF_SPEED_100M;
64		break;
65	default:
66		pr_err("speed %u not supported\n", speed);
67		return;
68	}
69
70	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
71	if (err)
72		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
73}
74
75static const struct emac_rockchip_soc_data emac_rockchip_dt_data[] = {
76	{ .grf_offset = 0x154 }, /* rk3066 */
77	{ .grf_offset = 0x0a4 }, /* rk3188 */
78};
79
80static const struct of_device_id emac_rockchip_dt_ids[] = {
81	{ .compatible = "rockchip,rk3066-emac", .data = &emac_rockchip_dt_data[0] },
82	{ .compatible = "rockchip,rk3188-emac", .data = &emac_rockchip_dt_data[1] },
83	{ /* Sentinel */ }
84};
85
86MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
87
88static int emac_rockchip_probe(struct platform_device *pdev)
89{
90	struct device *dev = &pdev->dev;
91	struct net_device *ndev;
92	struct rockchip_priv_data *priv;
93	const struct of_device_id *match;
94	u32 data;
95	int err, interface;
96
97	if (!pdev->dev.of_node)
98		return -ENODEV;
99
100	ndev = alloc_etherdev(sizeof(struct rockchip_priv_data));
101	if (!ndev)
102		return -ENOMEM;
103	platform_set_drvdata(pdev, ndev);
104	SET_NETDEV_DEV(ndev, dev);
105
106	priv = netdev_priv(ndev);
107	priv->emac.drv_name = DRV_NAME;
108	priv->emac.drv_version = DRV_VERSION;
109	priv->emac.set_mac_speed = emac_rockchip_set_mac_speed;
110
111	interface = of_get_phy_mode(dev->of_node);
112
113	/* RK3066 and RK3188 SoCs only support RMII */
114	if (interface != PHY_INTERFACE_MODE_RMII) {
115		dev_err(dev, "unsupported phy interface mode %d\n", interface);
116		err = -ENOTSUPP;
117		goto out_netdev;
118	}
119
120	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
121	if (IS_ERR(priv->grf)) {
122		dev_err(dev, "failed to retrieve global register file (%ld)\n", PTR_ERR(priv->grf));
123		err = PTR_ERR(priv->grf);
124		goto out_netdev;
125	}
126
127	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
128	priv->soc_data = match->data;
129
130	priv->emac.clk = devm_clk_get(dev, "hclk");
131	if (IS_ERR(priv->emac.clk)) {
132		dev_err(dev, "failed to retrieve host clock (%ld)\n", PTR_ERR(priv->emac.clk));
133		err = PTR_ERR(priv->emac.clk);
134		goto out_netdev;
135	}
136
137	priv->refclk = devm_clk_get(dev, "macref");
138	if (IS_ERR(priv->refclk)) {
139		dev_err(dev, "failed to retrieve reference clock (%ld)\n", PTR_ERR(priv->refclk));
140		err = PTR_ERR(priv->refclk);
141		goto out_netdev;
142	}
143
144	err = clk_prepare_enable(priv->refclk);
145	if (err) {
146		dev_err(dev, "failed to enable reference clock (%d)\n", err);
147		goto out_netdev;
148	}
149
150	/* Optional regulator for PHY */
151	priv->regulator = devm_regulator_get_optional(dev, "phy");
152	if (IS_ERR(priv->regulator)) {
153		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER)
154			return -EPROBE_DEFER;
155		dev_err(dev, "no regulator found\n");
156		priv->regulator = NULL;
157	}
158
159	if (priv->regulator) {
160		err = regulator_enable(priv->regulator);
161		if (err) {
162			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
163			goto out_clk_disable;
164		}
165	}
166
167	err = arc_emac_probe(ndev, interface);
168	if (err)
169		goto out_regulator_disable;
170
171	/* write-enable bits */
172	data = GRF_MODE_ENABLE_BIT | GRF_SPEED_ENABLE_BIT;
173
174	data |= GRF_SPEED_100M;
175	data |= GRF_MODE_RMII;
176
177	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
178	if (err) {
179		dev_err(dev, "unable to apply initial settings to grf (%d)\n", err);
180		goto out_regulator_disable;
181	}
182
183	/* RMII interface needs always a rate of 50MHz */
184	err = clk_set_rate(priv->refclk, 50000000);
185	if (err)
186		dev_err(dev, "failed to change reference clock rate (%d)\n", err);
187	return 0;
188
189out_regulator_disable:
190	if (priv->regulator)
191		regulator_disable(priv->regulator);
192out_clk_disable:
193	clk_disable_unprepare(priv->refclk);
194out_netdev:
195	free_netdev(ndev);
196	return err;
197}
198
199static int emac_rockchip_remove(struct platform_device *pdev)
200{
201	struct net_device *ndev = platform_get_drvdata(pdev);
202	struct rockchip_priv_data *priv = netdev_priv(ndev);
203	int err;
204
205	err = arc_emac_remove(ndev);
206
207	clk_disable_unprepare(priv->refclk);
208
209	if (priv->regulator)
210		regulator_disable(priv->regulator);
211
212	free_netdev(ndev);
213	return err;
214}
215
216static struct platform_driver emac_rockchip_driver = {
217	.probe = emac_rockchip_probe,
218	.remove = emac_rockchip_remove,
219	.driver = {
220		.name = DRV_NAME,
221		.of_match_table  = emac_rockchip_dt_ids,
222	},
223};
224
225module_platform_driver(emac_rockchip_driver);
226
227MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
228MODULE_DESCRIPTION("Rockchip EMAC platform driver");
229MODULE_LICENSE("GPL");
230