1 /* Copyright Altera Corporation (C) 2014. All rights reserved.
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License, version 2,
5  * as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
14  *
15  * Adopted from dwmac-sti.c
16  */
17 
18 #include <linux/mfd/syscon.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_net.h>
22 #include <linux/phy.h>
23 #include <linux/regmap.h>
24 #include <linux/reset.h>
25 #include <linux/stmmac.h>
26 #include "stmmac.h"
27 
28 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII 0x0
29 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII 0x1
30 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RMII 0x2
31 #define SYSMGR_EMACGRP_CTRL_PHYSEL_WIDTH 2
32 #define SYSMGR_EMACGRP_CTRL_PHYSEL_MASK 0x00000003
33 
34 #define EMAC_SPLITTER_CTRL_REG			0x0
35 #define EMAC_SPLITTER_CTRL_SPEED_MASK		0x3
36 #define EMAC_SPLITTER_CTRL_SPEED_10		0x2
37 #define EMAC_SPLITTER_CTRL_SPEED_100		0x3
38 #define EMAC_SPLITTER_CTRL_SPEED_1000		0x0
39 
40 struct socfpga_dwmac {
41 	int	interface;
42 	u32	reg_offset;
43 	u32	reg_shift;
44 	struct	device *dev;
45 	struct regmap *sys_mgr_base_addr;
46 	struct reset_control *stmmac_rst;
47 	void __iomem *splitter_base;
48 };
49 
50 static void socfpga_dwmac_fix_mac_speed(void *priv, unsigned int speed)
51 {
52 	struct socfpga_dwmac *dwmac = (struct socfpga_dwmac *)priv;
53 	void __iomem *splitter_base = dwmac->splitter_base;
54 	u32 val;
55 
56 	if (!splitter_base)
57 		return;
58 
59 	val = readl(splitter_base + EMAC_SPLITTER_CTRL_REG);
60 	val &= ~EMAC_SPLITTER_CTRL_SPEED_MASK;
61 
62 	switch (speed) {
63 	case 1000:
64 		val |= EMAC_SPLITTER_CTRL_SPEED_1000;
65 		break;
66 	case 100:
67 		val |= EMAC_SPLITTER_CTRL_SPEED_100;
68 		break;
69 	case 10:
70 		val |= EMAC_SPLITTER_CTRL_SPEED_10;
71 		break;
72 	default:
73 		return;
74 	}
75 
76 	writel(val, splitter_base + EMAC_SPLITTER_CTRL_REG);
77 }
78 
79 static int socfpga_dwmac_parse_data(struct socfpga_dwmac *dwmac, struct device *dev)
80 {
81 	struct device_node *np = dev->of_node;
82 	struct regmap *sys_mgr_base_addr;
83 	u32 reg_offset, reg_shift;
84 	int ret;
85 	struct device_node *np_splitter;
86 	struct resource res_splitter;
87 
88 	dwmac->stmmac_rst = devm_reset_control_get(dev,
89 						  STMMAC_RESOURCE_NAME);
90 	if (IS_ERR(dwmac->stmmac_rst)) {
91 		dev_info(dev, "Could not get reset control!\n");
92 		return -EINVAL;
93 	}
94 
95 	dwmac->interface = of_get_phy_mode(np);
96 
97 	sys_mgr_base_addr = syscon_regmap_lookup_by_phandle(np, "altr,sysmgr-syscon");
98 	if (IS_ERR(sys_mgr_base_addr)) {
99 		dev_info(dev, "No sysmgr-syscon node found\n");
100 		return PTR_ERR(sys_mgr_base_addr);
101 	}
102 
103 	ret = of_property_read_u32_index(np, "altr,sysmgr-syscon", 1, &reg_offset);
104 	if (ret) {
105 		dev_info(dev, "Could not read reg_offset from sysmgr-syscon!\n");
106 		return -EINVAL;
107 	}
108 
109 	ret = of_property_read_u32_index(np, "altr,sysmgr-syscon", 2, &reg_shift);
110 	if (ret) {
111 		dev_info(dev, "Could not read reg_shift from sysmgr-syscon!\n");
112 		return -EINVAL;
113 	}
114 
115 	np_splitter = of_parse_phandle(np, "altr,emac-splitter", 0);
116 	if (np_splitter) {
117 		if (of_address_to_resource(np_splitter, 0, &res_splitter)) {
118 			dev_info(dev, "Missing emac splitter address\n");
119 			return -EINVAL;
120 		}
121 
122 		dwmac->splitter_base = devm_ioremap_resource(dev, &res_splitter);
123 		if (!dwmac->splitter_base) {
124 			dev_info(dev, "Failed to mapping emac splitter\n");
125 			return -EINVAL;
126 		}
127 	}
128 
129 	dwmac->reg_offset = reg_offset;
130 	dwmac->reg_shift = reg_shift;
131 	dwmac->sys_mgr_base_addr = sys_mgr_base_addr;
132 	dwmac->dev = dev;
133 
134 	return 0;
135 }
136 
137 static int socfpga_dwmac_setup(struct socfpga_dwmac *dwmac)
138 {
139 	struct regmap *sys_mgr_base_addr = dwmac->sys_mgr_base_addr;
140 	int phymode = dwmac->interface;
141 	u32 reg_offset = dwmac->reg_offset;
142 	u32 reg_shift = dwmac->reg_shift;
143 	u32 ctrl, val;
144 
145 	switch (phymode) {
146 	case PHY_INTERFACE_MODE_RGMII:
147 	case PHY_INTERFACE_MODE_RGMII_ID:
148 		val = SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII;
149 		break;
150 	case PHY_INTERFACE_MODE_MII:
151 	case PHY_INTERFACE_MODE_GMII:
152 		val = SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII;
153 		break;
154 	default:
155 		dev_err(dwmac->dev, "bad phy mode %d\n", phymode);
156 		return -EINVAL;
157 	}
158 
159 	/* Overwrite val to GMII if splitter core is enabled. The phymode here
160 	 * is the actual phy mode on phy hardware, but phy interface from
161 	 * EMAC core is GMII.
162 	 */
163 	if (dwmac->splitter_base)
164 		val = SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII;
165 
166 	regmap_read(sys_mgr_base_addr, reg_offset, &ctrl);
167 	ctrl &= ~(SYSMGR_EMACGRP_CTRL_PHYSEL_MASK << reg_shift);
168 	ctrl |= val << reg_shift;
169 
170 	regmap_write(sys_mgr_base_addr, reg_offset, ctrl);
171 	return 0;
172 }
173 
174 static void *socfpga_dwmac_probe(struct platform_device *pdev)
175 {
176 	struct device		*dev = &pdev->dev;
177 	int			ret;
178 	struct socfpga_dwmac	*dwmac;
179 
180 	dwmac = devm_kzalloc(dev, sizeof(*dwmac), GFP_KERNEL);
181 	if (!dwmac)
182 		return ERR_PTR(-ENOMEM);
183 
184 	ret = socfpga_dwmac_parse_data(dwmac, dev);
185 	if (ret) {
186 		dev_err(dev, "Unable to parse OF data\n");
187 		return ERR_PTR(ret);
188 	}
189 
190 	ret = socfpga_dwmac_setup(dwmac);
191 	if (ret) {
192 		dev_err(dev, "couldn't setup SoC glue (%d)\n", ret);
193 		return ERR_PTR(ret);
194 	}
195 
196 	return dwmac;
197 }
198 
199 static void socfpga_dwmac_exit(struct platform_device *pdev, void *priv)
200 {
201 	struct socfpga_dwmac	*dwmac = priv;
202 
203 	/* On socfpga platform exit, assert and hold reset to the
204 	 * enet controller - the default state after a hard reset.
205 	 */
206 	if (dwmac->stmmac_rst)
207 		reset_control_assert(dwmac->stmmac_rst);
208 }
209 
210 static int socfpga_dwmac_init(struct platform_device *pdev, void *priv)
211 {
212 	struct socfpga_dwmac	*dwmac = priv;
213 	struct net_device *ndev = platform_get_drvdata(pdev);
214 	struct stmmac_priv *stpriv = NULL;
215 	int ret = 0;
216 
217 	if (ndev)
218 		stpriv = netdev_priv(ndev);
219 
220 	/* Assert reset to the enet controller before changing the phy mode */
221 	if (dwmac->stmmac_rst)
222 		reset_control_assert(dwmac->stmmac_rst);
223 
224 	/* Setup the phy mode in the system manager registers according to
225 	 * devicetree configuration
226 	 */
227 	ret = socfpga_dwmac_setup(dwmac);
228 
229 	/* Deassert reset for the phy configuration to be sampled by
230 	 * the enet controller, and operation to start in requested mode
231 	 */
232 	if (dwmac->stmmac_rst)
233 		reset_control_deassert(dwmac->stmmac_rst);
234 
235 	/* Before the enet controller is suspended, the phy is suspended.
236 	 * This causes the phy clock to be gated. The enet controller is
237 	 * resumed before the phy, so the clock is still gated "off" when
238 	 * the enet controller is resumed. This code makes sure the phy
239 	 * is "resumed" before reinitializing the enet controller since
240 	 * the enet controller depends on an active phy clock to complete
241 	 * a DMA reset. A DMA reset will "time out" if executed
242 	 * with no phy clock input on the Synopsys enet controller.
243 	 * Verified through Synopsys Case #8000711656.
244 	 *
245 	 * Note that the phy clock is also gated when the phy is isolated.
246 	 * Phy "suspend" and "isolate" controls are located in phy basic
247 	 * control register 0, and can be modified by the phy driver
248 	 * framework.
249 	 */
250 	if (stpriv && stpriv->phydev)
251 		phy_resume(stpriv->phydev);
252 
253 	return ret;
254 }
255 
256 const struct stmmac_of_data socfpga_gmac_data = {
257 	.setup = socfpga_dwmac_probe,
258 	.init = socfpga_dwmac_init,
259 	.exit = socfpga_dwmac_exit,
260 	.fix_mac_speed = socfpga_dwmac_fix_mac_speed,
261 };
262