1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Russell King, Deep Blue Solutions Ltd.
4  *
5  * Partly derived from CP110 comphy driver by Antoine Tenart
6  * <antoine.tenart@bootlin.com>
7  */
8 #include <linux/delay.h>
9 #include <linux/iopoll.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/phy/phy.h>
13 #include <linux/phy.h>
14 #include <linux/platform_device.h>
15 
16 #define MAX_A38X_COMPHY	6
17 #define MAX_A38X_PORTS	3
18 
19 #define COMPHY_CFG1		0x00
20 #define  COMPHY_CFG1_GEN_TX(x)		((x) << 26)
21 #define  COMPHY_CFG1_GEN_TX_MSK		COMPHY_CFG1_GEN_TX(15)
22 #define  COMPHY_CFG1_GEN_RX(x)		((x) << 22)
23 #define  COMPHY_CFG1_GEN_RX_MSK		COMPHY_CFG1_GEN_RX(15)
24 #define  GEN_SGMII_1_25GBPS		6
25 #define  GEN_SGMII_3_125GBPS		8
26 
27 #define COMPHY_STAT1		0x18
28 #define  COMPHY_STAT1_PLL_RDY_TX	BIT(3)
29 #define  COMPHY_STAT1_PLL_RDY_RX	BIT(2)
30 
31 #define COMPHY_SELECTOR		0xfc
32 
33 struct a38x_comphy;
34 
35 struct a38x_comphy_lane {
36 	void __iomem *base;
37 	struct a38x_comphy *priv;
38 	unsigned int n;
39 
40 	int port;
41 };
42 
43 struct a38x_comphy {
44 	void __iomem *base;
45 	void __iomem *conf;
46 	struct device *dev;
47 	struct a38x_comphy_lane lane[MAX_A38X_COMPHY];
48 };
49 
50 static const u8 gbe_mux[MAX_A38X_COMPHY][MAX_A38X_PORTS] = {
51 	{ 0, 0, 0 },
52 	{ 4, 5, 0 },
53 	{ 0, 4, 0 },
54 	{ 0, 0, 4 },
55 	{ 0, 3, 0 },
56 	{ 0, 0, 3 },
57 };
58 
59 static void a38x_set_conf(struct a38x_comphy_lane *lane, bool enable)
60 {
61 	struct a38x_comphy *priv = lane->priv;
62 	u32 conf;
63 
64 	if (priv->conf) {
65 		conf = readl_relaxed(priv->conf);
66 		if (enable)
67 			conf |= BIT(lane->port);
68 		else
69 			conf &= ~BIT(lane->port);
70 		writel(conf, priv->conf);
71 	}
72 }
73 
74 static void a38x_comphy_set_reg(struct a38x_comphy_lane *lane,
75 				unsigned int offset, u32 mask, u32 value)
76 {
77 	u32 val;
78 
79 	val = readl_relaxed(lane->base + offset) & ~mask;
80 	writel(val | value, lane->base + offset);
81 }
82 
83 static void a38x_comphy_set_speed(struct a38x_comphy_lane *lane,
84 				  unsigned int gen_tx, unsigned int gen_rx)
85 {
86 	a38x_comphy_set_reg(lane, COMPHY_CFG1,
87 			    COMPHY_CFG1_GEN_TX_MSK | COMPHY_CFG1_GEN_RX_MSK,
88 			    COMPHY_CFG1_GEN_TX(gen_tx) |
89 		            COMPHY_CFG1_GEN_RX(gen_rx));
90 }
91 
92 static int a38x_comphy_poll(struct a38x_comphy_lane *lane,
93 			    unsigned int offset, u32 mask, u32 value)
94 {
95 	u32 val;
96 	int ret;
97 
98 	ret = readl_relaxed_poll_timeout_atomic(lane->base + offset, val,
99 						(val & mask) == value,
100 						1000, 150000);
101 
102 	if (ret)
103 		dev_err(lane->priv->dev,
104 			"comphy%u: timed out waiting for status\n", lane->n);
105 
106 	return ret;
107 }
108 
109 /*
110  * We only support changing the speed for comphys configured for GBE.
111  * Since that is all we do, we only poll for PLL ready status.
112  */
113 static int a38x_comphy_set_mode(struct phy *phy, enum phy_mode mode, int sub)
114 {
115 	struct a38x_comphy_lane *lane = phy_get_drvdata(phy);
116 	unsigned int gen;
117 	int ret;
118 
119 	if (mode != PHY_MODE_ETHERNET)
120 		return -EINVAL;
121 
122 	switch (sub) {
123 	case PHY_INTERFACE_MODE_SGMII:
124 	case PHY_INTERFACE_MODE_1000BASEX:
125 		gen = GEN_SGMII_1_25GBPS;
126 		break;
127 
128 	case PHY_INTERFACE_MODE_2500BASEX:
129 		gen = GEN_SGMII_3_125GBPS;
130 		break;
131 
132 	default:
133 		return -EINVAL;
134 	}
135 
136 	a38x_set_conf(lane, false);
137 
138 	a38x_comphy_set_speed(lane, gen, gen);
139 
140 	ret = a38x_comphy_poll(lane, COMPHY_STAT1,
141 			       COMPHY_STAT1_PLL_RDY_TX |
142 			       COMPHY_STAT1_PLL_RDY_RX,
143 			       COMPHY_STAT1_PLL_RDY_TX |
144 			       COMPHY_STAT1_PLL_RDY_RX);
145 
146 	if (ret == 0)
147 		a38x_set_conf(lane, true);
148 
149 	return ret;
150 }
151 
152 static const struct phy_ops a38x_comphy_ops = {
153 	.set_mode	= a38x_comphy_set_mode,
154 	.owner		= THIS_MODULE,
155 };
156 
157 static struct phy *a38x_comphy_xlate(struct device *dev,
158 				     struct of_phandle_args *args)
159 {
160 	struct a38x_comphy_lane *lane;
161 	struct phy *phy;
162 	u32 val;
163 
164 	if (WARN_ON(args->args[0] >= MAX_A38X_PORTS))
165 		return ERR_PTR(-EINVAL);
166 
167 	phy = of_phy_simple_xlate(dev, args);
168 	if (IS_ERR(phy))
169 		return phy;
170 
171 	lane = phy_get_drvdata(phy);
172 	if (lane->port >= 0)
173 		return ERR_PTR(-EBUSY);
174 
175 	lane->port = args->args[0];
176 
177 	val = readl_relaxed(lane->priv->base + COMPHY_SELECTOR);
178 	val = (val >> (4 * lane->n)) & 0xf;
179 
180 	if (!gbe_mux[lane->n][lane->port] ||
181 	    val != gbe_mux[lane->n][lane->port]) {
182 		dev_warn(lane->priv->dev,
183 			 "comphy%u: not configured for GBE\n", lane->n);
184 		phy = ERR_PTR(-EINVAL);
185 	}
186 
187 	return phy;
188 }
189 
190 static int a38x_comphy_probe(struct platform_device *pdev)
191 {
192 	struct phy_provider *provider;
193 	struct device_node *child;
194 	struct a38x_comphy *priv;
195 	struct resource *res;
196 	void __iomem *base;
197 
198 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
199 	if (!priv)
200 		return -ENOMEM;
201 
202 	base = devm_platform_ioremap_resource(pdev, 0);
203 	if (IS_ERR(base))
204 		return PTR_ERR(base);
205 
206 	priv->dev = &pdev->dev;
207 	priv->base = base;
208 
209 	/* Optional */
210 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "conf");
211 	if (res) {
212 		priv->conf = devm_ioremap_resource(&pdev->dev, res);
213 		if (IS_ERR(priv->conf))
214 			return PTR_ERR(priv->conf);
215 	}
216 
217 	for_each_available_child_of_node(pdev->dev.of_node, child) {
218 		struct phy *phy;
219 		int ret;
220 		u32 val;
221 
222 		ret = of_property_read_u32(child, "reg", &val);
223 		if (ret < 0) {
224 			dev_err(&pdev->dev, "missing 'reg' property (%d)\n",
225 				ret);
226 			continue;
227 		}
228 
229 		if (val >= MAX_A38X_COMPHY || priv->lane[val].base) {
230 			dev_err(&pdev->dev, "invalid 'reg' property\n");
231 			continue;
232 		}
233 
234 		phy = devm_phy_create(&pdev->dev, child, &a38x_comphy_ops);
235 		if (IS_ERR(phy)) {
236 			of_node_put(child);
237 			return PTR_ERR(phy);
238 		}
239 
240 		priv->lane[val].base = base + 0x28 * val;
241 		priv->lane[val].priv = priv;
242 		priv->lane[val].n = val;
243 		priv->lane[val].port = -1;
244 		phy_set_drvdata(phy, &priv->lane[val]);
245 	}
246 
247 	dev_set_drvdata(&pdev->dev, priv);
248 
249 	provider = devm_of_phy_provider_register(&pdev->dev, a38x_comphy_xlate);
250 
251 	return PTR_ERR_OR_ZERO(provider);
252 }
253 
254 static const struct of_device_id a38x_comphy_of_match_table[] = {
255 	{ .compatible = "marvell,armada-380-comphy" },
256 	{ },
257 };
258 MODULE_DEVICE_TABLE(of, a38x_comphy_of_match_table);
259 
260 static struct platform_driver a38x_comphy_driver = {
261 	.probe	= a38x_comphy_probe,
262 	.driver	= {
263 		.name = "armada-38x-comphy",
264 		.of_match_table = a38x_comphy_of_match_table,
265 	},
266 };
267 module_platform_driver(a38x_comphy_driver);
268 
269 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
270 MODULE_DESCRIPTION("Common PHY driver for Armada 38x SoCs");
271 MODULE_LICENSE("GPL v2");
272