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