1 /*
2  * COMBPHY driver for HiSilicon STB SoCs
3  *
4  * Copyright (C) 2016-2017 HiSilicon Co., Ltd. http://www.hisilicon.com
5  *
6  * Authors: Jianguo Sun <sunjianguo1@huawei.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/mfd/syscon.h>
18 #include <linux/module.h>
19 #include <linux/of_device.h>
20 #include <linux/phy/phy.h>
21 #include <linux/regmap.h>
22 #include <linux/reset.h>
23 #include <dt-bindings/phy/phy.h>
24 
25 #define COMBPHY_MODE_PCIE		0
26 #define COMBPHY_MODE_USB3		1
27 #define COMBPHY_MODE_SATA		2
28 
29 #define COMBPHY_CFG_REG			0x0
30 #define COMBPHY_BYPASS_CODEC		BIT(31)
31 #define COMBPHY_TEST_WRITE		BIT(24)
32 #define COMBPHY_TEST_DATA_SHIFT		20
33 #define COMBPHY_TEST_DATA_MASK		GENMASK(23, 20)
34 #define COMBPHY_TEST_ADDR_SHIFT		12
35 #define COMBPHY_TEST_ADDR_MASK		GENMASK(16, 12)
36 #define COMBPHY_CLKREF_OUT_OEN		BIT(0)
37 
38 struct histb_combphy_mode {
39 	int fixed;
40 	int select;
41 	u32 reg;
42 	u32 shift;
43 	u32 mask;
44 };
45 
46 struct histb_combphy_priv {
47 	void __iomem *mmio;
48 	struct regmap *syscon;
49 	struct reset_control *por_rst;
50 	struct clk *ref_clk;
51 	struct phy *phy;
52 	struct histb_combphy_mode mode;
53 };
54 
55 static void nano_register_write(struct histb_combphy_priv *priv,
56 				u32 addr, u32 data)
57 {
58 	void __iomem *reg = priv->mmio + COMBPHY_CFG_REG;
59 	u32 val;
60 
61 	/* Set up address and data for the write */
62 	val = readl(reg);
63 	val &= ~COMBPHY_TEST_ADDR_MASK;
64 	val |= addr << COMBPHY_TEST_ADDR_SHIFT;
65 	val &= ~COMBPHY_TEST_DATA_MASK;
66 	val |= data << COMBPHY_TEST_DATA_SHIFT;
67 	writel(val, reg);
68 
69 	/* Flip strobe control to trigger the write */
70 	val &= ~COMBPHY_TEST_WRITE;
71 	writel(val, reg);
72 	val |= COMBPHY_TEST_WRITE;
73 	writel(val, reg);
74 }
75 
76 static int is_mode_fixed(struct histb_combphy_mode *mode)
77 {
78 	return (mode->fixed != PHY_NONE) ? true : false;
79 }
80 
81 static int histb_combphy_set_mode(struct histb_combphy_priv *priv)
82 {
83 	struct histb_combphy_mode *mode = &priv->mode;
84 	struct regmap *syscon = priv->syscon;
85 	u32 hw_sel;
86 
87 	if (is_mode_fixed(mode))
88 		return 0;
89 
90 	switch (mode->select) {
91 	case PHY_TYPE_SATA:
92 		hw_sel = COMBPHY_MODE_SATA;
93 		break;
94 	case PHY_TYPE_PCIE:
95 		hw_sel = COMBPHY_MODE_PCIE;
96 		break;
97 	case PHY_TYPE_USB3:
98 		hw_sel = COMBPHY_MODE_USB3;
99 		break;
100 	default:
101 		return -EINVAL;
102 	}
103 
104 	return regmap_update_bits(syscon, mode->reg, mode->mask,
105 				  hw_sel << mode->shift);
106 }
107 
108 static int histb_combphy_init(struct phy *phy)
109 {
110 	struct histb_combphy_priv *priv = phy_get_drvdata(phy);
111 	u32 val;
112 	int ret;
113 
114 	ret = histb_combphy_set_mode(priv);
115 	if (ret)
116 		return ret;
117 
118 	/* Clear bypass bit to enable encoding/decoding */
119 	val = readl(priv->mmio + COMBPHY_CFG_REG);
120 	val &= ~COMBPHY_BYPASS_CODEC;
121 	writel(val, priv->mmio + COMBPHY_CFG_REG);
122 
123 	ret = clk_prepare_enable(priv->ref_clk);
124 	if (ret)
125 		return ret;
126 
127 	reset_control_deassert(priv->por_rst);
128 
129 	/* Enable EP clock */
130 	val = readl(priv->mmio + COMBPHY_CFG_REG);
131 	val |= COMBPHY_CLKREF_OUT_OEN;
132 	writel(val, priv->mmio + COMBPHY_CFG_REG);
133 
134 	/* Need to wait for EP clock stable */
135 	mdelay(5);
136 
137 	/* Configure nano phy registers as suggested by vendor */
138 	nano_register_write(priv, 0x1, 0x8);
139 	nano_register_write(priv, 0xc, 0x9);
140 	nano_register_write(priv, 0x1a, 0x4);
141 
142 	return 0;
143 }
144 
145 static int histb_combphy_exit(struct phy *phy)
146 {
147 	struct histb_combphy_priv *priv = phy_get_drvdata(phy);
148 	u32 val;
149 
150 	/* Disable EP clock */
151 	val = readl(priv->mmio + COMBPHY_CFG_REG);
152 	val &= ~COMBPHY_CLKREF_OUT_OEN;
153 	writel(val, priv->mmio + COMBPHY_CFG_REG);
154 
155 	reset_control_assert(priv->por_rst);
156 	clk_disable_unprepare(priv->ref_clk);
157 
158 	return 0;
159 }
160 
161 static const struct phy_ops histb_combphy_ops = {
162 	.init = histb_combphy_init,
163 	.exit = histb_combphy_exit,
164 	.owner = THIS_MODULE,
165 };
166 
167 static struct phy *histb_combphy_xlate(struct device *dev,
168 				       struct of_phandle_args *args)
169 {
170 	struct histb_combphy_priv *priv = dev_get_drvdata(dev);
171 	struct histb_combphy_mode *mode = &priv->mode;
172 
173 	if (args->args_count < 1) {
174 		dev_err(dev, "invalid number of arguments\n");
175 		return ERR_PTR(-EINVAL);
176 	}
177 
178 	mode->select = args->args[0];
179 
180 	if (mode->select < PHY_TYPE_SATA || mode->select > PHY_TYPE_USB3) {
181 		dev_err(dev, "invalid phy mode select argument\n");
182 		return ERR_PTR(-EINVAL);
183 	}
184 
185 	if (is_mode_fixed(mode) && mode->select != mode->fixed) {
186 		dev_err(dev, "mode select %d mismatch fixed phy mode %d\n",
187 			mode->select, mode->fixed);
188 		return ERR_PTR(-EINVAL);
189 	}
190 
191 	return priv->phy;
192 }
193 
194 static int histb_combphy_probe(struct platform_device *pdev)
195 {
196 	struct phy_provider *phy_provider;
197 	struct device *dev = &pdev->dev;
198 	struct histb_combphy_priv *priv;
199 	struct device_node *np = dev->of_node;
200 	struct histb_combphy_mode *mode;
201 	struct resource *res;
202 	u32 vals[3];
203 	int ret;
204 
205 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
206 	if (!priv)
207 		return -ENOMEM;
208 
209 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
210 	priv->mmio = devm_ioremap_resource(dev, res);
211 	if (IS_ERR(priv->mmio)) {
212 		ret = PTR_ERR(priv->mmio);
213 		return ret;
214 	}
215 
216 	priv->syscon = syscon_node_to_regmap(np->parent);
217 	if (IS_ERR(priv->syscon)) {
218 		dev_err(dev, "failed to find peri_ctrl syscon regmap\n");
219 		return PTR_ERR(priv->syscon);
220 	}
221 
222 	mode = &priv->mode;
223 	mode->fixed = PHY_NONE;
224 
225 	ret = of_property_read_u32(np, "hisilicon,fixed-mode", &mode->fixed);
226 	if (ret == 0)
227 		dev_dbg(dev, "found fixed phy mode %d\n", mode->fixed);
228 
229 	ret = of_property_read_u32_array(np, "hisilicon,mode-select-bits",
230 					 vals, ARRAY_SIZE(vals));
231 	if (ret == 0) {
232 		if (is_mode_fixed(mode)) {
233 			dev_err(dev, "found select bits for fixed mode phy\n");
234 			return -EINVAL;
235 		}
236 
237 		mode->reg = vals[0];
238 		mode->shift = vals[1];
239 		mode->mask = vals[2];
240 		dev_dbg(dev, "found mode select bits\n");
241 	} else {
242 		if (!is_mode_fixed(mode)) {
243 			dev_err(dev, "no valid select bits found for non-fixed phy\n");
244 			return -ENODEV;
245 		}
246 	}
247 
248 	priv->ref_clk = devm_clk_get(dev, NULL);
249 	if (IS_ERR(priv->ref_clk)) {
250 		dev_err(dev, "failed to find ref clock\n");
251 		return PTR_ERR(priv->ref_clk);
252 	}
253 
254 	priv->por_rst = devm_reset_control_get(dev, NULL);
255 	if (IS_ERR(priv->por_rst)) {
256 		dev_err(dev, "failed to get poweron reset\n");
257 		return PTR_ERR(priv->por_rst);
258 	}
259 
260 	priv->phy = devm_phy_create(dev, NULL, &histb_combphy_ops);
261 	if (IS_ERR(priv->phy)) {
262 		dev_err(dev, "failed to create combphy\n");
263 		return PTR_ERR(priv->phy);
264 	}
265 
266 	dev_set_drvdata(dev, priv);
267 	phy_set_drvdata(priv->phy, priv);
268 
269 	phy_provider = devm_of_phy_provider_register(dev, histb_combphy_xlate);
270 	return PTR_ERR_OR_ZERO(phy_provider);
271 }
272 
273 static const struct of_device_id histb_combphy_of_match[] = {
274 	{ .compatible = "hisilicon,hi3798cv200-combphy" },
275 	{ },
276 };
277 MODULE_DEVICE_TABLE(of, histb_combphy_of_match);
278 
279 static struct platform_driver histb_combphy_driver = {
280 	.probe	= histb_combphy_probe,
281 	.driver = {
282 		.name = "combphy",
283 		.of_match_table = histb_combphy_of_match,
284 	},
285 };
286 module_platform_driver(histb_combphy_driver);
287 
288 MODULE_DESCRIPTION("HiSilicon STB COMBPHY driver");
289 MODULE_LICENSE("GPL v2");
290