xref: /linux/drivers/phy/eswin/phy-eic7700-sata.c (revision 0fc8f6200d2313278fbf4539bbab74677c685531)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ESWIN SATA PHY driver
4  *
5  * Copyright 2026, Beijing ESWIN Computing Technology Co., Ltd..
6  * All rights reserved.
7  *
8  * Authors: Yulin Lu <luyulin@eswincomputing.com>
9  */
10 
11 #include <linux/bitfield.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/phy/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 #include <linux/reset.h>
21 
22 #define SATA_AXI_LP_CTRL			0x08
23 #define SATA_MPLL_CTRL				0x20
24 #define SATA_P0_PHY_STAT			0x24
25 #define SATA_PHY_CTRL0				0x28
26 #define SATA_PHY_CTRL1				0x2c
27 #define SATA_REF_CTRL				0x34
28 #define SATA_REF_CTRL1				0x38
29 #define SATA_LOS_IDEN				0x3c
30 
31 #define SATA_CLK_RST_SOURCE_PHY			BIT(0)
32 #define SATA_P0_PHY_TX_AMPLITUDE_GEN1_MASK	GENMASK(6, 0)
33 #define SATA_P0_PHY_TX_AMPLITUDE_GEN1_DEFAULT	0x42
34 #define SATA_P0_PHY_TX_AMPLITUDE_GEN2_MASK	GENMASK(14, 8)
35 #define SATA_P0_PHY_TX_AMPLITUDE_GEN2_DEFAULT	0x46
36 #define SATA_P0_PHY_TX_AMPLITUDE_GEN3_MASK	GENMASK(22, 16)
37 #define SATA_P0_PHY_TX_AMPLITUDE_GEN3_DEFAULT	0x73
38 #define SATA_P0_PHY_TX_PREEMPH_GEN1_MASK	GENMASK(5, 0)
39 #define SATA_P0_PHY_TX_PREEMPH_GEN1_DEFAULT	0x5
40 #define SATA_P0_PHY_TX_PREEMPH_GEN2_MASK	GENMASK(13, 8)
41 #define SATA_P0_PHY_TX_PREEMPH_GEN2_DEFAULT	0x5
42 #define SATA_P0_PHY_TX_PREEMPH_GEN3_MASK	GENMASK(21, 16)
43 #define SATA_P0_PHY_TX_PREEMPH_GEN3_DEFAULT	0x23
44 #define SATA_LOS_LEVEL_MASK			GENMASK(4, 0)
45 #define SATA_LOS_BIAS_MASK			GENMASK(18, 16)
46 #define SATA_M_CSYSREQ				BIT(0)
47 #define SATA_S_CSYSREQ				BIT(16)
48 #define SATA_REF_REPEATCLK_EN			BIT(0)
49 #define SATA_REF_USE_PAD			BIT(20)
50 #define SATA_MPLL_MULTIPLIER_MASK		GENMASK(22, 16)
51 #define SATA_P0_PHY_READY			BIT(0)
52 
53 #define PLL_LOCK_SLEEP_US			10
54 #define PLL_LOCK_TIMEOUT_US			1000
55 
56 struct eic7700_sata_phy {
57 	u32 tx_amplitude_tuning_val[3];
58 	u32 tx_preemph_tuning_val[3];
59 	struct reset_control *rst;
60 	struct regmap *regmap;
61 	struct clk *clk;
62 	struct phy *phy;
63 };
64 
65 static const struct regmap_config eic7700_sata_phy_regmap_config = {
66 	.reg_bits = 32,
67 	.val_bits = 32,
68 	.reg_stride = 4,
69 	.max_register = SATA_LOS_IDEN,
70 };
71 
72 static int wait_for_phy_ready(struct regmap *regmap, u32 reg, u32 checkbit,
73 			      u32 status)
74 {
75 	u32 val;
76 	int ret;
77 
78 	ret = regmap_read_poll_timeout(regmap, reg, val,
79 				       (val & checkbit) == status,
80 				       PLL_LOCK_SLEEP_US, PLL_LOCK_TIMEOUT_US);
81 
82 	return ret;
83 }
84 
85 static int eic7700_sata_phy_init(struct phy *phy)
86 {
87 	struct eic7700_sata_phy *sata_phy = phy_get_drvdata(phy);
88 	u32 val;
89 	int ret;
90 
91 	ret = clk_prepare_enable(sata_phy->clk);
92 	if (ret)
93 		return ret;
94 
95 	regmap_write(sata_phy->regmap, SATA_REF_CTRL1, SATA_CLK_RST_SOURCE_PHY);
96 
97 	val = FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN1_MASK,
98 			 sata_phy->tx_amplitude_tuning_val[0]) |
99 	      FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN2_MASK,
100 			 sata_phy->tx_amplitude_tuning_val[1]) |
101 	      FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN3_MASK,
102 			 sata_phy->tx_amplitude_tuning_val[2]);
103 	regmap_write(sata_phy->regmap, SATA_PHY_CTRL0, val);
104 
105 	val = FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN1_MASK,
106 			 sata_phy->tx_preemph_tuning_val[0]) |
107 	      FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN2_MASK,
108 			 sata_phy->tx_preemph_tuning_val[1]) |
109 	      FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN3_MASK,
110 			 sata_phy->tx_preemph_tuning_val[2]);
111 	regmap_write(sata_phy->regmap, SATA_PHY_CTRL1, val);
112 
113 	val = FIELD_PREP(SATA_LOS_LEVEL_MASK, 0x9) |
114 	      FIELD_PREP(SATA_LOS_BIAS_MASK, 0x2);
115 	regmap_write(sata_phy->regmap, SATA_LOS_IDEN, val);
116 
117 	val = SATA_M_CSYSREQ | SATA_S_CSYSREQ;
118 	regmap_write(sata_phy->regmap, SATA_AXI_LP_CTRL, val);
119 
120 	val = SATA_REF_REPEATCLK_EN | SATA_REF_USE_PAD;
121 	regmap_write(sata_phy->regmap, SATA_REF_CTRL, val);
122 
123 	val = FIELD_PREP(SATA_MPLL_MULTIPLIER_MASK, 0x3c);
124 	regmap_write(sata_phy->regmap, SATA_MPLL_CTRL, val);
125 
126 	usleep_range(15, 20);
127 
128 	ret = reset_control_deassert(sata_phy->rst);
129 	if (ret)
130 		goto disable_clk;
131 
132 	ret = wait_for_phy_ready(sata_phy->regmap, SATA_P0_PHY_STAT,
133 				 SATA_P0_PHY_READY, 1);
134 	if (ret < 0) {
135 		dev_err(&sata_phy->phy->dev, "PHY READY check failed\n");
136 		goto disable_clk;
137 	}
138 
139 	return 0;
140 
141 disable_clk:
142 	clk_disable_unprepare(sata_phy->clk);
143 	return ret;
144 }
145 
146 static int eic7700_sata_phy_exit(struct phy *phy)
147 {
148 	struct eic7700_sata_phy *sata_phy = phy_get_drvdata(phy);
149 	int ret;
150 
151 	ret = reset_control_assert(sata_phy->rst);
152 	if (ret)
153 		return ret;
154 
155 	clk_disable_unprepare(sata_phy->clk);
156 
157 	return 0;
158 }
159 
160 static const struct phy_ops eic7700_sata_phy_ops = {
161 	.init		= eic7700_sata_phy_init,
162 	.exit		= eic7700_sata_phy_exit,
163 	.owner		= THIS_MODULE,
164 };
165 
166 static void eic7700_get_tuning_param(struct device_node *np,
167 				     struct eic7700_sata_phy *sata_phy)
168 {
169 	if (of_property_read_u32_array
170 		(np, "eswin,tx-amplitude-tuning",
171 		sata_phy->tx_amplitude_tuning_val,
172 		ARRAY_SIZE(sata_phy->tx_amplitude_tuning_val))) {
173 		sata_phy->tx_amplitude_tuning_val[0] =
174 			SATA_P0_PHY_TX_AMPLITUDE_GEN1_DEFAULT;
175 		sata_phy->tx_amplitude_tuning_val[1] =
176 			SATA_P0_PHY_TX_AMPLITUDE_GEN2_DEFAULT;
177 		sata_phy->tx_amplitude_tuning_val[2] =
178 			SATA_P0_PHY_TX_AMPLITUDE_GEN3_DEFAULT;
179 	}
180 
181 	if (of_property_read_u32_array
182 		(np, "eswin,tx-preemph-tuning",
183 		sata_phy->tx_preemph_tuning_val,
184 		ARRAY_SIZE(sata_phy->tx_preemph_tuning_val))) {
185 		sata_phy->tx_preemph_tuning_val[0] =
186 			SATA_P0_PHY_TX_PREEMPH_GEN1_DEFAULT;
187 		sata_phy->tx_preemph_tuning_val[1] =
188 			SATA_P0_PHY_TX_PREEMPH_GEN2_DEFAULT;
189 		sata_phy->tx_preemph_tuning_val[2] =
190 			SATA_P0_PHY_TX_PREEMPH_GEN3_DEFAULT;
191 	}
192 }
193 
194 static int eic7700_sata_phy_probe(struct platform_device *pdev)
195 {
196 	struct eic7700_sata_phy *sata_phy;
197 	struct phy_provider *phy_provider;
198 	struct device *dev = &pdev->dev;
199 	struct device_node *np = dev->of_node;
200 	struct resource *res;
201 	void __iomem *regs;
202 
203 	sata_phy = devm_kzalloc(dev, sizeof(*sata_phy), GFP_KERNEL);
204 	if (!sata_phy)
205 		return -ENOMEM;
206 
207 	/*
208 	 * Map the I/O resource with platform_get_resource and devm_ioremap
209 	 * instead of the devm_platform_ioremap_resource API, because the
210 	 * address region of the SATA-PHY falls into the region of the HSP
211 	 * clock & reset that has already been obtained by the HSP
212 	 * clock-and-reset driver.
213 	 */
214 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
215 	if (!res)
216 		return -ENOENT;
217 
218 	regs = devm_ioremap(dev, res->start, resource_size(res));
219 	if (IS_ERR(regs))
220 		return PTR_ERR(regs);
221 
222 	sata_phy->regmap = devm_regmap_init_mmio
223 			   (dev, regs, &eic7700_sata_phy_regmap_config);
224 	if (IS_ERR(sata_phy->regmap))
225 		return dev_err_probe(dev, PTR_ERR(sata_phy->regmap),
226 				     "failed to init regmap\n");
227 
228 	dev_set_drvdata(dev, sata_phy);
229 
230 	eic7700_get_tuning_param(np, sata_phy);
231 
232 	sata_phy->clk = devm_clk_get(dev, "phy");
233 	if (IS_ERR(sata_phy->clk))
234 		return PTR_ERR(sata_phy->clk);
235 
236 	sata_phy->rst = devm_reset_control_array_get_exclusive(dev);
237 	if (IS_ERR(sata_phy->rst))
238 		return dev_err_probe(dev, PTR_ERR(sata_phy->rst),
239 				     "failed to get reset control\n");
240 
241 	sata_phy->phy = devm_phy_create(dev, NULL, &eic7700_sata_phy_ops);
242 	if (IS_ERR(sata_phy->phy))
243 		return dev_err_probe(dev, PTR_ERR(sata_phy->phy),
244 				     "failed to create PHY\n");
245 
246 	phy_set_drvdata(sata_phy->phy, sata_phy);
247 
248 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
249 	if (IS_ERR(phy_provider))
250 		return dev_err_probe(dev, PTR_ERR(phy_provider),
251 				     "failed to register PHY provider\n");
252 
253 	return 0;
254 }
255 
256 static const struct of_device_id eic7700_sata_phy_of_match[] = {
257 	{ .compatible = "eswin,eic7700-sata-phy" },
258 	{ },
259 };
260 MODULE_DEVICE_TABLE(of, eic7700_sata_phy_of_match);
261 
262 static struct platform_driver eic7700_sata_phy_driver = {
263 	.probe	= eic7700_sata_phy_probe,
264 	.driver = {
265 		.of_match_table	= eic7700_sata_phy_of_match,
266 		.name  = "eic7700-sata-phy",
267 	}
268 };
269 module_platform_driver(eic7700_sata_phy_driver);
270 
271 MODULE_DESCRIPTION("SATA PHY driver for the ESWIN EIC7700 SoC");
272 MODULE_AUTHOR("Yulin Lu <luyulin@eswincomputing.com>");
273 MODULE_LICENSE("GPL");
274