1 /*
2  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/time.h>
20 #include <linux/delay.h>
21 #include <linux/clk.h>
22 #include <linux/slab.h>
23 #include <linux/platform_device.h>
24 #include <linux/phy/phy.h>
25 
26 struct qcom_ipq806x_sata_phy {
27 	void __iomem *mmio;
28 	struct clk *cfg_clk;
29 	struct device *dev;
30 };
31 
32 #define __set(v, a, b)	(((v) << (b)) & GENMASK(a, b))
33 
34 #define SATA_PHY_P0_PARAM0		0x200
35 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(x)	__set(x, 17, 12)
36 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK	GENMASK(17, 12)
37 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2(x)	__set(x, 11, 6)
38 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK	GENMASK(11, 6)
39 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1(x)	__set(x, 5, 0)
40 #define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK	GENMASK(5, 0)
41 
42 #define SATA_PHY_P0_PARAM1		0x204
43 #define SATA_PHY_P0_PARAM1_RESERVED_BITS31_21(x)	__set(x, 31, 21)
44 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(x)	__set(x, 20, 14)
45 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK	GENMASK(20, 14)
46 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(x)	__set(x, 13, 7)
47 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK	GENMASK(13, 7)
48 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(x)	__set(x, 6, 0)
49 #define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK	GENMASK(6, 0)
50 
51 #define SATA_PHY_P0_PARAM2		0x208
52 #define SATA_PHY_P0_PARAM2_RX_EQ(x)	__set(x, 20, 18)
53 #define SATA_PHY_P0_PARAM2_RX_EQ_MASK	GENMASK(20, 18)
54 
55 #define SATA_PHY_P0_PARAM3		0x20C
56 #define SATA_PHY_SSC_EN			0x8
57 #define SATA_PHY_P0_PARAM4		0x210
58 #define SATA_PHY_REF_SSP_EN		0x2
59 #define SATA_PHY_RESET			0x1
60 
61 static int qcom_ipq806x_sata_phy_init(struct phy *generic_phy)
62 {
63 	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
64 	u32 reg;
65 
66 	/* Setting SSC_EN to 1 */
67 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM3);
68 	reg = reg | SATA_PHY_SSC_EN;
69 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM3);
70 
71 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM0) &
72 			~(SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK |
73 			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK |
74 			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK);
75 	reg |= SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(0xf);
76 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM0);
77 
78 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM1) &
79 			~(SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK |
80 			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK |
81 			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK);
82 	reg |= SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(0x55) |
83 		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(0x55) |
84 		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(0x55);
85 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM1);
86 
87 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM2) &
88 		~SATA_PHY_P0_PARAM2_RX_EQ_MASK;
89 	reg |= SATA_PHY_P0_PARAM2_RX_EQ(0x3);
90 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM2);
91 
92 	/* Setting PHY_RESET to 1 */
93 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
94 	reg = reg | SATA_PHY_RESET;
95 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
96 
97 	/* Setting REF_SSP_EN to 1 */
98 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
99 	reg = reg | SATA_PHY_REF_SSP_EN | SATA_PHY_RESET;
100 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
101 
102 	/* make sure all changes complete before we let the PHY out of reset */
103 	mb();
104 
105 	/* sleep for max. 50us more to combine processor wakeups */
106 	usleep_range(20, 20 + 50);
107 
108 	/* Clearing PHY_RESET to 0 */
109 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
110 	reg = reg & ~SATA_PHY_RESET;
111 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
112 
113 	return 0;
114 }
115 
116 static int qcom_ipq806x_sata_phy_exit(struct phy *generic_phy)
117 {
118 	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
119 	u32 reg;
120 
121 	/* Setting PHY_RESET to 1 */
122 	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
123 	reg = reg | SATA_PHY_RESET;
124 	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
125 
126 	return 0;
127 }
128 
129 static const struct phy_ops qcom_ipq806x_sata_phy_ops = {
130 	.init		= qcom_ipq806x_sata_phy_init,
131 	.exit		= qcom_ipq806x_sata_phy_exit,
132 	.owner		= THIS_MODULE,
133 };
134 
135 static int qcom_ipq806x_sata_phy_probe(struct platform_device *pdev)
136 {
137 	struct qcom_ipq806x_sata_phy *phy;
138 	struct device *dev = &pdev->dev;
139 	struct resource *res;
140 	struct phy_provider *phy_provider;
141 	struct phy *generic_phy;
142 	int ret;
143 
144 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
145 	if (!phy)
146 		return -ENOMEM;
147 
148 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
149 	phy->mmio = devm_ioremap_resource(dev, res);
150 	if (IS_ERR(phy->mmio))
151 		return PTR_ERR(phy->mmio);
152 
153 	generic_phy = devm_phy_create(dev, NULL, &qcom_ipq806x_sata_phy_ops);
154 	if (IS_ERR(generic_phy)) {
155 		dev_err(dev, "%s: failed to create phy\n", __func__);
156 		return PTR_ERR(generic_phy);
157 	}
158 
159 	phy->dev = dev;
160 	phy_set_drvdata(generic_phy, phy);
161 	platform_set_drvdata(pdev, phy);
162 
163 	phy->cfg_clk = devm_clk_get(dev, "cfg");
164 	if (IS_ERR(phy->cfg_clk)) {
165 		dev_err(dev, "Failed to get sata cfg clock\n");
166 		return PTR_ERR(phy->cfg_clk);
167 	}
168 
169 	ret = clk_prepare_enable(phy->cfg_clk);
170 	if (ret)
171 		return ret;
172 
173 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
174 	if (IS_ERR(phy_provider)) {
175 		clk_disable_unprepare(phy->cfg_clk);
176 		dev_err(dev, "%s: failed to register phy\n", __func__);
177 		return PTR_ERR(phy_provider);
178 	}
179 
180 	return 0;
181 }
182 
183 static int qcom_ipq806x_sata_phy_remove(struct platform_device *pdev)
184 {
185 	struct qcom_ipq806x_sata_phy *phy = platform_get_drvdata(pdev);
186 
187 	clk_disable_unprepare(phy->cfg_clk);
188 
189 	return 0;
190 }
191 
192 static const struct of_device_id qcom_ipq806x_sata_phy_of_match[] = {
193 	{ .compatible = "qcom,ipq806x-sata-phy" },
194 	{ },
195 };
196 MODULE_DEVICE_TABLE(of, qcom_ipq806x_sata_phy_of_match);
197 
198 static struct platform_driver qcom_ipq806x_sata_phy_driver = {
199 	.probe	= qcom_ipq806x_sata_phy_probe,
200 	.remove	= qcom_ipq806x_sata_phy_remove,
201 	.driver = {
202 		.name	= "qcom-ipq806x-sata-phy",
203 		.of_match_table	= qcom_ipq806x_sata_phy_of_match,
204 	}
205 };
206 module_platform_driver(qcom_ipq806x_sata_phy_driver);
207 
208 MODULE_DESCRIPTION("QCOM IPQ806x SATA PHY driver");
209 MODULE_LICENSE("GPL v2");
210