1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MediaTek DisplayPort PHY driver
4 *
5 * Copyright (c) 2022, BayLibre Inc.
6 * Copyright (c) 2022, MediaTek Inc.
7 */
8
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/of.h>
13 #include <linux/phy/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16
17 #define PHY_OFFSET 0x1000
18
19 #define MTK_DP_PHY_DIG_PLL_CTL_1 (PHY_OFFSET + 0x14)
20 #define TPLL_SSC_EN BIT(3)
21
22 #define MTK_DP_PHY_DIG_BIT_RATE (PHY_OFFSET + 0x3C)
23 #define BIT_RATE_RBR 0
24 #define BIT_RATE_HBR 1
25 #define BIT_RATE_HBR2 2
26 #define BIT_RATE_HBR3 3
27
28 #define MTK_DP_PHY_DIG_SW_RST (PHY_OFFSET + 0x38)
29 #define DP_GLB_SW_RST_PHYD BIT(0)
30
31 #define MTK_DP_LANE0_DRIVING_PARAM_3 (PHY_OFFSET + 0x138)
32 #define MTK_DP_LANE1_DRIVING_PARAM_3 (PHY_OFFSET + 0x238)
33 #define MTK_DP_LANE2_DRIVING_PARAM_3 (PHY_OFFSET + 0x338)
34 #define MTK_DP_LANE3_DRIVING_PARAM_3 (PHY_OFFSET + 0x438)
35 #define XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT BIT(4)
36 #define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT (BIT(10) | BIT(12))
37 #define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT GENMASK(20, 19)
38 #define XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT GENMASK(29, 29)
39 #define DRIVING_PARAM_3_DEFAULT (XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT | \
40 XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT | \
41 XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT | \
42 XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT)
43
44 #define XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT GENMASK(4, 3)
45 #define XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT GENMASK(12, 9)
46 #define XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT (BIT(18) | BIT(21))
47 #define XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT GENMASK(29, 29)
48 #define DRIVING_PARAM_4_DEFAULT (XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT | \
49 XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT | \
50 XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT | \
51 XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT)
52
53 #define XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT (BIT(3) | BIT(5))
54 #define XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT GENMASK(13, 12)
55 #define DRIVING_PARAM_5_DEFAULT (XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT | \
56 XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT)
57
58 #define XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT 0
59 #define XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT GENMASK(10, 10)
60 #define XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT GENMASK(19, 19)
61 #define XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT GENMASK(28, 28)
62 #define DRIVING_PARAM_6_DEFAULT (XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT | \
63 XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT | \
64 XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT | \
65 XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT)
66
67 #define XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT 0
68 #define XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT GENMASK(10, 9)
69 #define XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT GENMASK(19, 18)
70 #define XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT 0
71 #define DRIVING_PARAM_7_DEFAULT (XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT | \
72 XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT | \
73 XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT | \
74 XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT)
75
76 #define XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT GENMASK(3, 3)
77 #define XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT 0
78 #define DRIVING_PARAM_8_DEFAULT (XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
79 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
80
81 struct mtk_dp_phy {
82 struct regmap *regs;
83 };
84
mtk_dp_phy_init(struct phy * phy)85 static int mtk_dp_phy_init(struct phy *phy)
86 {
87 struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
88 static const u32 driving_params[] = {
89 DRIVING_PARAM_3_DEFAULT,
90 DRIVING_PARAM_4_DEFAULT,
91 DRIVING_PARAM_5_DEFAULT,
92 DRIVING_PARAM_6_DEFAULT,
93 DRIVING_PARAM_7_DEFAULT,
94 DRIVING_PARAM_8_DEFAULT
95 };
96
97 regmap_bulk_write(dp_phy->regs, MTK_DP_LANE0_DRIVING_PARAM_3,
98 driving_params, ARRAY_SIZE(driving_params));
99 regmap_bulk_write(dp_phy->regs, MTK_DP_LANE1_DRIVING_PARAM_3,
100 driving_params, ARRAY_SIZE(driving_params));
101 regmap_bulk_write(dp_phy->regs, MTK_DP_LANE2_DRIVING_PARAM_3,
102 driving_params, ARRAY_SIZE(driving_params));
103 regmap_bulk_write(dp_phy->regs, MTK_DP_LANE3_DRIVING_PARAM_3,
104 driving_params, ARRAY_SIZE(driving_params));
105
106 return 0;
107 }
108
mtk_dp_phy_configure(struct phy * phy,union phy_configure_opts * opts)109 static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
110 {
111 struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
112 u32 val;
113
114 if (opts->dp.set_rate) {
115 switch (opts->dp.link_rate) {
116 default:
117 dev_err(&phy->dev,
118 "Implementation error, unknown linkrate %x\n",
119 opts->dp.link_rate);
120 return -EINVAL;
121 case 1620:
122 val = BIT_RATE_RBR;
123 break;
124 case 2700:
125 val = BIT_RATE_HBR;
126 break;
127 case 5400:
128 val = BIT_RATE_HBR2;
129 break;
130 case 8100:
131 val = BIT_RATE_HBR3;
132 break;
133 }
134 regmap_write(dp_phy->regs, MTK_DP_PHY_DIG_BIT_RATE, val);
135 }
136
137 regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_PLL_CTL_1,
138 TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
139
140 return 0;
141 }
142
mtk_dp_phy_reset(struct phy * phy)143 static int mtk_dp_phy_reset(struct phy *phy)
144 {
145 struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
146
147 regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
148 DP_GLB_SW_RST_PHYD, 0);
149 usleep_range(50, 200);
150 regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
151 DP_GLB_SW_RST_PHYD, 1);
152
153 return 0;
154 }
155
156 static const struct phy_ops mtk_dp_phy_dev_ops = {
157 .init = mtk_dp_phy_init,
158 .configure = mtk_dp_phy_configure,
159 .reset = mtk_dp_phy_reset,
160 .owner = THIS_MODULE,
161 };
162
mtk_dp_phy_probe(struct platform_device * pdev)163 static int mtk_dp_phy_probe(struct platform_device *pdev)
164 {
165 struct device *dev = &pdev->dev;
166 struct mtk_dp_phy *dp_phy;
167 struct phy *phy;
168 struct regmap *regs;
169
170 regs = *(struct regmap **)dev->platform_data;
171 if (!regs)
172 return dev_err_probe(dev, -EINVAL,
173 "No data passed, requires struct regmap**\n");
174
175 dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
176 if (!dp_phy)
177 return -ENOMEM;
178
179 dp_phy->regs = regs;
180 phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
181 if (IS_ERR(phy))
182 return dev_err_probe(dev, PTR_ERR(phy),
183 "Failed to create DP PHY\n");
184
185 phy_set_drvdata(phy, dp_phy);
186 if (!dev->of_node)
187 phy_create_lookup(phy, "dp", dev_name(dev));
188
189 return 0;
190 }
191
192 static struct platform_driver mtk_dp_phy_driver = {
193 .probe = mtk_dp_phy_probe,
194 .driver = {
195 .name = "mediatek-dp-phy",
196 },
197 };
198 module_platform_driver(mtk_dp_phy_driver);
199
200 MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
201 MODULE_DESCRIPTION("MediaTek DP PHY Driver");
202 MODULE_LICENSE("GPL");
203