xref: /linux/drivers/gpu/drm/bridge/th1520-dw-hdmi.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2025 Icenowy Zheng <uwu@icenowy.me>
4  *
5  * Based on rcar_dw_hdmi.c, which is:
6  *   Copyright (C) 2016 Renesas Electronics Corporation
7  * Based on imx8mp-hdmi-tx.c, which is:
8  *   Copyright (C) 2022 Pengutronix, Lucas Stach <kernel@pengutronix.de>
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/reset.h>
15 
16 #include <drm/bridge/dw_hdmi.h>
17 #include <drm/drm_modes.h>
18 
19 #define TH1520_HDMI_PHY_OPMODE_PLLCFG	0x06	/* Mode of operation and PLL dividers */
20 #define TH1520_HDMI_PHY_CKSYMTXCTRL	0x09	/* Clock Symbol and Transmitter Control Register */
21 #define TH1520_HDMI_PHY_VLEVCTRL	0x0e	/* Voltage Level Control Register */
22 #define TH1520_HDMI_PHY_PLLCURRGMPCTRL	0x10	/* PLL current and Gmp (conductance) */
23 #define TH1520_HDMI_PHY_PLLDIVCTRL	0x11	/* PLL dividers */
24 #define TH1520_HDMI_PHY_TXTERM		0x19	/* Transmission Termination Register */
25 
26 struct th1520_hdmi_phy_params {
27 	unsigned long mpixelclock;
28 	u16 opmode_pllcfg;
29 	u16 pllcurrgmpctrl;
30 	u16 plldivctrl;
31 	u16 cksymtxctrl;
32 	u16 vlevctrl;
33 	u16 txterm;
34 };
35 
36 static const struct th1520_hdmi_phy_params th1520_hdmi_phy_params[] = {
37 	{ 35500000,  0x0003, 0x0283, 0x0628, 0x8088, 0x01a0, 0x0007 },
38 	{ 44900000,  0x0003, 0x0285, 0x0228, 0x8088, 0x01a0, 0x0007 },
39 	{ 71000000,  0x0002, 0x1183, 0x0614, 0x8088, 0x01a0, 0x0007 },
40 	{ 90000000,  0x0002, 0x1142, 0x0214, 0x8088, 0x01a0, 0x0007 },
41 	{ 121750000, 0x0001, 0x20c0, 0x060a, 0x8088, 0x01a0, 0x0007 },
42 	{ 165000000, 0x0001, 0x2080, 0x020a, 0x8088, 0x01a0, 0x0007 },
43 	{ 198000000, 0x0000, 0x3040, 0x0605, 0x83c8, 0x0120, 0x0004 },
44 	{ 297000000, 0x0000, 0x3041, 0x0205, 0x81dc, 0x0200, 0x0005 },
45 	{ 371250000, 0x0640, 0x3041, 0x0205, 0x80f6, 0x0140, 0x0000 },
46 	{ 495000000, 0x0640, 0x3080, 0x0005, 0x80f6, 0x0140, 0x0000 },
47 	{ 594000000, 0x0640, 0x3080, 0x0005, 0x80fa, 0x01e0, 0x0004 },
48 };
49 
50 struct th1520_hdmi {
51 	struct dw_hdmi_plat_data plat_data;
52 	struct dw_hdmi *dw_hdmi;
53 	struct clk *pixclk;
54 	struct reset_control *mainrst, *prst;
55 };
56 
57 static enum drm_mode_status
58 th1520_hdmi_mode_valid(struct dw_hdmi *hdmi, void *data,
59 		       const struct drm_display_info *info,
60 		       const struct drm_display_mode *mode)
61 {
62 	/*
63 	 * The maximum supported clock frequency is 594 MHz, as shown in the PHY
64 	 * parameters table.
65 	 */
66 	if (mode->clock > 594000)
67 		return MODE_CLOCK_HIGH;
68 
69 	return MODE_OK;
70 }
71 
72 static void th1520_hdmi_phy_set_params(struct dw_hdmi *hdmi,
73 				const struct th1520_hdmi_phy_params *params)
74 {
75 	dw_hdmi_phy_i2c_write(hdmi, params->opmode_pllcfg,
76 			      TH1520_HDMI_PHY_OPMODE_PLLCFG);
77 	dw_hdmi_phy_i2c_write(hdmi, params->pllcurrgmpctrl,
78 			      TH1520_HDMI_PHY_PLLCURRGMPCTRL);
79 	dw_hdmi_phy_i2c_write(hdmi, params->plldivctrl,
80 			      TH1520_HDMI_PHY_PLLDIVCTRL);
81 	dw_hdmi_phy_i2c_write(hdmi, params->vlevctrl,
82 			      TH1520_HDMI_PHY_VLEVCTRL);
83 	dw_hdmi_phy_i2c_write(hdmi, params->cksymtxctrl,
84 			      TH1520_HDMI_PHY_CKSYMTXCTRL);
85 	dw_hdmi_phy_i2c_write(hdmi, params->txterm,
86 			      TH1520_HDMI_PHY_TXTERM);
87 }
88 
89 static int th1520_hdmi_phy_configure(struct dw_hdmi *hdmi, void *data,
90 				     unsigned long mpixelclock)
91 {
92 	unsigned int i;
93 
94 	for (i = 0; i < ARRAY_SIZE(th1520_hdmi_phy_params); i++) {
95 		if (mpixelclock <= th1520_hdmi_phy_params[i].mpixelclock) {
96 			th1520_hdmi_phy_set_params(hdmi,
97 						   &th1520_hdmi_phy_params[i]);
98 			return 0;
99 		}
100 	}
101 
102 	return -EINVAL;
103 }
104 
105 static int th1520_dw_hdmi_probe(struct platform_device *pdev)
106 {
107 	struct th1520_hdmi *hdmi;
108 	struct dw_hdmi_plat_data *plat_data;
109 	struct device *dev = &pdev->dev;
110 
111 	hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);
112 	if (!hdmi)
113 		return -ENOMEM;
114 
115 	plat_data = &hdmi->plat_data;
116 
117 	hdmi->pixclk = devm_clk_get_enabled(dev, "pix");
118 	if (IS_ERR(hdmi->pixclk))
119 		return dev_err_probe(dev, PTR_ERR(hdmi->pixclk),
120 				     "Unable to get pixel clock\n");
121 
122 	hdmi->mainrst = devm_reset_control_get_exclusive_deasserted(dev, "main");
123 	if (IS_ERR(hdmi->mainrst))
124 		return dev_err_probe(dev, PTR_ERR(hdmi->mainrst),
125 				     "Unable to get main reset\n");
126 
127 	hdmi->prst = devm_reset_control_get_exclusive_deasserted(dev, "apb");
128 	if (IS_ERR(hdmi->prst))
129 		return dev_err_probe(dev, PTR_ERR(hdmi->prst),
130 				     "Unable to get apb reset\n");
131 
132 	plat_data->output_port = 1;
133 	plat_data->mode_valid = th1520_hdmi_mode_valid;
134 	plat_data->configure_phy = th1520_hdmi_phy_configure;
135 	plat_data->priv_data = hdmi;
136 
137 	hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
138 	if (IS_ERR(hdmi))
139 		return PTR_ERR(hdmi);
140 
141 	platform_set_drvdata(pdev, hdmi);
142 
143 	return 0;
144 }
145 
146 static void th1520_dw_hdmi_remove(struct platform_device *pdev)
147 {
148 	struct dw_hdmi *hdmi = platform_get_drvdata(pdev);
149 
150 	dw_hdmi_remove(hdmi);
151 }
152 
153 static const struct of_device_id th1520_dw_hdmi_of_table[] = {
154 	{ .compatible = "thead,th1520-dw-hdmi" },
155 	{ /* Sentinel */ },
156 };
157 MODULE_DEVICE_TABLE(of, th1520_dw_hdmi_of_table);
158 
159 static struct platform_driver th1520_dw_hdmi_platform_driver = {
160 	.probe		= th1520_dw_hdmi_probe,
161 	.remove		= th1520_dw_hdmi_remove,
162 	.driver		= {
163 		.name	= "th1520-dw-hdmi",
164 		.of_match_table = th1520_dw_hdmi_of_table,
165 	},
166 };
167 
168 module_platform_driver(th1520_dw_hdmi_platform_driver);
169 
170 MODULE_AUTHOR("Icenowy Zheng <uwu@icenowy.me>");
171 MODULE_DESCRIPTION("T-Head TH1520 HDMI Encoder Driver");
172 MODULE_LICENSE("GPL");
173