1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * LG.Philips LB035Q02 LCD Panel Driver
4  *
5  * Copyright (C) 2019 Texas Instruments Incorporated
6  *
7  * Based on the omapdrm-specific panel-lgphilips-lb035q02 driver
8  *
9  * Copyright (C) 2013 Texas Instruments Incorporated
10  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
11  *
12  * Based on a driver by: Steve Sakoman <steve@sakoman.com>
13  */
14 
15 #include <linux/gpio/consumer.h>
16 #include <linux/module.h>
17 #include <linux/spi/spi.h>
18 
19 #include <drm/drm_connector.h>
20 #include <drm/drm_modes.h>
21 #include <drm/drm_panel.h>
22 
23 struct lb035q02_device {
24 	struct drm_panel panel;
25 
26 	struct spi_device *spi;
27 	struct gpio_desc *enable_gpio;
28 };
29 
30 #define to_lb035q02_device(p) container_of(p, struct lb035q02_device, panel)
31 
32 static int lb035q02_write(struct lb035q02_device *lcd, u16 reg, u16 val)
33 {
34 	struct spi_message msg;
35 	struct spi_transfer index_xfer = {
36 		.len		= 3,
37 		.cs_change	= 1,
38 	};
39 	struct spi_transfer value_xfer = {
40 		.len		= 3,
41 	};
42 	u8	buffer[16];
43 
44 	spi_message_init(&msg);
45 
46 	/* register index */
47 	buffer[0] = 0x70;
48 	buffer[1] = 0x00;
49 	buffer[2] = reg & 0x7f;
50 	index_xfer.tx_buf = buffer;
51 	spi_message_add_tail(&index_xfer, &msg);
52 
53 	/* register value */
54 	buffer[4] = 0x72;
55 	buffer[5] = val >> 8;
56 	buffer[6] = val;
57 	value_xfer.tx_buf = buffer + 4;
58 	spi_message_add_tail(&value_xfer, &msg);
59 
60 	return spi_sync(lcd->spi, &msg);
61 }
62 
63 static int lb035q02_init(struct lb035q02_device *lcd)
64 {
65 	/* Init sequence from page 28 of the lb035q02 spec. */
66 	static const struct {
67 		u16 index;
68 		u16 value;
69 	} init_data[] = {
70 		{ 0x01, 0x6300 },
71 		{ 0x02, 0x0200 },
72 		{ 0x03, 0x0177 },
73 		{ 0x04, 0x04c7 },
74 		{ 0x05, 0xffc0 },
75 		{ 0x06, 0xe806 },
76 		{ 0x0a, 0x4008 },
77 		{ 0x0b, 0x0000 },
78 		{ 0x0d, 0x0030 },
79 		{ 0x0e, 0x2800 },
80 		{ 0x0f, 0x0000 },
81 		{ 0x16, 0x9f80 },
82 		{ 0x17, 0x0a0f },
83 		{ 0x1e, 0x00c1 },
84 		{ 0x30, 0x0300 },
85 		{ 0x31, 0x0007 },
86 		{ 0x32, 0x0000 },
87 		{ 0x33, 0x0000 },
88 		{ 0x34, 0x0707 },
89 		{ 0x35, 0x0004 },
90 		{ 0x36, 0x0302 },
91 		{ 0x37, 0x0202 },
92 		{ 0x3a, 0x0a0d },
93 		{ 0x3b, 0x0806 },
94 	};
95 
96 	unsigned int i;
97 	int ret;
98 
99 	for (i = 0; i < ARRAY_SIZE(init_data); ++i) {
100 		ret = lb035q02_write(lcd, init_data[i].index,
101 				     init_data[i].value);
102 		if (ret < 0)
103 			return ret;
104 	}
105 
106 	return 0;
107 }
108 
109 static int lb035q02_disable(struct drm_panel *panel)
110 {
111 	struct lb035q02_device *lcd = to_lb035q02_device(panel);
112 
113 	gpiod_set_value_cansleep(lcd->enable_gpio, 0);
114 
115 	return 0;
116 }
117 
118 static int lb035q02_enable(struct drm_panel *panel)
119 {
120 	struct lb035q02_device *lcd = to_lb035q02_device(panel);
121 
122 	gpiod_set_value_cansleep(lcd->enable_gpio, 1);
123 
124 	return 0;
125 }
126 
127 static const struct drm_display_mode lb035q02_mode = {
128 	.clock = 6500,
129 	.hdisplay = 320,
130 	.hsync_start = 320 + 20,
131 	.hsync_end = 320 + 20 + 2,
132 	.htotal = 320 + 20 + 2 + 68,
133 	.vdisplay = 240,
134 	.vsync_start = 240 + 4,
135 	.vsync_end = 240 + 4 + 2,
136 	.vtotal = 240 + 4 + 2 + 18,
137 	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
138 	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
139 	.width_mm = 70,
140 	.height_mm = 53,
141 };
142 
143 static int lb035q02_get_modes(struct drm_panel *panel,
144 			      struct drm_connector *connector)
145 {
146 	struct drm_display_mode *mode;
147 
148 	mode = drm_mode_duplicate(connector->dev, &lb035q02_mode);
149 	if (!mode)
150 		return -ENOMEM;
151 
152 	drm_mode_set_name(mode);
153 	drm_mode_probed_add(connector, mode);
154 
155 	connector->display_info.width_mm = lb035q02_mode.width_mm;
156 	connector->display_info.height_mm = lb035q02_mode.height_mm;
157 	/*
158 	 * FIXME: According to the datasheet pixel data is sampled on the
159 	 * rising edge of the clock, but the code running on the Gumstix Overo
160 	 * Palo35 indicates sampling on the negative edge. This should be
161 	 * tested on a real device.
162 	 */
163 	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
164 					  | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE
165 					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
166 
167 	return 1;
168 }
169 
170 static const struct drm_panel_funcs lb035q02_funcs = {
171 	.disable = lb035q02_disable,
172 	.enable = lb035q02_enable,
173 	.get_modes = lb035q02_get_modes,
174 };
175 
176 static int lb035q02_probe(struct spi_device *spi)
177 {
178 	struct lb035q02_device *lcd;
179 	int ret;
180 
181 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
182 	if (!lcd)
183 		return -ENOMEM;
184 
185 	spi_set_drvdata(spi, lcd);
186 	lcd->spi = spi;
187 
188 	lcd->enable_gpio = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
189 	if (IS_ERR(lcd->enable_gpio)) {
190 		dev_err(&spi->dev, "failed to parse enable gpio\n");
191 		return PTR_ERR(lcd->enable_gpio);
192 	}
193 
194 	ret = lb035q02_init(lcd);
195 	if (ret < 0)
196 		return ret;
197 
198 	drm_panel_init(&lcd->panel, &lcd->spi->dev, &lb035q02_funcs,
199 		       DRM_MODE_CONNECTOR_DPI);
200 
201 	drm_panel_add(&lcd->panel);
202 
203 	return 0;
204 }
205 
206 static int lb035q02_remove(struct spi_device *spi)
207 {
208 	struct lb035q02_device *lcd = spi_get_drvdata(spi);
209 
210 	drm_panel_remove(&lcd->panel);
211 	drm_panel_disable(&lcd->panel);
212 
213 	return 0;
214 }
215 
216 static const struct of_device_id lb035q02_of_match[] = {
217 	{ .compatible = "lgphilips,lb035q02", },
218 	{ /* sentinel */ },
219 };
220 
221 MODULE_DEVICE_TABLE(of, lb035q02_of_match);
222 
223 static const struct spi_device_id lb035q02_ids[] = {
224 	{ "lb035q02", 0 },
225 	{ /* sentinel */ }
226 };
227 
228 MODULE_DEVICE_TABLE(spi, lb035q02_ids);
229 
230 static struct spi_driver lb035q02_driver = {
231 	.probe		= lb035q02_probe,
232 	.remove		= lb035q02_remove,
233 	.id_table	= lb035q02_ids,
234 	.driver		= {
235 		.name	= "panel-lg-lb035q02",
236 		.of_match_table = lb035q02_of_match,
237 	},
238 };
239 
240 module_spi_driver(lb035q02_driver);
241 
242 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
243 MODULE_DESCRIPTION("LG.Philips LB035Q02 LCD Panel driver");
244 MODULE_LICENSE("GPL");
245