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
23struct 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
32static 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
63static 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
109static 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
118static 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
127static 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
143static 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
170static const struct drm_panel_funcs lb035q02_funcs = {
171	.disable = lb035q02_disable,
172	.enable = lb035q02_enable,
173	.get_modes = lb035q02_get_modes,
174};
175
176static 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
206static void 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
214static const struct of_device_id lb035q02_of_match[] = {
215	{ .compatible = "lgphilips,lb035q02", },
216	{ /* sentinel */ },
217};
218
219MODULE_DEVICE_TABLE(of, lb035q02_of_match);
220
221static const struct spi_device_id lb035q02_ids[] = {
222	{ "lb035q02", 0 },
223	{ /* sentinel */ }
224};
225
226MODULE_DEVICE_TABLE(spi, lb035q02_ids);
227
228static struct spi_driver lb035q02_driver = {
229	.probe		= lb035q02_probe,
230	.remove		= lb035q02_remove,
231	.id_table	= lb035q02_ids,
232	.driver		= {
233		.name	= "panel-lg-lb035q02",
234		.of_match_table = lb035q02_of_match,
235	},
236};
237
238module_spi_driver(lb035q02_driver);
239
240MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
241MODULE_DESCRIPTION("LG.Philips LB035Q02 LCD Panel driver");
242MODULE_LICENSE("GPL");
243