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	.vrefresh = 60,
138	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
139	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
140	.width_mm = 70,
141	.height_mm = 53,
142};
143
144static int lb035q02_get_modes(struct drm_panel *panel)
145{
146	struct drm_connector *connector = panel->connector;
147	struct drm_display_mode *mode;
148
149	mode = drm_mode_duplicate(panel->drm, &lb035q02_mode);
150	if (!mode)
151		return -ENOMEM;
152
153	drm_mode_set_name(mode);
154	drm_mode_probed_add(connector, mode);
155
156	connector->display_info.width_mm = lb035q02_mode.width_mm;
157	connector->display_info.height_mm = lb035q02_mode.height_mm;
158	/*
159	 * FIXME: According to the datasheet pixel data is sampled on the
160	 * rising edge of the clock, but the code running on the Gumstix Overo
161	 * Palo35 indicates sampling on the negative edge. This should be
162	 * tested on a real device.
163	 */
164	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
165					  | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE
166					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
167
168	return 1;
169}
170
171static const struct drm_panel_funcs lb035q02_funcs = {
172	.disable = lb035q02_disable,
173	.enable = lb035q02_enable,
174	.get_modes = lb035q02_get_modes,
175};
176
177static int lb035q02_probe(struct spi_device *spi)
178{
179	struct lb035q02_device *lcd;
180	int ret;
181
182	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
183	if (!lcd)
184		return -ENOMEM;
185
186	spi_set_drvdata(spi, lcd);
187	lcd->spi = spi;
188
189	lcd->enable_gpio = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
190	if (IS_ERR(lcd->enable_gpio)) {
191		dev_err(&spi->dev, "failed to parse enable gpio\n");
192		return PTR_ERR(lcd->enable_gpio);
193	}
194
195	ret = lb035q02_init(lcd);
196	if (ret < 0)
197		return ret;
198
199	drm_panel_init(&lcd->panel);
200	lcd->panel.dev = &lcd->spi->dev;
201	lcd->panel.funcs = &lb035q02_funcs;
202
203	return drm_panel_add(&lcd->panel);
204}
205
206static 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
216static const struct of_device_id lb035q02_of_match[] = {
217	{ .compatible = "lgphilips,lb035q02", },
218	{ /* sentinel */ },
219};
220
221MODULE_DEVICE_TABLE(of, lb035q02_of_match);
222
223static const struct spi_device_id lb035q02_ids[] = {
224	{ "lb035q02", 0 },
225	{ /* sentinel */ }
226};
227
228MODULE_DEVICE_TABLE(spi, lb035q02_ids);
229
230static 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
240module_spi_driver(lb035q02_driver);
241
242MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
243MODULE_DESCRIPTION("LG.Philips LB035Q02 LCD Panel driver");
244MODULE_LICENSE("GPL");