1// SPDX-License-Identifier: GPL-2.0
2/*
3 * AU Optronics A030JTN01.0 TFT LCD panel driver
4 *
5 * Copyright (C) 2023, Paul Cercueil <paul@crapouillou.net>
6 * Copyright (C) 2023, Christophe Branchereau <cbranchereau@gmail.com>
7 */
8
9#include <linux/bitfield.h>
10#include <linux/delay.h>
11#include <linux/device.h>
12#include <linux/gpio/consumer.h>
13#include <linux/media-bus-format.h>
14#include <linux/mod_devicetable.h>
15#include <linux/module.h>
16#include <linux/regmap.h>
17#include <linux/regulator/consumer.h>
18#include <linux/spi/spi.h>
19
20#include <drm/drm_modes.h>
21#include <drm/drm_panel.h>
22
23#define REG05			0x05
24#define REG06			0x06
25#define REG07			0x07
26
27#define REG05_STDBY		BIT(0)
28#define REG06_VBLK		GENMASK(4, 0)
29#define REG07_HBLK		GENMASK(7, 0)
30
31
32struct a030jtn01_info {
33	const struct drm_display_mode *display_modes;
34	unsigned int num_modes;
35	u16 width_mm, height_mm;
36	u32 bus_format, bus_flags;
37};
38
39struct a030jtn01 {
40	struct drm_panel panel;
41	struct spi_device *spi;
42	struct regmap *map;
43
44	const struct a030jtn01_info *panel_info;
45
46	struct regulator *supply;
47	struct gpio_desc *reset_gpio;
48};
49
50static inline struct a030jtn01 *to_a030jtn01(struct drm_panel *panel)
51{
52	return container_of(panel, struct a030jtn01, panel);
53}
54
55static int a030jtn01_prepare(struct drm_panel *panel)
56{
57	struct a030jtn01 *priv = to_a030jtn01(panel);
58	struct device *dev = &priv->spi->dev;
59	unsigned int dummy;
60	int err;
61
62	err = regulator_enable(priv->supply);
63	if (err) {
64		dev_err(dev, "Failed to enable power supply: %d\n", err);
65		return err;
66	}
67
68	usleep_range(1000, 8000);
69
70	/* Reset the chip */
71	gpiod_set_value_cansleep(priv->reset_gpio, 1);
72	usleep_range(100, 8000);
73	gpiod_set_value_cansleep(priv->reset_gpio, 0);
74	usleep_range(2000, 8000);
75
76	/*
77	 * No idea why, but a register read (doesn't matter which) is needed to
78	 * properly initialize the chip after a reset; otherwise, the colors
79	 * will be wrong. It doesn't seem to be timing-related as a msleep(200)
80	 * doesn't fix it.
81	 */
82	err = regmap_read(priv->map, REG05, &dummy);
83	if (err)
84		goto err_disable_regulator;
85
86	/* Use (24 + 6) == 0x1e as the vertical back porch */
87	err = regmap_write(priv->map, REG06, FIELD_PREP(REG06_VBLK, 0x1e));
88	if (err)
89		goto err_disable_regulator;
90
91	/* Use (42 + 30) * 3 == 0xd8 as the horizontal back porch */
92	err = regmap_write(priv->map, REG07, FIELD_PREP(REG07_HBLK, 0xd8));
93	if (err)
94		goto err_disable_regulator;
95
96	return 0;
97
98err_disable_regulator:
99	gpiod_set_value_cansleep(priv->reset_gpio, 1);
100	regulator_disable(priv->supply);
101	return err;
102}
103
104static int a030jtn01_unprepare(struct drm_panel *panel)
105{
106	struct a030jtn01 *priv = to_a030jtn01(panel);
107
108	gpiod_set_value_cansleep(priv->reset_gpio, 1);
109	regulator_disable(priv->supply);
110
111	return 0;
112}
113
114static int a030jtn01_enable(struct drm_panel *panel)
115{
116	struct a030jtn01 *priv = to_a030jtn01(panel);
117	int ret;
118
119	ret = regmap_set_bits(priv->map, REG05, REG05_STDBY);
120	if (ret)
121		return ret;
122
123	/* Wait for the picture to be stable */
124	if (panel->backlight)
125		msleep(100);
126
127	return 0;
128}
129
130static int a030jtn01_disable(struct drm_panel *panel)
131{
132	struct a030jtn01 *priv = to_a030jtn01(panel);
133
134	return regmap_clear_bits(priv->map, REG05, REG05_STDBY);
135}
136
137static int a030jtn01_get_modes(struct drm_panel *panel,
138				struct drm_connector *connector)
139{
140	struct a030jtn01 *priv = to_a030jtn01(panel);
141	const struct a030jtn01_info *panel_info = priv->panel_info;
142	struct drm_display_mode *mode;
143	unsigned int i;
144
145	for (i = 0; i < panel_info->num_modes; i++) {
146		mode = drm_mode_duplicate(connector->dev,
147					  &panel_info->display_modes[i]);
148		if (!mode)
149			return -ENOMEM;
150
151		drm_mode_set_name(mode);
152
153		mode->type = DRM_MODE_TYPE_DRIVER;
154		if (panel_info->num_modes == 1)
155			mode->type |= DRM_MODE_TYPE_PREFERRED;
156
157		drm_mode_probed_add(connector, mode);
158	}
159
160	connector->display_info.bpc = 8;
161	connector->display_info.width_mm = panel_info->width_mm;
162	connector->display_info.height_mm = panel_info->height_mm;
163
164	drm_display_info_set_bus_formats(&connector->display_info,
165					 &panel_info->bus_format, 1);
166	connector->display_info.bus_flags = panel_info->bus_flags;
167
168	return panel_info->num_modes;
169}
170
171static const struct drm_panel_funcs a030jtn01_funcs = {
172	.prepare	= a030jtn01_prepare,
173	.unprepare	= a030jtn01_unprepare,
174	.enable		= a030jtn01_enable,
175	.disable	= a030jtn01_disable,
176	.get_modes	= a030jtn01_get_modes,
177};
178
179static bool a030jtn01_has_reg(struct device *dev, unsigned int reg)
180{
181	static const u32 a030jtn01_regs_mask = 0x001823f1fb;
182
183	return a030jtn01_regs_mask & BIT(reg);
184};
185
186static const struct regmap_config a030jtn01_regmap_config = {
187	.reg_bits = 8,
188	.val_bits = 8,
189	.read_flag_mask = 0x40,
190	.max_register = 0x1c,
191	.readable_reg = a030jtn01_has_reg,
192	.writeable_reg = a030jtn01_has_reg,
193};
194
195static int a030jtn01_probe(struct spi_device *spi)
196{
197	struct device *dev = &spi->dev;
198	struct a030jtn01 *priv;
199	int err;
200
201	spi->mode |= SPI_MODE_3 | SPI_3WIRE;
202
203	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
204	if (!priv)
205		return -ENOMEM;
206
207	priv->spi = spi;
208	spi_set_drvdata(spi, priv);
209
210	priv->map = devm_regmap_init_spi(spi, &a030jtn01_regmap_config);
211	if (IS_ERR(priv->map))
212		return dev_err_probe(dev, PTR_ERR(priv->map), "Unable to init regmap");
213
214	priv->panel_info = spi_get_device_match_data(spi);
215	if (!priv->panel_info)
216		return -EINVAL;
217
218	priv->supply = devm_regulator_get(dev, "power");
219	if (IS_ERR(priv->supply))
220		return dev_err_probe(dev, PTR_ERR(priv->supply), "Failed to get power supply");
221
222	priv->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
223	if (IS_ERR(priv->reset_gpio))
224		return dev_err_probe(dev, PTR_ERR(priv->reset_gpio), "Failed to get reset GPIO");
225
226	drm_panel_init(&priv->panel, dev, &a030jtn01_funcs,
227		       DRM_MODE_CONNECTOR_DPI);
228
229	err = drm_panel_of_backlight(&priv->panel);
230	if (err)
231		return err;
232
233	drm_panel_add(&priv->panel);
234
235	return 0;
236}
237
238static void a030jtn01_remove(struct spi_device *spi)
239{
240	struct a030jtn01 *priv = spi_get_drvdata(spi);
241
242	drm_panel_remove(&priv->panel);
243	drm_panel_disable(&priv->panel);
244	drm_panel_unprepare(&priv->panel);
245}
246
247static const struct drm_display_mode a030jtn01_modes[] = {
248	{ /* 60 Hz */
249		.clock = 14400,
250		.hdisplay = 320,
251		.hsync_start = 320 + 8,
252		.hsync_end = 320 + 8 + 42,
253		.htotal = 320 + 8 + 42 + 30,
254		.vdisplay = 480,
255		.vsync_start = 480 + 90,
256		.vsync_end = 480 + 90 + 24,
257		.vtotal = 480 + 90 + 24 + 6,
258		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
259	},
260	{ /* 50 Hz */
261		.clock = 12000,
262		.hdisplay = 320,
263		.hsync_start = 320 + 8,
264		.hsync_end = 320 + 8 + 42,
265		.htotal = 320 + 8 + 42 + 30,
266		.vdisplay = 480,
267		.vsync_start = 480 + 90,
268		.vsync_end = 480 + 90 + 24,
269		.vtotal = 480 + 90 + 24 + 6,
270		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
271	},
272};
273
274static const struct a030jtn01_info a030jtn01_info = {
275	.display_modes = a030jtn01_modes,
276	.num_modes = ARRAY_SIZE(a030jtn01_modes),
277	.width_mm = 70,
278	.height_mm = 51,
279	.bus_format = MEDIA_BUS_FMT_RGB888_3X8_DELTA,
280	.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
281};
282
283static const struct spi_device_id a030jtn01_id[] = {
284	{ "a030jtn01", (kernel_ulong_t) &a030jtn01_info },
285	{ /* sentinel */ }
286};
287MODULE_DEVICE_TABLE(spi, a030jtn01_id);
288
289static const struct of_device_id a030jtn01_of_match[] = {
290	{ .compatible = "auo,a030jtn01" },
291	{ /* sentinel */ }
292};
293MODULE_DEVICE_TABLE(of, a030jtn01_of_match);
294
295static struct spi_driver a030jtn01_driver = {
296	.driver = {
297		.name = "auo-a030jtn01",
298		.of_match_table = a030jtn01_of_match,
299	},
300	.id_table = a030jtn01_id,
301	.probe = a030jtn01_probe,
302	.remove = a030jtn01_remove,
303};
304module_spi_driver(a030jtn01_driver);
305
306MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
307MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
308MODULE_LICENSE("GPL");
309