panel-auo-a030jtn01.c

  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_drm_panel_alloc(dev, struct a030jtn01, panel,
204				    &a030jtn01_funcs, DRM_MODE_CONNECTOR_DPI);
205	if (IS_ERR(priv))
206		return PTR_ERR(priv);
207
208	priv->spi = spi;
209	spi_set_drvdata(spi, priv);
210
211	priv->map = devm_regmap_init_spi(spi, &a030jtn01_regmap_config);
212	if (IS_ERR(priv->map))
213		return dev_err_probe(dev, PTR_ERR(priv->map), "Unable to init regmap");
214
215	priv->panel_info = spi_get_device_match_data(spi);
216	if (!priv->panel_info)
217		return -EINVAL;
218
219	priv->supply = devm_regulator_get(dev, "power");
220	if (IS_ERR(priv->supply))
221		return dev_err_probe(dev, PTR_ERR(priv->supply), "Failed to get power supply");
222
223	priv->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
224	if (IS_ERR(priv->reset_gpio))
225		return dev_err_probe(dev, PTR_ERR(priv->reset_gpio), "Failed to get reset GPIO");
226
227	err = drm_panel_of_backlight(&priv->panel);
228	if (err)
229		return err;
230
231	drm_panel_add(&priv->panel);
232
233	return 0;
234}
235
236static void a030jtn01_remove(struct spi_device *spi)
237{
238	struct a030jtn01 *priv = spi_get_drvdata(spi);
239
240	drm_panel_remove(&priv->panel);
241	drm_panel_disable(&priv->panel);
242	drm_panel_unprepare(&priv->panel);
243}
244
245static const struct drm_display_mode a030jtn01_modes[] = {
246	{ /* 60 Hz */
247		.clock = 14400,
248		.hdisplay = 320,
249		.hsync_start = 320 + 8,
250		.hsync_end = 320 + 8 + 42,
251		.htotal = 320 + 8 + 42 + 30,
252		.vdisplay = 480,
253		.vsync_start = 480 + 90,
254		.vsync_end = 480 + 90 + 24,
255		.vtotal = 480 + 90 + 24 + 6,
256		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
257	},
258	{ /* 50 Hz */
259		.clock = 12000,
260		.hdisplay = 320,
261		.hsync_start = 320 + 8,
262		.hsync_end = 320 + 8 + 42,
263		.htotal = 320 + 8 + 42 + 30,
264		.vdisplay = 480,
265		.vsync_start = 480 + 90,
266		.vsync_end = 480 + 90 + 24,
267		.vtotal = 480 + 90 + 24 + 6,
268		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
269	},
270};
271
272static const struct a030jtn01_info a030jtn01_info = {
273	.display_modes = a030jtn01_modes,
274	.num_modes = ARRAY_SIZE(a030jtn01_modes),
275	.width_mm = 70,
276	.height_mm = 51,
277	.bus_format = MEDIA_BUS_FMT_RGB888_3X8_DELTA,
278	.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
279};
280
281static const struct spi_device_id a030jtn01_id[] = {
282	{ "a030jtn01", (kernel_ulong_t) &a030jtn01_info },
283	{ /* sentinel */ }
284};
285MODULE_DEVICE_TABLE(spi, a030jtn01_id);
286
287static const struct of_device_id a030jtn01_of_match[] = {
288	{ .compatible = "auo,a030jtn01" },
289	{ /* sentinel */ }
290};
291MODULE_DEVICE_TABLE(of, a030jtn01_of_match);
292
293static struct spi_driver a030jtn01_driver = {
294	.driver = {
295		.name = "auo-a030jtn01",
296		.of_match_table = a030jtn01_of_match,
297	},
298	.id_table = a030jtn01_id,
299	.probe = a030jtn01_probe,
300	.remove = a030jtn01_remove,
301};
302module_spi_driver(a030jtn01_driver);
303
304MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
305MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
306MODULE_DESCRIPTION("AU Optronics A030JTN01.0 TFT LCD panel driver");
307MODULE_LICENSE("GPL");