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