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(regulator: 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(min: 1000, max: 8000);
69
70 /* Reset the chip */
71 gpiod_set_value_cansleep(desc: priv->reset_gpio, value: 1);
72 usleep_range(min: 100, max: 8000);
73 gpiod_set_value_cansleep(desc: priv->reset_gpio, value: 0);
74 usleep_range(min: 2000, max: 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(map: priv->map, REG05, val: &dummy);
83 if (err)
84 goto err_disable_regulator;
85
86 /* Use (24 + 6) == 0x1e as the vertical back porch */
87 err = regmap_write(map: 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(map: 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(desc: priv->reset_gpio, value: 1);
100 regulator_disable(regulator: 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(desc: priv->reset_gpio, value: 1);
109 regulator_disable(regulator: 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(map: 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(msecs: 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(map: 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(dev: connector->dev,
147 mode: &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(info: &connector->display_info,
165 formats: &panel_info->bus_format, num_formats: 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, size: sizeof(*priv), GFP_KERNEL);
204 if (!priv)
205 return -ENOMEM;
206
207 priv->spi = spi;
208 spi_set_drvdata(spi, data: priv);
209
210 priv->map = devm_regmap_init_spi(spi, &a030jtn01_regmap_config);
211 if (IS_ERR(ptr: priv->map))
212 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->map), fmt: "Unable to init regmap");
213
214 priv->panel_info = spi_get_device_match_data(sdev: spi);
215 if (!priv->panel_info)
216 return -EINVAL;
217
218 priv->supply = devm_regulator_get(dev, id: "power");
219 if (IS_ERR(ptr: priv->supply))
220 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->supply), fmt: "Failed to get power supply");
221
222 priv->reset_gpio = devm_gpiod_get(dev, con_id: "reset", flags: GPIOD_OUT_HIGH);
223 if (IS_ERR(ptr: priv->reset_gpio))
224 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->reset_gpio), fmt: "Failed to get reset GPIO");
225
226 drm_panel_init(panel: &priv->panel, dev, funcs: &a030jtn01_funcs,
227 DRM_MODE_CONNECTOR_DPI);
228
229 err = drm_panel_of_backlight(panel: &priv->panel);
230 if (err)
231 return err;
232
233 drm_panel_add(panel: &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(panel: &priv->panel);
243 drm_panel_disable(panel: &priv->panel);
244 drm_panel_unprepare(panel: &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

source code of linux/drivers/gpu/drm/panel/panel-auo-a030jtn01.c