1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Orisetech OTA5601A TFT LCD panel driver
4 *
5 * Copyright (C) 2021, Christophe Branchereau <cbranchereau@gmail.com>
6 */
7
8 #include <linux/bits.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/media-bus-format.h>
13 #include <linux/module.h>
14 #include <linux/of.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 OTA5601A_CTL 0x01
23 #define OTA5601A_CTL_OFF 0x00
24 #define OTA5601A_CTL_ON BIT(0)
25
26 struct ota5601a_panel_info {
27 const struct drm_display_mode *display_modes;
28 unsigned int num_modes;
29 u16 width_mm, height_mm;
30 u32 bus_format, bus_flags;
31 };
32
33 struct ota5601a {
34 struct drm_panel drm_panel;
35 struct regmap *map;
36 struct regulator *supply;
37 const struct ota5601a_panel_info *panel_info;
38
39 struct gpio_desc *reset_gpio;
40 };
41
to_ota5601a(struct drm_panel * panel)42 static inline struct ota5601a *to_ota5601a(struct drm_panel *panel)
43 {
44 return container_of(panel, struct ota5601a, drm_panel);
45 }
46
47 static const struct reg_sequence ota5601a_panel_regs[] = {
48 { 0xfd, 0x00 }, /* Page Shift */
49 { 0x02, 0x00 }, /* Reset */
50
51 { 0x18, 0x00 }, /* Interface Sel: RGB 24 Bits */
52 { 0x34, 0x20 }, /* Undocumented */
53
54 { 0x0c, 0x01 }, /* Contrast set by CMD1 == within page 0x00 */
55 { 0x0d, 0x48 }, /* R Brightness */
56 { 0x0e, 0x48 }, /* G Brightness */
57 { 0x0f, 0x48 }, /* B Brightness */
58 { 0x07, 0x40 }, /* R Contrast */
59 { 0x08, 0x33 }, /* G Contrast */
60 { 0x09, 0x3a }, /* B Contrast */
61
62 { 0x16, 0x01 }, /* NTSC Sel */
63 { 0x19, 0x8d }, /* VBLK */
64 { 0x1a, 0x28 }, /* HBLK */
65 { 0x1c, 0x00 }, /* Scan Shift Dir. */
66
67 { 0xfd, 0xc5 }, /* Page Shift */
68 { 0x82, 0x0c }, /* PWR_CTRL Pump */
69 { 0xa2, 0xb4 }, /* PWR_CTRL VGH/VGL */
70
71 { 0xfd, 0xc4 }, /* Page Shift - What follows is listed as "RGB 24bit Timing Set" */
72 { 0x82, 0x45 },
73
74 { 0xfd, 0xc1 },
75 { 0x91, 0x02 },
76
77 { 0xfd, 0xc0 },
78 { 0xa1, 0x01 },
79 { 0xa2, 0x1f },
80 { 0xa3, 0x0b },
81 { 0xa4, 0x38 },
82 { 0xa5, 0x00 },
83 { 0xa6, 0x0a },
84 { 0xa7, 0x38 },
85 { 0xa8, 0x00 },
86 { 0xa9, 0x0a },
87 { 0xaa, 0x37 },
88
89 { 0xfd, 0xce },
90 { 0x81, 0x18 },
91 { 0x82, 0x43 },
92 { 0x83, 0x43 },
93 { 0x91, 0x06 },
94 { 0x93, 0x38 },
95 { 0x94, 0x02 },
96 { 0x95, 0x06 },
97 { 0x97, 0x38 },
98 { 0x98, 0x02 },
99 { 0x99, 0x06 },
100 { 0x9b, 0x38 },
101 { 0x9c, 0x02 },
102
103 { 0xfd, 0x00 }, /* Page Shift */
104 };
105
106 static const struct regmap_config ota5601a_regmap_config = {
107 .reg_bits = 8,
108 .val_bits = 8,
109 };
110
ota5601a_prepare(struct drm_panel * drm_panel)111 static int ota5601a_prepare(struct drm_panel *drm_panel)
112 {
113 struct ota5601a *panel = to_ota5601a(drm_panel);
114 int err;
115
116 err = regulator_enable(panel->supply);
117 if (err) {
118 dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err);
119 return err;
120 }
121
122 /* Reset to be held low for 10us min according to the doc, 10ms before sending commands */
123 gpiod_set_value_cansleep(panel->reset_gpio, 1);
124 usleep_range(10, 30);
125 gpiod_set_value_cansleep(panel->reset_gpio, 0);
126 usleep_range(10000, 20000);
127
128 /* Init all registers. */
129 err = regmap_multi_reg_write(panel->map, ota5601a_panel_regs,
130 ARRAY_SIZE(ota5601a_panel_regs));
131 if (err) {
132 dev_err(drm_panel->dev, "Failed to init registers: %d\n", err);
133 goto err_disable_regulator;
134 }
135
136 msleep(120);
137
138 return 0;
139
140 err_disable_regulator:
141 regulator_disable(panel->supply);
142 return err;
143 }
144
ota5601a_unprepare(struct drm_panel * drm_panel)145 static int ota5601a_unprepare(struct drm_panel *drm_panel)
146 {
147 struct ota5601a *panel = to_ota5601a(drm_panel);
148
149 gpiod_set_value_cansleep(panel->reset_gpio, 1);
150
151 regulator_disable(panel->supply);
152
153 return 0;
154 }
155
ota5601a_enable(struct drm_panel * drm_panel)156 static int ota5601a_enable(struct drm_panel *drm_panel)
157 {
158 struct ota5601a *panel = to_ota5601a(drm_panel);
159 int err;
160
161 err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_ON);
162
163 if (err) {
164 dev_err(drm_panel->dev, "Unable to enable panel: %d\n", err);
165 return err;
166 }
167
168 if (drm_panel->backlight) {
169 /* Wait for the picture to be ready before enabling backlight */
170 msleep(120);
171 }
172
173 return 0;
174 }
175
ota5601a_disable(struct drm_panel * drm_panel)176 static int ota5601a_disable(struct drm_panel *drm_panel)
177 {
178 struct ota5601a *panel = to_ota5601a(drm_panel);
179 int err;
180
181 err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_OFF);
182
183 if (err) {
184 dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err);
185 return err;
186 }
187
188 return 0;
189 }
190
ota5601a_get_modes(struct drm_panel * drm_panel,struct drm_connector * connector)191 static int ota5601a_get_modes(struct drm_panel *drm_panel,
192 struct drm_connector *connector)
193 {
194 struct ota5601a *panel = to_ota5601a(drm_panel);
195 const struct ota5601a_panel_info *panel_info = panel->panel_info;
196 struct drm_display_mode *mode;
197 unsigned int i;
198
199 for (i = 0; i < panel_info->num_modes; i++) {
200 mode = drm_mode_duplicate(connector->dev,
201 &panel_info->display_modes[i]);
202 if (!mode)
203 return -ENOMEM;
204
205 drm_mode_set_name(mode);
206
207 mode->type = DRM_MODE_TYPE_DRIVER;
208 if (panel_info->num_modes == 1)
209 mode->type |= DRM_MODE_TYPE_PREFERRED;
210
211 drm_mode_probed_add(connector, mode);
212 }
213
214 connector->display_info.bpc = 8;
215 connector->display_info.width_mm = panel_info->width_mm;
216 connector->display_info.height_mm = panel_info->height_mm;
217
218 drm_display_info_set_bus_formats(&connector->display_info,
219 &panel_info->bus_format, 1);
220 connector->display_info.bus_flags = panel_info->bus_flags;
221
222 return panel_info->num_modes;
223 }
224
225 static const struct drm_panel_funcs ota5601a_funcs = {
226 .prepare = ota5601a_prepare,
227 .unprepare = ota5601a_unprepare,
228 .enable = ota5601a_enable,
229 .disable = ota5601a_disable,
230 .get_modes = ota5601a_get_modes,
231 };
232
ota5601a_probe(struct spi_device * spi)233 static int ota5601a_probe(struct spi_device *spi)
234 {
235 const struct spi_device_id *id = spi_get_device_id(spi);
236 struct device *dev = &spi->dev;
237 struct ota5601a *panel;
238 int err;
239
240 panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
241 if (!panel)
242 return -ENOMEM;
243
244 spi_set_drvdata(spi, panel);
245
246 panel->panel_info = (const struct ota5601a_panel_info *)id->driver_data;
247 if (!panel->panel_info)
248 return -EINVAL;
249
250 panel->supply = devm_regulator_get(dev, "power");
251 if (IS_ERR(panel->supply)) {
252 dev_err(dev, "Failed to get power supply\n");
253 return PTR_ERR(panel->supply);
254 }
255
256 panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
257 if (IS_ERR(panel->reset_gpio)) {
258 dev_err(dev, "Failed to get reset GPIO\n");
259 return PTR_ERR(panel->reset_gpio);
260 }
261
262 spi->bits_per_word = 8;
263 spi->mode = SPI_MODE_3 | SPI_3WIRE;
264 err = spi_setup(spi);
265 if (err) {
266 dev_err(dev, "Failed to setup SPI\n");
267 return err;
268 }
269
270 panel->map = devm_regmap_init_spi(spi, &ota5601a_regmap_config);
271 if (IS_ERR(panel->map)) {
272 dev_err(dev, "Failed to init regmap\n");
273 return PTR_ERR(panel->map);
274 }
275
276 drm_panel_init(&panel->drm_panel, dev, &ota5601a_funcs,
277 DRM_MODE_CONNECTOR_DPI);
278
279 err = drm_panel_of_backlight(&panel->drm_panel);
280 if (err) {
281 if (err != -EPROBE_DEFER)
282 dev_err(dev, "Failed to get backlight handle\n");
283 return err;
284 }
285
286 drm_panel_add(&panel->drm_panel);
287
288 return 0;
289 }
290
ota5601a_remove(struct spi_device * spi)291 static void ota5601a_remove(struct spi_device *spi)
292 {
293 struct ota5601a *panel = spi_get_drvdata(spi);
294
295 drm_panel_remove(&panel->drm_panel);
296
297 ota5601a_disable(&panel->drm_panel);
298 ota5601a_unprepare(&panel->drm_panel);
299 }
300
301 static const struct drm_display_mode gpt3_display_modes[] = {
302 { /* 60 Hz */
303 .clock = 27000,
304 .hdisplay = 640,
305 .hsync_start = 640 + 220,
306 .hsync_end = 640 + 220 + 20,
307 .htotal = 640 + 220 + 20 + 20,
308 .vdisplay = 480,
309 .vsync_start = 480 + 7,
310 .vsync_end = 480 + 7 + 6,
311 .vtotal = 480 + 7 + 6 + 7,
312 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
313 },
314
315 { /* 50 Hz */
316 .clock = 24000,
317 .hdisplay = 640,
318 .hsync_start = 640 + 280,
319 .hsync_end = 640 + 280 + 20,
320 .htotal = 640 + 280 + 20 + 20,
321 .vdisplay = 480,
322 .vsync_start = 480 + 7,
323 .vsync_end = 480 + 7 + 6,
324 .vtotal = 480 + 7 + 6 + 7,
325 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
326 },
327 };
328
329 static const struct ota5601a_panel_info gpt3_info = {
330 .display_modes = gpt3_display_modes,
331 .num_modes = ARRAY_SIZE(gpt3_display_modes),
332 .width_mm = 71,
333 .height_mm = 51,
334 .bus_format = MEDIA_BUS_FMT_RGB888_1X24,
335 .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
336 };
337
338 static const struct spi_device_id gpt3_id[] = {
339 { "gpt3", (kernel_ulong_t)&gpt3_info },
340 { /* sentinel */ }
341 };
342 MODULE_DEVICE_TABLE(spi, gpt3_id);
343
344 static const struct of_device_id ota5601a_of_match[] = {
345 { .compatible = "focaltech,gpt3" },
346 { /* sentinel */ }
347 };
348 MODULE_DEVICE_TABLE(of, ota5601a_of_match);
349
350 static struct spi_driver ota5601a_driver = {
351 .driver = {
352 .name = "ota5601a",
353 .of_match_table = ota5601a_of_match,
354 },
355 .id_table = gpt3_id,
356 .probe = ota5601a_probe,
357 .remove = ota5601a_remove,
358 };
359
360 module_spi_driver(ota5601a_driver);
361
362 MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
363 MODULE_LICENSE("GPL");
364