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/of_device.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 OTA5601A_CTL 0x01
24 #define OTA5601A_CTL_OFF 0x00
25 #define OTA5601A_CTL_ON BIT(0)
26 
27 struct ota5601a_panel_info {
28 	const struct drm_display_mode *display_modes;
29 	unsigned int num_modes;
30 	u16 width_mm, height_mm;
31 	u32 bus_format, bus_flags;
32 };
33 
34 struct ota5601a {
35 	struct drm_panel drm_panel;
36 	struct regmap *map;
37 	struct regulator *supply;
38 	const struct ota5601a_panel_info *panel_info;
39 
40 	struct gpio_desc *reset_gpio;
41 };
42 
43 static inline struct ota5601a *to_ota5601a(struct drm_panel *panel)
44 {
45 	return container_of(panel, struct ota5601a, drm_panel);
46 }
47 
48 static const struct reg_sequence ota5601a_panel_regs[] = {
49 	{ 0xfd, 0x00 }, /* Page Shift */
50 	{ 0x02, 0x00 }, /* Reset */
51 
52 	{ 0x18, 0x00 }, /* Interface Sel: RGB 24 Bits */
53 	{ 0x34, 0x20 }, /* Undocumented */
54 
55 	{ 0x0c, 0x01 }, /* Contrast set by CMD1 == within page 0x00 */
56 	{ 0x0d, 0x48 }, /* R Brightness */
57 	{ 0x0e, 0x48 }, /* G Brightness */
58 	{ 0x0f, 0x48 }, /* B Brightness */
59 	{ 0x07, 0x40 }, /* R Contrast */
60 	{ 0x08, 0x33 }, /* G Contrast */
61 	{ 0x09, 0x3a }, /* B Contrast */
62 
63 	{ 0x16, 0x01 }, /* NTSC Sel */
64 	{ 0x19, 0x8d }, /* VBLK */
65 	{ 0x1a, 0x28 }, /* HBLK */
66 	{ 0x1c, 0x00 }, /* Scan Shift Dir. */
67 
68 	{ 0xfd, 0xc5 }, /* Page Shift */
69 	{ 0x82, 0x0c }, /* PWR_CTRL Pump */
70 	{ 0xa2, 0xb4 }, /* PWR_CTRL VGH/VGL */
71 
72 	{ 0xfd, 0xc4 }, /* Page Shift - What follows is listed as "RGB 24bit Timing Set" */
73 	{ 0x82, 0x45 },
74 
75 	{ 0xfd, 0xc1 },
76 	{ 0x91, 0x02 },
77 
78 	{ 0xfd, 0xc0 },
79 	{ 0xa1, 0x01 },
80 	{ 0xa2, 0x1f },
81 	{ 0xa3, 0x0b },
82 	{ 0xa4, 0x38 },
83 	{ 0xa5, 0x00 },
84 	{ 0xa6, 0x0a },
85 	{ 0xa7, 0x38 },
86 	{ 0xa8, 0x00 },
87 	{ 0xa9, 0x0a },
88 	{ 0xaa, 0x37 },
89 
90 	{ 0xfd, 0xce },
91 	{ 0x81, 0x18 },
92 	{ 0x82, 0x43 },
93 	{ 0x83, 0x43 },
94 	{ 0x91, 0x06 },
95 	{ 0x93, 0x38 },
96 	{ 0x94, 0x02 },
97 	{ 0x95, 0x06 },
98 	{ 0x97, 0x38 },
99 	{ 0x98, 0x02 },
100 	{ 0x99, 0x06 },
101 	{ 0x9b, 0x38 },
102 	{ 0x9c, 0x02 },
103 
104 	{ 0xfd, 0x00 }, /* Page Shift */
105 };
106 
107 static const struct regmap_config ota5601a_regmap_config = {
108 	.reg_bits = 8,
109 	.val_bits = 8,
110 };
111 
112 static int ota5601a_prepare(struct drm_panel *drm_panel)
113 {
114 	struct ota5601a *panel = to_ota5601a(drm_panel);
115 	int err;
116 
117 	err = regulator_enable(panel->supply);
118 	if (err) {
119 		dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err);
120 		return err;
121 	}
122 
123 	/* Reset to be held low for 10us min according to the doc, 10ms before sending commands */
124 	gpiod_set_value_cansleep(panel->reset_gpio, 1);
125 	usleep_range(10, 30);
126 	gpiod_set_value_cansleep(panel->reset_gpio, 0);
127 	usleep_range(10000, 20000);
128 
129 	/* Init all registers. */
130 	err = regmap_multi_reg_write(panel->map, ota5601a_panel_regs,
131 				     ARRAY_SIZE(ota5601a_panel_regs));
132 	if (err) {
133 		dev_err(drm_panel->dev, "Failed to init registers: %d\n", err);
134 		goto err_disable_regulator;
135 	}
136 
137 	msleep(120);
138 
139 	return 0;
140 
141 err_disable_regulator:
142 	regulator_disable(panel->supply);
143 	return err;
144 }
145 
146 static int ota5601a_unprepare(struct drm_panel *drm_panel)
147 {
148 	struct ota5601a *panel = to_ota5601a(drm_panel);
149 
150 	gpiod_set_value_cansleep(panel->reset_gpio, 1);
151 
152 	regulator_disable(panel->supply);
153 
154 	return 0;
155 }
156 
157 static int ota5601a_enable(struct drm_panel *drm_panel)
158 {
159 	struct ota5601a *panel = to_ota5601a(drm_panel);
160 	int err;
161 
162 	err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_ON);
163 
164 	if (err) {
165 		dev_err(drm_panel->dev, "Unable to enable panel: %d\n", err);
166 		return err;
167 	}
168 
169 	if (drm_panel->backlight) {
170 		/* Wait for the picture to be ready before enabling backlight */
171 		msleep(120);
172 	}
173 
174 	return 0;
175 }
176 
177 static int ota5601a_disable(struct drm_panel *drm_panel)
178 {
179 	struct ota5601a *panel = to_ota5601a(drm_panel);
180 	int err;
181 
182 	err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_OFF);
183 
184 	if (err) {
185 		dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err);
186 		return err;
187 	}
188 
189 	return 0;
190 }
191 
192 static int ota5601a_get_modes(struct drm_panel *drm_panel,
193 			      struct drm_connector *connector)
194 {
195 	struct ota5601a *panel = to_ota5601a(drm_panel);
196 	const struct ota5601a_panel_info *panel_info = panel->panel_info;
197 	struct drm_display_mode *mode;
198 	unsigned int i;
199 
200 	for (i = 0; i < panel_info->num_modes; i++) {
201 		mode = drm_mode_duplicate(connector->dev,
202 					  &panel_info->display_modes[i]);
203 		if (!mode)
204 			return -ENOMEM;
205 
206 		drm_mode_set_name(mode);
207 
208 		mode->type = DRM_MODE_TYPE_DRIVER;
209 		if (panel_info->num_modes == 1)
210 			mode->type |= DRM_MODE_TYPE_PREFERRED;
211 
212 		drm_mode_probed_add(connector, mode);
213 	}
214 
215 	connector->display_info.bpc = 8;
216 	connector->display_info.width_mm = panel_info->width_mm;
217 	connector->display_info.height_mm = panel_info->height_mm;
218 
219 	drm_display_info_set_bus_formats(&connector->display_info,
220 					 &panel_info->bus_format, 1);
221 	connector->display_info.bus_flags = panel_info->bus_flags;
222 
223 	return panel_info->num_modes;
224 }
225 
226 static const struct drm_panel_funcs ota5601a_funcs = {
227 	.prepare	= ota5601a_prepare,
228 	.unprepare	= ota5601a_unprepare,
229 	.enable		= ota5601a_enable,
230 	.disable	= ota5601a_disable,
231 	.get_modes	= ota5601a_get_modes,
232 };
233 
234 static int ota5601a_probe(struct spi_device *spi)
235 {
236 	const struct spi_device_id *id = spi_get_device_id(spi);
237 	struct device *dev = &spi->dev;
238 	struct ota5601a *panel;
239 	int err;
240 
241 	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
242 	if (!panel)
243 		return -ENOMEM;
244 
245 	spi_set_drvdata(spi, panel);
246 
247 	panel->panel_info = (const struct ota5601a_panel_info *)id->driver_data;
248 	if (!panel->panel_info)
249 		return -EINVAL;
250 
251 	panel->supply = devm_regulator_get(dev, "power");
252 	if (IS_ERR(panel->supply)) {
253 		dev_err(dev, "Failed to get power supply\n");
254 		return PTR_ERR(panel->supply);
255 	}
256 
257 	panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
258 	if (IS_ERR(panel->reset_gpio)) {
259 		dev_err(dev, "Failed to get reset GPIO\n");
260 		return PTR_ERR(panel->reset_gpio);
261 	}
262 
263 	spi->bits_per_word = 8;
264 	spi->mode = SPI_MODE_3 | SPI_3WIRE;
265 	err = spi_setup(spi);
266 	if (err) {
267 		dev_err(dev, "Failed to setup SPI\n");
268 		return err;
269 	}
270 
271 	panel->map = devm_regmap_init_spi(spi, &ota5601a_regmap_config);
272 	if (IS_ERR(panel->map)) {
273 		dev_err(dev, "Failed to init regmap\n");
274 		return PTR_ERR(panel->map);
275 	}
276 
277 	drm_panel_init(&panel->drm_panel, dev, &ota5601a_funcs,
278 		       DRM_MODE_CONNECTOR_DPI);
279 
280 	err = drm_panel_of_backlight(&panel->drm_panel);
281 	if (err) {
282 		if (err != -EPROBE_DEFER)
283 			dev_err(dev, "Failed to get backlight handle\n");
284 		return err;
285 	}
286 
287 	drm_panel_add(&panel->drm_panel);
288 
289 	return 0;
290 }
291 
292 static void ota5601a_remove(struct spi_device *spi)
293 {
294 	struct ota5601a *panel = spi_get_drvdata(spi);
295 
296 	drm_panel_remove(&panel->drm_panel);
297 
298 	ota5601a_disable(&panel->drm_panel);
299 	ota5601a_unprepare(&panel->drm_panel);
300 }
301 
302 static const struct drm_display_mode gpt3_display_modes[] = {
303 	{ /* 60 Hz */
304 		.clock = 27000,
305 		.hdisplay = 640,
306 		.hsync_start = 640 + 220,
307 		.hsync_end = 640 + 220 + 20,
308 		.htotal = 640 + 220 + 20 + 20,
309 		.vdisplay = 480,
310 		.vsync_start = 480 + 7,
311 		.vsync_end = 480 + 7 + 6,
312 		.vtotal = 480 + 7 + 6 + 7,
313 		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
314 	},
315 
316 	{ /* 50 Hz */
317 		.clock = 24000,
318 		.hdisplay = 640,
319 		.hsync_start = 640 + 280,
320 		.hsync_end = 640 + 280 + 20,
321 		.htotal = 640 + 280 + 20 + 20,
322 		.vdisplay = 480,
323 		.vsync_start = 480 + 7,
324 		.vsync_end = 480 + 7 + 6,
325 		.vtotal = 480 + 7 + 6 + 7,
326 		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
327 	},
328 };
329 
330 static const struct ota5601a_panel_info gpt3_info = {
331 	.display_modes = gpt3_display_modes,
332 	.num_modes = ARRAY_SIZE(gpt3_display_modes),
333 	.width_mm = 71,
334 	.height_mm = 51,
335 	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
336 	.bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
337 };
338 
339 static const struct spi_device_id gpt3_id[] = {
340 	{ "gpt3", (kernel_ulong_t)&gpt3_info },
341 	{ /* sentinel */ }
342 };
343 MODULE_DEVICE_TABLE(spi, gpt3_id);
344 
345 static const struct of_device_id ota5601a_of_match[] = {
346 	{ .compatible = "focaltech,gpt3" },
347 	{ /* sentinel */ }
348 };
349 MODULE_DEVICE_TABLE(of, ota5601a_of_match);
350 
351 static struct spi_driver ota5601a_driver = {
352 	.driver = {
353 		.name = "ota5601a",
354 		.of_match_table = ota5601a_of_match,
355 	},
356 	.id_table = gpt3_id,
357 	.probe = ota5601a_probe,
358 	.remove = ota5601a_remove,
359 };
360 
361 module_spi_driver(ota5601a_driver);
362 
363 MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
364 MODULE_LICENSE("GPL");
365