1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019, Amarula Solutions.
4  * Author: Jagan Teki <jagan@amarulasolutions.com>
5  */
6 
7 #include <drm/drm_mipi_dsi.h>
8 #include <drm/drm_modes.h>
9 #include <drm/drm_panel.h>
10 #include <drm/drm_print.h>
11 
12 #include <linux/gpio/consumer.h>
13 #include <linux/delay.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/regulator/consumer.h>
17 
18 #include <video/mipi_display.h>
19 
20 /* Command2 BKx selection command */
21 #define DSI_CMD2BKX_SEL			0xFF
22 
23 /* Command2, BK0 commands */
24 #define DSI_CMD2_BK0_PVGAMCTRL		0xB0 /* Positive Voltage Gamma Control */
25 #define DSI_CMD2_BK0_NVGAMCTRL		0xB1 /* Negative Voltage Gamma Control */
26 #define DSI_CMD2_BK0_LNESET		0xC0 /* Display Line setting */
27 #define DSI_CMD2_BK0_PORCTRL		0xC1 /* Porch control */
28 #define DSI_CMD2_BK0_INVSEL		0xC2 /* Inversion selection, Frame Rate Control */
29 
30 /* Command2, BK1 commands */
31 #define DSI_CMD2_BK1_VRHS		0xB0 /* Vop amplitude setting */
32 #define DSI_CMD2_BK1_VCOM		0xB1 /* VCOM amplitude setting */
33 #define DSI_CMD2_BK1_VGHSS		0xB2 /* VGH Voltage setting */
34 #define DSI_CMD2_BK1_TESTCMD		0xB3 /* TEST Command Setting */
35 #define DSI_CMD2_BK1_VGLS		0xB5 /* VGL Voltage setting */
36 #define DSI_CMD2_BK1_PWCTLR1		0xB7 /* Power Control 1 */
37 #define DSI_CMD2_BK1_PWCTLR2		0xB8 /* Power Control 2 */
38 #define DSI_CMD2_BK1_SPD1		0xC1 /* Source pre_drive timing set1 */
39 #define DSI_CMD2_BK1_SPD2		0xC2 /* Source EQ2 Setting */
40 #define DSI_CMD2_BK1_MIPISET1		0xD0 /* MIPI Setting 1 */
41 
42 /**
43  * Command2 with BK function selection.
44  *
45  * BIT[4, 0]: [CN2, BKXSEL]
46  * 10 = CMD2BK0, Command2 BK0
47  * 11 = CMD2BK1, Command2 BK1
48  * 00 = Command2 disable
49  */
50 #define DSI_CMD2BK1_SEL			0x11
51 #define DSI_CMD2BK0_SEL			0x10
52 #define DSI_CMD2BKX_SEL_NONE		0x00
53 
54 /* Command2, BK0 bytes */
55 #define DSI_LINESET_LINE		0x69
56 #define DSI_LINESET_LDE_EN		BIT(7)
57 #define DSI_LINESET_LINEDELTA		GENMASK(1, 0)
58 #define DSI_CMD2_BK0_LNESET_B1		DSI_LINESET_LINEDELTA
59 #define DSI_CMD2_BK0_LNESET_B0		(DSI_LINESET_LDE_EN | DSI_LINESET_LINE)
60 #define DSI_INVSEL_DEFAULT		GENMASK(5, 4)
61 #define DSI_INVSEL_NLINV		GENMASK(2, 0)
62 #define DSI_INVSEL_RTNI			GENMASK(2, 1)
63 #define DSI_CMD2_BK0_INVSEL_B1		DSI_INVSEL_RTNI
64 #define DSI_CMD2_BK0_INVSEL_B0		(DSI_INVSEL_DEFAULT | DSI_INVSEL_NLINV)
65 #define DSI_CMD2_BK0_PORCTRL_B0(m)	((m)->vtotal - (m)->vsync_end)
66 #define DSI_CMD2_BK0_PORCTRL_B1(m)	((m)->vsync_start - (m)->vdisplay)
67 
68 /* Command2, BK1 bytes */
69 #define DSI_CMD2_BK1_VRHA_SET		0x45
70 #define DSI_CMD2_BK1_VCOM_SET		0x13
71 #define DSI_CMD2_BK1_VGHSS_SET		GENMASK(2, 0)
72 #define DSI_CMD2_BK1_TESTCMD_VAL	BIT(7)
73 #define DSI_VGLS_DEFAULT		BIT(6)
74 #define DSI_VGLS_SEL			GENMASK(2, 0)
75 #define DSI_CMD2_BK1_VGLS_SET		(DSI_VGLS_DEFAULT | DSI_VGLS_SEL)
76 #define DSI_PWCTLR1_AP			BIT(7) /* Gamma OP bias, max */
77 #define DSI_PWCTLR1_APIS		BIT(2) /* Source OP input bias, min */
78 #define DSI_PWCTLR1_APOS		BIT(0) /* Source OP output bias, min */
79 #define DSI_CMD2_BK1_PWCTLR1_SET	(DSI_PWCTLR1_AP | DSI_PWCTLR1_APIS | \
80 					DSI_PWCTLR1_APOS)
81 #define DSI_PWCTLR2_AVDD		BIT(5) /* AVDD 6.6v */
82 #define DSI_PWCTLR2_AVCL		0x0    /* AVCL -4.4v */
83 #define DSI_CMD2_BK1_PWCTLR2_SET	(DSI_PWCTLR2_AVDD | DSI_PWCTLR2_AVCL)
84 #define DSI_SPD1_T2D			BIT(3)
85 #define DSI_CMD2_BK1_SPD1_SET		(GENMASK(6, 4) | DSI_SPD1_T2D)
86 #define DSI_CMD2_BK1_SPD2_SET		DSI_CMD2_BK1_SPD1_SET
87 #define DSI_MIPISET1_EOT_EN		BIT(3)
88 #define DSI_CMD2_BK1_MIPISET1_SET	(BIT(7) | DSI_MIPISET1_EOT_EN)
89 
90 struct st7701_panel_desc {
91 	const struct drm_display_mode *mode;
92 	unsigned int lanes;
93 	unsigned long flags;
94 	enum mipi_dsi_pixel_format format;
95 	const char *const *supply_names;
96 	unsigned int num_supplies;
97 	unsigned int panel_sleep_delay;
98 };
99 
100 struct st7701 {
101 	struct drm_panel panel;
102 	struct mipi_dsi_device *dsi;
103 	const struct st7701_panel_desc *desc;
104 
105 	struct regulator_bulk_data *supplies;
106 	struct gpio_desc *reset;
107 	unsigned int sleep_delay;
108 };
109 
110 static inline struct st7701 *panel_to_st7701(struct drm_panel *panel)
111 {
112 	return container_of(panel, struct st7701, panel);
113 }
114 
115 static inline int st7701_dsi_write(struct st7701 *st7701, const void *seq,
116 				   size_t len)
117 {
118 	return mipi_dsi_dcs_write_buffer(st7701->dsi, seq, len);
119 }
120 
121 #define ST7701_DSI(st7701, seq...)				\
122 	{							\
123 		const u8 d[] = { seq };				\
124 		st7701_dsi_write(st7701, d, ARRAY_SIZE(d));	\
125 	}
126 
127 static void st7701_init_sequence(struct st7701 *st7701)
128 {
129 	const struct drm_display_mode *mode = st7701->desc->mode;
130 
131 	ST7701_DSI(st7701, MIPI_DCS_SOFT_RESET, 0x00);
132 
133 	/* We need to wait 5ms before sending new commands */
134 	msleep(5);
135 
136 	ST7701_DSI(st7701, MIPI_DCS_EXIT_SLEEP_MODE, 0x00);
137 
138 	msleep(st7701->sleep_delay);
139 
140 	/* Command2, BK0 */
141 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
142 		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BK0_SEL);
143 	ST7701_DSI(st7701, DSI_CMD2_BK0_PVGAMCTRL, 0x00, 0x0E, 0x15, 0x0F,
144 		   0x11, 0x08, 0x08, 0x08, 0x08, 0x23, 0x04, 0x13, 0x12,
145 		   0x2B, 0x34, 0x1F);
146 	ST7701_DSI(st7701, DSI_CMD2_BK0_NVGAMCTRL, 0x00, 0x0E, 0x95, 0x0F,
147 		   0x13, 0x07, 0x09, 0x08, 0x08, 0x22, 0x04, 0x10, 0x0E,
148 		   0x2C, 0x34, 0x1F);
149 	ST7701_DSI(st7701, DSI_CMD2_BK0_LNESET,
150 		   DSI_CMD2_BK0_LNESET_B0, DSI_CMD2_BK0_LNESET_B1);
151 	ST7701_DSI(st7701, DSI_CMD2_BK0_PORCTRL,
152 		   DSI_CMD2_BK0_PORCTRL_B0(mode),
153 		   DSI_CMD2_BK0_PORCTRL_B1(mode));
154 	ST7701_DSI(st7701, DSI_CMD2_BK0_INVSEL,
155 		   DSI_CMD2_BK0_INVSEL_B0, DSI_CMD2_BK0_INVSEL_B1);
156 
157 	/* Command2, BK1 */
158 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
159 			0x77, 0x01, 0x00, 0x00, DSI_CMD2BK1_SEL);
160 	ST7701_DSI(st7701, DSI_CMD2_BK1_VRHS, DSI_CMD2_BK1_VRHA_SET);
161 	ST7701_DSI(st7701, DSI_CMD2_BK1_VCOM, DSI_CMD2_BK1_VCOM_SET);
162 	ST7701_DSI(st7701, DSI_CMD2_BK1_VGHSS, DSI_CMD2_BK1_VGHSS_SET);
163 	ST7701_DSI(st7701, DSI_CMD2_BK1_TESTCMD, DSI_CMD2_BK1_TESTCMD_VAL);
164 	ST7701_DSI(st7701, DSI_CMD2_BK1_VGLS, DSI_CMD2_BK1_VGLS_SET);
165 	ST7701_DSI(st7701, DSI_CMD2_BK1_PWCTLR1, DSI_CMD2_BK1_PWCTLR1_SET);
166 	ST7701_DSI(st7701, DSI_CMD2_BK1_PWCTLR2, DSI_CMD2_BK1_PWCTLR2_SET);
167 	ST7701_DSI(st7701, DSI_CMD2_BK1_SPD1, DSI_CMD2_BK1_SPD1_SET);
168 	ST7701_DSI(st7701, DSI_CMD2_BK1_SPD2, DSI_CMD2_BK1_SPD2_SET);
169 	ST7701_DSI(st7701, DSI_CMD2_BK1_MIPISET1, DSI_CMD2_BK1_MIPISET1_SET);
170 
171 	/**
172 	 * ST7701_SPEC_V1.2 is unable to provide enough information above this
173 	 * specific command sequence, so grab the same from vendor BSP driver.
174 	 */
175 	ST7701_DSI(st7701, 0xE0, 0x00, 0x00, 0x02);
176 	ST7701_DSI(st7701, 0xE1, 0x0B, 0x00, 0x0D, 0x00, 0x0C, 0x00, 0x0E,
177 		   0x00, 0x00, 0x44, 0x44);
178 	ST7701_DSI(st7701, 0xE2, 0x33, 0x33, 0x44, 0x44, 0x64, 0x00, 0x66,
179 		   0x00, 0x65, 0x00, 0x67, 0x00, 0x00);
180 	ST7701_DSI(st7701, 0xE3, 0x00, 0x00, 0x33, 0x33);
181 	ST7701_DSI(st7701, 0xE4, 0x44, 0x44);
182 	ST7701_DSI(st7701, 0xE5, 0x0C, 0x78, 0x3C, 0xA0, 0x0E, 0x78, 0x3C,
183 		   0xA0, 0x10, 0x78, 0x3C, 0xA0, 0x12, 0x78, 0x3C, 0xA0);
184 	ST7701_DSI(st7701, 0xE6, 0x00, 0x00, 0x33, 0x33);
185 	ST7701_DSI(st7701, 0xE7, 0x44, 0x44);
186 	ST7701_DSI(st7701, 0xE8, 0x0D, 0x78, 0x3C, 0xA0, 0x0F, 0x78, 0x3C,
187 		   0xA0, 0x11, 0x78, 0x3C, 0xA0, 0x13, 0x78, 0x3C, 0xA0);
188 	ST7701_DSI(st7701, 0xEB, 0x02, 0x02, 0x39, 0x39, 0xEE, 0x44, 0x00);
189 	ST7701_DSI(st7701, 0xEC, 0x00, 0x00);
190 	ST7701_DSI(st7701, 0xED, 0xFF, 0xF1, 0x04, 0x56, 0x72, 0x3F, 0xFF,
191 		   0xFF, 0xFF, 0xFF, 0xF3, 0x27, 0x65, 0x40, 0x1F, 0xFF);
192 
193 	/* disable Command2 */
194 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
195 		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BKX_SEL_NONE);
196 }
197 
198 static int st7701_prepare(struct drm_panel *panel)
199 {
200 	struct st7701 *st7701 = panel_to_st7701(panel);
201 	int ret;
202 
203 	gpiod_set_value(st7701->reset, 0);
204 
205 	ret = regulator_bulk_enable(st7701->desc->num_supplies,
206 				    st7701->supplies);
207 	if (ret < 0)
208 		return ret;
209 	msleep(20);
210 
211 	gpiod_set_value(st7701->reset, 1);
212 	msleep(150);
213 
214 	st7701_init_sequence(st7701);
215 
216 	return 0;
217 }
218 
219 static int st7701_enable(struct drm_panel *panel)
220 {
221 	struct st7701 *st7701 = panel_to_st7701(panel);
222 
223 	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_ON, 0x00);
224 
225 	return 0;
226 }
227 
228 static int st7701_disable(struct drm_panel *panel)
229 {
230 	struct st7701 *st7701 = panel_to_st7701(panel);
231 
232 	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_OFF, 0x00);
233 
234 	return 0;
235 }
236 
237 static int st7701_unprepare(struct drm_panel *panel)
238 {
239 	struct st7701 *st7701 = panel_to_st7701(panel);
240 
241 	ST7701_DSI(st7701, MIPI_DCS_ENTER_SLEEP_MODE, 0x00);
242 
243 	msleep(st7701->sleep_delay);
244 
245 	gpiod_set_value(st7701->reset, 0);
246 
247 	/**
248 	 * During the Resetting period, the display will be blanked
249 	 * (The display is entering blanking sequence, which maximum
250 	 * time is 120 ms, when Reset Starts in Sleep Out –mode. The
251 	 * display remains the blank state in Sleep In –mode.) and
252 	 * then return to Default condition for Hardware Reset.
253 	 *
254 	 * So we need wait sleep_delay time to make sure reset completed.
255 	 */
256 	msleep(st7701->sleep_delay);
257 
258 	regulator_bulk_disable(st7701->desc->num_supplies, st7701->supplies);
259 
260 	return 0;
261 }
262 
263 static int st7701_get_modes(struct drm_panel *panel,
264 			    struct drm_connector *connector)
265 {
266 	struct st7701 *st7701 = panel_to_st7701(panel);
267 	const struct drm_display_mode *desc_mode = st7701->desc->mode;
268 	struct drm_display_mode *mode;
269 
270 	mode = drm_mode_duplicate(connector->dev, desc_mode);
271 	if (!mode) {
272 		DRM_DEV_ERROR(&st7701->dsi->dev,
273 			      "failed to add mode %ux%ux@%u\n",
274 			      desc_mode->hdisplay, desc_mode->vdisplay,
275 			      desc_mode->vrefresh);
276 		return -ENOMEM;
277 	}
278 
279 	drm_mode_set_name(mode);
280 	drm_mode_probed_add(connector, mode);
281 
282 	connector->display_info.width_mm = desc_mode->width_mm;
283 	connector->display_info.height_mm = desc_mode->height_mm;
284 
285 	return 1;
286 }
287 
288 static const struct drm_panel_funcs st7701_funcs = {
289 	.disable	= st7701_disable,
290 	.unprepare	= st7701_unprepare,
291 	.prepare	= st7701_prepare,
292 	.enable		= st7701_enable,
293 	.get_modes	= st7701_get_modes,
294 };
295 
296 static const struct drm_display_mode ts8550b_mode = {
297 	.clock		= 27500,
298 
299 	.hdisplay	= 480,
300 	.hsync_start	= 480 + 38,
301 	.hsync_end	= 480 + 38 + 12,
302 	.htotal		= 480 + 38 + 12 + 12,
303 
304 	.vdisplay	= 854,
305 	.vsync_start	= 854 + 18,
306 	.vsync_end	= 854 + 18 + 8,
307 	.vtotal		= 854 + 18 + 8 + 4,
308 
309 	.width_mm	= 69,
310 	.height_mm	= 139,
311 
312 	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
313 };
314 
315 static const char * const ts8550b_supply_names[] = {
316 	"VCC",
317 	"IOVCC",
318 };
319 
320 static const struct st7701_panel_desc ts8550b_desc = {
321 	.mode = &ts8550b_mode,
322 	.lanes = 2,
323 	.flags = MIPI_DSI_MODE_VIDEO,
324 	.format = MIPI_DSI_FMT_RGB888,
325 	.supply_names = ts8550b_supply_names,
326 	.num_supplies = ARRAY_SIZE(ts8550b_supply_names),
327 	.panel_sleep_delay = 80, /* panel need extra 80ms for sleep out cmd */
328 };
329 
330 static int st7701_dsi_probe(struct mipi_dsi_device *dsi)
331 {
332 	const struct st7701_panel_desc *desc;
333 	struct st7701 *st7701;
334 	int ret, i;
335 
336 	st7701 = devm_kzalloc(&dsi->dev, sizeof(*st7701), GFP_KERNEL);
337 	if (!st7701)
338 		return -ENOMEM;
339 
340 	desc = of_device_get_match_data(&dsi->dev);
341 	dsi->mode_flags = desc->flags;
342 	dsi->format = desc->format;
343 	dsi->lanes = desc->lanes;
344 
345 	st7701->supplies = devm_kcalloc(&dsi->dev, desc->num_supplies,
346 					sizeof(*st7701->supplies),
347 					GFP_KERNEL);
348 	if (!st7701->supplies)
349 		return -ENOMEM;
350 
351 	for (i = 0; i < desc->num_supplies; i++)
352 		st7701->supplies[i].supply = desc->supply_names[i];
353 
354 	ret = devm_regulator_bulk_get(&dsi->dev, desc->num_supplies,
355 				      st7701->supplies);
356 	if (ret < 0)
357 		return ret;
358 
359 	st7701->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
360 	if (IS_ERR(st7701->reset)) {
361 		DRM_DEV_ERROR(&dsi->dev, "Couldn't get our reset GPIO\n");
362 		return PTR_ERR(st7701->reset);
363 	}
364 
365 	drm_panel_init(&st7701->panel, &dsi->dev, &st7701_funcs,
366 		       DRM_MODE_CONNECTOR_DSI);
367 
368 	/**
369 	 * Once sleep out has been issued, ST7701 IC required to wait 120ms
370 	 * before initiating new commands.
371 	 *
372 	 * On top of that some panels might need an extra delay to wait, so
373 	 * add panel specific delay for those cases. As now this panel specific
374 	 * delay information is referenced from those panel BSP driver, example
375 	 * ts8550b and there is no valid documentation for that.
376 	 */
377 	st7701->sleep_delay = 120 + desc->panel_sleep_delay;
378 
379 	ret = drm_panel_of_backlight(&st7701->panel);
380 	if (ret)
381 		return ret;
382 
383 	ret = drm_panel_add(&st7701->panel);
384 	if (ret < 0)
385 		return ret;
386 
387 	mipi_dsi_set_drvdata(dsi, st7701);
388 	st7701->dsi = dsi;
389 	st7701->desc = desc;
390 
391 	return mipi_dsi_attach(dsi);
392 }
393 
394 static int st7701_dsi_remove(struct mipi_dsi_device *dsi)
395 {
396 	struct st7701 *st7701 = mipi_dsi_get_drvdata(dsi);
397 
398 	mipi_dsi_detach(dsi);
399 	drm_panel_remove(&st7701->panel);
400 
401 	return 0;
402 }
403 
404 static const struct of_device_id st7701_of_match[] = {
405 	{ .compatible = "techstar,ts8550b", .data = &ts8550b_desc },
406 	{ }
407 };
408 MODULE_DEVICE_TABLE(of, st7701_of_match);
409 
410 static struct mipi_dsi_driver st7701_dsi_driver = {
411 	.probe		= st7701_dsi_probe,
412 	.remove		= st7701_dsi_remove,
413 	.driver = {
414 		.name		= "st7701",
415 		.of_match_table	= st7701_of_match,
416 	},
417 };
418 module_mipi_dsi_driver(st7701_dsi_driver);
419 
420 MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
421 MODULE_DESCRIPTION("Sitronix ST7701 LCD Panel Driver");
422 MODULE_LICENSE("GPL");
423