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/backlight.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/delay.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/regulator/consumer.h>
18 
19 #include <video/mipi_display.h>
20 
21 /* Command2 BKx selection command */
22 #define DSI_CMD2BKX_SEL			0xFF
23 
24 /* Command2, BK0 commands */
25 #define DSI_CMD2_BK0_PVGAMCTRL		0xB0 /* Positive Voltage Gamma Control */
26 #define DSI_CMD2_BK0_NVGAMCTRL		0xB1 /* Negative Voltage Gamma Control */
27 #define DSI_CMD2_BK0_LNESET		0xC0 /* Display Line setting */
28 #define DSI_CMD2_BK0_PORCTRL		0xC1 /* Porch control */
29 #define DSI_CMD2_BK0_INVSEL		0xC2 /* Inversion selection, Frame Rate Control */
30 
31 /* Command2, BK1 commands */
32 #define DSI_CMD2_BK1_VRHS		0xB0 /* Vop amplitude setting */
33 #define DSI_CMD2_BK1_VCOM		0xB1 /* VCOM amplitude setting */
34 #define DSI_CMD2_BK1_VGHSS		0xB2 /* VGH Voltage setting */
35 #define DSI_CMD2_BK1_TESTCMD		0xB3 /* TEST Command Setting */
36 #define DSI_CMD2_BK1_VGLS		0xB5 /* VGL Voltage setting */
37 #define DSI_CMD2_BK1_PWCTLR1		0xB7 /* Power Control 1 */
38 #define DSI_CMD2_BK1_PWCTLR2		0xB8 /* Power Control 2 */
39 #define DSI_CMD2_BK1_SPD1		0xC1 /* Source pre_drive timing set1 */
40 #define DSI_CMD2_BK1_SPD2		0xC2 /* Source EQ2 Setting */
41 #define DSI_CMD2_BK1_MIPISET1		0xD0 /* MIPI Setting 1 */
42 
43 /**
44  * Command2 with BK function selection.
45  *
46  * BIT[4, 0]: [CN2, BKXSEL]
47  * 10 = CMD2BK0, Command2 BK0
48  * 11 = CMD2BK1, Command2 BK1
49  * 00 = Command2 disable
50  */
51 #define DSI_CMD2BK1_SEL			0x11
52 #define DSI_CMD2BK0_SEL			0x10
53 #define DSI_CMD2BKX_SEL_NONE		0x00
54 
55 /* Command2, BK0 bytes */
56 #define DSI_LINESET_LINE		0x69
57 #define DSI_LINESET_LDE_EN		BIT(7)
58 #define DSI_LINESET_LINEDELTA		GENMASK(1, 0)
59 #define DSI_CMD2_BK0_LNESET_B1		DSI_LINESET_LINEDELTA
60 #define DSI_CMD2_BK0_LNESET_B0		(DSI_LINESET_LDE_EN | DSI_LINESET_LINE)
61 #define DSI_INVSEL_DEFAULT		GENMASK(5, 4)
62 #define DSI_INVSEL_NLINV		GENMASK(2, 0)
63 #define DSI_INVSEL_RTNI			GENMASK(2, 1)
64 #define DSI_CMD2_BK0_INVSEL_B1		DSI_INVSEL_RTNI
65 #define DSI_CMD2_BK0_INVSEL_B0		(DSI_INVSEL_DEFAULT | DSI_INVSEL_NLINV)
66 #define DSI_CMD2_BK0_PORCTRL_B0(m)	((m)->vtotal - (m)->vsync_end)
67 #define DSI_CMD2_BK0_PORCTRL_B1(m)	((m)->vsync_start - (m)->vdisplay)
68 
69 /* Command2, BK1 bytes */
70 #define DSI_CMD2_BK1_VRHA_SET		0x45
71 #define DSI_CMD2_BK1_VCOM_SET		0x13
72 #define DSI_CMD2_BK1_VGHSS_SET		GENMASK(2, 0)
73 #define DSI_CMD2_BK1_TESTCMD_VAL	BIT(7)
74 #define DSI_VGLS_DEFAULT		BIT(6)
75 #define DSI_VGLS_SEL			GENMASK(2, 0)
76 #define DSI_CMD2_BK1_VGLS_SET		(DSI_VGLS_DEFAULT | DSI_VGLS_SEL)
77 #define DSI_PWCTLR1_AP			BIT(7) /* Gamma OP bias, max */
78 #define DSI_PWCTLR1_APIS		BIT(2) /* Source OP input bias, min */
79 #define DSI_PWCTLR1_APOS		BIT(0) /* Source OP output bias, min */
80 #define DSI_CMD2_BK1_PWCTLR1_SET	(DSI_PWCTLR1_AP | DSI_PWCTLR1_APIS | \
81 					DSI_PWCTLR1_APOS)
82 #define DSI_PWCTLR2_AVDD		BIT(5) /* AVDD 6.6v */
83 #define DSI_PWCTLR2_AVCL		0x0    /* AVCL -4.4v */
84 #define DSI_CMD2_BK1_PWCTLR2_SET	(DSI_PWCTLR2_AVDD | DSI_PWCTLR2_AVCL)
85 #define DSI_SPD1_T2D			BIT(3)
86 #define DSI_CMD2_BK1_SPD1_SET		(GENMASK(6, 4) | DSI_SPD1_T2D)
87 #define DSI_CMD2_BK1_SPD2_SET		DSI_CMD2_BK1_SPD1_SET
88 #define DSI_MIPISET1_EOT_EN		BIT(3)
89 #define DSI_CMD2_BK1_MIPISET1_SET	(BIT(7) | DSI_MIPISET1_EOT_EN)
90 
91 struct st7701_panel_desc {
92 	const struct drm_display_mode *mode;
93 	unsigned int lanes;
94 	unsigned long flags;
95 	enum mipi_dsi_pixel_format format;
96 	const char *const *supply_names;
97 	unsigned int num_supplies;
98 	unsigned int panel_sleep_delay;
99 };
100 
101 struct st7701 {
102 	struct drm_panel panel;
103 	struct mipi_dsi_device *dsi;
104 	const struct st7701_panel_desc *desc;
105 
106 	struct backlight_device *backlight;
107 	struct regulator_bulk_data *supplies;
108 	struct gpio_desc *reset;
109 	unsigned int sleep_delay;
110 };
111 
112 static inline struct st7701 *panel_to_st7701(struct drm_panel *panel)
113 {
114 	return container_of(panel, struct st7701, panel);
115 }
116 
117 static inline int st7701_dsi_write(struct st7701 *st7701, const void *seq,
118 				   size_t len)
119 {
120 	return mipi_dsi_dcs_write_buffer(st7701->dsi, seq, len);
121 }
122 
123 #define ST7701_DSI(st7701, seq...)				\
124 	{							\
125 		const u8 d[] = { seq };				\
126 		st7701_dsi_write(st7701, d, ARRAY_SIZE(d));	\
127 	}
128 
129 static void st7701_init_sequence(struct st7701 *st7701)
130 {
131 	const struct drm_display_mode *mode = st7701->desc->mode;
132 
133 	ST7701_DSI(st7701, MIPI_DCS_SOFT_RESET, 0x00);
134 
135 	/* We need to wait 5ms before sending new commands */
136 	msleep(5);
137 
138 	ST7701_DSI(st7701, MIPI_DCS_EXIT_SLEEP_MODE, 0x00);
139 
140 	msleep(st7701->sleep_delay);
141 
142 	/* Command2, BK0 */
143 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
144 		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BK0_SEL);
145 	ST7701_DSI(st7701, DSI_CMD2_BK0_PVGAMCTRL, 0x00, 0x0E, 0x15, 0x0F,
146 		   0x11, 0x08, 0x08, 0x08, 0x08, 0x23, 0x04, 0x13, 0x12,
147 		   0x2B, 0x34, 0x1F);
148 	ST7701_DSI(st7701, DSI_CMD2_BK0_NVGAMCTRL, 0x00, 0x0E, 0x95, 0x0F,
149 		   0x13, 0x07, 0x09, 0x08, 0x08, 0x22, 0x04, 0x10, 0x0E,
150 		   0x2C, 0x34, 0x1F);
151 	ST7701_DSI(st7701, DSI_CMD2_BK0_LNESET,
152 		   DSI_CMD2_BK0_LNESET_B0, DSI_CMD2_BK0_LNESET_B1);
153 	ST7701_DSI(st7701, DSI_CMD2_BK0_PORCTRL,
154 		   DSI_CMD2_BK0_PORCTRL_B0(mode),
155 		   DSI_CMD2_BK0_PORCTRL_B1(mode));
156 	ST7701_DSI(st7701, DSI_CMD2_BK0_INVSEL,
157 		   DSI_CMD2_BK0_INVSEL_B0, DSI_CMD2_BK0_INVSEL_B1);
158 
159 	/* Command2, BK1 */
160 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
161 			0x77, 0x01, 0x00, 0x00, DSI_CMD2BK1_SEL);
162 	ST7701_DSI(st7701, DSI_CMD2_BK1_VRHS, DSI_CMD2_BK1_VRHA_SET);
163 	ST7701_DSI(st7701, DSI_CMD2_BK1_VCOM, DSI_CMD2_BK1_VCOM_SET);
164 	ST7701_DSI(st7701, DSI_CMD2_BK1_VGHSS, DSI_CMD2_BK1_VGHSS_SET);
165 	ST7701_DSI(st7701, DSI_CMD2_BK1_TESTCMD, DSI_CMD2_BK1_TESTCMD_VAL);
166 	ST7701_DSI(st7701, DSI_CMD2_BK1_VGLS, DSI_CMD2_BK1_VGLS_SET);
167 	ST7701_DSI(st7701, DSI_CMD2_BK1_PWCTLR1, DSI_CMD2_BK1_PWCTLR1_SET);
168 	ST7701_DSI(st7701, DSI_CMD2_BK1_PWCTLR2, DSI_CMD2_BK1_PWCTLR2_SET);
169 	ST7701_DSI(st7701, DSI_CMD2_BK1_SPD1, DSI_CMD2_BK1_SPD1_SET);
170 	ST7701_DSI(st7701, DSI_CMD2_BK1_SPD2, DSI_CMD2_BK1_SPD2_SET);
171 	ST7701_DSI(st7701, DSI_CMD2_BK1_MIPISET1, DSI_CMD2_BK1_MIPISET1_SET);
172 
173 	/**
174 	 * ST7701_SPEC_V1.2 is unable to provide enough information above this
175 	 * specific command sequence, so grab the same from vendor BSP driver.
176 	 */
177 	ST7701_DSI(st7701, 0xE0, 0x00, 0x00, 0x02);
178 	ST7701_DSI(st7701, 0xE1, 0x0B, 0x00, 0x0D, 0x00, 0x0C, 0x00, 0x0E,
179 		   0x00, 0x00, 0x44, 0x44);
180 	ST7701_DSI(st7701, 0xE2, 0x33, 0x33, 0x44, 0x44, 0x64, 0x00, 0x66,
181 		   0x00, 0x65, 0x00, 0x67, 0x00, 0x00);
182 	ST7701_DSI(st7701, 0xE3, 0x00, 0x00, 0x33, 0x33);
183 	ST7701_DSI(st7701, 0xE4, 0x44, 0x44);
184 	ST7701_DSI(st7701, 0xE5, 0x0C, 0x78, 0x3C, 0xA0, 0x0E, 0x78, 0x3C,
185 		   0xA0, 0x10, 0x78, 0x3C, 0xA0, 0x12, 0x78, 0x3C, 0xA0);
186 	ST7701_DSI(st7701, 0xE6, 0x00, 0x00, 0x33, 0x33);
187 	ST7701_DSI(st7701, 0xE7, 0x44, 0x44);
188 	ST7701_DSI(st7701, 0xE8, 0x0D, 0x78, 0x3C, 0xA0, 0x0F, 0x78, 0x3C,
189 		   0xA0, 0x11, 0x78, 0x3C, 0xA0, 0x13, 0x78, 0x3C, 0xA0);
190 	ST7701_DSI(st7701, 0xEB, 0x02, 0x02, 0x39, 0x39, 0xEE, 0x44, 0x00);
191 	ST7701_DSI(st7701, 0xEC, 0x00, 0x00);
192 	ST7701_DSI(st7701, 0xED, 0xFF, 0xF1, 0x04, 0x56, 0x72, 0x3F, 0xFF,
193 		   0xFF, 0xFF, 0xFF, 0xF3, 0x27, 0x65, 0x40, 0x1F, 0xFF);
194 
195 	/* disable Command2 */
196 	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
197 		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BKX_SEL_NONE);
198 }
199 
200 static int st7701_prepare(struct drm_panel *panel)
201 {
202 	struct st7701 *st7701 = panel_to_st7701(panel);
203 	int ret;
204 
205 	gpiod_set_value(st7701->reset, 0);
206 
207 	ret = regulator_bulk_enable(st7701->desc->num_supplies,
208 				    st7701->supplies);
209 	if (ret < 0)
210 		return ret;
211 	msleep(20);
212 
213 	gpiod_set_value(st7701->reset, 1);
214 	msleep(150);
215 
216 	st7701_init_sequence(st7701);
217 
218 	return 0;
219 }
220 
221 static int st7701_enable(struct drm_panel *panel)
222 {
223 	struct st7701 *st7701 = panel_to_st7701(panel);
224 
225 	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_ON, 0x00);
226 	backlight_enable(st7701->backlight);
227 
228 	return 0;
229 }
230 
231 static int st7701_disable(struct drm_panel *panel)
232 {
233 	struct st7701 *st7701 = panel_to_st7701(panel);
234 
235 	backlight_disable(st7701->backlight);
236 	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_OFF, 0x00);
237 
238 	return 0;
239 }
240 
241 static int st7701_unprepare(struct drm_panel *panel)
242 {
243 	struct st7701 *st7701 = panel_to_st7701(panel);
244 
245 	ST7701_DSI(st7701, MIPI_DCS_ENTER_SLEEP_MODE, 0x00);
246 
247 	msleep(st7701->sleep_delay);
248 
249 	gpiod_set_value(st7701->reset, 0);
250 
251 	/**
252 	 * During the Resetting period, the display will be blanked
253 	 * (The display is entering blanking sequence, which maximum
254 	 * time is 120 ms, when Reset Starts in Sleep Out –mode. The
255 	 * display remains the blank state in Sleep In –mode.) and
256 	 * then return to Default condition for Hardware Reset.
257 	 *
258 	 * So we need wait sleep_delay time to make sure reset completed.
259 	 */
260 	msleep(st7701->sleep_delay);
261 
262 	regulator_bulk_disable(st7701->desc->num_supplies, st7701->supplies);
263 
264 	return 0;
265 }
266 
267 static int st7701_get_modes(struct drm_panel *panel)
268 {
269 	struct st7701 *st7701 = panel_to_st7701(panel);
270 	const struct drm_display_mode *desc_mode = st7701->desc->mode;
271 	struct drm_display_mode *mode;
272 
273 	mode = drm_mode_duplicate(panel->drm, desc_mode);
274 	if (!mode) {
275 		DRM_DEV_ERROR(&st7701->dsi->dev,
276 			      "failed to add mode %ux%ux@%u\n",
277 			      desc_mode->hdisplay, desc_mode->vdisplay,
278 			      desc_mode->vrefresh);
279 		return -ENOMEM;
280 	}
281 
282 	drm_mode_set_name(mode);
283 	drm_mode_probed_add(panel->connector, mode);
284 
285 	panel->connector->display_info.width_mm = desc_mode->width_mm;
286 	panel->connector->display_info.height_mm = desc_mode->height_mm;
287 
288 	return 1;
289 }
290 
291 static const struct drm_panel_funcs st7701_funcs = {
292 	.disable	= st7701_disable,
293 	.unprepare	= st7701_unprepare,
294 	.prepare	= st7701_prepare,
295 	.enable		= st7701_enable,
296 	.get_modes	= st7701_get_modes,
297 };
298 
299 static const struct drm_display_mode ts8550b_mode = {
300 	.clock		= 27500,
301 
302 	.hdisplay	= 480,
303 	.hsync_start	= 480 + 38,
304 	.hsync_end	= 480 + 38 + 12,
305 	.htotal		= 480 + 38 + 12 + 12,
306 
307 	.vdisplay	= 854,
308 	.vsync_start	= 854 + 18,
309 	.vsync_end	= 854 + 18 + 8,
310 	.vtotal		= 854 + 18 + 8 + 4,
311 
312 	.width_mm	= 69,
313 	.height_mm	= 139,
314 
315 	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
316 };
317 
318 static const char * const ts8550b_supply_names[] = {
319 	"VCC",
320 	"IOVCC",
321 };
322 
323 static const struct st7701_panel_desc ts8550b_desc = {
324 	.mode = &ts8550b_mode,
325 	.lanes = 2,
326 	.flags = MIPI_DSI_MODE_VIDEO,
327 	.format = MIPI_DSI_FMT_RGB888,
328 	.supply_names = ts8550b_supply_names,
329 	.num_supplies = ARRAY_SIZE(ts8550b_supply_names),
330 	.panel_sleep_delay = 80, /* panel need extra 80ms for sleep out cmd */
331 };
332 
333 static int st7701_dsi_probe(struct mipi_dsi_device *dsi)
334 {
335 	const struct st7701_panel_desc *desc;
336 	struct st7701 *st7701;
337 	int ret, i;
338 
339 	st7701 = devm_kzalloc(&dsi->dev, sizeof(*st7701), GFP_KERNEL);
340 	if (!st7701)
341 		return -ENOMEM;
342 
343 	desc = of_device_get_match_data(&dsi->dev);
344 	dsi->mode_flags = desc->flags;
345 	dsi->format = desc->format;
346 	dsi->lanes = desc->lanes;
347 
348 	st7701->supplies = devm_kcalloc(&dsi->dev, desc->num_supplies,
349 					sizeof(*st7701->supplies),
350 					GFP_KERNEL);
351 	if (!st7701->supplies)
352 		return -ENOMEM;
353 
354 	for (i = 0; i < desc->num_supplies; i++)
355 		st7701->supplies[i].supply = desc->supply_names[i];
356 
357 	ret = devm_regulator_bulk_get(&dsi->dev, desc->num_supplies,
358 				      st7701->supplies);
359 	if (ret < 0)
360 		return ret;
361 
362 	st7701->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
363 	if (IS_ERR(st7701->reset)) {
364 		DRM_DEV_ERROR(&dsi->dev, "Couldn't get our reset GPIO\n");
365 		return PTR_ERR(st7701->reset);
366 	}
367 
368 	st7701->backlight = devm_of_find_backlight(&dsi->dev);
369 	if (IS_ERR(st7701->backlight))
370 		return PTR_ERR(st7701->backlight);
371 
372 	drm_panel_init(&st7701->panel);
373 
374 	/**
375 	 * Once sleep out has been issued, ST7701 IC required to wait 120ms
376 	 * before initiating new commands.
377 	 *
378 	 * On top of that some panels might need an extra delay to wait, so
379 	 * add panel specific delay for those cases. As now this panel specific
380 	 * delay information is referenced from those panel BSP driver, example
381 	 * ts8550b and there is no valid documentation for that.
382 	 */
383 	st7701->sleep_delay = 120 + desc->panel_sleep_delay;
384 	st7701->panel.funcs = &st7701_funcs;
385 	st7701->panel.dev = &dsi->dev;
386 
387 	ret = drm_panel_add(&st7701->panel);
388 	if (ret < 0)
389 		return ret;
390 
391 	mipi_dsi_set_drvdata(dsi, st7701);
392 	st7701->dsi = dsi;
393 	st7701->desc = desc;
394 
395 	return mipi_dsi_attach(dsi);
396 }
397 
398 static int st7701_dsi_remove(struct mipi_dsi_device *dsi)
399 {
400 	struct st7701 *st7701 = mipi_dsi_get_drvdata(dsi);
401 
402 	mipi_dsi_detach(dsi);
403 	drm_panel_remove(&st7701->panel);
404 
405 	return 0;
406 }
407 
408 static const struct of_device_id st7701_of_match[] = {
409 	{ .compatible = "techstar,ts8550b", .data = &ts8550b_desc },
410 	{ }
411 };
412 MODULE_DEVICE_TABLE(of, st7701_of_match);
413 
414 static struct mipi_dsi_driver st7701_dsi_driver = {
415 	.probe		= st7701_dsi_probe,
416 	.remove		= st7701_dsi_remove,
417 	.driver = {
418 		.name		= "st7701",
419 		.of_match_table	= st7701_of_match,
420 	},
421 };
422 module_mipi_dsi_driver(st7701_dsi_driver);
423 
424 MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
425 MODULE_DESCRIPTION("Sitronix ST7701 LCD Panel Driver");
426 MODULE_LICENSE("GPL");
427