summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/tinydrm/st7586.c
blob: 0a2c60da5c0e4b806e8eee167d26bb01bd145954 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/*
 * DRM driver for Sitronix ST7586 panels
 *
 * Copyright 2017 David Lechner <david@lechnology.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/delay.h>
#include <linux/dma-buf.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/spi/spi.h>
#include <video/mipi_display.h>

#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/tinydrm/mipi-dbi.h>
#include <drm/tinydrm/tinydrm-helpers.h>

/* controller-specific commands */
#define ST7586_DISP_MODE_GRAY	0x38
#define ST7586_DISP_MODE_MONO	0x39
#define ST7586_ENABLE_DDRAM	0x3a
#define ST7586_SET_DISP_DUTY	0xb0
#define ST7586_SET_PART_DISP	0xb4
#define ST7586_SET_NLINE_INV	0xb5
#define ST7586_SET_VOP		0xc0
#define ST7586_SET_BIAS_SYSTEM	0xc3
#define ST7586_SET_BOOST_LEVEL	0xc4
#define ST7586_SET_VOP_OFFSET	0xc7
#define ST7586_ENABLE_ANALOG	0xd0
#define ST7586_AUTO_READ_CTRL	0xd7
#define ST7586_OTP_RW_CTRL	0xe0
#define ST7586_OTP_CTRL_OUT	0xe1
#define ST7586_OTP_READ		0xe3

#define ST7586_DISP_CTRL_MX	BIT(6)
#define ST7586_DISP_CTRL_MY	BIT(7)

/*
 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
 * pixel using only 2 bits.
 *
 * |  D7  |  D6  |  D5  ||      |      || 2bpp |
 * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
 * +------+------+------++------+------++------+
 * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
 * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
 * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
 * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
 */

static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };

static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
				       struct drm_framebuffer *fb,
				       struct drm_clip_rect *clip)
{
	size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
	unsigned int x, y;
	u8 *src, *buf, val;

	buf = kmalloc(len, GFP_KERNEL);
	if (!buf)
		return;

	tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
	src = buf;

	for (y = clip->y1; y < clip->y2; y++) {
		for (x = clip->x1; x < clip->x2; x += 3) {
			val = st7586_lookup[*src++ >> 6] << 5;
			val |= st7586_lookup[*src++ >> 6] << 2;
			val |= st7586_lookup[*src++ >> 6] >> 1;
			*dst++ = val;
		}
	}

	kfree(buf);
}

static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
			   struct drm_clip_rect *clip)
{
	struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
	struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
	void *src = cma_obj->vaddr;
	int ret = 0;

	if (import_attach) {
		ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
					       DMA_FROM_DEVICE);
		if (ret)
			return ret;
	}

	st7586_xrgb8888_to_gray332(dst, src, fb, clip);

	if (import_attach)
		ret = dma_buf_end_cpu_access(import_attach->dmabuf,
					     DMA_FROM_DEVICE);

	return ret;
}

static int st7586_fb_dirty(struct drm_framebuffer *fb,
			   struct drm_file *file_priv, unsigned int flags,
			   unsigned int color, struct drm_clip_rect *clips,
			   unsigned int num_clips)
{
	struct tinydrm_device *tdev = fb->dev->dev_private;
	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
	struct drm_clip_rect clip;
	int start, end;
	int ret = 0;

	mutex_lock(&tdev->dirty_lock);

	if (!mipi->enabled)
		goto out_unlock;

	/* fbdev can flush even when we're not interested */
	if (tdev->pipe.plane.fb != fb)
		goto out_unlock;

	tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
			    fb->height);

	/* 3 pixels per byte, so grow clip to nearest multiple of 3 */
	clip.x1 = rounddown(clip.x1, 3);
	clip.x2 = roundup(clip.x2, 3);

	DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
		  clip.x1, clip.x2, clip.y1, clip.y2);

	ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
	if (ret)
		goto out_unlock;

	/* Pixels are packed 3 per byte */
	start = clip.x1 / 3;
	end = clip.x2 / 3;

	mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
			 (start >> 8) & 0xFF, start & 0xFF,
			 (end >> 8) & 0xFF, (end - 1) & 0xFF);
	mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
			 (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
			 (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);

	ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
				   (u8 *)mipi->tx_buf,
				   (end - start) * (clip.y2 - clip.y1));

out_unlock:
	mutex_unlock(&tdev->dirty_lock);

	if (ret)
		dev_err_once(fb->dev->dev, "Failed to update display %d\n",
			     ret);

	return ret;
}

static const struct drm_framebuffer_funcs st7586_fb_funcs = {
	.destroy	= drm_gem_fb_destroy,
	.create_handle	= drm_gem_fb_create_handle,
	.dirty		= st7586_fb_dirty,
};

static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
			       struct drm_crtc_state *crtc_state)
{
	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
	struct drm_framebuffer *fb = pipe->plane.fb;
	struct device *dev = tdev->drm->dev;
	int ret;
	u8 addr_mode;

	DRM_DEBUG_KMS("\n");

	mipi_dbi_hw_reset(mipi);
	ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
	if (ret) {
		DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
		return;
	}

	mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);

	msleep(10);

	mipi_dbi_command(mipi, ST7586_OTP_READ);

	msleep(20);

	mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
	mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);

	msleep(50);

	mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
	mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
	mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
	mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
	mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
	mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
	mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
	mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);

	switch (mipi->rotation) {
	default:
		addr_mode = 0x00;
		break;
	case 90:
		addr_mode = ST7586_DISP_CTRL_MY;
		break;
	case 180:
		addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
		break;
	case 270:
		addr_mode = ST7586_DISP_CTRL_MX;
		break;
	}
	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);

	mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
	mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
	mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
	mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);

	msleep(100);

	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);

	mipi->enabled = true;

	if (fb)
		fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
}

static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
{
	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);

	DRM_DEBUG_KMS("\n");

	if (!mipi->enabled)
		return;

	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
	mipi->enabled = false;
}

static const u32 st7586_formats[] = {
	DRM_FORMAT_XRGB8888,
};

static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
		const struct drm_simple_display_pipe_funcs *pipe_funcs,
		struct drm_driver *driver, const struct drm_display_mode *mode,
		unsigned int rotation)
{
	size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
	struct tinydrm_device *tdev = &mipi->tinydrm;
	int ret;

	mutex_init(&mipi->cmdlock);

	mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
	if (!mipi->tx_buf)
		return -ENOMEM;

	ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
	if (ret)
		return ret;

	ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
					DRM_MODE_CONNECTOR_VIRTUAL,
					st7586_formats,
					ARRAY_SIZE(st7586_formats),
					mode, rotation);
	if (ret)
		return ret;

	tdev->drm->mode_config.preferred_depth = 32;
	mipi->rotation = rotation;

	drm_mode_config_reset(tdev->drm);

	DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
		      tdev->drm->mode_config.preferred_depth, rotation);

	return 0;
}

static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
	.enable		= st7586_pipe_enable,
	.disable	= st7586_pipe_disable,
	.update		= tinydrm_display_pipe_update,
	.prepare_fb	= tinydrm_display_pipe_prepare_fb,
};

static const struct drm_display_mode st7586_mode = {
	TINYDRM_MODE(178, 128, 37, 27),
};

DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);

static struct drm_driver st7586_driver = {
	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
				  DRIVER_ATOMIC,
	.fops			= &st7586_fops,
	TINYDRM_GEM_DRIVER_OPS,
	.lastclose		= tinydrm_lastclose,
	.debugfs_init		= mipi_dbi_debugfs_init,
	.name			= "st7586",
	.desc			= "Sitronix ST7586",
	.date			= "20170801",
	.major			= 1,
	.minor			= 0,
};

static const struct of_device_id st7586_of_match[] = {
	{ .compatible = "lego,ev3-lcd" },
	{},
};
MODULE_DEVICE_TABLE(of, st7586_of_match);

static const struct spi_device_id st7586_id[] = {
	{ "ev3-lcd", 0 },
	{ },
};
MODULE_DEVICE_TABLE(spi, st7586_id);

static int st7586_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	struct mipi_dbi *mipi;
	struct gpio_desc *a0;
	u32 rotation = 0;
	int ret;

	mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
	if (!mipi)
		return -ENOMEM;

	mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(mipi->reset)) {
		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
		return PTR_ERR(mipi->reset);
	}

	a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
	if (IS_ERR(a0)) {
		DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
		return PTR_ERR(a0);
	}

	device_property_read_u32(dev, "rotation", &rotation);

	ret = mipi_dbi_spi_init(spi, mipi, a0);
	if (ret)
		return ret;

	/* Cannot read from this controller via SPI */
	mipi->read_commands = NULL;

	/*
	 * we are using 8-bit data, so we are not actually swapping anything,
	 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
	 * right thing and not use 16-bit transfers (which results in swapped
	 * bytes on little-endian systems and causes out of order data to be
	 * sent to the display).
	 */
	mipi->swap_bytes = true;

	ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
			  &st7586_mode, rotation);
	if (ret)
		return ret;

	spi_set_drvdata(spi, mipi);

	return devm_tinydrm_register(&mipi->tinydrm);
}

static void st7586_shutdown(struct spi_device *spi)
{
	struct mipi_dbi *mipi = spi_get_drvdata(spi);

	tinydrm_shutdown(&mipi->tinydrm);
}

static struct spi_driver st7586_spi_driver = {
	.driver = {
		.name = "st7586",
		.owner = THIS_MODULE,
		.of_match_table = st7586_of_match,
	},
	.id_table = st7586_id,
	.probe = st7586_probe,
	.shutdown = st7586_shutdown,
};
module_spi_driver(st7586_spi_driver);

MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
MODULE_AUTHOR("David Lechner <david@lechnology.com>");
MODULE_LICENSE("GPL");