xref: /openbmc/linux/drivers/gpu/drm/tiny/st7586.c (revision 3ea44105)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * DRM driver for Sitronix ST7586 panels
4  *
5  * Copyright 2017 David Lechner <david@lechnology.com>
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/module.h>
11 #include <linux/property.h>
12 #include <linux/spi/spi.h>
13 #include <video/mipi_display.h>
14 
15 #include <drm/drm_atomic_helper.h>
16 #include <drm/drm_damage_helper.h>
17 #include <drm/drm_drv.h>
18 #include <drm/drm_fb_dma_helper.h>
19 #include <drm/drm_fbdev_generic.h>
20 #include <drm/drm_format_helper.h>
21 #include <drm/drm_framebuffer.h>
22 #include <drm/drm_gem_atomic_helper.h>
23 #include <drm/drm_gem_dma_helper.h>
24 #include <drm/drm_gem_framebuffer_helper.h>
25 #include <drm/drm_managed.h>
26 #include <drm/drm_mipi_dbi.h>
27 #include <drm/drm_rect.h>
28 
29 /* controller-specific commands */
30 #define ST7586_DISP_MODE_GRAY	0x38
31 #define ST7586_DISP_MODE_MONO	0x39
32 #define ST7586_ENABLE_DDRAM	0x3a
33 #define ST7586_SET_DISP_DUTY	0xb0
34 #define ST7586_SET_PART_DISP	0xb4
35 #define ST7586_SET_NLINE_INV	0xb5
36 #define ST7586_SET_VOP		0xc0
37 #define ST7586_SET_BIAS_SYSTEM	0xc3
38 #define ST7586_SET_BOOST_LEVEL	0xc4
39 #define ST7586_SET_VOP_OFFSET	0xc7
40 #define ST7586_ENABLE_ANALOG	0xd0
41 #define ST7586_AUTO_READ_CTRL	0xd7
42 #define ST7586_OTP_RW_CTRL	0xe0
43 #define ST7586_OTP_CTRL_OUT	0xe1
44 #define ST7586_OTP_READ		0xe3
45 
46 #define ST7586_DISP_CTRL_MX	BIT(6)
47 #define ST7586_DISP_CTRL_MY	BIT(7)
48 
49 /*
50  * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
51  * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
52  * pixel using only 2 bits.
53  *
54  * |  D7  |  D6  |  D5  ||      |      || 2bpp |
55  * | (D4) | (D3) | (D2) ||  D1  |  D0  || GRAY |
56  * +------+------+------++------+------++------+
57  * |  1   |  1   |  1   ||  1   |  1   || 0  0 | black
58  * |  1   |  0   |  0   ||  1   |  0   || 0  1 | dark gray
59  * |  0   |  1   |  0   ||  0   |  1   || 1  0 | light gray
60  * |  0   |  0   |  0   ||  0   |  0   || 1  1 | white
61  */
62 
63 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
64 
st7586_xrgb8888_to_gray332(u8 * dst,void * vaddr,struct drm_framebuffer * fb,struct drm_rect * clip)65 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
66 				       struct drm_framebuffer *fb,
67 				       struct drm_rect *clip)
68 {
69 	size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
70 	unsigned int x, y;
71 	u8 *src, *buf, val;
72 	struct iosys_map dst_map, vmap;
73 
74 	buf = kmalloc(len, GFP_KERNEL);
75 	if (!buf)
76 		return;
77 
78 	iosys_map_set_vaddr(&dst_map, buf);
79 	iosys_map_set_vaddr(&vmap, vaddr);
80 	drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip);
81 	src = buf;
82 
83 	for (y = clip->y1; y < clip->y2; y++) {
84 		for (x = clip->x1; x < clip->x2; x += 3) {
85 			val = st7586_lookup[*src++ >> 6] << 5;
86 			val |= st7586_lookup[*src++ >> 6] << 2;
87 			val |= st7586_lookup[*src++ >> 6] >> 1;
88 			*dst++ = val;
89 		}
90 	}
91 
92 	kfree(buf);
93 }
94 
st7586_buf_copy(void * dst,struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * clip)95 static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
96 			   struct drm_rect *clip)
97 {
98 	int ret;
99 
100 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
101 	if (ret)
102 		return ret;
103 
104 	st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip);
105 
106 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
107 
108 	return 0;
109 }
110 
st7586_fb_dirty(struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * rect)111 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
112 			    struct drm_rect *rect)
113 {
114 	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
115 	struct mipi_dbi *dbi = &dbidev->dbi;
116 	int start, end, ret = 0;
117 
118 	/* 3 pixels per byte, so grow clip to nearest multiple of 3 */
119 	rect->x1 = rounddown(rect->x1, 3);
120 	rect->x2 = roundup(rect->x2, 3);
121 
122 	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
123 
124 	ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect);
125 	if (ret)
126 		goto err_msg;
127 
128 	/* Pixels are packed 3 per byte */
129 	start = rect->x1 / 3;
130 	end = rect->x2 / 3;
131 
132 	mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
133 			 (start >> 8) & 0xFF, start & 0xFF,
134 			 (end >> 8) & 0xFF, (end - 1) & 0xFF);
135 	mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
136 			 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
137 			 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
138 
139 	ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
140 				   (u8 *)dbidev->tx_buf,
141 				   (end - start) * (rect->y2 - rect->y1));
142 err_msg:
143 	if (ret)
144 		dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
145 }
146 
st7586_pipe_update(struct drm_simple_display_pipe * pipe,struct drm_plane_state * old_state)147 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
148 			       struct drm_plane_state *old_state)
149 {
150 	struct drm_plane_state *state = pipe->plane.state;
151 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
152 	struct drm_framebuffer *fb = state->fb;
153 	struct drm_rect rect;
154 	int idx;
155 
156 	if (!pipe->crtc.state->active)
157 		return;
158 
159 	if (!drm_dev_enter(fb->dev, &idx))
160 		return;
161 
162 	if (drm_atomic_helper_damage_merged(old_state, state, &rect))
163 		st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect);
164 
165 	drm_dev_exit(idx);
166 }
167 
st7586_pipe_enable(struct drm_simple_display_pipe * pipe,struct drm_crtc_state * crtc_state,struct drm_plane_state * plane_state)168 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
169 			       struct drm_crtc_state *crtc_state,
170 			       struct drm_plane_state *plane_state)
171 {
172 	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
173 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
174 	struct drm_framebuffer *fb = plane_state->fb;
175 	struct mipi_dbi *dbi = &dbidev->dbi;
176 	struct drm_rect rect = {
177 		.x1 = 0,
178 		.x2 = fb->width,
179 		.y1 = 0,
180 		.y2 = fb->height,
181 	};
182 	int idx, ret;
183 	u8 addr_mode;
184 
185 	if (!drm_dev_enter(pipe->crtc.dev, &idx))
186 		return;
187 
188 	DRM_DEBUG_KMS("\n");
189 
190 	ret = mipi_dbi_poweron_reset(dbidev);
191 	if (ret)
192 		goto out_exit;
193 
194 	mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
195 	mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
196 
197 	msleep(10);
198 
199 	mipi_dbi_command(dbi, ST7586_OTP_READ);
200 
201 	msleep(20);
202 
203 	mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
204 	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
205 	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
206 
207 	msleep(50);
208 
209 	mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
210 	mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
211 	mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
212 	mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
213 	mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
214 	mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
215 	mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
216 	mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
217 
218 	switch (dbidev->rotation) {
219 	default:
220 		addr_mode = 0x00;
221 		break;
222 	case 90:
223 		addr_mode = ST7586_DISP_CTRL_MY;
224 		break;
225 	case 180:
226 		addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
227 		break;
228 	case 270:
229 		addr_mode = ST7586_DISP_CTRL_MX;
230 		break;
231 	}
232 	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
233 
234 	mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
235 	mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
236 	mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
237 	mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
238 
239 	msleep(100);
240 
241 	st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect);
242 
243 	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
244 out_exit:
245 	drm_dev_exit(idx);
246 }
247 
st7586_pipe_disable(struct drm_simple_display_pipe * pipe)248 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
249 {
250 	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
251 
252 	/*
253 	 * This callback is not protected by drm_dev_enter/exit since we want to
254 	 * turn off the display on regular driver unload. It's highly unlikely
255 	 * that the underlying SPI controller is gone should this be called after
256 	 * unplug.
257 	 */
258 
259 	DRM_DEBUG_KMS("\n");
260 
261 	mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
262 }
263 
264 static const u32 st7586_formats[] = {
265 	DRM_FORMAT_XRGB8888,
266 };
267 
268 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
269 	.mode_valid	= mipi_dbi_pipe_mode_valid,
270 	.enable		= st7586_pipe_enable,
271 	.disable	= st7586_pipe_disable,
272 	.update		= st7586_pipe_update,
273 	.begin_fb_access = mipi_dbi_pipe_begin_fb_access,
274 	.end_fb_access	= mipi_dbi_pipe_end_fb_access,
275 	.reset_plane	= mipi_dbi_pipe_reset_plane,
276 	.duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
277 	.destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
278 };
279 
280 static const struct drm_display_mode st7586_mode = {
281 	DRM_SIMPLE_MODE(178, 128, 37, 27),
282 };
283 
284 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
285 
286 static const struct drm_driver st7586_driver = {
287 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
288 	.fops			= &st7586_fops,
289 	DRM_GEM_DMA_DRIVER_OPS_VMAP,
290 	.debugfs_init		= mipi_dbi_debugfs_init,
291 	.name			= "st7586",
292 	.desc			= "Sitronix ST7586",
293 	.date			= "20170801",
294 	.major			= 1,
295 	.minor			= 0,
296 };
297 
298 static const struct of_device_id st7586_of_match[] = {
299 	{ .compatible = "lego,ev3-lcd" },
300 	{},
301 };
302 MODULE_DEVICE_TABLE(of, st7586_of_match);
303 
304 static const struct spi_device_id st7586_id[] = {
305 	{ "ev3-lcd", 0 },
306 	{ },
307 };
308 MODULE_DEVICE_TABLE(spi, st7586_id);
309 
st7586_probe(struct spi_device * spi)310 static int st7586_probe(struct spi_device *spi)
311 {
312 	struct device *dev = &spi->dev;
313 	struct mipi_dbi_dev *dbidev;
314 	struct drm_device *drm;
315 	struct mipi_dbi *dbi;
316 	struct gpio_desc *a0;
317 	u32 rotation = 0;
318 	size_t bufsize;
319 	int ret;
320 
321 	dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
322 				    struct mipi_dbi_dev, drm);
323 	if (IS_ERR(dbidev))
324 		return PTR_ERR(dbidev);
325 
326 	dbi = &dbidev->dbi;
327 	drm = &dbidev->drm;
328 
329 	bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
330 
331 	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
332 	if (IS_ERR(dbi->reset))
333 		return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
334 
335 	a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
336 	if (IS_ERR(a0))
337 		return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
338 
339 	device_property_read_u32(dev, "rotation", &rotation);
340 
341 	ret = mipi_dbi_spi_init(spi, dbi, a0);
342 	if (ret)
343 		return ret;
344 
345 	/* Cannot read from this controller via SPI */
346 	dbi->read_commands = NULL;
347 
348 	ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
349 					     st7586_formats, ARRAY_SIZE(st7586_formats),
350 					     &st7586_mode, rotation, bufsize);
351 	if (ret)
352 		return ret;
353 
354 	/*
355 	 * we are using 8-bit data, so we are not actually swapping anything,
356 	 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
357 	 * right thing and not use 16-bit transfers (which results in swapped
358 	 * bytes on little-endian systems and causes out of order data to be
359 	 * sent to the display).
360 	 */
361 	dbi->swap_bytes = true;
362 
363 	drm_mode_config_reset(drm);
364 
365 	ret = drm_dev_register(drm, 0);
366 	if (ret)
367 		return ret;
368 
369 	spi_set_drvdata(spi, drm);
370 
371 	drm_fbdev_generic_setup(drm, 0);
372 
373 	return 0;
374 }
375 
st7586_remove(struct spi_device * spi)376 static void st7586_remove(struct spi_device *spi)
377 {
378 	struct drm_device *drm = spi_get_drvdata(spi);
379 
380 	drm_dev_unplug(drm);
381 	drm_atomic_helper_shutdown(drm);
382 }
383 
st7586_shutdown(struct spi_device * spi)384 static void st7586_shutdown(struct spi_device *spi)
385 {
386 	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
387 }
388 
389 static struct spi_driver st7586_spi_driver = {
390 	.driver = {
391 		.name = "st7586",
392 		.owner = THIS_MODULE,
393 		.of_match_table = st7586_of_match,
394 	},
395 	.id_table = st7586_id,
396 	.probe = st7586_probe,
397 	.remove = st7586_remove,
398 	.shutdown = st7586_shutdown,
399 };
400 module_spi_driver(st7586_spi_driver);
401 
402 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
403 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
404 MODULE_LICENSE("GPL");
405