st7586.c

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