1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * DRM driver for display panels connected to a Sitronix ST7715R or ST7735R
4 * display controller in SPI mode.
5 *
6 * Copyright 2017 David Lechner <david@lechnology.com>
7 * Copyright (C) 2019 Glider bvba
8 */
9
10#include <linux/backlight.h>
11#include <linux/delay.h>
12#include <linux/dma-buf.h>
13#include <linux/gpio/consumer.h>
14#include <linux/module.h>
15#include <linux/property.h>
16#include <linux/spi/spi.h>
17#include <video/mipi_display.h>
18
19#include <drm/drm_atomic_helper.h>
20#include <drm/drm_drv.h>
21#include <drm/drm_fb_helper.h>
22#include <drm/drm_gem_cma_helper.h>
23#include <drm/drm_gem_framebuffer_helper.h>
24#include <drm/drm_managed.h>
25#include <drm/drm_mipi_dbi.h>
26
27#define ST7735R_FRMCTR1		0xb1
28#define ST7735R_FRMCTR2		0xb2
29#define ST7735R_FRMCTR3		0xb3
30#define ST7735R_INVCTR		0xb4
31#define ST7735R_PWCTR1		0xc0
32#define ST7735R_PWCTR2		0xc1
33#define ST7735R_PWCTR3		0xc2
34#define ST7735R_PWCTR4		0xc3
35#define ST7735R_PWCTR5		0xc4
36#define ST7735R_VMCTR1		0xc5
37#define ST7735R_GAMCTRP1	0xe0
38#define ST7735R_GAMCTRN1	0xe1
39
40#define ST7735R_MY	BIT(7)
41#define ST7735R_MX	BIT(6)
42#define ST7735R_MV	BIT(5)
43#define ST7735R_RGB	BIT(3)
44
45struct st7735r_cfg {
46	const struct drm_display_mode mode;
47	unsigned int left_offset;
48	unsigned int top_offset;
49	unsigned int write_only:1;
50	unsigned int rgb:1;		/* RGB (vs. BGR) */
51};
52
53struct st7735r_priv {
54	struct mipi_dbi_dev dbidev;	/* Must be first for .release() */
55	const struct st7735r_cfg *cfg;
56};
57
58static void st7735r_pipe_enable(struct drm_simple_display_pipe *pipe,
59				struct drm_crtc_state *crtc_state,
60				struct drm_plane_state *plane_state)
61{
62	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
63	struct st7735r_priv *priv = container_of(dbidev, struct st7735r_priv,
64						 dbidev);
65	struct mipi_dbi *dbi = &dbidev->dbi;
66	int ret, idx;
67	u8 addr_mode;
68
69	if (!drm_dev_enter(pipe->crtc.dev, &idx))
70		return;
71
72	DRM_DEBUG_KMS("\n");
73
74	ret = mipi_dbi_poweron_reset(dbidev);
75	if (ret)
76		goto out_exit;
77
78	msleep(150);
79
80	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
81	msleep(500);
82
83	mipi_dbi_command(dbi, ST7735R_FRMCTR1, 0x01, 0x2c, 0x2d);
84	mipi_dbi_command(dbi, ST7735R_FRMCTR2, 0x01, 0x2c, 0x2d);
85	mipi_dbi_command(dbi, ST7735R_FRMCTR3, 0x01, 0x2c, 0x2d, 0x01, 0x2c,
86			 0x2d);
87	mipi_dbi_command(dbi, ST7735R_INVCTR, 0x07);
88	mipi_dbi_command(dbi, ST7735R_PWCTR1, 0xa2, 0x02, 0x84);
89	mipi_dbi_command(dbi, ST7735R_PWCTR2, 0xc5);
90	mipi_dbi_command(dbi, ST7735R_PWCTR3, 0x0a, 0x00);
91	mipi_dbi_command(dbi, ST7735R_PWCTR4, 0x8a, 0x2a);
92	mipi_dbi_command(dbi, ST7735R_PWCTR5, 0x8a, 0xee);
93	mipi_dbi_command(dbi, ST7735R_VMCTR1, 0x0e);
94	mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
95	switch (dbidev->rotation) {
96	default:
97		addr_mode = ST7735R_MX | ST7735R_MY;
98		break;
99	case 90:
100		addr_mode = ST7735R_MX | ST7735R_MV;
101		break;
102	case 180:
103		addr_mode = 0;
104		break;
105	case 270:
106		addr_mode = ST7735R_MY | ST7735R_MV;
107		break;
108	}
109
110	if (priv->cfg->rgb)
111		addr_mode |= ST7735R_RGB;
112
113	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
114	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,
115			 MIPI_DCS_PIXEL_FMT_16BIT);
116	mipi_dbi_command(dbi, ST7735R_GAMCTRP1, 0x02, 0x1c, 0x07, 0x12, 0x37,
117			 0x32, 0x29, 0x2d, 0x29, 0x25, 0x2b, 0x39, 0x00, 0x01,
118			 0x03, 0x10);
119	mipi_dbi_command(dbi, ST7735R_GAMCTRN1, 0x03, 0x1d, 0x07, 0x06, 0x2e,
120			 0x2c, 0x29, 0x2d, 0x2e, 0x2e, 0x37, 0x3f, 0x00, 0x00,
121			 0x02, 0x10);
122	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
123
124	msleep(100);
125
126	mipi_dbi_command(dbi, MIPI_DCS_ENTER_NORMAL_MODE);
127
128	msleep(20);
129
130	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
131out_exit:
132	drm_dev_exit(idx);
133}
134
135static const struct drm_simple_display_pipe_funcs st7735r_pipe_funcs = {
136	.enable		= st7735r_pipe_enable,
137	.disable	= mipi_dbi_pipe_disable,
138	.update		= mipi_dbi_pipe_update,
139	.prepare_fb	= drm_gem_fb_simple_display_pipe_prepare_fb,
140};
141
142static const struct st7735r_cfg jd_t18003_t01_cfg = {
143	.mode		= { DRM_SIMPLE_MODE(128, 160, 28, 35) },
144	/* Cannot read from Adafruit 1.8" display via SPI */
145	.write_only	= true,
146};
147
148static const struct st7735r_cfg rh128128t_cfg = {
149	.mode		= { DRM_SIMPLE_MODE(128, 128, 25, 26) },
150	.left_offset	= 2,
151	.top_offset	= 3,
152	.rgb		= true,
153};
154
155DEFINE_DRM_GEM_CMA_FOPS(st7735r_fops);
156
157static struct drm_driver st7735r_driver = {
158	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
159	.fops			= &st7735r_fops,
160	DRM_GEM_CMA_DRIVER_OPS_VMAP,
161	.debugfs_init		= mipi_dbi_debugfs_init,
162	.name			= "st7735r",
163	.desc			= "Sitronix ST7735R",
164	.date			= "20171128",
165	.major			= 1,
166	.minor			= 0,
167};
168
169static const struct of_device_id st7735r_of_match[] = {
170	{ .compatible = "jianda,jd-t18003-t01", .data = &jd_t18003_t01_cfg },
171	{ .compatible = "okaya,rh128128t", .data = &rh128128t_cfg },
172	{ },
173};
174MODULE_DEVICE_TABLE(of, st7735r_of_match);
175
176static const struct spi_device_id st7735r_id[] = {
177	{ "jd-t18003-t01", (uintptr_t)&jd_t18003_t01_cfg },
178	{ "rh128128t", (uintptr_t)&rh128128t_cfg },
179	{ },
180};
181MODULE_DEVICE_TABLE(spi, st7735r_id);
182
183static int st7735r_probe(struct spi_device *spi)
184{
185	struct device *dev = &spi->dev;
186	const struct st7735r_cfg *cfg;
187	struct mipi_dbi_dev *dbidev;
188	struct st7735r_priv *priv;
189	struct drm_device *drm;
190	struct mipi_dbi *dbi;
191	struct gpio_desc *dc;
192	u32 rotation = 0;
193	int ret;
194
195	cfg = device_get_match_data(&spi->dev);
196	if (!cfg)
197		cfg = (void *)spi_get_device_id(spi)->driver_data;
198
199	priv = devm_drm_dev_alloc(dev, &st7735r_driver,
200				  struct st7735r_priv, dbidev.drm);
201	if (IS_ERR(priv))
202		return PTR_ERR(priv);
203
204	dbidev = &priv->dbidev;
205	priv->cfg = cfg;
206
207	dbi = &dbidev->dbi;
208	drm = &dbidev->drm;
209
210	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
211	if (IS_ERR(dbi->reset)) {
212		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
213		return PTR_ERR(dbi->reset);
214	}
215
216	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
217	if (IS_ERR(dc)) {
218		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
219		return PTR_ERR(dc);
220	}
221
222	dbidev->backlight = devm_of_find_backlight(dev);
223	if (IS_ERR(dbidev->backlight))
224		return PTR_ERR(dbidev->backlight);
225
226	device_property_read_u32(dev, "rotation", &rotation);
227
228	ret = mipi_dbi_spi_init(spi, dbi, dc);
229	if (ret)
230		return ret;
231
232	if (cfg->write_only)
233		dbi->read_commands = NULL;
234
235	dbidev->left_offset = cfg->left_offset;
236	dbidev->top_offset = cfg->top_offset;
237
238	ret = mipi_dbi_dev_init(dbidev, &st7735r_pipe_funcs, &cfg->mode,
239				rotation);
240	if (ret)
241		return ret;
242
243	drm_mode_config_reset(drm);
244
245	ret = drm_dev_register(drm, 0);
246	if (ret)
247		return ret;
248
249	spi_set_drvdata(spi, drm);
250
251	drm_fbdev_generic_setup(drm, 0);
252
253	return 0;
254}
255
256static int st7735r_remove(struct spi_device *spi)
257{
258	struct drm_device *drm = spi_get_drvdata(spi);
259
260	drm_dev_unplug(drm);
261	drm_atomic_helper_shutdown(drm);
262
263	return 0;
264}
265
266static void st7735r_shutdown(struct spi_device *spi)
267{
268	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
269}
270
271static struct spi_driver st7735r_spi_driver = {
272	.driver = {
273		.name = "st7735r",
274		.of_match_table = st7735r_of_match,
275	},
276	.id_table = st7735r_id,
277	.probe = st7735r_probe,
278	.remove = st7735r_remove,
279	.shutdown = st7735r_shutdown,
280};
281module_spi_driver(st7735r_spi_driver);
282
283MODULE_DESCRIPTION("Sitronix ST7735R DRM driver");
284MODULE_AUTHOR("David Lechner <david@lechnology.com>");
285MODULE_LICENSE("GPL");
286