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_fbdev_dma.h>
22  #include <drm/drm_gem_atomic_helper.h>
23  #include <drm/drm_gem_dma_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  
45  struct 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  
53  struct st7735r_priv {
54  	struct mipi_dbi_dev dbidev;	/* Must be first for .release() */
55  	const struct st7735r_cfg *cfg;
56  };
57  
st7735r_pipe_enable(struct drm_simple_display_pipe * pipe,struct drm_crtc_state * crtc_state,struct drm_plane_state * plane_state)58  static 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);
131  out_exit:
132  	drm_dev_exit(idx);
133  }
134  
135  static const struct drm_simple_display_pipe_funcs st7735r_pipe_funcs = {
136  	DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(st7735r_pipe_enable),
137  };
138  
139  static const struct st7735r_cfg jd_t18003_t01_cfg = {
140  	.mode		= { DRM_SIMPLE_MODE(128, 160, 28, 35) },
141  	/* Cannot read from Adafruit 1.8" display via SPI */
142  	.write_only	= true,
143  };
144  
145  static const struct st7735r_cfg rh128128t_cfg = {
146  	.mode		= { DRM_SIMPLE_MODE(128, 128, 25, 26) },
147  	.left_offset	= 2,
148  	.top_offset	= 3,
149  	.rgb		= true,
150  };
151  
152  DEFINE_DRM_GEM_DMA_FOPS(st7735r_fops);
153  
154  static const struct drm_driver st7735r_driver = {
155  	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
156  	.fops			= &st7735r_fops,
157  	DRM_GEM_DMA_DRIVER_OPS_VMAP,
158  	.debugfs_init		= mipi_dbi_debugfs_init,
159  	.name			= "st7735r",
160  	.desc			= "Sitronix ST7735R",
161  	.date			= "20171128",
162  	.major			= 1,
163  	.minor			= 0,
164  };
165  
166  static const struct of_device_id st7735r_of_match[] = {
167  	{ .compatible = "jianda,jd-t18003-t01", .data = &jd_t18003_t01_cfg },
168  	{ .compatible = "okaya,rh128128t", .data = &rh128128t_cfg },
169  	{ },
170  };
171  MODULE_DEVICE_TABLE(of, st7735r_of_match);
172  
173  static const struct spi_device_id st7735r_id[] = {
174  	{ "jd-t18003-t01", (uintptr_t)&jd_t18003_t01_cfg },
175  	{ "rh128128t", (uintptr_t)&rh128128t_cfg },
176  	{ },
177  };
178  MODULE_DEVICE_TABLE(spi, st7735r_id);
179  
st7735r_probe(struct spi_device * spi)180  static int st7735r_probe(struct spi_device *spi)
181  {
182  	struct device *dev = &spi->dev;
183  	const struct st7735r_cfg *cfg;
184  	struct mipi_dbi_dev *dbidev;
185  	struct st7735r_priv *priv;
186  	struct drm_device *drm;
187  	struct mipi_dbi *dbi;
188  	struct gpio_desc *dc;
189  	u32 rotation = 0;
190  	int ret;
191  
192  	cfg = device_get_match_data(&spi->dev);
193  	if (!cfg)
194  		cfg = (void *)spi_get_device_id(spi)->driver_data;
195  
196  	priv = devm_drm_dev_alloc(dev, &st7735r_driver,
197  				  struct st7735r_priv, dbidev.drm);
198  	if (IS_ERR(priv))
199  		return PTR_ERR(priv);
200  
201  	dbidev = &priv->dbidev;
202  	priv->cfg = cfg;
203  
204  	dbi = &dbidev->dbi;
205  	drm = &dbidev->drm;
206  
207  	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
208  	if (IS_ERR(dbi->reset))
209  		return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
210  
211  	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
212  	if (IS_ERR(dc))
213  		return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");
214  
215  	dbidev->backlight = devm_of_find_backlight(dev);
216  	if (IS_ERR(dbidev->backlight))
217  		return PTR_ERR(dbidev->backlight);
218  
219  	device_property_read_u32(dev, "rotation", &rotation);
220  
221  	ret = mipi_dbi_spi_init(spi, dbi, dc);
222  	if (ret)
223  		return ret;
224  
225  	if (cfg->write_only)
226  		dbi->read_commands = NULL;
227  
228  	dbidev->left_offset = cfg->left_offset;
229  	dbidev->top_offset = cfg->top_offset;
230  
231  	ret = mipi_dbi_dev_init(dbidev, &st7735r_pipe_funcs, &cfg->mode,
232  				rotation);
233  	if (ret)
234  		return ret;
235  
236  	drm_mode_config_reset(drm);
237  
238  	ret = drm_dev_register(drm, 0);
239  	if (ret)
240  		return ret;
241  
242  	spi_set_drvdata(spi, drm);
243  
244  	drm_fbdev_dma_setup(drm, 0);
245  
246  	return 0;
247  }
248  
st7735r_remove(struct spi_device * spi)249  static void st7735r_remove(struct spi_device *spi)
250  {
251  	struct drm_device *drm = spi_get_drvdata(spi);
252  
253  	drm_dev_unplug(drm);
254  	drm_atomic_helper_shutdown(drm);
255  }
256  
st7735r_shutdown(struct spi_device * spi)257  static void st7735r_shutdown(struct spi_device *spi)
258  {
259  	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
260  }
261  
262  static struct spi_driver st7735r_spi_driver = {
263  	.driver = {
264  		.name = "st7735r",
265  		.of_match_table = st7735r_of_match,
266  	},
267  	.id_table = st7735r_id,
268  	.probe = st7735r_probe,
269  	.remove = st7735r_remove,
270  	.shutdown = st7735r_shutdown,
271  };
272  module_spi_driver(st7735r_spi_driver);
273  
274  MODULE_DESCRIPTION("Sitronix ST7735R DRM driver");
275  MODULE_AUTHOR("David Lechner <david@lechnology.com>");
276  MODULE_LICENSE("GPL");
277