xref: /openbmc/linux/drivers/gpu/drm/tiny/ili9486.c (revision 15e3ae36)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * DRM driver for Ilitek ILI9486 panels
4  *
5  * Copyright 2020 Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>
6  */
7 
8 #include <linux/backlight.h>
9 #include <linux/delay.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/module.h>
12 #include <linux/property.h>
13 #include <linux/spi/spi.h>
14 
15 #include <video/mipi_display.h>
16 
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_drv.h>
19 #include <drm/drm_fb_helper.h>
20 #include <drm/drm_gem_cma_helper.h>
21 #include <drm/drm_gem_framebuffer_helper.h>
22 #include <drm/drm_mipi_dbi.h>
23 #include <drm/drm_modeset_helper.h>
24 
25 #define ILI9486_ITFCTR1         0xb0
26 #define ILI9486_PWCTRL1         0xc2
27 #define ILI9486_VMCTRL1         0xc5
28 #define ILI9486_PGAMCTRL        0xe0
29 #define ILI9486_NGAMCTRL        0xe1
30 #define ILI9486_DGAMCTRL        0xe2
31 #define ILI9486_MADCTL_BGR      BIT(3)
32 #define ILI9486_MADCTL_MV       BIT(5)
33 #define ILI9486_MADCTL_MX       BIT(6)
34 #define ILI9486_MADCTL_MY       BIT(7)
35 
36 /*
37  * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter
38  * in front of the  display controller. This means that 8-bit values have to be
39  * transferred as 16-bit.
40  */
41 static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,
42 			     size_t num)
43 {
44 	struct spi_device *spi = mipi->spi;
45 	void *data = par;
46 	u32 speed_hz;
47 	int i, ret;
48 	__be16 *buf;
49 
50 	buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
51 	if (!buf)
52 		return -ENOMEM;
53 
54 	/*
55 	 * The displays are Raspberry Pi HATs and connected to the 8-bit only
56 	 * SPI controller, so 16-bit command and parameters need byte swapping
57 	 * before being transferred as 8-bit on the big endian SPI bus.
58 	 * Pixel data bytes have already been swapped before this function is
59 	 * called.
60 	 */
61 	buf[0] = cpu_to_be16(*cmd);
62 	gpiod_set_value_cansleep(mipi->dc, 0);
63 	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
64 	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
65 	if (ret || !num)
66 		goto free;
67 
68 	/* 8-bit configuration data, not 16-bit pixel data */
69 	if (num <= 32) {
70 		for (i = 0; i < num; i++)
71 			buf[i] = cpu_to_be16(par[i]);
72 		num *= 2;
73 		speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
74 		data = buf;
75 	}
76 
77 	gpiod_set_value_cansleep(mipi->dc, 1);
78 	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, data, num);
79  free:
80 	kfree(buf);
81 
82 	return ret;
83 }
84 
85 static void waveshare_enable(struct drm_simple_display_pipe *pipe,
86 			     struct drm_crtc_state *crtc_state,
87 			     struct drm_plane_state *plane_state)
88 {
89 	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
90 	struct mipi_dbi *dbi = &dbidev->dbi;
91 	u8 addr_mode;
92 	int ret, idx;
93 
94 	if (!drm_dev_enter(pipe->crtc.dev, &idx))
95 		return;
96 
97 	DRM_DEBUG_KMS("\n");
98 
99 	ret = mipi_dbi_poweron_conditional_reset(dbidev);
100 	if (ret < 0)
101 		goto out_exit;
102 	if (ret == 1)
103 		goto out_enable;
104 
105 	mipi_dbi_command(dbi, ILI9486_ITFCTR1);
106 	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
107 	msleep(250);
108 
109 	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
110 
111 	mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
112 
113 	mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
114 
115 	mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
116 			 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
117 			 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
118 	mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
119 			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
120 			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
121 	mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
122 			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
123 			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
124 
125 	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
126 	msleep(100);
127 
128  out_enable:
129 	switch (dbidev->rotation) {
130 	case 90:
131 		addr_mode = ILI9486_MADCTL_MY;
132 		break;
133 	case 180:
134 		addr_mode = ILI9486_MADCTL_MV;
135 		break;
136 	case 270:
137 		addr_mode = ILI9486_MADCTL_MX;
138 		break;
139 	default:
140 		addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
141 			ILI9486_MADCTL_MX;
142 		break;
143 	}
144 	addr_mode |= ILI9486_MADCTL_BGR;
145 	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
146 	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
147  out_exit:
148 	drm_dev_exit(idx);
149 }
150 
151 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
152 	.enable = waveshare_enable,
153 	.disable = mipi_dbi_pipe_disable,
154 	.update = mipi_dbi_pipe_update,
155 	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
156 };
157 
158 static const struct drm_display_mode waveshare_mode = {
159 	DRM_SIMPLE_MODE(480, 320, 73, 49),
160 };
161 
162 DEFINE_DRM_GEM_CMA_FOPS(ili9486_fops);
163 
164 static struct drm_driver ili9486_driver = {
165 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
166 	.fops			= &ili9486_fops,
167 	.release		= mipi_dbi_release,
168 	DRM_GEM_CMA_VMAP_DRIVER_OPS,
169 	.debugfs_init		= mipi_dbi_debugfs_init,
170 	.name			= "ili9486",
171 	.desc			= "Ilitek ILI9486",
172 	.date			= "20200118",
173 	.major			= 1,
174 	.minor			= 0,
175 };
176 
177 static const struct of_device_id ili9486_of_match[] = {
178 	{ .compatible = "waveshare,rpi-lcd-35" },
179 	{ .compatible = "ozzmaker,piscreen" },
180 	{},
181 };
182 MODULE_DEVICE_TABLE(of, ili9486_of_match);
183 
184 static const struct spi_device_id ili9486_id[] = {
185 	{ "ili9486", 0 },
186 	{ }
187 };
188 MODULE_DEVICE_TABLE(spi, ili9486_id);
189 
190 static int ili9486_probe(struct spi_device *spi)
191 {
192 	struct device *dev = &spi->dev;
193 	struct mipi_dbi_dev *dbidev;
194 	struct drm_device *drm;
195 	struct mipi_dbi *dbi;
196 	struct gpio_desc *dc;
197 	u32 rotation = 0;
198 	int ret;
199 
200 	dbidev = kzalloc(sizeof(*dbidev), GFP_KERNEL);
201 	if (!dbidev)
202 		return -ENOMEM;
203 
204 	dbi = &dbidev->dbi;
205 	drm = &dbidev->drm;
206 	ret = devm_drm_dev_init(dev, drm, &ili9486_driver);
207 	if (ret) {
208 		kfree(dbidev);
209 		return ret;
210 	}
211 
212 	drm_mode_config_init(drm);
213 
214 	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
215 	if (IS_ERR(dbi->reset)) {
216 		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
217 		return PTR_ERR(dbi->reset);
218 	}
219 
220 	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
221 	if (IS_ERR(dc)) {
222 		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
223 		return PTR_ERR(dc);
224 	}
225 
226 	dbidev->backlight = devm_of_find_backlight(dev);
227 	if (IS_ERR(dbidev->backlight))
228 		return PTR_ERR(dbidev->backlight);
229 
230 	device_property_read_u32(dev, "rotation", &rotation);
231 
232 	ret = mipi_dbi_spi_init(spi, dbi, dc);
233 	if (ret)
234 		return ret;
235 
236 	dbi->command = waveshare_command;
237 	dbi->read_commands = NULL;
238 
239 	ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs,
240 				&waveshare_mode, rotation);
241 	if (ret)
242 		return ret;
243 
244 	drm_mode_config_reset(drm);
245 
246 	ret = drm_dev_register(drm, 0);
247 	if (ret)
248 		return ret;
249 
250 	spi_set_drvdata(spi, drm);
251 
252 	drm_fbdev_generic_setup(drm, 0);
253 
254 	return 0;
255 }
256 
257 static int ili9486_remove(struct spi_device *spi)
258 {
259 	struct drm_device *drm = spi_get_drvdata(spi);
260 
261 	drm_dev_unplug(drm);
262 	drm_atomic_helper_shutdown(drm);
263 
264 	return 0;
265 }
266 
267 static void ili9486_shutdown(struct spi_device *spi)
268 {
269 	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
270 }
271 
272 static struct spi_driver ili9486_spi_driver = {
273 	.driver = {
274 		.name = "ili9486",
275 		.of_match_table = ili9486_of_match,
276 	},
277 	.id_table = ili9486_id,
278 	.probe = ili9486_probe,
279 	.remove = ili9486_remove,
280 	.shutdown = ili9486_shutdown,
281 };
282 module_spi_driver(ili9486_spi_driver);
283 
284 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
285 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
286 MODULE_LICENSE("GPL");
287