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