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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/clients/drm_client_setup.h>
18#include <drm/drm_atomic_helper.h>
19#include <drm/drm_drv.h>
20#include <drm/drm_fbdev_dma.h>
21#include <drm/drm_gem_atomic_helper.h>
22#include <drm/drm_gem_dma_helper.h>
23#include <drm/drm_managed.h>
24#include <drm/drm_mipi_dbi.h>
25#include <drm/drm_modeset_helper.h>
26#include <drm/drm_print.h>
27
28#define ILI9486_ITFCTR1 0xb0
29#define ILI9486_PWCTRL1 0xc2
30#define ILI9486_VMCTRL1 0xc5
31#define ILI9486_PGAMCTRL 0xe0
32#define ILI9486_NGAMCTRL 0xe1
33#define ILI9486_DGAMCTRL 0xe2
34#define ILI9486_MADCTL_BGR BIT(3)
35#define ILI9486_MADCTL_MV BIT(5)
36#define ILI9486_MADCTL_MX BIT(6)
37#define ILI9486_MADCTL_MY BIT(7)
38
39/*
40 * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter
41 * in front of the display controller. This means that 8-bit values have to be
42 * transferred as 16-bit.
43 */
44static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,
45 size_t num)
46{
47 struct spi_device *spi = mipi->spi;
48 unsigned int bpw = 8;
49 void *data = par;
50 u32 speed_hz;
51 int i, ret;
52 __be16 *buf;
53
54 buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
55 if (!buf)
56 return -ENOMEM;
57
58 /*
59 * The displays are Raspberry Pi HATs and connected to the 8-bit only
60 * SPI controller, so 16-bit command and parameters need byte swapping
61 * before being transferred as 8-bit on the big endian SPI bus.
62 */
63 buf[0] = cpu_to_be16(*cmd);
64 spi_bus_lock(spi->controller);
65 gpiod_set_value_cansleep(mipi->dc, 0);
66 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
67 ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
68 spi_bus_unlock(spi->controller);
69 if (ret || !num)
70 goto free;
71
72 /* 8-bit configuration data, not 16-bit pixel data */
73 if (num <= 32) {
74 for (i = 0; i < num; i++)
75 buf[i] = cpu_to_be16(par[i]);
76 num *= 2;
77 data = buf;
78 }
79
80 /*
81 * Check whether pixel data bytes needs to be swapped or not
82 */
83 if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
84 bpw = 16;
85
86 spi_bus_lock(spi->controller);
87 gpiod_set_value_cansleep(mipi->dc, 1);
88 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
89 ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
90 spi_bus_unlock(spi->controller);
91 free:
92 kfree(buf);
93
94 return ret;
95}
96
97static void waveshare_enable(struct drm_simple_display_pipe *pipe,
98 struct drm_crtc_state *crtc_state,
99 struct drm_plane_state *plane_state)
100{
101 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
102 struct mipi_dbi *dbi = &dbidev->dbi;
103 u8 addr_mode;
104 int ret, idx;
105
106 if (!drm_dev_enter(pipe->crtc.dev, &idx))
107 return;
108
109 DRM_DEBUG_KMS("\n");
110
111 ret = mipi_dbi_poweron_conditional_reset(dbidev);
112 if (ret < 0)
113 goto out_exit;
114 if (ret == 1)
115 goto out_enable;
116
117 mipi_dbi_command(dbi, ILI9486_ITFCTR1);
118 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
119 msleep(250);
120
121 mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
122
123 mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
124
125 mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
126
127 mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
128 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
129 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
130 mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
131 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
132 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
133 mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
134 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
135 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
136
137 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
138 msleep(100);
139
140 out_enable:
141 switch (dbidev->rotation) {
142 case 90:
143 addr_mode = ILI9486_MADCTL_MY;
144 break;
145 case 180:
146 addr_mode = ILI9486_MADCTL_MV;
147 break;
148 case 270:
149 addr_mode = ILI9486_MADCTL_MX;
150 break;
151 default:
152 addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
153 ILI9486_MADCTL_MX;
154 break;
155 }
156 addr_mode |= ILI9486_MADCTL_BGR;
157 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
158 mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
159 out_exit:
160 drm_dev_exit(idx);
161}
162
163static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
164 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable),
165};
166
167static const struct drm_display_mode waveshare_mode = {
168 DRM_SIMPLE_MODE(480, 320, 73, 49),
169};
170
171DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops);
172
173static const struct drm_driver ili9486_driver = {
174 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
175 .fops = &ili9486_fops,
176 DRM_GEM_DMA_DRIVER_OPS_VMAP,
177 DRM_FBDEV_DMA_DRIVER_OPS,
178 .debugfs_init = mipi_dbi_debugfs_init,
179 .name = "ili9486",
180 .desc = "Ilitek ILI9486",
181 .major = 1,
182 .minor = 0,
183};
184
185static const struct of_device_id ili9486_of_match[] = {
186 { .compatible = "waveshare,rpi-lcd-35" },
187 { .compatible = "ozzmaker,piscreen" },
188 {},
189};
190MODULE_DEVICE_TABLE(of, ili9486_of_match);
191
192static const struct spi_device_id ili9486_id[] = {
193 { "ili9486", 0 },
194 { "rpi-lcd-35", 0 },
195 { "piscreen", 0 },
196 { }
197};
198MODULE_DEVICE_TABLE(spi, ili9486_id);
199
200static int ili9486_probe(struct spi_device *spi)
201{
202 struct device *dev = &spi->dev;
203 struct mipi_dbi_dev *dbidev;
204 struct drm_device *drm;
205 struct mipi_dbi *dbi;
206 struct gpio_desc *dc;
207 u32 rotation = 0;
208 int ret;
209
210 dbidev = devm_drm_dev_alloc(dev, &ili9486_driver,
211 struct mipi_dbi_dev, drm);
212 if (IS_ERR(dbidev))
213 return PTR_ERR(dbidev);
214
215 dbi = &dbidev->dbi;
216 drm = &dbidev->drm;
217
218 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
219 if (IS_ERR(dbi->reset))
220 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
221
222 dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
223 if (IS_ERR(dc))
224 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");
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_client_setup(drm, NULL);
253
254 return 0;
255}
256
257static void 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
265static void ili9486_shutdown(struct spi_device *spi)
266{
267 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
268}
269
270static struct spi_driver ili9486_spi_driver = {
271 .driver = {
272 .name = "ili9486",
273 .of_match_table = ili9486_of_match,
274 },
275 .id_table = ili9486_id,
276 .probe = ili9486_probe,
277 .remove = ili9486_remove,
278 .shutdown = ili9486_shutdown,
279};
280module_spi_driver(ili9486_spi_driver);
281
282MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
283MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
284MODULE_LICENSE("GPL");