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_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 */
42static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,
43			     size_t num)
44{
45	struct spi_device *spi = mipi->spi;
46	unsigned int bpw = 8;
47	void *data = par;
48	u32 speed_hz;
49	int i, ret;
50	__be16 *buf;
51
52	buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
53	if (!buf)
54		return -ENOMEM;
55
56	/*
57	 * The displays are Raspberry Pi HATs and connected to the 8-bit only
58	 * SPI controller, so 16-bit command and parameters need byte swapping
59	 * before being transferred as 8-bit on the big endian SPI bus.
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		data = buf;
74	}
75
76	/*
77	 * Check whether pixel data bytes needs to be swapped or not
78	 */
79	if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
80		bpw = 16;
81
82	gpiod_set_value_cansleep(mipi->dc, 1);
83	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
84	ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
85 free:
86	kfree(buf);
87
88	return ret;
89}
90
91static void waveshare_enable(struct drm_simple_display_pipe *pipe,
92			     struct drm_crtc_state *crtc_state,
93			     struct drm_plane_state *plane_state)
94{
95	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
96	struct mipi_dbi *dbi = &dbidev->dbi;
97	u8 addr_mode;
98	int ret, idx;
99
100	if (!drm_dev_enter(pipe->crtc.dev, &idx))
101		return;
102
103	DRM_DEBUG_KMS("\n");
104
105	ret = mipi_dbi_poweron_conditional_reset(dbidev);
106	if (ret < 0)
107		goto out_exit;
108	if (ret == 1)
109		goto out_enable;
110
111	mipi_dbi_command(dbi, ILI9486_ITFCTR1);
112	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
113	msleep(250);
114
115	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
116
117	mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
118
119	mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
120
121	mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
122			 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
123			 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
124	mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
125			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
126			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
127	mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
128			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
129			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
130
131	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
132	msleep(100);
133
134 out_enable:
135	switch (dbidev->rotation) {
136	case 90:
137		addr_mode = ILI9486_MADCTL_MY;
138		break;
139	case 180:
140		addr_mode = ILI9486_MADCTL_MV;
141		break;
142	case 270:
143		addr_mode = ILI9486_MADCTL_MX;
144		break;
145	default:
146		addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
147			ILI9486_MADCTL_MX;
148		break;
149	}
150	addr_mode |= ILI9486_MADCTL_BGR;
151	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
152	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
153 out_exit:
154	drm_dev_exit(idx);
155}
156
157static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
158	.enable = waveshare_enable,
159	.disable = mipi_dbi_pipe_disable,
160	.update = mipi_dbi_pipe_update,
161	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
162};
163
164static const struct drm_display_mode waveshare_mode = {
165	DRM_SIMPLE_MODE(480, 320, 73, 49),
166};
167
168DEFINE_DRM_GEM_CMA_FOPS(ili9486_fops);
169
170static struct drm_driver ili9486_driver = {
171	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
172	.fops			= &ili9486_fops,
173	DRM_GEM_CMA_DRIVER_OPS_VMAP,
174	.debugfs_init		= mipi_dbi_debugfs_init,
175	.name			= "ili9486",
176	.desc			= "Ilitek ILI9486",
177	.date			= "20200118",
178	.major			= 1,
179	.minor			= 0,
180};
181
182static const struct of_device_id ili9486_of_match[] = {
183	{ .compatible = "waveshare,rpi-lcd-35" },
184	{ .compatible = "ozzmaker,piscreen" },
185	{},
186};
187MODULE_DEVICE_TABLE(of, ili9486_of_match);
188
189static const struct spi_device_id ili9486_id[] = {
190	{ "ili9486", 0 },
191	{ }
192};
193MODULE_DEVICE_TABLE(spi, ili9486_id);
194
195static int ili9486_probe(struct spi_device *spi)
196{
197	struct device *dev = &spi->dev;
198	struct mipi_dbi_dev *dbidev;
199	struct drm_device *drm;
200	struct mipi_dbi *dbi;
201	struct gpio_desc *dc;
202	u32 rotation = 0;
203	int ret;
204
205	dbidev = devm_drm_dev_alloc(dev, &ili9486_driver,
206				    struct mipi_dbi_dev, drm);
207	if (IS_ERR(dbidev))
208		return PTR_ERR(dbidev);
209
210	dbi = &dbidev->dbi;
211	drm = &dbidev->drm;
212
213	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
214	if (IS_ERR(dbi->reset)) {
215		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
216		return PTR_ERR(dbi->reset);
217	}
218
219	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
220	if (IS_ERR(dc)) {
221		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
222		return PTR_ERR(dc);
223	}
224
225	dbidev->backlight = devm_of_find_backlight(dev);
226	if (IS_ERR(dbidev->backlight))
227		return PTR_ERR(dbidev->backlight);
228
229	device_property_read_u32(dev, "rotation", &rotation);
230
231	ret = mipi_dbi_spi_init(spi, dbi, dc);
232	if (ret)
233		return ret;
234
235	dbi->command = waveshare_command;
236	dbi->read_commands = NULL;
237
238	ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs,
239				&waveshare_mode, 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 ili9486_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 ili9486_shutdown(struct spi_device *spi)
267{
268	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
269}
270
271static struct spi_driver ili9486_spi_driver = {
272	.driver = {
273		.name = "ili9486",
274		.of_match_table = ili9486_of_match,
275	},
276	.id_table = ili9486_id,
277	.probe = ili9486_probe,
278	.remove = ili9486_remove,
279	.shutdown = ili9486_shutdown,
280};
281module_spi_driver(ili9486_spi_driver);
282
283MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
284MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
285MODULE_LICENSE("GPL");
286