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_fbdev_generic.h>
 20#include <drm/drm_gem_atomic_helper.h>
 21#include <drm/drm_gem_dma_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	spi_bus_lock(spi->controller);
 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	spi_bus_unlock(spi->controller);
 67	if (ret || !num)
 68		goto free;
 69
 70	/* 8-bit configuration data, not 16-bit pixel data */
 71	if (num <= 32) {
 72		for (i = 0; i < num; i++)
 73			buf[i] = cpu_to_be16(par[i]);
 74		num *= 2;
 75		data = buf;
 76	}
 77
 78	/*
 79	 * Check whether pixel data bytes needs to be swapped or not
 80	 */
 81	if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
 82		bpw = 16;
 83
 84	spi_bus_lock(spi->controller);
 85	gpiod_set_value_cansleep(mipi->dc, 1);
 86	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
 87	ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
 88	spi_bus_unlock(spi->controller);
 89 free:
 90	kfree(buf);
 91
 92	return ret;
 93}
 94
 95static void waveshare_enable(struct drm_simple_display_pipe *pipe,
 96			     struct drm_crtc_state *crtc_state,
 97			     struct drm_plane_state *plane_state)
 98{
 99	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
100	struct mipi_dbi *dbi = &dbidev->dbi;
101	u8 addr_mode;
102	int ret, idx;
103
104	if (!drm_dev_enter(pipe->crtc.dev, &idx))
105		return;
106
107	DRM_DEBUG_KMS("\n");
108
109	ret = mipi_dbi_poweron_conditional_reset(dbidev);
110	if (ret < 0)
111		goto out_exit;
112	if (ret == 1)
113		goto out_enable;
114
115	mipi_dbi_command(dbi, ILI9486_ITFCTR1);
116	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
117	msleep(250);
118
119	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
120
121	mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
122
123	mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
124
125	mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
126			 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
127			 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
128	mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
129			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
130			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
131	mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
132			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
133			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
134
135	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
136	msleep(100);
137
138 out_enable:
139	switch (dbidev->rotation) {
140	case 90:
141		addr_mode = ILI9486_MADCTL_MY;
142		break;
143	case 180:
144		addr_mode = ILI9486_MADCTL_MV;
145		break;
146	case 270:
147		addr_mode = ILI9486_MADCTL_MX;
148		break;
149	default:
150		addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
151			ILI9486_MADCTL_MX;
152		break;
153	}
154	addr_mode |= ILI9486_MADCTL_BGR;
155	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
156	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
157 out_exit:
158	drm_dev_exit(idx);
159}
160
161static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
162	DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable),
163};
164
165static const struct drm_display_mode waveshare_mode = {
166	DRM_SIMPLE_MODE(480, 320, 73, 49),
167};
168
169DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops);
170
171static const struct drm_driver ili9486_driver = {
172	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
173	.fops			= &ili9486_fops,
174	DRM_GEM_DMA_DRIVER_OPS_VMAP,
175	.debugfs_init		= mipi_dbi_debugfs_init,
176	.name			= "ili9486",
177	.desc			= "Ilitek ILI9486",
178	.date			= "20200118",
179	.major			= 1,
180	.minor			= 0,
181};
182
183static const struct of_device_id ili9486_of_match[] = {
184	{ .compatible = "waveshare,rpi-lcd-35" },
185	{ .compatible = "ozzmaker,piscreen" },
186	{},
187};
188MODULE_DEVICE_TABLE(of, ili9486_of_match);
189
190static const struct spi_device_id ili9486_id[] = {
191	{ "ili9486", 0 },
192	{ "rpi-lcd-35", 0 },
193	{ "piscreen", 0 },
194	{ }
195};
196MODULE_DEVICE_TABLE(spi, ili9486_id);
197
198static int ili9486_probe(struct spi_device *spi)
199{
200	struct device *dev = &spi->dev;
201	struct mipi_dbi_dev *dbidev;
202	struct drm_device *drm;
203	struct mipi_dbi *dbi;
204	struct gpio_desc *dc;
205	u32 rotation = 0;
206	int ret;
207
208	dbidev = devm_drm_dev_alloc(dev, &ili9486_driver,
209				    struct mipi_dbi_dev, drm);
210	if (IS_ERR(dbidev))
211		return PTR_ERR(dbidev);
212
213	dbi = &dbidev->dbi;
214	drm = &dbidev->drm;
215
216	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
217	if (IS_ERR(dbi->reset))
218		return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
219
220	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
221	if (IS_ERR(dc))
222		return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");
223
224	dbidev->backlight = devm_of_find_backlight(dev);
225	if (IS_ERR(dbidev->backlight))
226		return PTR_ERR(dbidev->backlight);
227
228	device_property_read_u32(dev, "rotation", &rotation);
229
230	ret = mipi_dbi_spi_init(spi, dbi, dc);
231	if (ret)
232		return ret;
233
234	dbi->command = waveshare_command;
235	dbi->read_commands = NULL;
236
237	ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs,
238				&waveshare_mode, rotation);
239	if (ret)
240		return ret;
241
242	drm_mode_config_reset(drm);
243
244	ret = drm_dev_register(drm, 0);
245	if (ret)
246		return ret;
247
248	spi_set_drvdata(spi, drm);
249
250	drm_fbdev_generic_setup(drm, 0);
251
252	return 0;
253}
254
255static void ili9486_remove(struct spi_device *spi)
256{
257	struct drm_device *drm = spi_get_drvdata(spi);
258
259	drm_dev_unplug(drm);
260	drm_atomic_helper_shutdown(drm);
261}
262
263static void ili9486_shutdown(struct spi_device *spi)
264{
265	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
266}
267
268static struct spi_driver ili9486_spi_driver = {
269	.driver = {
270		.name = "ili9486",
271		.of_match_table = ili9486_of_match,
272	},
273	.id_table = ili9486_id,
274	.probe = ili9486_probe,
275	.remove = ili9486_remove,
276	.shutdown = ili9486_shutdown,
277};
278module_spi_driver(ili9486_spi_driver);
279
280MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
281MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
282MODULE_LICENSE("GPL");