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 */ 44 static 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 97 static 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 } 162 163 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = { 164 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable), 165 }; 166 167 static const struct drm_display_mode waveshare_mode = { 168 DRM_SIMPLE_MODE(480, 320, 73, 49), 169 }; 170 171 DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops); 172 173 static 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 }; 184 185 static const struct of_device_id ili9486_of_match[] = { 186 { .compatible = "waveshare,rpi-lcd-35" }, 187 { .compatible = "ozzmaker,piscreen" }, 188 {}, 189 }; 190 MODULE_DEVICE_TABLE(of, ili9486_of_match); 191 192 static const struct spi_device_id ili9486_id[] = { 193 { "ili9486", 0 }, 194 { "rpi-lcd-35", 0 }, 195 { "piscreen", 0 }, 196 { } 197 }; 198 MODULE_DEVICE_TABLE(spi, ili9486_id); 199 200 static 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 } 256 257 static 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 } 264 265 static void ili9486_shutdown(struct spi_device *spi) 266 { 267 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 268 } 269 270 static 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 }; 280 module_spi_driver(ili9486_spi_driver); 281 282 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver"); 283 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>"); 284 MODULE_LICENSE("GPL"); 285