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 */ 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 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 95 static 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 } 160 161 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = { 162 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable), 163 }; 164 165 static const struct drm_display_mode waveshare_mode = { 166 DRM_SIMPLE_MODE(480, 320, 73, 49), 167 }; 168 169 DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops); 170 171 static 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 }; 182 183 static const struct of_device_id ili9486_of_match[] = { 184 { .compatible = "waveshare,rpi-lcd-35" }, 185 { .compatible = "ozzmaker,piscreen" }, 186 {}, 187 }; 188 MODULE_DEVICE_TABLE(of, ili9486_of_match); 189 190 static const struct spi_device_id ili9486_id[] = { 191 { "ili9486", 0 }, 192 { "rpi-lcd-35", 0 }, 193 { "piscreen", 0 }, 194 { } 195 }; 196 MODULE_DEVICE_TABLE(spi, ili9486_id); 197 198 static 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 } 254 255 static 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 } 262 263 static void ili9486_shutdown(struct spi_device *spi) 264 { 265 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 266 } 267 268 static 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 }; 278 module_spi_driver(ili9486_spi_driver); 279 280 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver"); 281 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>"); 282 MODULE_LICENSE("GPL"); 283