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 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 91 static 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 } 156 157 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = { 158 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable), 159 }; 160 161 static const struct drm_display_mode waveshare_mode = { 162 DRM_SIMPLE_MODE(480, 320, 73, 49), 163 }; 164 165 DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops); 166 167 static const struct drm_driver ili9486_driver = { 168 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 169 .fops = &ili9486_fops, 170 DRM_GEM_DMA_DRIVER_OPS_VMAP, 171 .debugfs_init = mipi_dbi_debugfs_init, 172 .name = "ili9486", 173 .desc = "Ilitek ILI9486", 174 .date = "20200118", 175 .major = 1, 176 .minor = 0, 177 }; 178 179 static const struct of_device_id ili9486_of_match[] = { 180 { .compatible = "waveshare,rpi-lcd-35" }, 181 { .compatible = "ozzmaker,piscreen" }, 182 {}, 183 }; 184 MODULE_DEVICE_TABLE(of, ili9486_of_match); 185 186 static const struct spi_device_id ili9486_id[] = { 187 { "ili9486", 0 }, 188 { "rpi-lcd-35", 0 }, 189 { "piscreen", 0 }, 190 { } 191 }; 192 MODULE_DEVICE_TABLE(spi, ili9486_id); 193 194 static int ili9486_probe(struct spi_device *spi) 195 { 196 struct device *dev = &spi->dev; 197 struct mipi_dbi_dev *dbidev; 198 struct drm_device *drm; 199 struct mipi_dbi *dbi; 200 struct gpio_desc *dc; 201 u32 rotation = 0; 202 int ret; 203 204 dbidev = devm_drm_dev_alloc(dev, &ili9486_driver, 205 struct mipi_dbi_dev, drm); 206 if (IS_ERR(dbidev)) 207 return PTR_ERR(dbidev); 208 209 dbi = &dbidev->dbi; 210 drm = &dbidev->drm; 211 212 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 213 if (IS_ERR(dbi->reset)) 214 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n"); 215 216 dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW); 217 if (IS_ERR(dc)) 218 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n"); 219 220 dbidev->backlight = devm_of_find_backlight(dev); 221 if (IS_ERR(dbidev->backlight)) 222 return PTR_ERR(dbidev->backlight); 223 224 device_property_read_u32(dev, "rotation", &rotation); 225 226 ret = mipi_dbi_spi_init(spi, dbi, dc); 227 if (ret) 228 return ret; 229 230 dbi->command = waveshare_command; 231 dbi->read_commands = NULL; 232 233 ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs, 234 &waveshare_mode, rotation); 235 if (ret) 236 return ret; 237 238 drm_mode_config_reset(drm); 239 240 ret = drm_dev_register(drm, 0); 241 if (ret) 242 return ret; 243 244 spi_set_drvdata(spi, drm); 245 246 drm_fbdev_generic_setup(drm, 0); 247 248 return 0; 249 } 250 251 static void ili9486_remove(struct spi_device *spi) 252 { 253 struct drm_device *drm = spi_get_drvdata(spi); 254 255 drm_dev_unplug(drm); 256 drm_atomic_helper_shutdown(drm); 257 } 258 259 static void ili9486_shutdown(struct spi_device *spi) 260 { 261 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 262 } 263 264 static struct spi_driver ili9486_spi_driver = { 265 .driver = { 266 .name = "ili9486", 267 .of_match_table = ili9486_of_match, 268 }, 269 .id_table = ili9486_id, 270 .probe = ili9486_probe, 271 .remove = ili9486_remove, 272 .shutdown = ili9486_shutdown, 273 }; 274 module_spi_driver(ili9486_spi_driver); 275 276 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver"); 277 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>"); 278 MODULE_LICENSE("GPL"); 279