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_mipi_dbi.h> 23 #include <drm/drm_modeset_helper.h> 24 25 #define ILI9486_ITFCTR1 0xb0 26 #define ILI9486_PWCTRL1 0xc2 27 #define ILI9486_VMCTRL1 0xc5 28 #define ILI9486_PGAMCTRL 0xe0 29 #define ILI9486_NGAMCTRL 0xe1 30 #define ILI9486_DGAMCTRL 0xe2 31 #define ILI9486_MADCTL_BGR BIT(3) 32 #define ILI9486_MADCTL_MV BIT(5) 33 #define ILI9486_MADCTL_MX BIT(6) 34 #define ILI9486_MADCTL_MY BIT(7) 35 36 /* 37 * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter 38 * in front of the display controller. This means that 8-bit values have to be 39 * transferred as 16-bit. 40 */ 41 static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par, 42 size_t num) 43 { 44 struct spi_device *spi = mipi->spi; 45 void *data = par; 46 u32 speed_hz; 47 int i, ret; 48 __be16 *buf; 49 50 buf = kmalloc(32 * sizeof(u16), GFP_KERNEL); 51 if (!buf) 52 return -ENOMEM; 53 54 /* 55 * The displays are Raspberry Pi HATs and connected to the 8-bit only 56 * SPI controller, so 16-bit command and parameters need byte swapping 57 * before being transferred as 8-bit on the big endian SPI bus. 58 * Pixel data bytes have already been swapped before this function is 59 * called. 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 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num); 74 data = buf; 75 } 76 77 gpiod_set_value_cansleep(mipi->dc, 1); 78 ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, data, num); 79 free: 80 kfree(buf); 81 82 return ret; 83 } 84 85 static void waveshare_enable(struct drm_simple_display_pipe *pipe, 86 struct drm_crtc_state *crtc_state, 87 struct drm_plane_state *plane_state) 88 { 89 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 90 struct mipi_dbi *dbi = &dbidev->dbi; 91 u8 addr_mode; 92 int ret, idx; 93 94 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 95 return; 96 97 DRM_DEBUG_KMS("\n"); 98 99 ret = mipi_dbi_poweron_conditional_reset(dbidev); 100 if (ret < 0) 101 goto out_exit; 102 if (ret == 1) 103 goto out_enable; 104 105 mipi_dbi_command(dbi, ILI9486_ITFCTR1); 106 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 107 msleep(250); 108 109 mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55); 110 111 mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44); 112 113 mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00); 114 115 mipi_dbi_command(dbi, ILI9486_PGAMCTRL, 116 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98, 117 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0); 118 mipi_dbi_command(dbi, ILI9486_NGAMCTRL, 119 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 120 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00); 121 mipi_dbi_command(dbi, ILI9486_DGAMCTRL, 122 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 123 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00); 124 125 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); 126 msleep(100); 127 128 out_enable: 129 switch (dbidev->rotation) { 130 case 90: 131 addr_mode = ILI9486_MADCTL_MY; 132 break; 133 case 180: 134 addr_mode = ILI9486_MADCTL_MV; 135 break; 136 case 270: 137 addr_mode = ILI9486_MADCTL_MX; 138 break; 139 default: 140 addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY | 141 ILI9486_MADCTL_MX; 142 break; 143 } 144 addr_mode |= ILI9486_MADCTL_BGR; 145 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 146 mipi_dbi_enable_flush(dbidev, crtc_state, plane_state); 147 out_exit: 148 drm_dev_exit(idx); 149 } 150 151 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = { 152 .enable = waveshare_enable, 153 .disable = mipi_dbi_pipe_disable, 154 .update = mipi_dbi_pipe_update, 155 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 156 }; 157 158 static const struct drm_display_mode waveshare_mode = { 159 DRM_SIMPLE_MODE(480, 320, 73, 49), 160 }; 161 162 DEFINE_DRM_GEM_CMA_FOPS(ili9486_fops); 163 164 static struct drm_driver ili9486_driver = { 165 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 166 .fops = &ili9486_fops, 167 .release = mipi_dbi_release, 168 DRM_GEM_CMA_VMAP_DRIVER_OPS, 169 .debugfs_init = mipi_dbi_debugfs_init, 170 .name = "ili9486", 171 .desc = "Ilitek ILI9486", 172 .date = "20200118", 173 .major = 1, 174 .minor = 0, 175 }; 176 177 static const struct of_device_id ili9486_of_match[] = { 178 { .compatible = "waveshare,rpi-lcd-35" }, 179 { .compatible = "ozzmaker,piscreen" }, 180 {}, 181 }; 182 MODULE_DEVICE_TABLE(of, ili9486_of_match); 183 184 static const struct spi_device_id ili9486_id[] = { 185 { "ili9486", 0 }, 186 { } 187 }; 188 MODULE_DEVICE_TABLE(spi, ili9486_id); 189 190 static int ili9486_probe(struct spi_device *spi) 191 { 192 struct device *dev = &spi->dev; 193 struct mipi_dbi_dev *dbidev; 194 struct drm_device *drm; 195 struct mipi_dbi *dbi; 196 struct gpio_desc *dc; 197 u32 rotation = 0; 198 int ret; 199 200 dbidev = kzalloc(sizeof(*dbidev), GFP_KERNEL); 201 if (!dbidev) 202 return -ENOMEM; 203 204 dbi = &dbidev->dbi; 205 drm = &dbidev->drm; 206 ret = devm_drm_dev_init(dev, drm, &ili9486_driver); 207 if (ret) { 208 kfree(dbidev); 209 return ret; 210 } 211 212 drm_mode_config_init(drm); 213 214 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 215 if (IS_ERR(dbi->reset)) { 216 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); 217 return PTR_ERR(dbi->reset); 218 } 219 220 dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW); 221 if (IS_ERR(dc)) { 222 DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n"); 223 return PTR_ERR(dc); 224 } 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_fbdev_generic_setup(drm, 0); 253 254 return 0; 255 } 256 257 static int 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 return 0; 265 } 266 267 static void ili9486_shutdown(struct spi_device *spi) 268 { 269 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 270 } 271 272 static struct spi_driver ili9486_spi_driver = { 273 .driver = { 274 .name = "ili9486", 275 .of_match_table = ili9486_of_match, 276 }, 277 .id_table = ili9486_id, 278 .probe = ili9486_probe, 279 .remove = ili9486_remove, 280 .shutdown = ili9486_shutdown, 281 }; 282 module_spi_driver(ili9486_spi_driver); 283 284 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver"); 285 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>"); 286 MODULE_LICENSE("GPL"); 287