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 void *data = par; 47 u32 speed_hz; 48 int i, ret; 49 __be16 *buf; 50 51 buf = kmalloc(32 * sizeof(u16), GFP_KERNEL); 52 if (!buf) 53 return -ENOMEM; 54 55 /* 56 * The displays are Raspberry Pi HATs and connected to the 8-bit only 57 * SPI controller, so 16-bit command and parameters need byte swapping 58 * before being transferred as 8-bit on the big endian SPI bus. 59 * Pixel data bytes have already been swapped before this function is 60 * called. 61 */ 62 buf[0] = cpu_to_be16(*cmd); 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 if (ret || !num) 67 goto free; 68 69 /* 8-bit configuration data, not 16-bit pixel data */ 70 if (num <= 32) { 71 for (i = 0; i < num; i++) 72 buf[i] = cpu_to_be16(par[i]); 73 num *= 2; 74 speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num); 75 data = buf; 76 } 77 78 gpiod_set_value_cansleep(mipi->dc, 1); 79 ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, data, num); 80 free: 81 kfree(buf); 82 83 return ret; 84 } 85 86 static void waveshare_enable(struct drm_simple_display_pipe *pipe, 87 struct drm_crtc_state *crtc_state, 88 struct drm_plane_state *plane_state) 89 { 90 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 91 struct mipi_dbi *dbi = &dbidev->dbi; 92 u8 addr_mode; 93 int ret, idx; 94 95 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 96 return; 97 98 DRM_DEBUG_KMS("\n"); 99 100 ret = mipi_dbi_poweron_conditional_reset(dbidev); 101 if (ret < 0) 102 goto out_exit; 103 if (ret == 1) 104 goto out_enable; 105 106 mipi_dbi_command(dbi, ILI9486_ITFCTR1); 107 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 108 msleep(250); 109 110 mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55); 111 112 mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44); 113 114 mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00); 115 116 mipi_dbi_command(dbi, ILI9486_PGAMCTRL, 117 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98, 118 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0); 119 mipi_dbi_command(dbi, ILI9486_NGAMCTRL, 120 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 121 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00); 122 mipi_dbi_command(dbi, ILI9486_DGAMCTRL, 123 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 124 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00); 125 126 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); 127 msleep(100); 128 129 out_enable: 130 switch (dbidev->rotation) { 131 case 90: 132 addr_mode = ILI9486_MADCTL_MY; 133 break; 134 case 180: 135 addr_mode = ILI9486_MADCTL_MV; 136 break; 137 case 270: 138 addr_mode = ILI9486_MADCTL_MX; 139 break; 140 default: 141 addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY | 142 ILI9486_MADCTL_MX; 143 break; 144 } 145 addr_mode |= ILI9486_MADCTL_BGR; 146 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 147 mipi_dbi_enable_flush(dbidev, crtc_state, plane_state); 148 out_exit: 149 drm_dev_exit(idx); 150 } 151 152 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = { 153 .mode_valid = mipi_dbi_pipe_mode_valid, 154 .enable = waveshare_enable, 155 .disable = mipi_dbi_pipe_disable, 156 .update = mipi_dbi_pipe_update, 157 }; 158 159 static const struct drm_display_mode waveshare_mode = { 160 DRM_SIMPLE_MODE(480, 320, 73, 49), 161 }; 162 163 DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops); 164 165 static const struct drm_driver ili9486_driver = { 166 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 167 .fops = &ili9486_fops, 168 DRM_GEM_DMA_DRIVER_OPS_VMAP, 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 = devm_drm_dev_alloc(dev, &ili9486_driver, 201 struct mipi_dbi_dev, drm); 202 if (IS_ERR(dbidev)) 203 return PTR_ERR(dbidev); 204 205 dbi = &dbidev->dbi; 206 drm = &dbidev->drm; 207 208 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 209 if (IS_ERR(dbi->reset)) 210 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n"); 211 212 dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW); 213 if (IS_ERR(dc)) 214 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n"); 215 216 dbidev->backlight = devm_of_find_backlight(dev); 217 if (IS_ERR(dbidev->backlight)) 218 return PTR_ERR(dbidev->backlight); 219 220 device_property_read_u32(dev, "rotation", &rotation); 221 222 ret = mipi_dbi_spi_init(spi, dbi, dc); 223 if (ret) 224 return ret; 225 226 dbi->command = waveshare_command; 227 dbi->read_commands = NULL; 228 229 ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs, 230 &waveshare_mode, rotation); 231 if (ret) 232 return ret; 233 234 drm_mode_config_reset(drm); 235 236 ret = drm_dev_register(drm, 0); 237 if (ret) 238 return ret; 239 240 spi_set_drvdata(spi, drm); 241 242 drm_fbdev_generic_setup(drm, 0); 243 244 return 0; 245 } 246 247 static void ili9486_remove(struct spi_device *spi) 248 { 249 struct drm_device *drm = spi_get_drvdata(spi); 250 251 drm_dev_unplug(drm); 252 drm_atomic_helper_shutdown(drm); 253 } 254 255 static void ili9486_shutdown(struct spi_device *spi) 256 { 257 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 258 } 259 260 static struct spi_driver ili9486_spi_driver = { 261 .driver = { 262 .name = "ili9486", 263 .of_match_table = ili9486_of_match, 264 }, 265 .id_table = ili9486_id, 266 .probe = ili9486_probe, 267 .remove = ili9486_remove, 268 .shutdown = ili9486_shutdown, 269 }; 270 module_spi_driver(ili9486_spi_driver); 271 272 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver"); 273 MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>"); 274 MODULE_LICENSE("GPL"); 275