drivers/gpu/drm/tiny/ili9486.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * DRM driver for Ilitek ILI9486 panels
   4  *
   5  * Copyright 2020 Kamlesh Gurudasani <[email protected]>
   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
  27 #define ILI9486_ITFCTR1         0xb0
  28 #define ILI9486_PWCTRL1         0xc2
  29 #define ILI9486_VMCTRL1         0xc5
  30 #define ILI9486_PGAMCTRL        0xe0
  31 #define ILI9486_NGAMCTRL        0xe1
  32 #define ILI9486_DGAMCTRL        0xe2
  33 #define ILI9486_MADCTL_BGR      BIT(3)
  34 #define ILI9486_MADCTL_MV       BIT(5)
  35 #define ILI9486_MADCTL_MX       BIT(6)
  36 #define ILI9486_MADCTL_MY       BIT(7)
  37
  38 /*
  39  * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter
  40  * in front of the  display controller. This means that 8-bit values have to be
  41  * transferred as 16-bit.
  42  */
  43 static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,
  44                              size_t num)
  45 {
  46         struct spi_device *spi = mipi->spi;
  47         unsigned int bpw = 8;
  48         void *data = par;
  49         u32 speed_hz;
  50         int i, ret;
  51         __be16 *buf;
  52
  53         buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
  54         if (!buf)
  55                 return -ENOMEM;
  56
  57         /*
  58          * The displays are Raspberry Pi HATs and connected to the 8-bit only
  59          * SPI controller, so 16-bit command and parameters need byte swapping
  60          * before being transferred as 8-bit on the big endian SPI bus.
  61          */
  62         buf[0] = cpu_to_be16(*cmd);
  63         spi_bus_lock(spi->controller);
  64         gpiod_set_value_cansleep(mipi->dc, 0);
  65         speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
  66         ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
  67         spi_bus_unlock(spi->controller);
  68         if (ret || !num)
  69                 goto free;
  70
  71         /* 8-bit configuration data, not 16-bit pixel data */
  72         if (num <= 32) {
  73                 for (i = 0; i < num; i++)
  74                         buf[i] = cpu_to_be16(par[i]);
  75                 num *= 2;
  76                 data = buf;
  77         }
  78
  79         /*
  80          * Check whether pixel data bytes needs to be swapped or not
  81          */
  82         if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
  83                 bpw = 16;
  84
  85         spi_bus_lock(spi->controller);
  86         gpiod_set_value_cansleep(mipi->dc, 1);
  87         speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
  88         ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
  89         spi_bus_unlock(spi->controller);
  90  free:
  91         kfree(buf);
  92
  93         return ret;
  94 }
  95
  96 static void waveshare_enable(struct drm_simple_display_pipe *pipe,
  97                              struct drm_crtc_state *crtc_state,
  98                              struct drm_plane_state *plane_state)
  99 {
 100         struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
 101         struct mipi_dbi *dbi = &dbidev->dbi;
 102         u8 addr_mode;
 103         int ret, idx;
 104
 105         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 106                 return;
 107
 108         DRM_DEBUG_KMS("\n");
 109
 110         ret = mipi_dbi_poweron_conditional_reset(dbidev);
 111         if (ret < 0)
 112                 goto out_exit;
 113         if (ret == 1)
 114                 goto out_enable;
 115
 116         mipi_dbi_command(dbi, ILI9486_ITFCTR1);
 117         mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
 118         msleep(250);
 119
 120         mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
 121
 122         mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);
 123
 124         mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);
 125
 126         mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
 127                          0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
 128                          0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
 129         mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
 130                          0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
 131                          0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
 132         mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
 133                          0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
 134                          0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
 135
 136         mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
 137         msleep(100);
 138
 139  out_enable:
 140         switch (dbidev->rotation) {
 141         case 90:
 142                 addr_mode = ILI9486_MADCTL_MY;
 143                 break;
 144         case 180:
 145                 addr_mode = ILI9486_MADCTL_MV;
 146                 break;
 147         case 270:
 148                 addr_mode = ILI9486_MADCTL_MX;
 149                 break;
 150         default:
 151                 addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |
 152                         ILI9486_MADCTL_MX;
 153                 break;
 154         }
 155         addr_mode |= ILI9486_MADCTL_BGR;
 156         mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
 157         mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
 158  out_exit:
 159         drm_dev_exit(idx);
 160 }
 161
 162 static const struct drm_simple_display_pipe_funcs waveshare_pipe_funcs = {
 163         DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(waveshare_enable),
 164 };
 165
 166 static const struct drm_display_mode waveshare_mode = {
 167         DRM_SIMPLE_MODE(480, 320, 73, 49),
 168 };
 169
 170 DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops);
 171
 172 static const struct drm_driver ili9486_driver = {
 173         .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 174         .fops                   = &ili9486_fops,
 175         DRM_GEM_DMA_DRIVER_OPS_VMAP,
 176         DRM_FBDEV_DMA_DRIVER_OPS,
 177         .debugfs_init           = mipi_dbi_debugfs_init,
 178         .name                   = "ili9486",
 179         .desc                   = "Ilitek ILI9486",
 180         .major                  = 1,
 181         .minor                  = 0,
 182 };
 183
 184 static const struct of_device_id ili9486_of_match[] = {
 185         { .compatible = "waveshare,rpi-lcd-35" },
 186         { .compatible = "ozzmaker,piscreen" },
 187         {},
 188 };
 189 MODULE_DEVICE_TABLE(of, ili9486_of_match);
 190
 191 static const struct spi_device_id ili9486_id[] = {
 192         { "ili9486", 0 },
 193         { "rpi-lcd-35", 0 },
 194         { "piscreen", 0 },
 195         { }
 196 };
 197 MODULE_DEVICE_TABLE(spi, ili9486_id);
 198
 199 static int ili9486_probe(struct spi_device *spi)
 200 {
 201         struct device *dev = &spi->dev;
 202         struct mipi_dbi_dev *dbidev;
 203         struct drm_device *drm;
 204         struct mipi_dbi *dbi;
 205         struct gpio_desc *dc;
 206         u32 rotation = 0;
 207         int ret;
 208
 209         dbidev = devm_drm_dev_alloc(dev, &ili9486_driver,
 210                                     struct mipi_dbi_dev, drm);
 211         if (IS_ERR(dbidev))
 212                 return PTR_ERR(dbidev);
 213
 214         dbi = &dbidev->dbi;
 215         drm = &dbidev->drm;
 216
 217         dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 218         if (IS_ERR(dbi->reset))
 219                 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
 220
 221         dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
 222         if (IS_ERR(dc))
 223                 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");
 224
 225         dbidev->backlight = devm_of_find_backlight(dev);
 226         if (IS_ERR(dbidev->backlight))
 227                 return PTR_ERR(dbidev->backlight);
 228
 229         device_property_read_u32(dev, "rotation", &rotation);
 230
 231         ret = mipi_dbi_spi_init(spi, dbi, dc);
 232         if (ret)
 233                 return ret;
 234
 235         dbi->command = waveshare_command;
 236         dbi->read_commands = NULL;
 237
 238         ret = mipi_dbi_dev_init(dbidev, &waveshare_pipe_funcs,
 239                                 &waveshare_mode, rotation);
 240         if (ret)
 241                 return ret;
 242
 243         drm_mode_config_reset(drm);
 244
 245         ret = drm_dev_register(drm, 0);
 246         if (ret)
 247                 return ret;
 248
 249         spi_set_drvdata(spi, drm);
 250
 251         drm_client_setup(drm, NULL);
 252
 253         return 0;
 254 }
 255
 256 static void ili9486_remove(struct spi_device *spi)
 257 {
 258         struct drm_device *drm = spi_get_drvdata(spi);
 259
 260         drm_dev_unplug(drm);
 261         drm_atomic_helper_shutdown(drm);
 262 }
 263
 264 static void ili9486_shutdown(struct spi_device *spi)
 265 {
 266         drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 267 }
 268
 269 static struct spi_driver ili9486_spi_driver = {
 270         .driver = {
 271                 .name = "ili9486",
 272                 .of_match_table = ili9486_of_match,
 273         },
 274         .id_table = ili9486_id,
 275         .probe = ili9486_probe,
 276         .remove = ili9486_remove,
 277         .shutdown = ili9486_shutdown,
 278 };
 279 module_spi_driver(ili9486_spi_driver);
 280
 281 MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
 282 MODULE_AUTHOR("Kamlesh Gurudasani <[email protected]>");
 283 MODULE_LICENSE("GPL");