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/drm_atomic_helper.h>
  18 #include <drm/drm_drv.h>
  19 #include <drm/drm_fbdev_dma.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_dma_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 <[email protected]>");
 282 MODULE_LICENSE("GPL");