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