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_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");