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1// SPDX-License-Identifier: GPL-2.02/*3 * DRM driver for MIPI DBI compatible display panels4 *5 * Copyright 2022 Noralf Trønnes6 */7 8#include <linux/backlight.h>9#include <linux/delay.h>10#include <linux/firmware.h>11#include <linux/gpio/consumer.h>12#include <linux/module.h>13#include <linux/property.h>14#include <linux/regulator/consumer.h>15#include <linux/spi/spi.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_modes.h>25#include <drm/drm_modeset_helper.h>26 27#include <video/mipi_display.h>28 29struct panel_mipi_dbi_format {30 const char *name;31 u32 fourcc;32 unsigned int bpp;33};34 35static const struct panel_mipi_dbi_format panel_mipi_dbi_formats[] = {36 { "r5g6b5", DRM_FORMAT_RGB565, 16 },37 { "b6x2g6x2r6x2", DRM_FORMAT_RGB888, 24 },38};39 40static int panel_mipi_dbi_get_format(struct device *dev, u32 *formats, unsigned int *bpp)41{42 const char *format_name;43 unsigned int i;44 int ret;45 46 formats[1] = DRM_FORMAT_XRGB8888;47 48 ret = device_property_read_string(dev, "format", &format_name);49 if (ret) {50 /* Old Device Trees don't have this property */51 formats[0] = DRM_FORMAT_RGB565;52 *bpp = 16;53 return 0;54 }55 56 for (i = 0; i < ARRAY_SIZE(panel_mipi_dbi_formats); i++) {57 const struct panel_mipi_dbi_format *format = &panel_mipi_dbi_formats[i];58 59 if (strcmp(format_name, format->name))60 continue;61 62 formats[0] = format->fourcc;63 *bpp = format->bpp;64 return 0;65 }66 67 dev_err(dev, "Pixel format is not supported: '%s'\n", format_name);68 69 return -EINVAL;70}71 72static const u8 panel_mipi_dbi_magic[15] = { 'M', 'I', 'P', 'I', ' ', 'D', 'B', 'I',73 0, 0, 0, 0, 0, 0, 0 };74 75/*76 * The display controller configuration is stored in a firmware file.77 * The Device Tree 'compatible' property value with a '.bin' suffix is passed78 * to request_firmware() to fetch this file.79 */80struct panel_mipi_dbi_config {81 /* Magic string: panel_mipi_dbi_magic */82 u8 magic[15];83 84 /* Config file format version */85 u8 file_format_version;86 87 /*88 * MIPI commands to execute when the display pipeline is enabled.89 * This is used to configure the display controller.90 *91 * The commands are stored in a byte array with the format:92 * command, num_parameters, [ parameter, ...], command, ...93 *94 * Some commands require a pause before the next command can be received.95 * Inserting a delay in the command sequence is done by using the NOP command with one96 * parameter: delay in miliseconds (the No Operation command is part of the MIPI Display97 * Command Set where it has no parameters).98 *99 * Example:100 * command 0x11101 * sleep 120ms102 * command 0xb1 parameters 0x01, 0x2c, 0x2d103 * command 0x29104 *105 * Byte sequence:106 * 0x11 0x00107 * 0x00 0x01 0x78108 * 0xb1 0x03 0x01 0x2c 0x2d109 * 0x29 0x00110 */111 u8 commands[];112};113 114struct panel_mipi_dbi_commands {115 const u8 *buf;116 size_t len;117};118 119static struct panel_mipi_dbi_commands *120panel_mipi_dbi_check_commands(struct device *dev, const struct firmware *fw)121{122 const struct panel_mipi_dbi_config *config = (struct panel_mipi_dbi_config *)fw->data;123 struct panel_mipi_dbi_commands *commands;124 size_t size = fw->size, commands_len;125 unsigned int i = 0;126 127 if (size < sizeof(*config) + 2) { /* At least 1 command */128 dev_err(dev, "config: file size=%zu is too small\n", size);129 return ERR_PTR(-EINVAL);130 }131 132 if (memcmp(config->magic, panel_mipi_dbi_magic, sizeof(config->magic))) {133 dev_err(dev, "config: Bad magic: %15ph\n", config->magic);134 return ERR_PTR(-EINVAL);135 }136 137 if (config->file_format_version != 1) {138 dev_err(dev, "config: version=%u is not supported\n", config->file_format_version);139 return ERR_PTR(-EINVAL);140 }141 142 drm_dev_dbg(dev, DRM_UT_DRIVER, "size=%zu version=%u\n", size, config->file_format_version);143 144 commands_len = size - sizeof(*config);145 146 while ((i + 1) < commands_len) {147 u8 command = config->commands[i++];148 u8 num_parameters = config->commands[i++];149 const u8 *parameters = &config->commands[i];150 151 i += num_parameters;152 if (i > commands_len) {153 dev_err(dev, "config: command=0x%02x num_parameters=%u overflows\n",154 command, num_parameters);155 return ERR_PTR(-EINVAL);156 }157 158 if (command == 0x00 && num_parameters == 1)159 drm_dev_dbg(dev, DRM_UT_DRIVER, "sleep %ums\n", parameters[0]);160 else161 drm_dev_dbg(dev, DRM_UT_DRIVER, "command %02x %*ph\n",162 command, num_parameters, parameters);163 }164 165 if (i != commands_len) {166 dev_err(dev, "config: malformed command array\n");167 return ERR_PTR(-EINVAL);168 }169 170 commands = devm_kzalloc(dev, sizeof(*commands), GFP_KERNEL);171 if (!commands)172 return ERR_PTR(-ENOMEM);173 174 commands->len = commands_len;175 commands->buf = devm_kmemdup(dev, config->commands, commands->len, GFP_KERNEL);176 if (!commands->buf)177 return ERR_PTR(-ENOMEM);178 179 return commands;180}181 182static struct panel_mipi_dbi_commands *panel_mipi_dbi_commands_from_fw(struct device *dev)183{184 struct panel_mipi_dbi_commands *commands;185 const struct firmware *fw;186 const char *compatible;187 char fw_name[40];188 int ret;189 190 ret = of_property_read_string_index(dev->of_node, "compatible", 0, &compatible);191 if (ret)192 return ERR_PTR(ret);193 194 snprintf(fw_name, sizeof(fw_name), "%s.bin", compatible);195 ret = request_firmware(&fw, fw_name, dev);196 if (ret) {197 dev_err(dev, "No config file found for compatible '%s' (error=%d)\n",198 compatible, ret);199 200 return ERR_PTR(ret);201 }202 203 commands = panel_mipi_dbi_check_commands(dev, fw);204 release_firmware(fw);205 206 return commands;207}208 209static void panel_mipi_dbi_commands_execute(struct mipi_dbi *dbi,210 struct panel_mipi_dbi_commands *commands)211{212 unsigned int i = 0;213 214 if (!commands)215 return;216 217 while (i < commands->len) {218 u8 command = commands->buf[i++];219 u8 num_parameters = commands->buf[i++];220 const u8 *parameters = &commands->buf[i];221 222 if (command == 0x00 && num_parameters == 1)223 msleep(parameters[0]);224 else if (num_parameters)225 mipi_dbi_command_stackbuf(dbi, command, parameters, num_parameters);226 else227 mipi_dbi_command(dbi, command);228 229 i += num_parameters;230 }231}232 233static void panel_mipi_dbi_enable(struct drm_simple_display_pipe *pipe,234 struct drm_crtc_state *crtc_state,235 struct drm_plane_state *plane_state)236{237 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);238 struct mipi_dbi *dbi = &dbidev->dbi;239 int ret, idx;240 241 if (!drm_dev_enter(pipe->crtc.dev, &idx))242 return;243 244 drm_dbg(pipe->crtc.dev, "\n");245 246 ret = mipi_dbi_poweron_conditional_reset(dbidev);247 if (ret < 0)248 goto out_exit;249 if (!ret)250 panel_mipi_dbi_commands_execute(dbi, dbidev->driver_private);251 252 mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);253out_exit:254 drm_dev_exit(idx);255}256 257static const struct drm_simple_display_pipe_funcs panel_mipi_dbi_pipe_funcs = {258 DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(panel_mipi_dbi_enable),259};260 261DEFINE_DRM_GEM_DMA_FOPS(panel_mipi_dbi_fops);262 263static const struct drm_driver panel_mipi_dbi_driver = {264 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,265 .fops = &panel_mipi_dbi_fops,266 DRM_GEM_DMA_DRIVER_OPS_VMAP,267 .debugfs_init = mipi_dbi_debugfs_init,268 .name = "panel-mipi-dbi",269 .desc = "MIPI DBI compatible display panel",270 .date = "20220103",271 .major = 1,272 .minor = 0,273};274 275static int panel_mipi_dbi_get_mode(struct mipi_dbi_dev *dbidev, struct drm_display_mode *mode)276{277 struct device *dev = dbidev->drm.dev;278 u16 hback_porch, vback_porch;279 int ret;280 281 ret = of_get_drm_panel_display_mode(dev->of_node, mode, NULL);282 if (ret) {283 dev_err(dev, "%pOF: failed to get panel-timing (error=%d)\n", dev->of_node, ret);284 return ret;285 }286 287 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;288 289 hback_porch = mode->htotal - mode->hsync_end;290 vback_porch = mode->vtotal - mode->vsync_end;291 292 /*293 * Make sure width and height are set and that only back porch and294 * pixelclock are set in the other timing values. Also check that295 * width and height don't exceed the 16-bit value specified by MIPI DCS.296 */297 if (!mode->hdisplay || !mode->vdisplay || mode->flags ||298 mode->hsync_end > mode->hdisplay || (hback_porch + mode->hdisplay) > 0xffff ||299 mode->vsync_end > mode->vdisplay || (vback_porch + mode->vdisplay) > 0xffff) {300 dev_err(dev, "%pOF: panel-timing out of bounds\n", dev->of_node);301 return -EINVAL;302 }303 304 /* The driver doesn't use the pixel clock but it is mandatory so fake one if not set */305 if (!mode->clock)306 mode->clock = mode->htotal * mode->vtotal * 60 / 1000;307 308 dbidev->top_offset = vback_porch;309 dbidev->left_offset = hback_porch;310 311 return 0;312}313 314static int panel_mipi_dbi_spi_probe(struct spi_device *spi)315{316 struct device *dev = &spi->dev;317 struct drm_display_mode mode;318 struct mipi_dbi_dev *dbidev;319 struct drm_device *drm;320 struct mipi_dbi *dbi;321 struct gpio_desc *dc;322 unsigned int bpp;323 size_t buf_size;324 u32 formats[2];325 int ret;326 327 dbidev = devm_drm_dev_alloc(dev, &panel_mipi_dbi_driver, struct mipi_dbi_dev, drm);328 if (IS_ERR(dbidev))329 return PTR_ERR(dbidev);330 331 dbi = &dbidev->dbi;332 drm = &dbidev->drm;333 334 ret = panel_mipi_dbi_get_mode(dbidev, &mode);335 if (ret)336 return ret;337 338 dbidev->regulator = devm_regulator_get(dev, "power");339 if (IS_ERR(dbidev->regulator))340 return dev_err_probe(dev, PTR_ERR(dbidev->regulator),341 "Failed to get regulator 'power'\n");342 343 dbidev->io_regulator = devm_regulator_get(dev, "io");344 if (IS_ERR(dbidev->io_regulator))345 return dev_err_probe(dev, PTR_ERR(dbidev->io_regulator),346 "Failed to get regulator 'io'\n");347 348 dbidev->backlight = devm_of_find_backlight(dev);349 if (IS_ERR(dbidev->backlight))350 return dev_err_probe(dev, PTR_ERR(dbidev->backlight), "Failed to get backlight\n");351 352 dbi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);353 if (IS_ERR(dbi->reset))354 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");355 356 /* Multiple panels can share the "dc" GPIO, but only if they are on the same SPI bus! */357 dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE);358 if (IS_ERR(dc))359 return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");360 361 ret = mipi_dbi_spi_init(spi, dbi, dc);362 if (ret)363 return ret;364 365 if (device_property_present(dev, "write-only"))366 dbi->read_commands = NULL;367 368 dbidev->driver_private = panel_mipi_dbi_commands_from_fw(dev);369 if (IS_ERR(dbidev->driver_private))370 return PTR_ERR(dbidev->driver_private);371 372 ret = panel_mipi_dbi_get_format(dev, formats, &bpp);373 if (ret)374 return ret;375 376 buf_size = DIV_ROUND_UP(mode.hdisplay * mode.vdisplay * bpp, 8);377 ret = mipi_dbi_dev_init_with_formats(dbidev, &panel_mipi_dbi_pipe_funcs,378 formats, ARRAY_SIZE(formats),379 &mode, 0, buf_size);380 if (ret)381 return ret;382 383 drm_mode_config_reset(drm);384 385 ret = drm_dev_register(drm, 0);386 if (ret)387 return ret;388 389 spi_set_drvdata(spi, drm);390 391 drm_fbdev_dma_setup(drm, 0);392 393 return 0;394}395 396static void panel_mipi_dbi_spi_remove(struct spi_device *spi)397{398 struct drm_device *drm = spi_get_drvdata(spi);399 400 drm_dev_unplug(drm);401 drm_atomic_helper_shutdown(drm);402}403 404static void panel_mipi_dbi_spi_shutdown(struct spi_device *spi)405{406 drm_atomic_helper_shutdown(spi_get_drvdata(spi));407}408 409static int __maybe_unused panel_mipi_dbi_pm_suspend(struct device *dev)410{411 return drm_mode_config_helper_suspend(dev_get_drvdata(dev));412}413 414static int __maybe_unused panel_mipi_dbi_pm_resume(struct device *dev)415{416 drm_mode_config_helper_resume(dev_get_drvdata(dev));417 418 return 0;419}420 421static const struct dev_pm_ops panel_mipi_dbi_pm_ops = {422 SET_SYSTEM_SLEEP_PM_OPS(panel_mipi_dbi_pm_suspend, panel_mipi_dbi_pm_resume)423};424 425static const struct of_device_id panel_mipi_dbi_spi_of_match[] = {426 { .compatible = "panel-mipi-dbi-spi" },427 {},428};429MODULE_DEVICE_TABLE(of, panel_mipi_dbi_spi_of_match);430 431static const struct spi_device_id panel_mipi_dbi_spi_id[] = {432 { "panel-mipi-dbi-spi", 0 },433 { },434};435MODULE_DEVICE_TABLE(spi, panel_mipi_dbi_spi_id);436 437static struct spi_driver panel_mipi_dbi_spi_driver = {438 .driver = {439 .name = "panel-mipi-dbi-spi",440 .of_match_table = panel_mipi_dbi_spi_of_match,441 .pm = &panel_mipi_dbi_pm_ops,442 },443 .id_table = panel_mipi_dbi_spi_id,444 .probe = panel_mipi_dbi_spi_probe,445 .remove = panel_mipi_dbi_spi_remove,446 .shutdown = panel_mipi_dbi_spi_shutdown,447};448module_spi_driver(panel_mipi_dbi_spi_driver);449 450MODULE_DESCRIPTION("MIPI DBI compatible display panel driver");451MODULE_AUTHOR("Noralf Trønnes");452MODULE_LICENSE("GPL");453