--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DRM driver for MIPI DBI compatible display panels
+ *
+ * Copyright 2022 Noralf Trønnes
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_modeset_helper.h>
+
+#include <video/mipi_display.h>
+
+static const u8 panel_mipi_dbi_magic[15] = { 'M', 'I', 'P', 'I', ' ', 'D', 'B', 'I',
+ 0, 0, 0, 0, 0, 0, 0 };
+
+/*
+ * The display controller configuration is stored in a firmware file.
+ * The Device Tree 'compatible' property value with a '.bin' suffix is passed
+ * to request_firmware() to fetch this file.
+ */
+struct panel_mipi_dbi_config {
+ /* Magic string: panel_mipi_dbi_magic */
+ u8 magic[15];
+
+ /* Config file format version */
+ u8 file_format_version;
+
+ /*
+ * MIPI commands to execute when the display pipeline is enabled.
+ * This is used to configure the display controller.
+ *
+ * The commands are stored in a byte array with the format:
+ * command, num_parameters, [ parameter, ...], command, ...
+ *
+ * Some commands require a pause before the next command can be received.
+ * Inserting a delay in the command sequence is done by using the NOP command with one
+ * parameter: delay in miliseconds (the No Operation command is part of the MIPI Display
+ * Command Set where it has no parameters).
+ *
+ * Example:
+ * command 0x11
+ * sleep 120ms
+ * command 0xb1 parameters 0x01, 0x2c, 0x2d
+ * command 0x29
+ *
+ * Byte sequence:
+ * 0x11 0x00
+ * 0x00 0x01 0x78
+ * 0xb1 0x03 0x01 0x2c 0x2d
+ * 0x29 0x00
+ */
+ u8 commands[];
+};
+
+struct panel_mipi_dbi_commands {
+ const u8 *buf;
+ size_t len;
+};
+
+static struct panel_mipi_dbi_commands *
+panel_mipi_dbi_check_commands(struct device *dev, const struct firmware *fw)
+{
+ const struct panel_mipi_dbi_config *config = (struct panel_mipi_dbi_config *)fw->data;
+ struct panel_mipi_dbi_commands *commands;
+ size_t size = fw->size, commands_len;
+ unsigned int i = 0;
+
+ if (size < sizeof(*config) + 2) { /* At least 1 command */
+ dev_err(dev, "config: file size=%zu is too small\n", size);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (memcmp(config->magic, panel_mipi_dbi_magic, sizeof(config->magic))) {
+ dev_err(dev, "config: Bad magic: %15ph\n", config->magic);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (config->file_format_version != 1) {
+ dev_err(dev, "config: version=%u is not supported\n", config->file_format_version);
+ return ERR_PTR(-EINVAL);
+ }
+
+ drm_dev_dbg(dev, DRM_UT_DRIVER, "size=%zu version=%u\n", size, config->file_format_version);
+
+ commands_len = size - sizeof(*config);
+
+ while ((i + 1) < commands_len) {
+ u8 command = config->commands[i++];
+ u8 num_parameters = config->commands[i++];
+ const u8 *parameters = &config->commands[i];
+
+ i += num_parameters;
+ if (i > commands_len) {
+ dev_err(dev, "config: command=0x%02x num_parameters=%u overflows\n",
+ command, num_parameters);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (command == 0x00 && num_parameters == 1)
+ drm_dev_dbg(dev, DRM_UT_DRIVER, "sleep %ums\n", parameters[0]);
+ else
+ drm_dev_dbg(dev, DRM_UT_DRIVER, "command %02x %*ph\n",
+ command, num_parameters, parameters);
+ }
+
+ if (i != commands_len) {
+ dev_err(dev, "config: malformed command array\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ commands = devm_kzalloc(dev, sizeof(*commands), GFP_KERNEL);
+ if (!commands)
+ return ERR_PTR(-ENOMEM);
+
+ commands->len = commands_len;
+ commands->buf = devm_kmemdup(dev, config->commands, commands->len, GFP_KERNEL);
+ if (!commands->buf)
+ return ERR_PTR(-ENOMEM);
+
+ return commands;
+}
+
+static struct panel_mipi_dbi_commands *panel_mipi_dbi_commands_from_fw(struct device *dev)
+{
+ struct panel_mipi_dbi_commands *commands;
+ const struct firmware *fw;
+ const char *compatible;
+ char fw_name[40];
+ int ret;
+
+ ret = of_property_read_string_index(dev->of_node, "compatible", 0, &compatible);
+ if (ret)
+ return ERR_PTR(ret);
+
+ snprintf(fw_name, sizeof(fw_name), "%s.bin", compatible);
+ ret = request_firmware(&fw, fw_name, dev);
+ if (ret) {
+ dev_err(dev, "No config file found for compatible '%s' (error=%d)\n",
+ compatible, ret);
+
+ return ERR_PTR(ret);
+ }
+
+ commands = panel_mipi_dbi_check_commands(dev, fw);
+ release_firmware(fw);
+
+ return commands;
+}
+
+static void panel_mipi_dbi_commands_execute(struct mipi_dbi *dbi,
+ struct panel_mipi_dbi_commands *commands)
+{
+ unsigned int i = 0;
+
+ if (!commands)
+ return;
+
+ while (i < commands->len) {
+ u8 command = commands->buf[i++];
+ u8 num_parameters = commands->buf[i++];
+ const u8 *parameters = &commands->buf[i];
+
+ if (command == 0x00 && num_parameters == 1)
+ msleep(parameters[0]);
+ else if (num_parameters)
+ mipi_dbi_command_stackbuf(dbi, command, parameters, num_parameters);
+ else
+ mipi_dbi_command(dbi, command);
+
+ i += num_parameters;
+ }
+}
+
+static void panel_mipi_dbi_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state,
+ struct drm_plane_state *plane_state)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int ret, idx;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ drm_dbg(pipe->crtc.dev, "\n");
+
+ ret = mipi_dbi_poweron_conditional_reset(dbidev);
+ if (ret < 0)
+ goto out_exit;
+ if (!ret)
+ panel_mipi_dbi_commands_execute(dbi, dbidev->driver_private);
+
+ mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
+out_exit:
+ drm_dev_exit(idx);
+}
+
+static const struct drm_simple_display_pipe_funcs panel_mipi_dbi_pipe_funcs = {
+ .enable = panel_mipi_dbi_enable,
+ .disable = mipi_dbi_pipe_disable,
+ .update = mipi_dbi_pipe_update,
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(panel_mipi_dbi_fops);
+
+static const struct drm_driver panel_mipi_dbi_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &panel_mipi_dbi_fops,
+ DRM_GEM_CMA_DRIVER_OPS_VMAP,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "panel-mipi-dbi",
+ .desc = "MIPI DBI compatible display panel",
+ .date = "20220103",
+ .major = 1,
+ .minor = 0,
+};
+
+static int panel_mipi_dbi_get_mode(struct mipi_dbi_dev *dbidev, struct drm_display_mode *mode)
+{
+ struct device *dev = dbidev->drm.dev;
+ u16 hback_porch, vback_porch;
+ int ret;
+
+ ret = of_get_drm_panel_display_mode(dev->of_node, mode, NULL);
+ if (ret) {
+ dev_err(dev, "%pOF: failed to get panel-timing (error=%d)\n", dev->of_node, ret);
+ return ret;
+ }
+
+ mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+
+ hback_porch = mode->htotal - mode->hsync_end;
+ vback_porch = mode->vtotal - mode->vsync_end;
+
+ /*
+ * Make sure width and height are set and that only back porch and
+ * pixelclock are set in the other timing values. Also check that
+ * width and height don't exceed the 16-bit value specified by MIPI DCS.
+ */
+ if (!mode->hdisplay || !mode->vdisplay || mode->flags ||
+ mode->hsync_end > mode->hdisplay || (hback_porch + mode->hdisplay) > 0xffff ||
+ mode->vsync_end > mode->vdisplay || (vback_porch + mode->vdisplay) > 0xffff) {
+ dev_err(dev, "%pOF: panel-timing out of bounds\n", dev->of_node);
+ return -EINVAL;
+ }
+
+ /* The driver doesn't use the pixel clock but it is mandatory so fake one if not set */
+ if (!mode->clock)
+ mode->clock = mode->htotal * mode->vtotal * 60 / 1000;
+
+ dbidev->top_offset = vback_porch;
+ dbidev->left_offset = hback_porch;
+
+ return 0;
+}
+
+static int panel_mipi_dbi_spi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct drm_display_mode mode;
+ struct mipi_dbi_dev *dbidev;
+ struct drm_device *drm;
+ struct mipi_dbi *dbi;
+ struct gpio_desc *dc;
+ int ret;
+
+ dbidev = devm_drm_dev_alloc(dev, &panel_mipi_dbi_driver, struct mipi_dbi_dev, drm);
+ if (IS_ERR(dbidev))
+ return PTR_ERR(dbidev);
+
+ dbi = &dbidev->dbi;
+ drm = &dbidev->drm;
+
+ ret = panel_mipi_dbi_get_mode(dbidev, &mode);
+ if (ret)
+ return ret;
+
+ dbidev->regulator = devm_regulator_get(dev, "power");
+ if (IS_ERR(dbidev->regulator))
+ return dev_err_probe(dev, PTR_ERR(dbidev->regulator),
+ "Failed to get regulator 'power'\n");
+
+ dbidev->backlight = devm_of_find_backlight(dev);
+ if (IS_ERR(dbidev->backlight))
+ return dev_err_probe(dev, PTR_ERR(dbidev->backlight), "Failed to get backlight\n");
+
+ dbi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(dbi->reset))
+ return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
+
+ dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(dc))
+ return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");
+
+ ret = mipi_dbi_spi_init(spi, dbi, dc);
+ if (ret)
+ return ret;
+
+ if (device_property_present(dev, "write-only"))
+ dbi->read_commands = NULL;
+
+ dbidev->driver_private = panel_mipi_dbi_commands_from_fw(dev);
+ if (IS_ERR(dbidev->driver_private))
+ return PTR_ERR(dbidev->driver_private);
+
+ ret = mipi_dbi_dev_init(dbidev, &panel_mipi_dbi_pipe_funcs, &mode, 0);
+ if (ret)
+ return ret;
+
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, drm);
+
+ drm_fbdev_generic_setup(drm, 0);
+
+ return 0;
+}
+
+static int panel_mipi_dbi_spi_remove(struct spi_device *spi)
+{
+ struct drm_device *drm = spi_get_drvdata(spi);
+
+ drm_dev_unplug(drm);
+ drm_atomic_helper_shutdown(drm);
+
+ return 0;
+}
+
+static void panel_mipi_dbi_spi_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static int __maybe_unused panel_mipi_dbi_pm_suspend(struct device *dev)
+{
+ return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
+}
+
+static int __maybe_unused panel_mipi_dbi_pm_resume(struct device *dev)
+{
+ drm_mode_config_helper_resume(dev_get_drvdata(dev));
+
+ return 0;
+}
+
+static const struct dev_pm_ops panel_mipi_dbi_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(panel_mipi_dbi_pm_suspend, panel_mipi_dbi_pm_resume)
+};
+
+static const struct of_device_id panel_mipi_dbi_spi_of_match[] = {
+ { .compatible = "panel-mipi-dbi-spi" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, panel_mipi_dbi_spi_of_match);
+
+static const struct spi_device_id panel_mipi_dbi_spi_id[] = {
+ { "panel-mipi-dbi-spi", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, panel_mipi_dbi_spi_id);
+
+static struct spi_driver panel_mipi_dbi_spi_driver = {
+ .driver = {
+ .name = "panel-mipi-dbi-spi",
+ .owner = THIS_MODULE,
+ .of_match_table = panel_mipi_dbi_spi_of_match,
+ .pm = &panel_mipi_dbi_pm_ops,
+ },
+ .id_table = panel_mipi_dbi_spi_id,
+ .probe = panel_mipi_dbi_spi_probe,
+ .remove = panel_mipi_dbi_spi_remove,
+ .shutdown = panel_mipi_dbi_spi_shutdown,
+};
+module_spi_driver(panel_mipi_dbi_spi_driver);
+
+MODULE_DESCRIPTION("MIPI DBI compatible display panel driver");
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff