@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * DRM driver for display panels with configuration preset and needs only
+ * standard MIPI DCS commands to bring up.
+ *
+ * Copyright (C) 2021 Sipeed
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.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>
+
+#define MIPI_DCS_ADDRESS_MODE_BGR BIT(3)
+#define MIPI_DCS_ADDRESS_MODE_REVERSE BIT(5)
+#define MIPI_DCS_ADDRESS_MODE_RTL BIT(6)
+#define MIPI_DCS_ADDRESS_MODE_BTT BIT(7)
+
+struct simple_dbi_cfg {
+ const struct drm_display_mode mode;
+ unsigned int left_offset;
+ unsigned int top_offset;
+ bool inverted;
+ bool write_only;
+ bool bgr;
+ bool right_to_left;
+ bool bottom_to_top;
+};
+
+struct simple_dbi_priv {
+ struct mipi_dbi_dev dbidev; /* Must be first for .release() */
+ const struct simple_dbi_cfg *cfg;
+};
+
+static void simple_dbi_pipe_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 simple_dbi_priv *priv = container_of(dbidev,
+ struct simple_dbi_priv,
+ dbidev);
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int ret, idx;
+ u8 addr_mode = 0x00;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ DRM_DEBUG_KMS("\n");
+
+ ret = mipi_dbi_poweron_reset(dbidev);
+ if (ret)
+ goto out_exit;
+
+ mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+ msleep(5);
+
+ /* Currently tinydrm supports 16bit only now */
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,
+ MIPI_DCS_PIXEL_FMT_16BIT);
+
+ if (priv->cfg->inverted)
+ mipi_dbi_command(dbi, MIPI_DCS_ENTER_INVERT_MODE);
+ else
+ mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
+
+ if (priv->cfg->bgr)
+ addr_mode |= MIPI_DCS_ADDRESS_MODE_BGR;
+
+ if (priv->cfg->right_to_left)
+ addr_mode |= MIPI_DCS_ADDRESS_MODE_RTL;
+
+ if (priv->cfg->bottom_to_top)
+ addr_mode |= MIPI_DCS_ADDRESS_MODE_BTT;
+
+ switch (dbidev->rotation) {
+ default:
+ break;
+ case 90:
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;
+ break;
+ case 180:
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;
+ break;
+ case 270:
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;
+ addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;
+ break;
+ }
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+
+ mipi_dbi_command(dbi, MIPI_DCS_ENTER_NORMAL_MODE);
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+
+ mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
+out_exit:
+ drm_dev_exit(idx);
+}
+
+static const struct drm_simple_display_pipe_funcs simple_dbi_pipe_funcs = {
+ .enable = simple_dbi_pipe_enable,
+ .disable = mipi_dbi_pipe_disable,
+ .update = mipi_dbi_pipe_update,
+ .prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
+};
+
+static const struct simple_dbi_cfg zsx154_b1206_cfg = {
+ .mode = { DRM_SIMPLE_MODE(240, 240, 28, 28) },
+ .inverted = true,
+ .write_only = true,
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(simple_dbi_fops);
+
+static const struct drm_driver simple_dbi_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &simple_dbi_fops,
+ DRM_GEM_CMA_DRIVER_OPS_VMAP,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "simple-dbi",
+ .desc = "Generic MIPI-DCS compatible DBI panel",
+ .date = "20210723",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id simple_dbi_of_match[] = {
+ { .compatible = "zsx,zsx154-b1206", .data = &zsx154_b1206_cfg },
+ { },
+}
+MODULE_DEVICE_TABLE(of, simple_dbi_of_match);
+
+static int simple_dbi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ const struct simple_dbi_cfg *cfg;
+ struct mipi_dbi_dev *dbidev;
+ struct simple_dbi_priv *priv;
+ struct drm_device *drm;
+ struct mipi_dbi *dbi;
+ struct gpio_desc *dc;
+ u32 rotation = 0;
+ int ret;
+
+ cfg = device_get_match_data(&spi->dev);
+ if (!cfg)
+ cfg = (void *)spi_get_device_id(spi)->driver_data;
+
+ priv = devm_drm_dev_alloc(dev, &simple_dbi_driver,
+ struct simple_dbi_priv, dbidev.drm);
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);
+
+ dbidev = &priv->dbidev;
+ priv->cfg = cfg;
+
+ dbi = &dbidev->dbi;
+ drm = &dbidev->drm;
+
+ dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(dbi->reset))
+ return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get reset GPIO\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 D/C GPIO\n");
+
+ dbidev->backlight = devm_of_find_backlight(dev);
+ if (IS_ERR(dbidev->backlight))
+ return PTR_ERR(dbidev->backlight);
+
+ device_property_read_u32(dev, "rotation", &rotation);
+
+ ret = mipi_dbi_spi_init(spi, dbi, dc);
+ if (ret)
+ return ret;
+
+ if (cfg->write_only)
+ dbi->read_commands = NULL;
+
+ ret = mipi_dbi_dev_init(dbidev, &simple_dbi_pipe_funcs, &cfg->mode,
+ rotation);
+ 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 simple_dbi_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 simple_dbi_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static struct spi_driver simple_dbi_spi_driver = {
+ .driver = {
+ .name = "simple-dbi",
+ .of_match_table = simple_dbi_of_match,
+ },
+ .probe = simple_dbi_probe,
+ .remove = simple_dbi_remove,
+ .shutdown = simple_dbi_shutdown,
+};
+module_spi_driver(simple_dbi_spi_driver);
+
+MODULE_DESCRIPTION("Simple DBI panel DRM driver");
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_LICENSE("GPL");