[PATCH 2/2] drm/tiny: add support for tft displays based on ilitek,ili9488

From: Tommaso Merciai
Date: Tue Oct 18 2022 - 12:46:20 EST


This adds support for ilitek,ili9488 based displays with shift register
in front of controller. Waveshare,pico-restouch-lcd-3.5 are such displays

Signed-off-by: Tommaso Merciai <tommaso.merciai@xxxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/tiny/Kconfig | 13 +
drivers/gpu/drm/tiny/Makefile | 1 +
drivers/gpu/drm/tiny/ili9488.c | 440 +++++++++++++++++++++++++++++++++
3 files changed, 454 insertions(+)
create mode 100644 drivers/gpu/drm/tiny/ili9488.c

diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index 027cd87c3d0d7..6e708e8414806 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig
@@ -148,6 +148,19 @@ config TINYDRM_ILI9486

If M is selected the module will be called ili9486.

+config TINYDRM_ILI9488
+ tristate "DRM support for ILI9488 display panels"
+ depends on DRM && SPI
+ select DRM_KMS_HELPER
+ select DRM_GEM_CMA_HELPER
+ select DRM_MIPI_DBI
+ select BACKLIGHT_CLASS_DEVICE
+ help
+ DRM driver for the following Ilitek ILI9488 panels:
+ * LCD 3.5" 320x480 TFT (Waveshare Pico-ResTouch-LCD-3.5")
+
+ If M is selected the module will be called ili9486.
+
config TINYDRM_MI0283QT
tristate "DRM support for MI0283QT"
depends on DRM && SPI
diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile
index 1d9d6227e7ab7..aad6683b2ac40 100644
--- a/drivers/gpu/drm/tiny/Makefile
+++ b/drivers/gpu/drm/tiny/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_TINYDRM_ILI9163) += ili9163.o
obj-$(CONFIG_TINYDRM_ILI9225) += ili9225.o
obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o
obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o
+obj-$(CONFIG_TINYDRM_ILI9488) += ili9488.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
diff --git a/drivers/gpu/drm/tiny/ili9488.c b/drivers/gpu/drm/tiny/ili9488.c
new file mode 100644
index 0000000000000..b94d9d4ff4544
--- /dev/null
+++ b/drivers/gpu/drm/tiny/ili9488.c
@@ -0,0 +1,440 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * DRM driver for Ilitek ILI9488 panels
+ *
+ * Copyright 2020 Kamlesh Gurudasani <kamlesh.gurudasani@xxxxxxxxx>
+ */
+
+#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_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_framebuffer.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_modeset_helper.h>
+
+#define ILI9488_VCOM_CONTROL_1 0xC5
+#define ILI9488_COLUMN_ADDRESS_SET 0x2A
+#define ILI9488_PAGE_ADDRESS_SET 0x2B
+#define ILI9488_MEMORY_WRITE 0x2C
+#define ILI9488_POSITIVE_GAMMA_CORRECTION 0xE0
+#define ILI9488_NEGATIVE_GAMMA_CORRECTION 0xE1
+#define ILI9488_POWER_CONTROL_1 0xC0
+#define ILI9488_POWER_CONTROL_2 0xC1
+#define ILI9488_POWER_CONTROL_3 0xC2
+#define ILI9488_MEM_ACCESS_CONTROL 0x36
+#define ILI9488_COLMOD_PIXEL_FORMAT_SET 0x3A
+#define ILI9488_INTERFACE_MODE_CONTROL 0xB0
+#define ILI9488_FRAME_RATE_CONTROL_PARTIAL 0xB3
+#define ILI9488_DISPLAY_INVERSION_ON 0x21
+#define ILI9488_DISPLAY_INVERSION_CONTROL 0xB4
+#define ILI9488_DISPLAY_FUNCTION_CONTROL 0xB6
+#define ILI9488_ENTRY_MODE_SET 0xB7
+#define ILI9488_HS_LANES_CONTROL 0xBE
+#define ILI9488_SET_IMAGE_FUNCTION 0xE9
+#define ILI9488_ADJUST_CONTROL_3 0xF7
+#define ILI9488_DISPLAY_ON 0x29
+#define ILI9488_DISPLAY_OFF 0x28
+#define ILI9488_ENTER_SLEEP_MODE 0x10
+#define ILI9488_DBI_BPP18 0x06
+#define ILI9488_DBI_BPP16 0x05
+#define ILI9488_DPI_BPP24 0x70
+#define ILI9488_DPI_BPP18 0x60
+#define ILI9488_DPI_BPP16 0x50
+#define ILI9488_FRAME_RATE_CONTROL_NORMAL 0xB1
+#define ILI9488_SLEEP_OUT 0x11
+
+#define ILI9488_MADCTL_RGB BIT(2)
+#define ILI9488_MADCTL_BGR BIT(3)
+#define ILI9488_MADCTL_MV BIT(5)
+#define ILI9488_MADCTL_MX BIT(6)
+#define ILI9488_MADCTL_MY BIT(7)
+
+static void ili9488_rgb565_to_rgb666_line(u8 *dst, u16 *sbuf,
+ unsigned int pixels)
+{
+ unsigned int x;
+
+ for (x = 0; x < pixels; x++) {
+ *dst++ = ((*sbuf & 0xF800) >> 8);
+ *dst++ = ((*sbuf & 0x07E0) >> 3);
+ *dst++ = ((*sbuf & 0x001F) << 3);
+ sbuf++;
+ }
+}
+
+static void ili9488_rgb565_to_rgb666(u8 *dst, void *vaddr,
+ struct drm_framebuffer *fb,
+ struct drm_rect *rect)
+{
+ unsigned long linepixels = drm_rect_width(rect);
+ unsigned long lines = drm_rect_height(rect);
+ size_t dst_len = linepixels * 3;
+ size_t src_len = linepixels * fb->format->cpp[0];
+ unsigned int y;
+ u16 *sbuf;
+
+ /*
+ * The cma memory is write-combined so reads are uncached.
+ * Speed up by fetching one line at a time.
+ */
+ sbuf = kmalloc(src_len, GFP_KERNEL);
+ if (!sbuf)
+ return;
+
+ memset(sbuf, 0, src_len);
+
+ vaddr += rect->y1 * fb->pitches[0] + rect->x1 * fb->format->cpp[0];
+ for (y = 0; y < lines; y++) {
+ memcpy(sbuf, vaddr, src_len);
+ ili9488_rgb565_to_rgb666_line(dst, sbuf, linepixels);
+ vaddr += fb->pitches[0];
+ dst += dst_len;
+ }
+ kfree(sbuf);
+}
+
+static int ili9488_buf_copy(void *dst, struct drm_framebuffer *fb,
+ struct drm_rect *rect)
+{
+ struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+ void *src = cma_obj->vaddr;
+ int ret = 0;
+
+ ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+ if (ret)
+ return ret;
+
+ switch (fb->format->format) {
+ case DRM_FORMAT_RGB565:
+ ili9488_rgb565_to_rgb666(dst, src, fb, rect);
+ break;
+ default:
+ dev_err_once(fb->dev->dev, "Format is not supported: %p4cc\n",
+ &fb->format->format);
+ return -EINVAL;
+ }
+
+ drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+ return ret;
+}
+
+static void ili9488_dbi_set_window_address(struct mipi_dbi_dev *dbidev,
+ unsigned int xs, unsigned int xe,
+ unsigned int ys, unsigned int ye)
+{
+ struct mipi_dbi *dbi = &dbidev->dbi;
+
+ xs += dbidev->left_offset;
+ xe += dbidev->left_offset;
+ ys += dbidev->top_offset;
+ ye += dbidev->top_offset;
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, (xs >> 8) & 0xff,
+ xs & 0xff, (xe >> 8) & 0xff, xe & 0xff);
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, (ys >> 8) & 0xff,
+ ys & 0xff, (ye >> 8) & 0xff, ye & 0xff);
+}
+
+static void ili9488_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
+{
+ struct iosys_map map[DRM_FORMAT_MAX_PLANES];
+ struct iosys_map data[DRM_FORMAT_MAX_PLANES];
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
+ unsigned int height = rect->y2 - rect->y1;
+ unsigned int width = rect->x2 - rect->x1;
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int idx, ret = 0;
+ bool full;
+ void *tr;
+
+ if (WARN_ON(!fb))
+ return;
+
+ if (!drm_dev_enter(fb->dev, &idx))
+ return;
+
+ ret = drm_gem_fb_vmap(fb, map, data);
+ if (ret)
+ goto err_drm_dev_exit;
+
+ full = width == fb->width && height == fb->height;
+
+ DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
+
+ if (!dbi->dc || !full ||
+ fb->format->format == DRM_FORMAT_RGB565) {
+ tr = dbidev->tx_buf;
+ ret = ili9488_buf_copy(dbidev->tx_buf, fb, rect);
+ if (ret)
+ goto err_msg;
+ } else {
+ tr = data[0].vaddr; /* TODO: Use mapping abstraction properly */
+ }
+
+ ili9488_dbi_set_window_address(dbidev, rect->x1, rect->x2 - 1, rect->y1,
+ rect->y2 - 1);
+
+ ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr,
+ width * height * 3);
+err_msg:
+ if (ret)
+ drm_err_once(fb->dev, "Failed to update display %d\n", ret);
+
+ drm_gem_fb_vunmap(fb, map);
+
+err_drm_dev_exit:
+ drm_dev_exit(idx);
+}
+
+static void ili9488_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_state)
+{
+ struct drm_plane_state *state = pipe->plane.state;
+ struct drm_rect rect;
+
+ if (!pipe->crtc.state->active)
+ return;
+
+ if (drm_atomic_helper_damage_merged(old_state, state, &rect))
+ ili9488_fb_dirty(state->fb, &rect);
+}
+
+static void ili9488_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 drm_framebuffer *fb = plane_state->fb;
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ u8 addr_mode;
+ struct drm_rect rect = {
+ .x1 = 0,
+ .x2 = fb->width,
+ .y1 = 0,
+ .y2 = fb->height,
+ };
+ int ret, idx;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ DRM_DEBUG_KMS("\n");
+
+ ret = mipi_dbi_poweron_conditional_reset(dbidev);
+ if (ret < 0)
+ goto out_exit;
+ if (ret == 1)
+ goto out_enable;
+
+ mipi_dbi_command(dbi, ILI9488_DISPLAY_INVERSION_ON);
+ mipi_dbi_command(dbi, ILI9488_POWER_CONTROL_3, 0x33);
+ mipi_dbi_command(dbi, ILI9488_FRAME_RATE_CONTROL_NORMAL, 0xB0);
+ mipi_dbi_command(dbi, ILI9488_MEM_ACCESS_CONTROL, 0x28);
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x65);
+
+ mipi_dbi_command(dbi, ILI9488_POSITIVE_GAMMA_CORRECTION,
+ 0x00, 0x13, 0x18, 0x04, 0x0F,
+ 0x06, 0x3A, 0x56, 0x4D, 0x03,
+ 0x0A, 0x06, 0x30, 0x3E, 0x0F);
+ mipi_dbi_command(dbi, ILI9488_NEGATIVE_GAMMA_CORRECTION,
+ 0x00, 0x13, 0x18, 0x01, 0x11,
+ 0x06, 0x38, 0x3A, 0x4D, 0x06,
+ 0x0D, 0x0B, 0x31, 0x37, 0x0F);
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_18BIT);
+ mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+ msleep(120);
+ mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+ msleep(100);
+
+out_enable:
+ switch (dbidev->rotation) {
+ default:
+ addr_mode = ILI9488_MADCTL_MX;
+ break;
+ case 90:
+ addr_mode = ILI9488_MADCTL_MV;
+ break;
+ case 180:
+ addr_mode = ILI9488_MADCTL_MY;
+ break;
+ case 270:
+ addr_mode = ILI9488_MADCTL_MV | ILI9488_MADCTL_MY |
+ ILI9488_MADCTL_MX;
+ break;
+ }
+ addr_mode |= ILI9488_MADCTL_BGR;
+ mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+ ili9488_fb_dirty(fb, &rect);
+out_exit:
+ drm_dev_exit(idx);
+}
+
+static void ili9488_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
+ /*
+ * This callback is not protected by drm_dev_enter/exit since we want to
+ * turn off the display on regular driver unload. It's highly unlikely
+ * that the underlying SPI controller is gone should this be called
+ * after unplug.
+ */
+
+ DRM_DEBUG_KMS("\n");
+
+ mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
+}
+
+static const u32 ili9488_formats[] = {
+ DRM_FORMAT_RGB565,
+};
+
+static const struct drm_simple_display_pipe_funcs ili9488_pipe_funcs = {
+ .enable = ili9488_pipe_enable,
+ .disable = ili9488_pipe_disable,
+ .update = ili9488_pipe_update,
+};
+
+static const struct drm_display_mode ili9488_mode = {
+ DRM_SIMPLE_MODE(320, 480, 49, 73),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(ili9488_fops);
+
+static struct drm_driver ili9488_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &ili9488_fops,
+ DRM_GEM_CMA_DRIVER_OPS_VMAP,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "ili9488",
+ .desc = "Ilitek ILI9488",
+ .date = "20221017",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id ili9488_of_match[] = {
+ { .compatible = "waveshare,pico-rt-lcd-35" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ili9488_of_match);
+
+static const struct spi_device_id ili9488_id[] = {
+ { "ili9488", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ili9488_id);
+
+static int ili9488_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct mipi_dbi_dev *dbidev;
+ struct drm_device *drm;
+ struct mipi_dbi *dbi;
+ struct gpio_desc *dc;
+ u32 rotation = 0;
+ size_t bufsize;
+ int ret;
+
+ dbidev = devm_drm_dev_alloc(dev, &ili9488_driver,
+ struct mipi_dbi_dev, drm);
+ if (IS_ERR(dbidev))
+ return PTR_ERR(dbidev);
+
+ dbi = &dbidev->dbi;
+ drm = &dbidev->drm;
+
+ bufsize = ili9488_mode.vdisplay * ili9488_mode.hdisplay * 3;
+
+ dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(dbi->reset)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
+ return PTR_ERR(dbi->reset);
+ }
+
+ dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(dc)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
+ return PTR_ERR(dc);
+ }
+
+ 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;
+
+ dbidev->drm.mode_config.preferred_depth = 16;
+
+ ret = mipi_dbi_dev_init_with_formats(dbidev, &ili9488_pipe_funcs,
+ ili9488_formats,
+ ARRAY_SIZE(ili9488_formats),
+ &ili9488_mode, rotation, bufsize);
+ if (ret)
+ return ret;
+
+ dbi->swap_bytes = true;
+ 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 void ili9488_remove(struct spi_device *spi)
+{
+ struct drm_device *drm = spi_get_drvdata(spi);
+
+ drm_dev_unplug(drm);
+ drm_atomic_helper_shutdown(drm);
+}
+
+static void ili9488_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static struct spi_driver ili9488_spi_driver = {
+ .driver = {
+ .name = "ili9488",
+ .owner = THIS_MODULE,
+ .of_match_table = ili9488_of_match,
+ },
+ .id_table = ili9488_id,
+ .probe = ili9488_probe,
+ .remove = ili9488_remove,
+ .shutdown = ili9488_shutdown,
+};
+module_spi_driver(ili9488_spi_driver);
+
+MODULE_DESCRIPTION("Ilitek ILI9488 DRM driver");
+MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@xxxxxxxxx>");
+MODULE_AUTHOR("Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
\ No newline at end of file
--
2.25.1