* [PATCH 2/3] drm: tiny: Add support for Mayqueen Pixpaper e-ink panel
2025-07-08 10:06 [PATCH 0/3] Add support for Mayqueen Pixpaper e-ink panel LiangCheng Wang
2025-07-08 10:06 ` [PATCH 1/3] dt-bindings: vendor-prefixes: Add Mayqueen name LiangCheng Wang
@ 2025-07-08 10:06 ` LiangCheng Wang
2025-07-09 15:02 ` kernel test robot
2025-07-08 10:06 ` [PATCH 3/3] dt-bindings: display: Add " LiangCheng Wang
2 siblings, 1 reply; 7+ messages in thread
From: LiangCheng Wang @ 2025-07-08 10:06 UTC (permalink / raw)
To: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Simona Vetter,
Sumit Semwal, Christian König, Wig Cheng
Cc: devicetree, linux-kernel, dri-devel, linux-media, linaro-mm-sig,
LiangCheng Wang
Introduce a DRM driver for the Mayqueen Pixpaper e-ink display panel,
which is controlled via SPI. The driver supports a 122x250 resolution
display with XRGB8888 format.
Also, add a MAINTAINERS entry for the Pixpaper driver.
Signed-off-by: LiangCheng Wang <zaq14760@gmail.com>
---
MAINTAINERS | 6 +
drivers/gpu/drm/tiny/Kconfig | 15 +
drivers/gpu/drm/tiny/Makefile | 1 +
drivers/gpu/drm/tiny/pixpaper.c | 784 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 806 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index fad6cb025a1918beec113b576cf28b76151745ef..0613f32ef8a702e508c9a2e51853f8fe6a38ba42 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7756,6 +7756,12 @@ T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
F: Documentation/devicetree/bindings/display/repaper.txt
F: drivers/gpu/drm/tiny/repaper.c
+DRM DRIVER FOR PIXPAPER E-INK PANEL
+M: LiangCheng Wang <zaq14760@gmail.com>
+S: Maintained
+F: Documentation/devicetree/bindings/display/mayqueen,pixpaper.yaml
+F: drivers/gpu/drm/tiny/pixpaper.c
+
DRM DRIVER FOR QEMU'S CIRRUS DEVICE
M: Dave Airlie <airlied@redhat.com>
M: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index 06e54694a7f2fe1649e1886f039926b24f698e0d..f9b814e87348cad1946dd5e2ff54d304100ef264 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig
@@ -164,6 +164,21 @@ config TINYDRM_MI0283QT
DRM driver for the Multi-Inno MI0283QT display panel
If M is selected the module will be called mi0283qt.
+config TINYDRM_PIXPAPER
+ tristate "DRM support for PIXPAPER display panels"
+ depends on DRM && SPI
+ select DRM_CLIENT_SELECTION
+ select DRM_KMS_HELPER
+ select DRM_GEM_DMA_HELPER
+ help
+ DRM driver for the Mayqueen Pixpaper e-ink display panel.
+
+ This driver supports small e-paper displays connected over SPI,
+ with a resolution of 122x250 and XRGB8888 framebuffer format.
+ It is intended for low-power embedded applications.
+
+ If M is selected, the module will be built as pixpaper.ko.
+
config TINYDRM_REPAPER
tristate "DRM support for Pervasive Displays RePaper panels (V231)"
depends on DRM && SPI
diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile
index 4a9ff61ec25420e2c0a648c04eaab7ca25dd5407..40d613b57f5ee990dbf170d69939a39546be21b7 100644
--- a/drivers/gpu/drm/tiny/Makefile
+++ b/drivers/gpu/drm/tiny/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_TINYDRM_ILI9225) += ili9225.o
obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o
obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
+obj-$(CONFIG_TINYDRM_PIXPAPER) += pixpaper.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
obj-$(CONFIG_TINYDRM_SHARP_MEMORY) += sharp-memory.o
diff --git a/drivers/gpu/drm/tiny/pixpaper.c b/drivers/gpu/drm/tiny/pixpaper.c
new file mode 100644
index 0000000000000000000000000000000000000000..14768144997205319215784fa3c3a904fed8d1e1
--- /dev/null
+++ b/drivers/gpu/drm/tiny/pixpaper.c
@@ -0,0 +1,784 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DRM driver for PIXPAPER e-ink panel
+ *
+ * Author: LiangCheng Wang <zaq14760@gmail.com>,
+ */
+#include <drm/clients/drm_client_setup.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fbdev_dma.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_probe_helper.h>
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+MODULE_IMPORT_NS("DMA_BUF");
+
+#define PIXPAPER_WIDTH 122
+#define PIXPAPER_HEIGHT 250
+
+#define PANEL_BUFFER_WIDTH 128
+#define PANEL_BUFFER_TWO_BYTES_PER_ROW (PANEL_BUFFER_WIDTH / 4)
+
+#define PIXPAPER_SPI_SPEED_DEFAULT 1000000
+
+#define PIXPAPER_CMD_PANEL_SETTING 0x00
+#define PIXPAPER_CMD_POWER_SETTING 0x01
+#define PIXPAPER_CMD_POWER_OFF 0x02
+#define PIXPAPER_CMD_POWER_OFF_SEQUENCE 0x03
+#define PIXPAPER_CMD_POWER_ON 0x04
+#define PIXPAPER_CMD_BOOSTER_SOFT_START 0x06
+#define PIXPAPER_CMD_DEEP_SLEEP 0x07
+#define PIXPAPER_CMD_DATA_START_TRANSMISSION 0x10
+#define PIXPAPER_CMD_DISPLAY_REFRESH 0x12
+#define PIXPAPER_CMD_PLL_CONTROL 0x30
+#define PIXPAPER_CMD_TEMP_SENSOR_CALIB 0x41
+#define PIXPAPER_CMD_UNKNOWN_4D 0x4D
+#define PIXPAPER_CMD_VCOM_INTERVAL 0x50
+#define PIXPAPER_CMD_TCON_SETTING 0x60
+#define PIXPAPER_CMD_RESOLUTION_SETTING 0x61
+#define PIXPAPER_CMD_GATE_SOURCE_START 0x65
+#define PIXPAPER_CMD_UNKNOWN_B4 0xB4
+#define PIXPAPER_CMD_UNKNOWN_B5 0xB5
+#define PIXPAPER_CMD_CASCADE_SETTING 0xE0
+#define PIXPAPER_CMD_POWER_SAVING 0xE3
+#define PIXPAPER_CMD_AUTO_MEASURE_VCOM 0xE7
+#define PIXPAPER_CMD_UNKNOWN_E9 0xE9
+
+static int pixpaper_crtc_helper_atomic_check(struct drm_crtc *crtc,
+ struct drm_atomic_state *state);
+static int pixpaper_plane_helper_atomic_check(struct drm_plane *plane,
+ struct drm_atomic_state *state);
+static void pixpaper_crtc_atomic_enable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state);
+static void pixpaper_crtc_atomic_disable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state);
+static void pixpaper_plane_atomic_update(struct drm_plane *plane,
+ struct drm_atomic_state *state);
+static int pixpaper_connector_get_modes(struct drm_connector *connector);
+
+struct pixpaper_panel {
+ struct drm_device drm;
+ struct drm_plane plane;
+ struct drm_crtc crtc;
+ struct drm_encoder encoder;
+ struct drm_connector connector;
+
+ struct spi_device *spi;
+ struct gpio_desc *reset;
+ struct gpio_desc *busy;
+ struct gpio_desc *dc;
+};
+
+static const struct drm_plane_funcs pixpaper_plane_funcs = {
+ .update_plane = drm_atomic_helper_update_plane,
+ .disable_plane = drm_atomic_helper_disable_plane,
+ .destroy = drm_plane_cleanup,
+ .reset = drm_atomic_helper_plane_reset,
+ DRM_GEM_SHADOW_PLANE_FUNCS,
+};
+
+static const struct drm_plane_helper_funcs pixpaper_plane_helper_funcs = {
+ DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
+ .atomic_check = pixpaper_plane_helper_atomic_check,
+ .atomic_update = pixpaper_plane_atomic_update,
+};
+
+static const struct drm_crtc_funcs pixpaper_crtc_funcs = {
+ .set_config = drm_atomic_helper_set_config,
+ .page_flip = drm_atomic_helper_page_flip,
+ .reset = drm_atomic_helper_crtc_reset,
+ .destroy = drm_crtc_cleanup,
+ .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static const struct drm_crtc_helper_funcs pixpaper_crtc_helper_funcs = {
+ .atomic_check = pixpaper_crtc_helper_atomic_check,
+ .atomic_enable = pixpaper_crtc_atomic_enable,
+ .atomic_disable = pixpaper_crtc_atomic_disable,
+};
+
+static const struct drm_encoder_funcs pixpaper_encoder_funcs = {
+ .destroy = drm_encoder_cleanup,
+};
+
+static const struct drm_connector_funcs pixpaper_connector_funcs = {
+ .reset = drm_atomic_helper_connector_reset,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = drm_connector_cleanup,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_connector_helper_funcs pixpaper_connector_helper_funcs = {
+ .get_modes = pixpaper_connector_get_modes,
+};
+
+static int pixpaper_plane_helper_atomic_check(struct drm_plane *plane,
+ struct drm_atomic_state *state)
+{
+ struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
+ struct drm_crtc *new_crtc = new_plane_state->crtc;
+ struct drm_crtc_state *new_crtc_state = NULL;
+ int ret;
+
+ if (new_crtc)
+ new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
+
+ ret = drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
+ DRM_PLANE_NO_SCALING,
+ DRM_PLANE_NO_SCALING,
+ false, false);
+ if (ret)
+ return ret;
+ else if (!new_plane_state->visible)
+ return 0;
+
+ return 0;
+}
+
+static int pixpaper_crtc_helper_atomic_check(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+
+ if (!crtc_state->enable)
+ return 0;
+
+ return drm_atomic_helper_check_crtc_primary_plane(crtc_state);
+}
+
+static void pixpaper_wait_busy(struct pixpaper_panel *panel)
+{
+ unsigned int delay_us = 1000;
+
+ usleep_range(delay_us, delay_us + 500);
+ while (true)
+ if (gpiod_get_value_cansleep(panel->busy) == 1)
+ break;
+}
+
+static int pixpaper_spi_sync(struct spi_device *spi, struct spi_message *msg)
+{
+ int ret;
+
+ ret = spi_sync(spi, msg);
+ if (ret < 0)
+ dev_err(&spi->dev, "SPI sync failed: %d\n", ret);
+
+ return ret;
+}
+
+static int pixpaper_send_cmd(struct pixpaper_panel *panel, u8 cmd)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = &cmd,
+ .len = 1,
+ };
+ struct spi_message msg;
+ int ret;
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfer, &msg);
+
+ gpiod_set_value_cansleep(panel->dc, 0);
+ usleep_range(1, 5);
+ ret = pixpaper_spi_sync(panel->spi, &msg);
+
+ return ret;
+}
+
+static int pixpaper_send_data(struct pixpaper_panel *panel, u8 data)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = &data,
+ .len = 1,
+ };
+ struct spi_message msg;
+ int ret;
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfer, &msg);
+
+ gpiod_set_value_cansleep(panel->dc, 1);
+ usleep_range(1, 5);
+ ret = pixpaper_spi_sync(panel->spi, &msg);
+
+ return ret;
+}
+
+static int pixpaper_panel_hw_init(struct pixpaper_panel *panel)
+{
+ struct device *dev = &panel->spi->dev;
+ int ret = 0;
+
+ dev_info(dev, "%s: Starting hardware initialization\n", __func__);
+
+ gpiod_set_value_cansleep(panel->reset, 0);
+ msleep(50);
+ gpiod_set_value_cansleep(panel->reset, 1);
+ msleep(50);
+
+ pixpaper_wait_busy(panel);
+ dev_info(dev, "Hardware reset complete, panel idle.\n");
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_UNKNOWN_4D);
+ ret |= pixpaper_send_data(panel, 0x78);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_PANEL_SETTING);
+ ret |= pixpaper_send_data(panel, 0x0F);
+ ret |= pixpaper_send_data(panel, 0x09);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_SETTING);
+ ret |= pixpaper_send_data(panel, 0x07);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0x22);
+ ret |= pixpaper_send_data(panel, 0x78);
+ ret |= pixpaper_send_data(panel, 0x0A);
+ ret |= pixpaper_send_data(panel, 0x22);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_OFF_SEQUENCE);
+ ret |= pixpaper_send_data(panel, 0x10);
+ ret |= pixpaper_send_data(panel, 0x54);
+ ret |= pixpaper_send_data(panel, 0x44);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_BOOSTER_SOFT_START);
+ ret |= pixpaper_send_data(panel, 0x0F);
+ ret |= pixpaper_send_data(panel, 0x0A);
+ ret |= pixpaper_send_data(panel, 0x2F);
+ ret |= pixpaper_send_data(panel, 0x25);
+ ret |= pixpaper_send_data(panel, 0x22);
+ ret |= pixpaper_send_data(panel, 0x2E);
+ ret |= pixpaper_send_data(panel, 0x21);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_PLL_CONTROL);
+ ret |= pixpaper_send_data(panel, 0x02);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_TEMP_SENSOR_CALIB);
+ ret |= pixpaper_send_data(panel, 0x00);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_VCOM_INTERVAL);
+ ret |= pixpaper_send_data(panel, 0x37);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_TCON_SETTING);
+ ret |= pixpaper_send_data(panel, 0x02);
+ ret |= pixpaper_send_data(panel, 0x02);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_RESOLUTION_SETTING);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0x80);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0xFA);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_GATE_SOURCE_START);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0x00);
+ ret |= pixpaper_send_data(panel, 0x00);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_AUTO_MEASURE_VCOM);
+ ret |= pixpaper_send_data(panel, 0x1C);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_SAVING);
+ ret |= pixpaper_send_data(panel, 0x22);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_CASCADE_SETTING);
+ ret |= pixpaper_send_data(panel, 0x00);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_UNKNOWN_B4);
+ ret |= pixpaper_send_data(panel, 0xD0);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_UNKNOWN_B5);
+ ret |= pixpaper_send_data(panel, 0x03);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ ret |= pixpaper_send_cmd(panel, PIXPAPER_CMD_UNKNOWN_E9);
+ ret |= pixpaper_send_data(panel, 0x01);
+ if (ret)
+ goto init_fail;
+ pixpaper_wait_busy(panel);
+
+ dev_info(dev, "%s: Hardware initialization successful\n", __func__);
+ return 0;
+
+init_fail:
+ dev_err(dev, "%s: Hardware initialization failed (err=%d)\n", __func__,
+ ret);
+ return ret;
+}
+
+static void pixpaper_crtc_atomic_enable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct pixpaper_panel *panel =
+ container_of(crtc, struct pixpaper_panel, crtc);
+ struct drm_device *drm = &panel->drm;
+ int ret;
+
+ dev_info(drm->dev, "%s: Enabling pipe\n", __func__);
+
+ ret = pixpaper_panel_hw_init(panel);
+ if (ret) {
+ dev_err(drm->dev, "Panel HW Init failed during enable: %d\n",
+ ret);
+ return;
+ }
+
+ dev_info(drm->dev, "Sending Power ON (PON)\n");
+ ret = pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_ON);
+ if (ret) {
+ dev_err(drm->dev, "Failed to send PON command: %d\n", ret);
+ return;
+ }
+
+ usleep_range(10000, 11000);
+
+ pixpaper_wait_busy(panel);
+
+ dev_info(drm->dev, "Panel enabled and powered on\n");
+}
+
+static void pixpaper_crtc_atomic_disable(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct pixpaper_panel *panel =
+ container_of(crtc, struct pixpaper_panel, crtc);
+ struct drm_device *drm = &panel->drm;
+ int ret;
+
+ dev_dbg(drm->dev, "%s: Disabling pipe\n", __func__);
+
+ ret = pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_OFF);
+ if (!ret) {
+ usleep_range(10000, 11000);
+ pixpaper_wait_busy(panel);
+ } else {
+ dev_warn(drm->dev, "Failed to send POF command: %d\n", ret);
+ }
+ dev_info(drm->dev, "Panel disabled\n");
+}
+
+static u8 pack_pixels_to_byte(u32 *src_pixels, int i, int j,
+ struct drm_framebuffer *fb)
+{
+ u8 packed_byte = 0;
+ int k;
+
+ for (k = 0; k < 4; k++) {
+ int current_pixel_x = j * 4 + k;
+ u8 two_bit_val;
+
+ if (current_pixel_x < PIXPAPER_WIDTH) {
+ u32 pixel_offset =
+ (i * (fb->pitches[0] / 4)) + current_pixel_x;
+ u32 pixel = src_pixels[pixel_offset];
+ u32 r = (pixel >> 16) & 0xFF;
+ u32 g = (pixel >> 8) & 0xFF;
+ u32 b = pixel & 0xFF;
+ u32 gray_val =
+ (r * 299 + g * 587 + b * 114 + 500) / 1000;
+
+ if (gray_val < 64)
+ two_bit_val = 0b00;
+ else if (gray_val < 128)
+ two_bit_val = 0b01;
+ else if (gray_val < 192)
+ two_bit_val = 0b10;
+ else
+ two_bit_val = 0b11;
+ } else {
+ two_bit_val = 0b11;
+ }
+
+ packed_byte |= two_bit_val << ((3 - k) * 2);
+ }
+
+ return packed_byte;
+}
+
+static void pixpaper_plane_atomic_update(struct drm_plane *plane,
+ struct drm_atomic_state *state)
+{
+ struct drm_plane_state *plane_state =
+ drm_atomic_get_new_plane_state(state, plane);
+ struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+ struct drm_crtc *crtc = plane_state->crtc;
+ struct pixpaper_panel *panel =
+ container_of(crtc, struct pixpaper_panel, crtc);
+
+ struct drm_device *drm = &panel->drm;
+ struct drm_framebuffer *fb = plane_state->fb;
+ struct iosys_map map = shadow_plane_state->data[0];
+ void *vaddr = map.vaddr;
+ int i, j, ret = 0;
+ u32 *src_pixels = NULL;
+
+ dev_info(drm->dev, "Starting frame update (phys=%dx%d, buf_w=%d)\n",
+ PIXPAPER_WIDTH, PIXPAPER_HEIGHT, PANEL_BUFFER_WIDTH);
+
+ if (!fb || !plane_state->visible) {
+ dev_err(drm->dev,
+ "No framebuffer or plane not visible, skipping update\n");
+ return;
+ }
+
+ if (ret) {
+ dev_err(drm->dev, "Failed to vmap dma_buf\n");
+ return;
+ }
+
+ src_pixels = (u32 *)vaddr;
+
+ dev_info(drm->dev, "Sending DTM command\n");
+ ret = pixpaper_send_cmd(panel, PIXPAPER_CMD_DATA_START_TRANSMISSION);
+ if (ret)
+ goto update_cleanup;
+
+ usleep_range(10000, 11000);
+ pixpaper_wait_busy(panel);
+
+ dev_info(drm->dev,
+ "Panel idle after DTM command, starting data batch send.\n");
+
+ for (i = 0; i < PIXPAPER_HEIGHT; i++) {
+ for (j = 0; j < PANEL_BUFFER_TWO_BYTES_PER_ROW; j++) {
+ u8 packed_byte =
+ pack_pixels_to_byte(src_pixels, i, j, fb);
+
+ pixpaper_wait_busy(panel);
+ pixpaper_send_data(panel, packed_byte);
+ }
+ }
+ pixpaper_wait_busy(panel);
+
+ dev_info(drm->dev, "Sending PON + 0x00 before DRF\n");
+ ret = pixpaper_send_cmd(panel, PIXPAPER_CMD_POWER_ON);
+ if (ret)
+ goto update_cleanup;
+ ret = pixpaper_send_data(panel, 0x00);
+ if (ret) {
+ dev_err(drm->dev,
+ "Failed sending data after PON-before-DRF: %d\n", ret);
+ goto update_cleanup;
+ }
+ usleep_range(10000, 11000);
+ pixpaper_wait_busy(panel);
+
+ dev_info(drm->dev, "Triggering display refresh (DRF)\n");
+ ret = pixpaper_send_cmd(panel, PIXPAPER_CMD_DISPLAY_REFRESH);
+ if (ret)
+ goto update_cleanup;
+ ret = pixpaper_send_data(panel, 0x00);
+ if (ret) {
+ dev_err(drm->dev, "Failed sending data after DRF: %d\n", ret);
+ goto update_cleanup;
+ }
+ usleep_range(10000, 11000);
+ pixpaper_wait_busy(panel);
+
+ dev_info(drm->dev, "Frame update completed and refresh triggered\n");
+
+update_cleanup:
+ if (ret && ret != -ETIMEDOUT)
+ dev_err(drm->dev,
+ "Frame update function failed with error %d\n", ret);
+
+}
+
+static int pixpaper_connector_get_modes(struct drm_connector *connector)
+{
+ struct drm_display_mode *mode;
+
+ dev_info(connector->dev->dev, "%s: CALLED for connector %s (id: %d)\n",
+ __func__, connector->name, connector->base.id);
+
+ mode = drm_mode_create(connector->dev);
+ if (!mode) {
+ DRM_ERROR("Failed to create mode for connector %s\n",
+ connector->name);
+ return 0;
+ }
+
+ mode->hdisplay = PIXPAPER_WIDTH;
+ mode->vdisplay = PIXPAPER_HEIGHT;
+
+ mode->htotal = mode->hdisplay + 80;
+ mode->hsync_start = mode->hdisplay + 8;
+ mode->hsync_end = mode->hdisplay + 8 + 32;
+ mode->vtotal = mode->vdisplay + 10;
+ mode->vsync_start = mode->vdisplay + 2;
+ mode->vsync_end = mode->vdisplay + 2 + 2;
+
+ mode->clock = 6000;
+
+ mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+ drm_mode_set_name(mode);
+
+ if (drm_mode_validate_size(mode, connector->dev->mode_config.max_width,
+ connector->dev->mode_config.max_height) !=
+ MODE_OK) {
+ DRM_WARN(
+ "%s: Mode %s (%dx%d) failed size validation against max %dx%d\n",
+ __func__, mode->name, mode->hdisplay, mode->vdisplay,
+ connector->dev->mode_config.max_width,
+ connector->dev->mode_config.max_height);
+ drm_mode_destroy(connector->dev, mode);
+ return 0;
+ }
+
+ drm_mode_probed_add(connector, mode);
+ dev_info(connector->dev->dev,
+ "%s: Added mode '%s' (%dx%d@%d) to connector %s\n", __func__,
+ mode->name, mode->hdisplay, mode->vdisplay,
+ drm_mode_vrefresh(mode), connector->name);
+
+ connector->display_info.width_mm = 30;
+ connector->display_info.height_mm = 47;
+
+ return 1;
+}
+
+DEFINE_DRM_GEM_DMA_FOPS(pixpaper_fops);
+
+static struct drm_driver pixpaper_drm_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &pixpaper_fops,
+ .name = "pixpaper",
+ .desc = "DRM driver for PIXPAPER e-ink",
+ .major = 1,
+ .minor = 0,
+ .fops = &pixpaper_fops,
+ DRM_GEM_DMA_DRIVER_OPS_VMAP,
+ DRM_FBDEV_DMA_DRIVER_OPS,
+};
+
+static int pixpaper_mode_valid(struct drm_device *dev,
+ const struct drm_display_mode *mode)
+{
+ if (mode->hdisplay == PIXPAPER_WIDTH &&
+ mode->vdisplay == PIXPAPER_HEIGHT) {
+ return MODE_OK;
+ }
+ dev_dbg(dev->dev, "Rejecting mode %dx%d (supports only %dx%d)\n",
+ mode->hdisplay, mode->vdisplay, PIXPAPER_WIDTH,
+ PIXPAPER_HEIGHT);
+ return MODE_BAD;
+}
+
+static const struct drm_mode_config_funcs pixpaper_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create_with_dirty,
+ .mode_valid = pixpaper_mode_valid,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static int pixpaper_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct pixpaper_panel *panel;
+ struct drm_device *drm;
+ int ret;
+
+ dev_info(dev, "Probing PIXPAPER panel driver\n");
+
+ panel = devm_drm_dev_alloc(dev, &pixpaper_drm_driver,
+ struct pixpaper_panel, drm);
+ if (IS_ERR(panel)) {
+ ret = PTR_ERR(panel);
+ dev_err(dev, "Failed to allocate DRM device: %d\n", ret);
+ return ret;
+ }
+ drm = &panel->drm;
+ panel->spi = spi;
+ spi_set_drvdata(spi, panel);
+
+ spi->mode = SPI_MODE_0;
+ spi->bits_per_word = 8;
+
+ if (!spi->max_speed_hz) {
+ dev_warn(
+ dev,
+ "spi-max-frequency not specified in DT, using default %u Hz\n",
+ PIXPAPER_SPI_SPEED_DEFAULT);
+ spi->max_speed_hz = PIXPAPER_SPI_SPEED_DEFAULT;
+ } else {
+ dev_info(dev, "Using spi-max-frequency from DT: %u Hz\n",
+ spi->max_speed_hz);
+ }
+
+ ret = spi_setup(spi);
+ if (ret < 0) {
+ dev_err(dev, "SPI setup failed: %d\n", ret);
+ return ret;
+ }
+ dev_info(dev, "SPI setup OK (mode=%d, speed=%u Hz, bpw=%d)\n",
+ spi->mode, spi->max_speed_hz, spi->bits_per_word);
+
+ if (!dev->dma_mask)
+ dev->dma_mask = &dev->coherent_dma_mask;
+ ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (ret) {
+ dev_err(dev, "Failed to set DMA mask: %d\n", ret);
+ return ret;
+ }
+ dev_dbg(dev, "DMA mask set\n");
+
+ panel->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(panel->reset))
+ return dev_err_probe(dev, PTR_ERR(panel->reset),
+ "Failed to get 'reset' GPIO\n");
+ panel->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
+ if (IS_ERR(panel->busy))
+ return dev_err_probe(dev, PTR_ERR(panel->busy),
+ "Failed to get 'busy' GPIO\n");
+ panel->dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_HIGH);
+ if (IS_ERR(panel->dc))
+ return dev_err_probe(dev, PTR_ERR(panel->dc),
+ "Failed to get 'dc' GPIO\n");
+ dev_info(dev, "All required GPIOs obtained successfully.\n");
+
+ ret = drmm_mode_config_init(drm);
+ if (ret)
+ return ret;
+ drm->mode_config.funcs = &pixpaper_mode_config_funcs;
+ drm->mode_config.min_width = PIXPAPER_WIDTH;
+ drm->mode_config.max_width = PIXPAPER_WIDTH;
+ drm->mode_config.min_height = PIXPAPER_HEIGHT;
+ drm->mode_config.max_height = PIXPAPER_HEIGHT;
+
+ ret = drm_universal_plane_init(
+ drm, &panel->plane, 1, &pixpaper_plane_funcs,
+ (const uint32_t[]){ DRM_FORMAT_XRGB8888 }, 1, NULL,
+ DRM_PLANE_TYPE_PRIMARY, NULL);
+ drm_plane_enable_fb_damage_clips(&panel->plane);
+ if (ret)
+ return ret;
+ drm_plane_helper_add(&panel->plane, &pixpaper_plane_helper_funcs);
+
+ ret = drm_crtc_init_with_planes(drm, &panel->crtc, &panel->plane, NULL,
+ &pixpaper_crtc_funcs, NULL);
+ if (ret)
+ return ret;
+ drm_crtc_helper_add(&panel->crtc, &pixpaper_crtc_helper_funcs);
+
+ ret = drm_encoder_init(drm, &panel->encoder, &pixpaper_encoder_funcs,
+ DRM_MODE_ENCODER_DAC, NULL);
+ if (ret)
+ return ret;
+ panel->encoder.possible_crtcs = drm_crtc_mask(&panel->crtc);
+
+ ret = drm_connector_init(drm, &panel->connector,
+ &pixpaper_connector_funcs,
+ DRM_MODE_CONNECTOR_SPI);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(&panel->connector,
+ &pixpaper_connector_helper_funcs);
+ drm_connector_attach_encoder(&panel->connector, &panel->encoder);
+
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ret;
+
+ drm_client_setup(drm, NULL);
+
+ dev_info(dev, "Initialized PIXPAPER panel driver successfully\n");
+ return 0;
+}
+
+static void pixpaper_remove(struct spi_device *spi)
+{
+ struct pixpaper_panel *panel = spi_get_drvdata(spi);
+
+ if (!panel)
+ return;
+
+ dev_info(&spi->dev, "Removing PIXPAPER panel driver\n");
+
+ drm_dev_unplug(&panel->drm);
+ drm_atomic_helper_shutdown(&panel->drm);
+}
+
+static const struct spi_device_id pixpaper_ids[] = { { "pixpaper", 0 }, {} };
+MODULE_DEVICE_TABLE(spi, pixpaper_ids);
+
+static const struct of_device_id pixpaper_dt_ids[] = {
+ { .compatible = "mayqueen,pixpaper" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pixpaper_dt_ids);
+
+static struct spi_driver pixpaper_spi_driver = {
+ .driver = {
+ .name = "pixpaper",
+ .of_match_table = pixpaper_dt_ids,
+ },
+ .id_table = pixpaper_ids,
+ .probe = pixpaper_probe,
+ .remove = pixpaper_remove,
+};
+
+module_spi_driver(pixpaper_spi_driver);
+
+MODULE_AUTHOR("LiangCheng Wang");
+MODULE_DESCRIPTION("DRM SPI driver for PIXPAPER e-ink panel");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread