* [PATCH v4 2/3] drm/ch1115: add support for Chipwealth CH1115 OLED controller
2026-09-07 12:23 [PATCH v4 0/3] Add support for CH1115 Controller Nicolás Antinori
2026-09-07 12:23 ` [PATCH v4 1/3] dt-bindings: display: add Chipwealth CH1115 OLED Controller Nicolás Antinori
@ 2026-09-07 12:23 ` Nicolás Antinori
2026-09-07 12:43 ` sashiko-bot
2026-09-07 12:23 ` [PATCH v4 3/3] MAINTAINERS: add entry for Chipwealth CH1115 OLED Controller Nicolás Antinori
2 siblings, 1 reply; 5+ messages in thread
From: Nicolás Antinori @ 2026-09-07 12:23 UTC (permalink / raw)
To: Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: Nicolás Antinori, Brigham Campbell, Christophe JAILLET,
Jori Koolstra, Shuah Khan, devicetree, dri-devel, linux-kernel,
linux-kernel-mentees
Chipwealth CH1115 is a controller for monochrome dot matrix OLED panels.
Add DRM support for this chip using i2c bus.
Signed-off-by: Nicolás Antinori <nico.antinori.7@gmail.com>
---
Notes:
- Patch series based on 7.3-rc1
drivers/gpu/drm/Kconfig | 1 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/chipwealth/Kconfig | 16 +
drivers/gpu/drm/chipwealth/Makefile | 3 +
drivers/gpu/drm/chipwealth/ch1115-i2c.c | 885 ++++++++++++++++++++++++
5 files changed, 906 insertions(+)
create mode 100644 drivers/gpu/drm/chipwealth/Kconfig
create mode 100644 drivers/gpu/drm/chipwealth/Makefile
create mode 100644 drivers/gpu/drm/chipwealth/ch1115-i2c.c
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index ba242a8318a8..7aa3ca225434 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -307,6 +307,7 @@ source "drivers/gpu/drm/aspeed/Kconfig"
source "drivers/gpu/drm/ast/Kconfig"
source "drivers/gpu/drm/atmel-hlcdc/Kconfig"
source "drivers/gpu/drm/bridge/Kconfig"
+source "drivers/gpu/drm/chipwealth/Kconfig"
source "drivers/gpu/drm/etnaviv/Kconfig"
source "drivers/gpu/drm/exynos/Kconfig"
source "drivers/gpu/drm/fsl-dcu/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 1e21c2ae8730..1160659aa0bf 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -238,6 +238,7 @@ obj-$(CONFIG_DRM_SPRD) += sprd/
obj-$(CONFIG_DRM_LOONGSON) += loongson/
obj-$(CONFIG_DRM_POWERVR) += imagination/
obj-$(CONFIG_DRM_VERISILICON_DC) += verisilicon/
+obj-y += chipwealth/
# Ensure drm headers are self-contained and pass kernel-doc
hdrtest-files := \
diff --git a/drivers/gpu/drm/chipwealth/Kconfig b/drivers/gpu/drm/chipwealth/Kconfig
new file mode 100644
index 000000000000..1cc5adc1e28e
--- /dev/null
+++ b/drivers/gpu/drm/chipwealth/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config DRM_CH1115_I2C
+ tristate "DRM support for Ch1115 OLED panels (I2C BUS)"
+ depends on DRM && I2C
+ select DRM_CLIENT_SELECTION
+ select DRM_GEM_SHMEM_HELPER
+ select DRM_KMS_HELPER
+ select REGMAP_I2C
+ select VIDEOMODE_HELPERS
+ help
+ Chipwealth CH1115 is a controller for monochrome dot matrix OLED
+ panels.
+
+ DRM Driver for Ch1115 OLED panels connected via I2C.
+
+ If M is selected the module will be called ch1115-i2c.
diff --git a/drivers/gpu/drm/chipwealth/Makefile b/drivers/gpu/drm/chipwealth/Makefile
new file mode 100644
index 000000000000..dc915b7d5e93
--- /dev/null
+++ b/drivers/gpu/drm/chipwealth/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_DRM_CH1115_I2C) += ch1115-i2c.o
diff --git a/drivers/gpu/drm/chipwealth/ch1115-i2c.c b/drivers/gpu/drm/chipwealth/ch1115-i2c.c
new file mode 100644
index 000000000000..ddcf25d19b5e
--- /dev/null
+++ b/drivers/gpu/drm/chipwealth/ch1115-i2c.c
@@ -0,0 +1,885 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DRM driver for Ch1115 panels
+ *
+ * Copyright (C) 2026 Nicolás Antinori <nico.antinori.7@gmail.com>
+ *
+ * Datasheet: https://datasheet4u.com/download/1576606/CH1115.html
+ *
+ * Based on
+ * - drivers/gpu/drm/sitronix/st7571-i2c.c
+ * - drivers/gpu/drm/sitronix/st7571.c
+ * Copyright (C) 2025 Marcus Folkesson <marcus.folkesson@gmail.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <drm/clients/drm_client_setup.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_blend.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_fbdev_shmem.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_plane.h>
+#include <drm/drm_probe_helper.h>
+
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+
+#define CH1115_VAL_CLOCK_DIVIDE_RATIO(c, d) (FIELD_PREP(GENMASK(7, 4), (c)) | \
+ FIELD_PREP(GENMASK(3, 0), (d)))
+#define CH1115_VAL_DC_DC_OFF 0x8a
+#define CH1115_VAL_DC_DC_ON 0x8b
+#define CH1115_VAL_PRECHARGE_PERIOD 0x22
+#define CH1115_VAL_CLOCK_OSC_FREQ 0x8
+#define CH1115_VAL_CLOCK_DIV_RATIO 0x0
+#define CH1115_VAL_VCOM_DESELECT_LVL 0x20
+#define CH1115_VAL_CONTRAST 0x7f
+
+#define CH1115_PAGE_HEIGHT 8
+#define CH1115_MAX_WIDTH 128
+#define CH1115_MAX_HEIGHT 64
+#define CH1115_MAX_PAGES 7
+#define CH1115_MAX_CONTRAST 255
+
+#define CH1115_COMMAND_MODE 0x00
+#define CH1115_DATA_MODE 0x40
+
+#define CH1115_CMD_START_LINE 0x40
+#define CH1115_CMD_CONTRAST 0x81
+#define CH1115_CMD_SEG_REMAP_NORMAL 0xa0
+#define CH1115_CMD_SEG_REMAP_FLIP 0xa1
+#define CH1115_CMD_FOLLOW_RAM 0xa4
+#define CH1115_CMD_ALL_ON 0xa5
+#define CH1115_CMD_NORMAL 0xa6
+#define CH1115_CMD_INVERTED 0xa7
+#define CH1115_CMD_MUX_RATIO 0xa8
+#define CH1115_CMD_DC_DC 0xad
+#define CH1115_CMD_OFF 0xae
+#define CH1115_CMD_ON 0xaf
+#define CH1115_CMD_COM_REMAP_NORMAL 0xc0
+#define CH1115_CMD_COM_REMAP_FLIP 0xc8
+#define CH1115_CMD_OFFSET 0xd3
+#define CH1115_CMD_CLOCK_DIVIDE_RATIO 0xd5
+#define CH1115_CMD_PRECHARGE_PERIOD 0xd9
+#define CH1115_CMD_VCOM_DESELECT_LVL 0xdb
+
+#define CH1115_SET_COLUMN_LSB(c) (0x00 | FIELD_PREP(GENMASK(3, 0), (c)))
+#define CH1115_SET_COLUMN_MSB(c) (0x10 | FIELD_PREP(GENMASK(2, 0), (c) >> 4))
+#define CH1115_SET_PAGE(p) (0xb0 | FIELD_PREP(GENMASK(3, 0), (p)))
+
+#define DRIVER_NAME "ch1115"
+#define DRIVER_DESC "ch1115 DRM driver"
+#define DRIVER_MAJOR 1
+#define DRIVER_MINOR 0
+
+struct ch1115_device {
+ struct drm_device dev;
+
+ struct drm_connector connector;
+ struct drm_crtc crtc;
+ struct drm_display_mode mode;
+ struct drm_encoder encoder;
+ struct drm_plane primary_plane;
+
+ struct backlight_device *bl_dev;
+
+ struct i2c_client *client;
+ struct regmap *regmap;
+
+ bool inverted;
+ bool flip_horizontal;
+ bool flip_vertical;
+ u8 contrast;
+
+ u8 pages;
+ u8 bytes_per_row;
+
+ u8 width;
+ u8 height;
+ u32 width_mm;
+ u32 height_mm;
+ u8 x_start_offset;
+ u8 y_start_offset;
+
+ u8 *hwbuf;
+ u8 *row;
+};
+
+static inline int ch1115_send_command_list(struct ch1115_device *ch1115,
+ const u8 *cmd_list, size_t len)
+{
+ return regmap_raw_write(ch1115->regmap, CH1115_COMMAND_MODE, cmd_list, len);
+}
+
+static inline int ch1115_draw_screen(struct ch1115_device *ch1115,
+ const u8 *data, size_t len)
+{
+ return regmap_raw_write(ch1115->regmap, CH1115_DATA_MODE, data, len);
+}
+
+static inline struct ch1115_device *drm_to_ch1115(struct drm_device *dev)
+{
+ return container_of(dev, struct ch1115_device, dev);
+}
+
+static int ch1115_set_position(struct ch1115_device *ch1115, int x, int y)
+{
+ u8 cmd_list[] = {
+ CH1115_SET_PAGE(y / CH1115_PAGE_HEIGHT),
+ CH1115_SET_COLUMN_LSB(x),
+ CH1115_SET_COLUMN_MSB(x),
+ };
+
+ return ch1115_send_command_list(ch1115, cmd_list, ARRAY_SIZE(cmd_list));
+}
+
+static void ch1115_shutdown(struct i2c_client *client)
+{
+ struct ch1115_device *ch1115 = i2c_get_clientdata(client);
+ struct drm_device *drm_dev = &ch1115->dev;
+
+ drm_atomic_helper_shutdown(drm_dev);
+}
+
+static int ch1115_clear_screen(struct ch1115_device *ch1115)
+{
+ int ret;
+ int y = 0;
+ char *row = ch1115->row;
+
+ for (int i = 0; i < ch1115->width; i++)
+ row[i] = 0x00;
+
+ do {
+ ret = ch1115_set_position(ch1115, ch1115->x_start_offset, y);
+ if (ret < 0)
+ return ret;
+
+ ret = ch1115_draw_screen(ch1115, row, ch1115->width);
+ if (ret < 0)
+ return ret;
+
+ y += CH1115_PAGE_HEIGHT;
+ } while (y < ch1115->height);
+
+ return 0;
+}
+
+static int ch1115_oled_init(struct ch1115_device *ch1115)
+{
+ u8 commands[] = {
+ CH1115_CMD_OFF,
+
+ CH1115_CMD_CLOCK_DIVIDE_RATIO,
+ CH1115_VAL_CLOCK_DIVIDE_RATIO(CH1115_VAL_CLOCK_OSC_FREQ,
+ CH1115_VAL_CLOCK_DIV_RATIO),
+
+ CH1115_CMD_MUX_RATIO,
+ ch1115->height - 1,
+
+ CH1115_CMD_OFFSET,
+ ch1115->flip_vertical
+ ? ch1115->y_start_offset
+ : CH1115_MAX_HEIGHT - ch1115->y_start_offset,
+
+ CH1115_CMD_START_LINE,
+
+ CH1115_CMD_DC_DC,
+ CH1115_VAL_DC_DC_ON,
+
+ ch1115->flip_horizontal
+ ? CH1115_CMD_SEG_REMAP_FLIP
+ : CH1115_CMD_SEG_REMAP_NORMAL,
+
+ ch1115->flip_vertical
+ ? CH1115_CMD_COM_REMAP_FLIP
+ : CH1115_CMD_COM_REMAP_NORMAL,
+
+ CH1115_CMD_CONTRAST,
+ ch1115->contrast,
+
+ CH1115_CMD_PRECHARGE_PERIOD,
+ CH1115_VAL_PRECHARGE_PERIOD,
+
+ CH1115_CMD_VCOM_DESELECT_LVL,
+ CH1115_VAL_VCOM_DESELECT_LVL,
+
+ CH1115_CMD_FOLLOW_RAM,
+
+ ch1115->inverted
+ ? CH1115_CMD_INVERTED
+ : CH1115_CMD_NORMAL,
+ };
+
+ return ch1115_send_command_list(ch1115, commands, ARRAY_SIZE(commands));
+}
+
+static void ch1115_prepare_buffer(struct ch1115_device *ch1115,
+ const struct iosys_map *vmap,
+ struct drm_framebuffer *fb,
+ struct drm_rect *rect,
+ struct drm_format_conv_state *fmtcnv_state)
+{
+ unsigned int dst_pitch;
+ struct iosys_map dst;
+
+ dst_pitch = DIV_ROUND_UP(ch1115->width, 8);
+ rect->y1 = round_down(rect->y1, CH1115_PAGE_HEIGHT);
+ rect->y2 = min_t(unsigned int, round_up(rect->y2, CH1115_PAGE_HEIGHT), ch1115->height);
+
+ iosys_map_set_vaddr(&dst, ch1115->hwbuf + rect->y1 * dst_pitch + rect->x1 / 8);
+ drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_state);
+}
+
+static inline u8 ch1115_transform_xy(const char *p, int x, int y, u8 bytes_per_row)
+{
+ int xrest = x % 8;
+ u8 result = 0;
+
+ /*
+ * Transforms an (x, y) pixel coordinate into a vertical 8-bit
+ * column from the framebuffer. It calculates the corresponding byte in the
+ * framebuffer, extracts the bit at the given x position across 8 consecutive
+ * rows, and packs those bits into a single byte.
+ *
+ * Return an 8-bit value representing a vertical column of pixels.
+ */
+
+ x = x / 8;
+ y = (y / 8) * 8;
+
+ for (int i = 0; i < 8; i++) {
+ int row_idx = y + i;
+ u8 byte = p[row_idx * bytes_per_row + x];
+ u8 bit = (byte >> xrest) & 1;
+
+ result |= (bit << i);
+ }
+
+ return result;
+}
+
+static int ch1115_fb_update_rect(struct drm_framebuffer *fb, struct drm_rect *rect)
+{
+ struct ch1115_device *ch1115 = drm_to_ch1115(fb->dev);
+ char *row = ch1115->row;
+ int ret;
+
+ rect->y1 = round_down(rect->y1, CH1115_PAGE_HEIGHT);
+ rect->y2 = min_t(unsigned int, round_up(rect->y2, CH1115_PAGE_HEIGHT), ch1115->height);
+
+ for (int y = rect->y1; y < rect->y2; y += CH1115_PAGE_HEIGHT) {
+ for (int x = rect->x1; x < rect->x2; x++)
+ row[x] = ch1115_transform_xy(ch1115->hwbuf, x, y, ch1115->bytes_per_row);
+
+ ret = ch1115_set_position(ch1115, ch1115->x_start_offset + rect->x1, y);
+ if (ret < 0)
+ return ret;
+
+ ret = ch1115_draw_screen(ch1115, row + rect->x1, rect->x2 - rect->x1);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * DRM
+ */
+DEFINE_DRM_GEM_FOPS(ch1115_fops);
+static const struct drm_driver ch1115_driver = {
+ .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+
+ .name = DRIVER_NAME,
+ .desc = DRIVER_DESC,
+ .major = DRIVER_MAJOR,
+ .minor = DRIVER_MINOR,
+
+ .fops = &ch1115_fops,
+ DRM_GEM_SHMEM_DRIVER_OPS,
+ DRM_FBDEV_SHMEM_DRIVER_OPS,
+};
+
+/*
+ * Modeset
+ */
+static struct drm_display_mode ch1115_mode(struct ch1115_device *ch1115)
+{
+ struct drm_display_mode mode = {
+ DRM_SIMPLE_MODE(ch1115->width, ch1115->height,
+ ch1115->width_mm, ch1115->height_mm),
+ };
+
+ return mode;
+}
+
+static const struct drm_mode_config_funcs ch1115_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create_with_dirty,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static int ch1115_mode_config_init(struct ch1115_device *ch1115)
+{
+ struct drm_device *dev = &ch1115->dev;
+ int ret;
+
+ ret = drmm_mode_config_init(dev);
+ if (ret)
+ return ret;
+
+ dev->mode_config.min_width = ch1115->width;
+ dev->mode_config.max_width = ch1115->width;
+ dev->mode_config.min_height = ch1115->height;
+ dev->mode_config.max_height = ch1115->height;
+ dev->mode_config.preferred_depth = 24;
+ dev->mode_config.funcs = &ch1115_mode_config_funcs;
+
+ return 0;
+}
+
+/*
+ * Plane
+ */
+static const struct drm_plane_funcs ch1115_primary_plane_funcs = {
+ .update_plane = drm_atomic_helper_update_plane,
+ .disable_plane = drm_atomic_helper_disable_plane,
+ .destroy = drm_plane_cleanup,
+ DRM_GEM_SHADOW_PLANE_FUNCS,
+};
+
+static int ch1115_primary_plane_helper_atomic_check(struct drm_plane *plane,
+ struct drm_atomic_commit *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;
+
+ if (new_crtc)
+ new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
+
+ return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
+ DRM_PLANE_NO_SCALING,
+ DRM_PLANE_NO_SCALING,
+ false, false);
+}
+
+static void ch1115_primary_plane_helper_atomic_update(struct drm_plane *plane,
+ struct drm_atomic_commit *state)
+{
+ struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
+ 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_framebuffer *fb = plane_state->fb;
+ struct drm_atomic_helper_damage_iter iter;
+ struct drm_device *dev = plane->dev;
+ struct drm_rect damage;
+ struct ch1115_device *ch1115 = drm_to_ch1115(plane->dev);
+ int idx;
+
+ if (!fb)
+ return;
+
+ if (drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE))
+ return;
+
+ if (!drm_dev_enter(dev, &idx))
+ goto out_drm_gem_fb_end_cpu_access;
+
+ drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
+ drm_atomic_for_each_plane_damage(&iter, &damage) {
+ ch1115_prepare_buffer(ch1115,
+ &shadow_plane_state->data[0],
+ fb, &damage,
+ &shadow_plane_state->fmtcnv_state);
+
+ ch1115_fb_update_rect(fb, &damage);
+ }
+
+ drm_dev_exit(idx);
+
+out_drm_gem_fb_end_cpu_access:
+ drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+}
+
+static void ch1115_primary_plane_helper_atomic_disable(struct drm_plane *plane,
+ struct drm_atomic_commit *state)
+{
+ struct drm_device *dev = plane->dev;
+ struct ch1115_device *ch1115 = drm_to_ch1115(plane->dev);
+ int idx;
+
+ if (!drm_dev_enter(dev, &idx))
+ return;
+
+ ch1115_clear_screen(ch1115);
+ drm_dev_exit(idx);
+}
+
+static const struct drm_plane_helper_funcs ch1115_primary_plane_helper_funcs = {
+ DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
+ .atomic_check = ch1115_primary_plane_helper_atomic_check,
+ .atomic_update = ch1115_primary_plane_helper_atomic_update,
+ .atomic_disable = ch1115_primary_plane_helper_atomic_disable,
+};
+
+static const u64 ch1115_primary_plane_fmtmods[] = {
+ DRM_FORMAT_MOD_LINEAR,
+ DRM_FORMAT_MOD_INVALID
+};
+
+static const u32 ch1115_primary_plane_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static int ch1115_plane_init(struct ch1115_device *ch1115)
+{
+ struct drm_plane *plane = &ch1115->primary_plane;
+ struct drm_device *dev = &ch1115->dev;
+ int ret;
+
+ ret = drm_universal_plane_init(dev, plane, 0,
+ &ch1115_primary_plane_funcs,
+ ch1115_primary_plane_formats,
+ ARRAY_SIZE(ch1115_primary_plane_formats),
+ ch1115_primary_plane_fmtmods,
+ DRM_PLANE_TYPE_PRIMARY, NULL);
+ if (ret)
+ return ret;
+
+ drm_plane_helper_add(plane, &ch1115_primary_plane_helper_funcs);
+ drm_plane_enable_fb_damage_clips(plane);
+
+ return 0;
+}
+
+/*
+ * CRTC
+ */
+static enum drm_mode_status ch1115_crtc_mode_valid(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode)
+{
+ struct ch1115_device *ch1115 = drm_to_ch1115(crtc->dev);
+
+ return drm_crtc_helper_mode_valid_fixed(crtc, mode, &ch1115->mode);
+}
+
+static const struct drm_crtc_helper_funcs ch1115_crtc_helper_funcs = {
+ .atomic_check = drm_crtc_helper_atomic_check,
+ .mode_valid = ch1115_crtc_mode_valid,
+};
+
+static const struct drm_crtc_funcs ch1115_crtc_funcs = {
+ .reset = drm_atomic_helper_crtc_reset,
+ .destroy = drm_crtc_cleanup,
+ .set_config = drm_atomic_helper_set_config,
+ .page_flip = drm_atomic_helper_page_flip,
+ .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static int ch1115_crtc_init(struct ch1115_device *ch1115)
+{
+ struct drm_plane *primary_plane = &ch1115->primary_plane;
+ struct drm_crtc *crtc = &ch1115->crtc;
+ struct drm_device *dev = &ch1115->dev;
+ int ret;
+
+ ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
+ &ch1115_crtc_funcs, NULL);
+ if (ret)
+ return ret;
+
+ drm_crtc_helper_add(crtc, &ch1115_crtc_helper_funcs);
+
+ return 0;
+}
+
+/*
+ * Encoder
+ */
+static void ch1115_encoder_atomic_enable(struct drm_encoder *encoder,
+ struct drm_atomic_commit *state)
+{
+ struct drm_device *drm = encoder->dev;
+ struct ch1115_device *ch1115 = drm_to_ch1115(drm);
+
+ ch1115_oled_init(ch1115);
+
+ u8 command = CH1115_CMD_ON;
+
+ ch1115_send_command_list(ch1115, &command, 1);
+
+ backlight_enable(ch1115->bl_dev);
+}
+
+static void ch1115_encoder_atomic_disable(struct drm_encoder *encoder,
+ struct drm_atomic_commit *state)
+{
+ struct drm_device *drm = encoder->dev;
+ struct ch1115_device *ch1115 = drm_to_ch1115(drm);
+
+ u8 command = CH1115_CMD_OFF;
+
+ ch1115_send_command_list(ch1115, &command, 1);
+
+ backlight_disable(ch1115->bl_dev);
+}
+
+static const struct drm_encoder_funcs ch1115_encoder_funcs = {
+ .destroy = drm_encoder_cleanup,
+};
+
+static const struct drm_encoder_helper_funcs ch1115_encoder_helper_funcs = {
+ .atomic_enable = ch1115_encoder_atomic_enable,
+ .atomic_disable = ch1115_encoder_atomic_disable,
+};
+
+static int ch1115_encoder_init(struct ch1115_device *ch1115)
+{
+ struct drm_encoder *encoder = &ch1115->encoder;
+ struct drm_crtc *crtc = &ch1115->crtc;
+ struct drm_device *dev = &ch1115->dev;
+ int ret;
+
+ ret = drm_encoder_init(dev, encoder, &ch1115_encoder_funcs, DRM_MODE_ENCODER_NONE, NULL);
+ if (ret)
+ return ret;
+
+ drm_encoder_helper_add(encoder, &ch1115_encoder_helper_funcs);
+
+ encoder->possible_crtcs = drm_crtc_mask(crtc);
+
+ return 0;
+}
+
+/*
+ * Connector
+ */
+static int ch1115_connector_get_modes(struct drm_connector *conn)
+{
+ struct ch1115_device *ch1115 = drm_to_ch1115(conn->dev);
+
+ return drm_connector_helper_get_modes_fixed(conn, &ch1115->mode);
+}
+
+static const struct drm_connector_helper_funcs ch1115_connector_helper_funcs = {
+ .get_modes = ch1115_connector_get_modes,
+};
+
+static const struct drm_connector_funcs ch1115_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 int ch1115_connector_init(struct ch1115_device *ch1115)
+{
+ struct drm_connector *connector = &ch1115->connector;
+ struct drm_encoder *encoder = &ch1115->encoder;
+ struct drm_device *dev = &ch1115->dev;
+ int ret;
+
+ ret = drm_connector_init(dev, connector, &ch1115_connector_funcs,
+ DRM_MODE_CONNECTOR_Unknown);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(connector, &ch1115_connector_helper_funcs);
+
+ return drm_connector_attach_encoder(connector, encoder);
+}
+
+/*
+ * Backlight
+ */
+static int ch1115_update_bl(struct backlight_device *bdev)
+{
+ struct ch1115_device *ch1115 = bl_get_data(bdev);
+ u8 brightness = backlight_get_brightness(bdev);
+
+ ch1115->contrast = brightness;
+
+ u8 cmd_list[] = {
+ CH1115_CMD_CONTRAST,
+ brightness
+ };
+
+ return ch1115_send_command_list(ch1115, cmd_list, ARRAY_SIZE(cmd_list));
+}
+
+static const struct backlight_ops ch1115_bl_ops = {
+ .update_status = ch1115_update_bl,
+};
+
+/*
+ * I2c
+ */
+
+/* The ch1115 driver does not read registers but regmap expects a .read */
+static int ch1115_regmap_read(void *context, const void *reg_buf,
+ size_t reg_size, void *val_buf, size_t val_size)
+{
+ return -EOPNOTSUPP;
+}
+
+static int ch1115_regmap_write(void *context, const void *data, size_t count)
+{
+ struct i2c_client *client = context;
+ struct ch1115_device *ch1115 = i2c_get_clientdata(client);
+ int ret;
+
+ struct i2c_msg msg = {
+ .addr = ch1115->client->addr,
+ .len = count,
+ .buf = (u8 *)data,
+ };
+
+ ret = i2c_transfer(ch1115->client->adapter, &msg, 1);
+
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static const struct regmap_bus ch1115_regmap_bus = {
+ .read = ch1115_regmap_read,
+ .write = ch1115_regmap_write,
+};
+
+static const struct regmap_config ch1115_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int ch1115_parse_dt(struct ch1115_device *ch1115)
+{
+ struct device *dev = &ch1115->client->dev;
+ struct device_node *np = dev->of_node;
+ struct display_timing dt;
+ int ret;
+ u32 val;
+
+ if (!np) {
+ dev_err(dev, "No Device Tree entry\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(np, "chipwealth,offset", &val);
+ if (ret) {
+ ch1115->y_start_offset = 0;
+ } else {
+ if (val > CH1115_MAX_HEIGHT - 1) {
+ dev_err(dev, "chipwealth,offset=%d must be [0-%d]\n",
+ val, CH1115_MAX_HEIGHT - 1);
+ return -EINVAL;
+ }
+ ch1115->y_start_offset = (u8)val;
+ }
+
+ ret = of_property_read_u32(np, "width-mm", &ch1115->width_mm);
+ if (ret) {
+ dev_err(dev, "Failed to get width-mm from DT\n");
+ return ret;
+ }
+ if (ch1115->width_mm == 0) {
+ dev_err(dev, "Invalid width-mm 0\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(np, "height-mm", &ch1115->height_mm);
+ if (ret) {
+ dev_err(dev, "Failed to get height-mm from DT\n");
+ return ret;
+ }
+ if (ch1115->height_mm == 0) {
+ dev_err(dev, "Invalid height-mm 0\n");
+ return -EINVAL;
+ }
+
+ ret = of_get_display_timing(np, "panel-timing", &dt);
+ if (ret) {
+ dev_err(dev, "Failed to get display timing from DT\n");
+ return ret;
+ }
+ if (dt.hactive.typ <= 0 || dt.hactive.typ > CH1115_MAX_WIDTH) {
+ dev_err(dev, "hactive=%d must be greater than 0 and less than %d\n",
+ dt.hactive.typ, CH1115_MAX_WIDTH);
+ return -EINVAL;
+ }
+ if (dt.vactive.typ <= 0 || dt.vactive.typ > CH1115_MAX_HEIGHT) {
+ dev_err(dev, "vactive=%d must be greater than 0 and less than %d\n",
+ dt.vactive.typ, CH1115_MAX_HEIGHT);
+ return -EINVAL;
+ }
+
+ ch1115->width = dt.hactive.typ;
+ ch1115->height = dt.vactive.typ;
+
+ ch1115->inverted = of_property_read_bool(np, "chipwealth,inverted");
+ ch1115->flip_horizontal = of_property_read_bool(np, "flip-horizontal");
+ ch1115->flip_vertical = of_property_read_bool(np, "flip-vertical");
+ ch1115->contrast = CH1115_VAL_CONTRAST;
+
+ return 0;
+}
+
+static int ch1115_probe(struct i2c_client *client)
+{
+ struct ch1115_device *ch1115;
+ struct device *dev;
+ struct backlight_device *bl;
+ int ret;
+
+ dev = &client->dev;
+ ch1115 = devm_drm_dev_alloc(&client->dev, &ch1115_driver,
+ struct ch1115_device, dev);
+ if (IS_ERR(ch1115))
+ return PTR_ERR(ch1115);
+
+ i2c_set_clientdata(client, ch1115);
+
+ ch1115->client = client;
+ ch1115->regmap = devm_regmap_init(dev, &ch1115_regmap_bus,
+ client, &ch1115_regmap_config);
+ if (IS_ERR(ch1115->regmap))
+ return dev_err_probe(dev, PTR_ERR(ch1115->regmap),
+ "Failed to initialize regmap\n");
+
+ ret = ch1115_parse_dt(ch1115);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to parse DT\n");
+
+ ch1115->pages = DIV_ROUND_UP(ch1115->height, CH1115_PAGE_HEIGHT);
+ ch1115->bytes_per_row = DIV_ROUND_UP(ch1115->width, 8);
+ ch1115->x_start_offset = ch1115->flip_horizontal
+ ? CH1115_MAX_WIDTH - ch1115->width
+ : 0;
+ ch1115->mode = ch1115_mode(ch1115);
+
+ ch1115->hwbuf = devm_kzalloc(dev, (ch1115->width * ch1115->height) / 8,
+ GFP_KERNEL);
+ if (!ch1115->hwbuf)
+ return -ENOMEM;
+
+ ch1115->row = devm_kzalloc(dev, ch1115->width, GFP_KERNEL);
+ if (!ch1115->row)
+ return -ENOMEM;
+
+ // Backlight
+ bl = devm_backlight_device_register(dev, dev_name(dev), dev, ch1115,
+ &ch1115_bl_ops, NULL);
+ if (IS_ERR(bl))
+ return dev_err_probe(dev, PTR_ERR(bl),
+ "Unable to register backlight device\n");
+
+ bl->props.brightness = ch1115->contrast;
+ bl->props.max_brightness = CH1115_MAX_CONTRAST;
+ ch1115->bl_dev = bl;
+
+ // DRM
+ ret = ch1115_mode_config_init(ch1115);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to initialize mode config\n");
+
+ ret = ch1115_plane_init(ch1115);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to initialize primary plane\n");
+
+ ret = ch1115_crtc_init(ch1115);
+ if (ret < 0)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to initialize CRTC\n");
+
+ ret = ch1115_encoder_init(ch1115);
+ if (ret < 0)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to initialize encoder\n");
+
+ ret = ch1115_connector_init(ch1115);
+ if (ret < 0)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to initialize connector\n");
+
+ drm_mode_config_reset(&ch1115->dev);
+
+ ret = drm_dev_register(&ch1115->dev, 0);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "Failed to register DRM device\n");
+
+ drm_client_setup(&ch1115->dev, NULL);
+
+ return 0;
+}
+
+static void ch1115_remove(struct i2c_client *client)
+{
+ struct ch1115_device *ch1115 = i2c_get_clientdata(client);
+ int ret;
+
+ u8 cmd_list[] = {
+ CH1115_CMD_OFF,
+
+ CH1115_CMD_ALL_ON,
+
+ CH1115_CMD_DC_DC,
+ CH1115_VAL_DC_DC_OFF,
+ };
+
+ drm_dev_unplug(&ch1115->dev);
+ drm_atomic_helper_shutdown(&ch1115->dev);
+
+ ret = ch1115_send_command_list(ch1115, cmd_list, ARRAY_SIZE(cmd_list));
+ if (ret < 0)
+ dev_err(&client->dev, "Shutdown command sequence failed\n");
+}
+
+static const struct i2c_device_id ch1115_id[] = {
+ { .name = "ch1115" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ch1115_id);
+
+static const struct of_device_id ch1115_of_match[] = {
+ { .compatible = "chipwealth,ch1115" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ch1115_of_match);
+
+static struct i2c_driver ch1115_i2c_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = ch1115_of_match,
+ },
+ .probe = ch1115_probe,
+ .remove = ch1115_remove,
+ .shutdown = ch1115_shutdown,
+ .id_table = ch1115_id,
+};
+module_i2c_driver(ch1115_i2c_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Nicolás Antinori <nico.antinori.7@gmail.com>");
+MODULE_LICENSE("GPL");
--
2.47.3
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