Split up the driver to make it possible to add support for hw interfaces
other than I2C.

Signed-off-by: Marcus Folkesson <[email protected]>
---
 MAINTAINERS                           |   1 +
 drivers/gpu/drm/sitronix/Kconfig      |  26 +-
 drivers/gpu/drm/sitronix/Makefile     |   1 +
 drivers/gpu/drm/sitronix/st7571-i2c.c | 924 +---------------------------------
 drivers/gpu/drm/sitronix/st7571.c     | 918 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/sitronix/st7571.h     |   6 +
 6 files changed, 959 insertions(+), 917 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 
2814faae61eceecae1bccaaf92010e22dca81376..66e9ffb757c8bb19dbb894eb51f88f589ee83af6
 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8083,6 +8083,7 @@ S:        Maintained
 F:     Documentation/devicetree/bindings/display/sitronix,st7567.yaml
 F:     Documentation/devicetree/bindings/display/sitronix,st7571.yaml
 F:     drivers/gpu/drm/sitronix/st7571-i2c.c
+F:     drivers/gpu/drm/sitronix/st7571.c
 F:     drivers/gpu/drm/sitronix/st7571.h
 
 DRM DRIVER FOR SITRONIX ST7701 PANELS
diff --git a/drivers/gpu/drm/sitronix/Kconfig b/drivers/gpu/drm/sitronix/Kconfig
index 
6de7d92d9b74c72746915b945869dba91f161d2b..0676a86661caa4ab81f226ff2e990a3e2526f74d
 100644
--- a/drivers/gpu/drm/sitronix/Kconfig
+++ b/drivers/gpu/drm/sitronix/Kconfig
@@ -1,13 +1,29 @@
-config DRM_ST7571_I2C
-       tristate "DRM support for Sitronix ST7571 display panels (I2C)"
-       depends on DRM && I2C && MMU
+config DRM_ST7571
+       tristate "DRM support for Sitronix ST7567/ST7571 display panels"
+       depends on DRM && MMU
        select DRM_CLIENT_SELECTION
        select DRM_GEM_SHMEM_HELPER
        select DRM_KMS_HELPER
-       select REGMAP_I2C
        select VIDEOMODE_HELPERS
        help
-         DRM driver for Sitronix ST7571 panels controlled over I2C.
+         Sitronix ST7571 is a driver and controller for 4-level gray
+         scale and monochrome dot matrix LCD panels.
+
+         DRM driver for Sitronix ST7567/ST7571 panels.
+         This is only the core driver, a driver for the appropriate bus
+         transport in your chip also must be selected.
+
+         if M is selected the module will be called st7571.
+
+config DRM_ST7571_I2C
+       tristate "DRM support for Sitronix ST7567/ST7571 display panels (I2C)"
+       depends on DRM_ST7571 && I2C
+       select REGMAP_I2C
+       help
+         Sitronix ST7571 is a driver and controller for 4-level gray
+         scale and monochrome dot matrix LCD panels.
+
+         DRM driver for Sitronix ST7565/ST7571 panels connected via I2C bus.
 
          if M is selected the module will be called st7571-i2c.
 
diff --git a/drivers/gpu/drm/sitronix/Makefile 
b/drivers/gpu/drm/sitronix/Makefile
index 
bd139e5a6995fa026cc635b3c29782473d1efad7..8073bb776ff94de750f350b636fd9db3d54fdd46
 100644
--- a/drivers/gpu/drm/sitronix/Makefile
+++ b/drivers/gpu/drm/sitronix/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_DRM_ST7571)               += st7571.o
 obj-$(CONFIG_DRM_ST7571_I2C)           += st7571-i2c.o
 obj-$(CONFIG_DRM_ST7586)               += st7586.o
 obj-$(CONFIG_DRM_ST7735R)              += st7735r.o
diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c 
b/drivers/gpu/drm/sitronix/st7571-i2c.c
index 
f994ace407390dba30c0968ca99f437382badfab..038a7c2b6f26169f40305a382dace7031d9efc43
 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -1,85 +1,16 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * Driver for Sitronix ST7571, a 4 level gray scale dot matrix LCD controller
+ * Driver for Sitronix ST7571 connected via I2C bus.
  *
  * Copyright (C) 2025 Marcus Folkesson <[email protected]>
  */
 
-#include <linux/bitfield.h>
-#include <linux/delay.h>
-#include <linux/gpio/consumer.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_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_fb_helper.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_modeset_helper_vtables.h>
-#include <drm/drm_module.h>
-#include <drm/drm_plane.h>
-#include <drm/drm_probe_helper.h>
-
-#include <video/display_timing.h>
-#include <video/of_display_timing.h>
-
 #include "st7571.h"
 
-#define ST7571_COMMAND_MODE                    (0x00)
-#define ST7571_DATA_MODE                       (0x40)
-
-/* Normal mode command set */
-#define ST7571_DISPLAY_OFF                     (0xae)
-#define ST7571_DISPLAY_ON                      (0xaf)
-#define ST7571_OSC_ON                          (0xab)
-#define ST7571_SET_COLUMN_LSB(c)               (0x00 | FIELD_PREP(GENMASK(3, 
0), (c)))
-#define ST7571_SET_COLUMN_MSB(c)               (0x10 | FIELD_PREP(GENMASK(2, 
0), (c) >> 4))
-#define ST7571_SET_COM0_LSB(x)                 (FIELD_PREP(GENMASK(6, 0), (x)))
-#define ST7571_SET_COM0_MSB                    (0x44)
-#define ST7571_SET_COM_SCAN_DIR(d)             (0xc0 | FIELD_PREP(GENMASK(3, 
3), (d)))
-#define ST7571_SET_CONTRAST_LSB(c)             (FIELD_PREP(GENMASK(5, 0), (c)))
-#define ST7571_SET_CONTRAST_MSB                        (0x81)
-#define ST7571_SET_DISPLAY_DUTY_LSB(d)         (FIELD_PREP(GENMASK(7, 0), (d)))
-#define ST7571_SET_DISPLAY_DUTY_MSB            (0x48)
-#define ST7571_SET_ENTIRE_DISPLAY_ON(p)                (0xa4 | 
FIELD_PREP(GENMASK(0, 0), (p)))
-#define ST7571_SET_LCD_BIAS(b)                 (0x50 | FIELD_PREP(GENMASK(2, 
0), (b)))
-#define ST7571_SET_MODE_LSB(m)                 (FIELD_PREP(GENMASK(7, 2), (m)))
-#define ST7571_SET_MODE_MSB                    (0x38)
-#define ST7571_SET_PAGE(p)                     (0xb0 | FIELD_PREP(GENMASK(3, 
0), (p)))
-#define ST7571_SET_POWER(p)                    (0x28 | FIELD_PREP(GENMASK(2, 
0), (p)))
-#define ST7571_SET_REGULATOR_REG(r)            (0x20 | FIELD_PREP(GENMASK(2, 
0), (r)))
-#define ST7571_SET_REVERSE(r)                  (0xa6 | FIELD_PREP(GENMASK(0, 
0), (r)))
-#define ST7571_SET_SEG_SCAN_DIR(d)             (0xa0 | FIELD_PREP(GENMASK(0, 
0), (d)))
-#define ST7571_SET_START_LINE_LSB(l)           (FIELD_PREP(GENMASK(6, 0), (l)))
-#define ST7571_SET_START_LINE_MSB              (0x40)
-
-/* Extension command set 3 */
-#define ST7571_COMMAND_SET_3                   (0x7b)
-#define ST7571_SET_COLOR_MODE(c)               (0x10 | FIELD_PREP(GENMASK(0, 
0), (c)))
-#define ST7571_COMMAND_SET_NORMAL              (0x00)
-
-/* ST7567 commands */
-#define ST7567_SET_LCD_BIAS(m) (0xa2 | FIELD_PREP(GENMASK(0, 0), (m)))
-
-#define ST7571_PAGE_HEIGHT 8
-
-#define DRIVER_NAME "st7571"
-#define DRIVER_DESC "ST7571 DRM driver"
-#define DRIVER_MAJOR 1
-#define DRIVER_MINOR 0
-
 struct st7571_i2c_transport {
        struct i2c_client *client;
 
@@ -107,12 +38,7 @@ struct st7571_i2c_transport {
        bool ignore_nak;
 };
 
-static inline struct st7571_device *drm_to_st7571(struct drm_device *drm)
-{
-       return container_of(drm, struct st7571_device, drm);
-}
-
-static int st7571_regmap_write(void *context, const void *data, size_t count)
+static int st7571_i2c_regmap_write(void *context, const void *data, size_t 
count)
 {
        struct st7571_i2c_transport *t = context;
        int ret;
@@ -139,825 +65,23 @@ static int st7571_regmap_write(void *context, const void 
*data, size_t count)
 }
 
 /* The st7571 driver does not read registers but regmap expects a .read */
-static int st7571_regmap_read(void *context, const void *reg_buf,
-                             size_t reg_size, void *val_buf, size_t val_size)
+static int st7571_i2c_regmap_read(void *context, const void *reg_buf,
+                                 size_t reg_size, void *val_buf, size_t 
val_size)
 {
        return -EOPNOTSUPP;
 }
 
-static int st7571_send_command_list(struct st7571_device *st7571,
-                                   const u8 *cmd_list, size_t len)
-{
-       int ret;
-
-       for (int i = 0; i < len; i++) {
-               ret = regmap_write(st7571->regmap, ST7571_COMMAND_MODE, 
cmd_list[i]);
-               if (ret < 0)
-                       return ret;
-       }
-
-       return ret;
-}
-
-static inline u8 st7571_transform_xy(const char *p, int x, int y, u8 bpp)
-{
-       int xrest = x % 8;
-       u8 result = 0;
-       u8 row_len = 16 * bpp;
-
-       /*
-        * 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 * row_len + x];
-               u8 bit = (byte >> xrest) & 1;
-
-               result |= (bit << i);
-       }
-
-       return result;
-}
-
-static int st7571_set_position(struct st7571_device *st7571, int x, int y)
-{
-       u8 cmd_list[] = {
-               ST7571_SET_COLUMN_LSB(x),
-               ST7571_SET_COLUMN_MSB(x),
-               ST7571_SET_PAGE(y / ST7571_PAGE_HEIGHT),
-       };
-
-       return st7571_send_command_list(st7571, cmd_list, ARRAY_SIZE(cmd_list));
-}
-
-static int st7571_fb_clear_screen(struct st7571_device *st7571)
-{
-       u32 npixels = st7571->ncols * round_up(st7571->nlines, 
ST7571_PAGE_HEIGHT) * st7571->bpp;
-       char pixelvalue = 0x00;
-
-       st7571_set_position(st7571, 0, 0);
-       for (int i = 0; i < npixels; i++)
-               regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, 
&pixelvalue, 1);
-
-       return 0;
-}
-
-static void st7571_prepare_buffer_monochrome(struct st7571_device *st7571,
-                                            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;
-       u32 size;
-
-       switch (fb->format->format) {
-       case DRM_FORMAT_XRGB8888:
-               dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
-               iosys_map_set_vaddr(&dst, st7571->hwbuf);
-
-               drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect, 
fmtcnv_state);
-               break;
-
-       case DRM_FORMAT_R1:
-               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
-               memcpy(st7571->hwbuf, vmap->vaddr, size);
-               break;
-       }
-}
-
-static void st7571_prepare_buffer_grayscale(struct st7571_device *st7571,
-                                           const struct iosys_map *vmap,
-                                           struct drm_framebuffer *fb,
-                                           struct drm_rect *rect,
-                                           struct drm_format_conv_state 
*fmtcnv_state)
-{
-       u32 size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
-       unsigned int dst_pitch;
-       struct iosys_map dst;
-
-       switch (fb->format->format) {
-       case DRM_FORMAT_XRGB8888:
-               dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 4);
-               iosys_map_set_vaddr(&dst, st7571->hwbuf);
-
-               drm_fb_xrgb8888_to_gray2(&dst, &dst_pitch, vmap, fb, rect, 
fmtcnv_state);
-               break;
-
-       case DRM_FORMAT_R1:
-               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
-               memcpy(st7571->hwbuf, vmap->vaddr, size);
-               break;
-
-       case DRM_FORMAT_R2:
-               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 4;
-               memcpy(st7571->hwbuf, vmap->vaddr, size);
-               break;
-       }
-}
-
-static int st7571_fb_update_rect_monochrome(struct drm_framebuffer *fb, struct 
drm_rect *rect)
-{
-       struct st7571_device *st7571 = drm_to_st7571(fb->dev);
-       char *row = st7571->row;
-
-       /* Align y to display page boundaries */
-       rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
-       rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), 
st7571->nlines);
-
-       for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {
-               for (int x = rect->x1; x < rect->x2; x++)
-                       row[x] = st7571_transform_xy(st7571->hwbuf, x, y, 1);
-
-               st7571_set_position(st7571, rect->x1, y);
-
-               /* TODO: Investige why we can't write multiple bytes at once */
-               for (int x = rect->x1; x < rect->x2; x++)
-                       regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, row 
+ x, 1);
-       }
-
-       return 0;
-}
-
-static int st7571_fb_update_rect_grayscale(struct drm_framebuffer *fb, struct 
drm_rect *rect)
-{
-       struct st7571_device *st7571 = drm_to_st7571(fb->dev);
-       u32 format = fb->format->format;
-       char *row = st7571->row;
-       int x1;
-       int x2;
-
-       /* Align y to display page boundaries */
-       rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
-       rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), 
st7571->nlines);
-
-       switch (format) {
-       case DRM_FORMAT_R1:
-               x1 = rect->x1 * 1;
-               x2 = rect->x2 * 1;
-               break;
-       case DRM_FORMAT_R2:
-               fallthrough;
-       case DRM_FORMAT_XRGB8888:
-               x1 = rect->x1 * 2;
-               x2 = rect->x2 * 2;
-               break;
-       }
-
-       for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {
-               for (int x = x1; x < x2; x++)
-                       row[x] = st7571_transform_xy(st7571->hwbuf, x, y, 2);
-
-               st7571_set_position(st7571, rect->x1, y);
-
-               /* TODO: Investige why we can't write multiple bytes at once */
-               for (int x = x1; x < x2; x++) {
-                       regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, row 
+ x, 1);
-
-                       /*
-                        * As the display supports grayscale, all pixels must 
be written as two bits
-                        * even if the format is monochrome.
-                        *
-                        * The bit values maps to the following grayscale:
-                        * 0 0 = Black
-                        * 0 1 = Dark gray
-                        * 1 0 = Light gray
-                        * 1 1 = White
-                        *
-                        * For monochrome formats, write the same value twice 
to get
-                        * either a black or white pixel.
-                        */
-                       if (format == DRM_FORMAT_R1)
-                               regmap_bulk_write(st7571->regmap, 
ST7571_DATA_MODE, row + x, 1);
-               }
-       }
-
-       return 0;
-}
-
-static int st7571_connector_get_modes(struct drm_connector *conn)
-{
-       struct st7571_device *st7571 = drm_to_st7571(conn->dev);
-
-       return drm_connector_helper_get_modes_fixed(conn, &st7571->mode);
-}
-
-static const struct drm_connector_helper_funcs st7571_connector_helper_funcs = 
{
-       .get_modes = st7571_connector_get_modes,
-};
-
-static const struct st7571_panel_format st7571_monochrome = {
-       .prepare_buffer = st7571_prepare_buffer_monochrome,
-       .update_rect = st7571_fb_update_rect_monochrome,
-       .mode = ST7571_COLOR_MODE_BLACKWHITE,
-       .formats = {
-               DRM_FORMAT_XRGB8888,
-               DRM_FORMAT_R1,
-       },
-       .nformats = 2,
-};
-
-static const struct st7571_panel_format st7571_grayscale = {
-       .prepare_buffer = st7571_prepare_buffer_grayscale,
-       .update_rect = st7571_fb_update_rect_grayscale,
-       .mode = ST7571_COLOR_MODE_GRAY,
-       .formats = {
-               DRM_FORMAT_XRGB8888,
-               DRM_FORMAT_R1,
-               DRM_FORMAT_R2,
-       },
-       .nformats = 3,
-};
-
-static const u64 st7571_primary_plane_fmtmods[] = {
-       DRM_FORMAT_MOD_LINEAR,
-       DRM_FORMAT_MOD_INVALID
-};
-
-static int st7571_primary_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;
-
-       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 st7571_primary_plane_helper_atomic_update(struct drm_plane *plane,
-                                                     struct drm_atomic_state 
*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 *drm = plane->dev;
-       struct drm_rect damage;
-       struct st7571_device *st7571 = drm_to_st7571(plane->dev);
-       int ret, idx;
-
-       if (!fb)
-               return; /* no framebuffer; plane is disabled */
-
-       ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
-       if (ret)
-               return;
-
-       if (!drm_dev_enter(drm, &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) {
-               st7571->pformat->prepare_buffer(st7571,
-                                               &shadow_plane_state->data[0],
-                                               fb, &damage,
-                                               
&shadow_plane_state->fmtcnv_state);
-
-               st7571->pformat->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 st7571_primary_plane_helper_atomic_disable(struct drm_plane *plane,
-                                                      struct drm_atomic_state 
*state)
-{
-       struct drm_device *drm = plane->dev;
-       struct st7571_device *st7571 = drm_to_st7571(plane->dev);
-       int idx;
-
-       if (!drm_dev_enter(drm, &idx))
-               return;
-
-       st7571_fb_clear_screen(st7571);
-       drm_dev_exit(idx);
-}
-
-static const struct drm_plane_helper_funcs st7571_primary_plane_helper_funcs = 
{
-       DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
-       .atomic_check = st7571_primary_plane_helper_atomic_check,
-       .atomic_update = st7571_primary_plane_helper_atomic_update,
-       .atomic_disable = st7571_primary_plane_helper_atomic_disable,
-};
-
-static const struct drm_plane_funcs st7571_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,
-};
-
-/*
- * CRTC
- */
-
-static enum drm_mode_status st7571_crtc_mode_valid(struct drm_crtc *crtc,
-                                                  const struct 
drm_display_mode *mode)
-{
-       struct st7571_device *st7571 = drm_to_st7571(crtc->dev);
-
-       return drm_crtc_helper_mode_valid_fixed(crtc, mode, &st7571->mode);
-}
-
-static const struct drm_crtc_helper_funcs st7571_crtc_helper_funcs = {
-       .atomic_check = drm_crtc_helper_atomic_check,
-       .mode_valid = st7571_crtc_mode_valid,
-};
-
-static const struct drm_crtc_funcs st7571_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,
-};
-
-/*
- * Encoder
- */
-
-static void st7571_encoder_atomic_enable(struct drm_encoder *encoder,
-                                        struct drm_atomic_state *state)
-{
-       struct drm_device *drm = encoder->dev;
-       struct st7571_device *st7571 = drm_to_st7571(drm);
-       u8 command = ST7571_DISPLAY_ON;
-       int ret;
-
-       ret = st7571->pdata->init(st7571);
-       if (ret)
-               return;
-
-       st7571_send_command_list(st7571, &command, 1);
-}
-
-static void st7571_encoder_atomic_disable(struct drm_encoder *encoder,
-                                         struct drm_atomic_state *state)
-{
-       struct drm_device *drm = encoder->dev;
-       struct st7571_device *st7571 = drm_to_st7571(drm);
-       u8 command = ST7571_DISPLAY_OFF;
-
-       st7571_send_command_list(st7571, &command, 1);
-}
-
-static const struct drm_encoder_funcs st7571_encoder_funcs = {
-       .destroy = drm_encoder_cleanup,
-
-};
-
-static const struct drm_encoder_helper_funcs st7571_encoder_helper_funcs = {
-       .atomic_enable = st7571_encoder_atomic_enable,
-       .atomic_disable = st7571_encoder_atomic_disable,
-};
-
-/*
- * Connector
- */
-
-static const struct drm_connector_funcs st7571_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_mode_config_funcs st7571_mode_config_funcs = {
-       .fb_create = drm_gem_fb_create_with_dirty,
-       .atomic_check = drm_atomic_helper_check,
-       .atomic_commit = drm_atomic_helper_commit,
+static const struct regmap_bus st7571_i2c_regmap_bus = {
+       .read = st7571_i2c_regmap_read,
+       .write = st7571_i2c_regmap_write,
 };
 
-static struct drm_display_mode st7571_mode(struct st7571_device *st7571)
-{
-       struct drm_display_mode mode = {
-               DRM_SIMPLE_MODE(st7571->ncols, st7571->nlines,
-                               st7571->width_mm, st7571->height_mm),
-       };
-
-       return mode;
-}
-
-static int st7571_mode_config_init(struct st7571_device *st7571)
-{
-       struct drm_device *drm = &st7571->drm;
-       const struct st7571_panel_constraints *constraints = 
&st7571->pdata->constraints;
-       int ret;
-
-       ret = drmm_mode_config_init(drm);
-       if (ret)
-               return ret;
-
-       drm->mode_config.min_width = constraints->min_ncols;
-       drm->mode_config.min_height = constraints->min_nlines;
-       drm->mode_config.max_width = constraints->max_ncols;
-       drm->mode_config.max_height = constraints->max_nlines;
-       drm->mode_config.preferred_depth = 24;
-       drm->mode_config.funcs = &st7571_mode_config_funcs;
-
-       return 0;
-}
-
-static int st7571_plane_init(struct st7571_device *st7571,
-                            const struct st7571_panel_format *pformat)
-{
-       struct drm_plane *primary_plane = &st7571->primary_plane;
-       struct drm_device *drm = &st7571->drm;
-       int ret;
-
-       ret = drm_universal_plane_init(drm, primary_plane, 0,
-                                      &st7571_primary_plane_funcs,
-                                      pformat->formats,
-                                      pformat->nformats,
-                                      st7571_primary_plane_fmtmods,
-                                      DRM_PLANE_TYPE_PRIMARY, NULL);
-       if (ret)
-               return ret;
-
-       drm_plane_helper_add(primary_plane, &st7571_primary_plane_helper_funcs);
-       drm_plane_enable_fb_damage_clips(primary_plane);
-
-       return 0;
-}
-
-static int st7571_crtc_init(struct st7571_device *st7571)
-{
-       struct drm_plane *primary_plane = &st7571->primary_plane;
-       struct drm_crtc *crtc = &st7571->crtc;
-       struct drm_device *drm = &st7571->drm;
-       int ret;
-
-       ret = drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
-                                       &st7571_crtc_funcs, NULL);
-       if (ret)
-               return ret;
-
-       drm_crtc_helper_add(crtc, &st7571_crtc_helper_funcs);
-
-       return 0;
-}
-
-static int st7571_encoder_init(struct st7571_device *st7571)
-{
-       struct drm_encoder *encoder = &st7571->encoder;
-       struct drm_crtc *crtc = &st7571->crtc;
-       struct drm_device *drm = &st7571->drm;
-       int ret;
-
-       ret = drm_encoder_init(drm, encoder, &st7571_encoder_funcs, 
DRM_MODE_ENCODER_NONE, NULL);
-       if (ret)
-               return ret;
-
-       drm_encoder_helper_add(encoder, &st7571_encoder_helper_funcs);
-
-       encoder->possible_crtcs = drm_crtc_mask(crtc);
-
-       return 0;
-}
-
-static int st7571_connector_init(struct st7571_device *st7571)
-{
-       struct drm_connector *connector = &st7571->connector;
-       struct drm_encoder *encoder = &st7571->encoder;
-       struct drm_device *drm = &st7571->drm;
-       int ret;
-
-       ret = drm_connector_init(drm, connector, &st7571_connector_funcs,
-                                DRM_MODE_CONNECTOR_Unknown);
-       if (ret)
-               return ret;
-
-       drm_connector_helper_add(connector, &st7571_connector_helper_funcs);
-
-       return drm_connector_attach_encoder(connector, encoder);
-}
-
-DEFINE_DRM_GEM_FOPS(st7571_fops);
-
-static const struct drm_driver st7571_driver = {
-       .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
-
-       .name            = DRIVER_NAME,
-       .desc            = DRIVER_DESC,
-       .major           = DRIVER_MAJOR,
-       .minor           = DRIVER_MINOR,
-
-       .fops            = &st7571_fops,
-       DRM_GEM_SHMEM_DRIVER_OPS,
-       DRM_FBDEV_SHMEM_DRIVER_OPS,
-};
-
-static const struct regmap_bus st7571_regmap_bus = {
-       .read = st7571_regmap_read,
-       .write = st7571_regmap_write,
-};
-
-static const struct regmap_config st7571_regmap_config = {
+static const struct regmap_config st7571_i2c_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .use_single_write = true,
 };
 
-static int st7571_validate_parameters(struct st7571_device *st7571)
-{
-       struct device *dev = st7571->dev;
-       const struct st7571_panel_constraints *constraints = 
&st7571->pdata->constraints;
-
-       if (st7571->width_mm  == 0) {
-               dev_err(dev, "Invalid panel width\n");
-               return -EINVAL;
-       }
-
-       if (st7571->height_mm == 0) {
-               dev_err(dev, "Invalid panel height\n");
-               return -EINVAL;
-       }
-
-       if (st7571->nlines < constraints->min_nlines ||
-           st7571->nlines > constraints->max_nlines) {
-               dev_err(dev, "Invalid timing configuration.\n");
-               return -EINVAL;
-       }
-
-       if (st7571->startline + st7571->nlines > constraints->max_nlines) {
-               dev_err(dev, "Invalid timing configuration.\n");
-               return -EINVAL;
-       }
-
-       if (st7571->ncols < constraints->min_ncols ||
-           st7571->ncols > constraints->max_ncols) {
-               dev_err(dev, "Invalid timing configuration.\n");
-               return -EINVAL;
-       }
-
-       if (st7571->grayscale && !constraints->support_grayscale) {
-               dev_err(dev, "Grayscale not supported\n");
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-static int st7567_parse_dt(struct st7571_device *st7567)
-{
-       struct device *dev = st7567->dev;
-       struct device_node *np = dev->of_node;
-       struct display_timing dt;
-       int ret;
-
-       ret = of_get_display_timing(np, "panel-timing", &dt);
-       if (ret) {
-               dev_err(dev, "Failed to get display timing from DT\n");
-               return ret;
-       }
-
-       of_property_read_u32(np, "width-mm", &st7567->width_mm);
-       of_property_read_u32(np, "height-mm", &st7567->height_mm);
-       st7567->inverted = of_property_read_bool(np, "sitronix,inverted");
-
-       st7567->pformat = &st7571_monochrome;
-       st7567->bpp = 1;
-
-       st7567->startline = dt.vfront_porch.typ;
-       st7567->nlines = dt.vactive.typ;
-       st7567->ncols = dt.hactive.typ;
-
-       return 0;
-}
-
-static int st7571_parse_dt(struct st7571_device *st7571)
-{
-       struct device *dev = st7571->dev;
-       struct device_node *np = dev->of_node;
-       struct display_timing dt;
-       int ret;
-
-       ret = of_get_display_timing(np, "panel-timing", &dt);
-       if (ret) {
-               dev_err(dev, "Failed to get display timing from DT\n");
-               return ret;
-       }
-
-       of_property_read_u32(np, "width-mm", &st7571->width_mm);
-       of_property_read_u32(np, "height-mm", &st7571->height_mm);
-       st7571->grayscale = of_property_read_bool(np, "sitronix,grayscale");
-       st7571->inverted = of_property_read_bool(np, "sitronix,inverted");
-
-       if (st7571->grayscale) {
-               st7571->pformat = &st7571_grayscale;
-               st7571->bpp = 2;
-       } else {
-               st7571->pformat = &st7571_monochrome;
-               st7571->bpp = 1;
-       }
-
-       st7571->startline = dt.vfront_porch.typ;
-       st7571->nlines = dt.vactive.typ;
-       st7571->ncols = dt.hactive.typ;
-
-       st7571->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
-       if (IS_ERR(st7571->reset))
-               return dev_err_probe(dev, PTR_ERR(st7571->reset),
-                                    "Failed to get reset gpio\n");
-
-
-       return 0;
-}
-
-static void st7571_reset(struct st7571_device *st7571)
-{
-       gpiod_set_value_cansleep(st7571->reset, 1);
-       fsleep(20);
-       gpiod_set_value_cansleep(st7571->reset, 0);
-}
-
-static int st7567_lcd_init(struct st7571_device *st7567)
-{
-       /*
-        * Most of the initialization sequence is taken directly from the
-        * referential initial code in the ST7567 datasheet.
-        */
-       u8 commands[] = {
-               ST7571_DISPLAY_OFF,
-
-               ST7567_SET_LCD_BIAS(1),
-
-               ST7571_SET_SEG_SCAN_DIR(0),
-               ST7571_SET_COM_SCAN_DIR(1),
-
-               ST7571_SET_REGULATOR_REG(4),
-               ST7571_SET_CONTRAST_MSB,
-               ST7571_SET_CONTRAST_LSB(0x20),
-
-               ST7571_SET_START_LINE_MSB,
-               ST7571_SET_START_LINE_LSB(st7567->startline),
-
-               ST7571_SET_POWER(0x4),  /* Power Control, VC: ON, VR: OFF, VF: 
OFF */
-               ST7571_SET_POWER(0x6),  /* Power Control, VC: ON, VR: ON, VF: 
OFF */
-               ST7571_SET_POWER(0x7),  /* Power Control, VC: ON, VR: ON, VF: 
ON */
-
-               ST7571_SET_REVERSE(st7567->inverted ? 1 : 0),
-               ST7571_SET_ENTIRE_DISPLAY_ON(0),
-       };
-
-       return st7571_send_command_list(st7567, commands, ARRAY_SIZE(commands));
-}
-
-static int st7571_lcd_init(struct st7571_device *st7571)
-{
-       /*
-        * Most of the initialization sequence is taken directly from the
-        * referential initial code in the ST7571 datasheet.
-        */
-       u8 commands[] = {
-               ST7571_DISPLAY_OFF,
-
-               ST7571_SET_MODE_MSB,
-               ST7571_SET_MODE_LSB(0x2e),
-
-               ST7571_SET_SEG_SCAN_DIR(0),
-               ST7571_SET_COM_SCAN_DIR(1),
-
-               ST7571_SET_COM0_MSB,
-               ST7571_SET_COM0_LSB(0x00),
-
-               ST7571_SET_START_LINE_MSB,
-               ST7571_SET_START_LINE_LSB(st7571->startline),
-
-               ST7571_OSC_ON,
-               ST7571_SET_REGULATOR_REG(5),
-               ST7571_SET_CONTRAST_MSB,
-               ST7571_SET_CONTRAST_LSB(0x33),
-               ST7571_SET_LCD_BIAS(0x04),
-               ST7571_SET_DISPLAY_DUTY_MSB,
-               ST7571_SET_DISPLAY_DUTY_LSB(st7571->nlines),
-
-               ST7571_SET_POWER(0x4),  /* Power Control, VC: ON, VR: OFF, VF: 
OFF */
-               ST7571_SET_POWER(0x6),  /* Power Control, VC: ON, VR: ON, VF: 
OFF */
-               ST7571_SET_POWER(0x7),  /* Power Control, VC: ON, VR: ON, VF: 
ON */
-
-               ST7571_COMMAND_SET_3,
-               ST7571_SET_COLOR_MODE(st7571->pformat->mode),
-               ST7571_COMMAND_SET_NORMAL,
-
-               ST7571_SET_REVERSE(st7571->inverted ? 1 : 0),
-               ST7571_SET_ENTIRE_DISPLAY_ON(0),
-       };
-
-       /* Perform a reset before initializing the controller */
-       st7571_reset(st7571);
-
-       return st7571_send_command_list(st7571, commands, ARRAY_SIZE(commands));
-}
-
-static struct st7571_device *st7571_probe(struct device *dev,
-                                         struct regmap *regmap)
-{
-       struct st7571_device *st7571;
-       struct drm_device *drm;
-       int ret;
-
-       st7571 = devm_drm_dev_alloc(dev, &st7571_driver,
-                                   struct st7571_device, drm);
-       if (IS_ERR(st7571))
-               return st7571;
-
-       drm = &st7571->drm;
-       st7571->dev = dev;
-       st7571->pdata = device_get_match_data(st7571->dev);
-
-       ret = st7571->pdata->parse_dt(st7571);
-       if (ret)
-               return ERR_PTR(ret);
-
-       ret = st7571_validate_parameters(st7571);
-       if (ret)
-               return ERR_PTR(ret);
-
-       st7571->mode = st7571_mode(st7571);
-       st7571->regmap = regmap;
-
-
-       st7571->hwbuf = devm_kzalloc(st7571->dev,
-                                    (st7571->nlines * st7571->ncols * 
st7571->bpp) / 8,
-                                    GFP_KERNEL);
-       if (!st7571->hwbuf)
-               return ERR_PTR(-ENOMEM);
-
-       st7571->row = devm_kzalloc(st7571->dev,
-                                  (st7571->ncols * st7571->bpp),
-                                  GFP_KERNEL);
-       if (!st7571->row)
-               return ERR_PTR(-ENOMEM);
-
-       ret = st7571_mode_config_init(st7571);
-       if (ret) {
-               dev_err(st7571->dev, "Failed to initialize mode config\n");
-               return ERR_PTR(ret);
-       }
-
-       ret = st7571_plane_init(st7571, st7571->pformat);
-       if (ret) {
-               dev_err(st7571->dev, "Failed to initialize primary plane\n");
-               return ERR_PTR(ret);
-       }
-
-       ret = st7571_crtc_init(st7571);
-       if (ret < 0) {
-               dev_err(st7571->dev, "Failed to initialize CRTC\n");
-               return ERR_PTR(ret);
-       }
-
-       ret = st7571_encoder_init(st7571);
-       if (ret < 0) {
-               dev_err(st7571->dev, "Failed to initialize encoder\n");
-               return ERR_PTR(ret);
-       }
-
-       ret = st7571_connector_init(st7571);
-       if (ret < 0) {
-               dev_err(st7571->dev, "Failed to initialize connector\n");
-               return ERR_PTR(ret);
-       }
-
-       drm_mode_config_reset(drm);
-
-       ret = drm_dev_register(drm, 0);
-       if (ret) {
-               dev_err(st7571->dev, "Failed to register DRM device\n");
-               return ERR_PTR(ret);
-       }
-
-       drm_client_setup(drm, NULL);
-       return st7571;
-}
-
-static void st7571_remove(struct st7571_device *st7571)
-{
-       drm_dev_unplug(&st7571->drm);
-}
-
 static int st7571_i2c_probe(struct i2c_client *client)
 {
        struct st7571_device *st7571;
@@ -979,8 +103,8 @@ static int st7571_i2c_probe(struct i2c_client *client)
        if (i2c_check_functionality(client->adapter, 
I2C_FUNC_PROTOCOL_MANGLING))
                t->ignore_nak = true;
 
-       regmap = devm_regmap_init(&client->dev, &st7571_regmap_bus,
-                                 t, &st7571_regmap_config);
+       regmap = devm_regmap_init(&client->dev, &st7571_i2c_regmap_bus,
+                                 t, &st7571_i2c_regmap_config);
        if (IS_ERR(regmap)) {
                return dev_err_probe(&client->dev, PTR_ERR(regmap),
                                     "Failed to initialize regmap\n");
@@ -1002,30 +126,6 @@ static void st7571_i2c_remove(struct i2c_client *client)
        st7571_remove(st7571);
 }
 
-static const struct st7571_panel_data st7567_config = {
-       .init = st7567_lcd_init,
-       .parse_dt = st7567_parse_dt,
-       .constraints = {
-               .min_nlines = 1,
-               .max_nlines = 64,
-               .min_ncols = 128,
-               .max_ncols = 128,
-               .support_grayscale = false,
-       },
-};
-
-static const struct st7571_panel_data st7571_config = {
-       .init = st7571_lcd_init,
-       .parse_dt = st7571_parse_dt,
-       .constraints = {
-               .min_nlines = 1,
-               .max_nlines = 128,
-               .min_ncols = 128,
-               .max_ncols = 128,
-               .support_grayscale = true,
-       },
-};
-
 static const struct of_device_id st7571_of_match[] = {
        { .compatible = "sitronix,st7567", .data = &st7567_config },
        { .compatible = "sitronix,st7571", .data = &st7571_config },
@@ -1042,7 +142,7 @@ MODULE_DEVICE_TABLE(i2c, st7571_id);
 
 static struct i2c_driver st7571_i2c_driver = {
        .driver = {
-               .name = "st7571",
+               .name = "st7571-i2c",
                .of_match_table = st7571_of_match,
        },
        .probe = st7571_i2c_probe,
@@ -1053,5 +153,5 @@ static struct i2c_driver st7571_i2c_driver = {
 module_i2c_driver(st7571_i2c_driver);
 
 MODULE_AUTHOR("Marcus Folkesson <[email protected]>");
-MODULE_DESCRIPTION("DRM Driver for Sitronix ST7571 LCD controller");
+MODULE_DESCRIPTION("DRM Driver for Sitronix ST7571 LCD controller (I2C)");
 MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/sitronix/st7571.c 
b/drivers/gpu/drm/sitronix/st7571.c
new file mode 100644
index 
0000000000000000000000000000000000000000..5fd575d972a2e3b6654af7ed0a4ab5c4323e7a33
--- /dev/null
+++ b/drivers/gpu/drm/sitronix/st7571.c
@@ -0,0 +1,918 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Sitronix ST7571, a 4 level gray scale dot matrix LCD controller
+ *
+ * Copyright (C) 2025 Marcus Folkesson <[email protected]>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.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_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_fb_helper.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_modeset_helper_vtables.h>
+#include <drm/drm_module.h>
+#include <drm/drm_plane.h>
+#include <drm/drm_probe_helper.h>
+
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+
+#include "st7571.h"
+
+#define ST7571_COMMAND_MODE                    (0x00)
+#define ST7571_DATA_MODE                       (0x40)
+
+/* Normal mode command set */
+#define ST7571_DISPLAY_OFF                     (0xae)
+#define ST7571_DISPLAY_ON                      (0xaf)
+#define ST7571_OSC_ON                          (0xab)
+#define ST7571_SET_COLUMN_LSB(c)               (0x00 | FIELD_PREP(GENMASK(3, 
0), (c)))
+#define ST7571_SET_COLUMN_MSB(c)               (0x10 | FIELD_PREP(GENMASK(2, 
0), (c) >> 4))
+#define ST7571_SET_COM0_LSB(x)                 (FIELD_PREP(GENMASK(6, 0), (x)))
+#define ST7571_SET_COM0_MSB                    (0x44)
+#define ST7571_SET_COM_SCAN_DIR(d)             (0xc0 | FIELD_PREP(GENMASK(3, 
3), (d)))
+#define ST7571_SET_CONTRAST_LSB(c)             (FIELD_PREP(GENMASK(5, 0), (c)))
+#define ST7571_SET_CONTRAST_MSB                        (0x81)
+#define ST7571_SET_DISPLAY_DUTY_LSB(d)         (FIELD_PREP(GENMASK(7, 0), (d)))
+#define ST7571_SET_DISPLAY_DUTY_MSB            (0x48)
+#define ST7571_SET_ENTIRE_DISPLAY_ON(p)                (0xa4 | 
FIELD_PREP(GENMASK(0, 0), (p)))
+#define ST7571_SET_LCD_BIAS(b)                 (0x50 | FIELD_PREP(GENMASK(2, 
0), (b)))
+#define ST7571_SET_MODE_LSB(m)                 (FIELD_PREP(GENMASK(7, 2), (m)))
+#define ST7571_SET_MODE_MSB                    (0x38)
+#define ST7571_SET_PAGE(p)                     (0xb0 | FIELD_PREP(GENMASK(3, 
0), (p)))
+#define ST7571_SET_POWER(p)                    (0x28 | FIELD_PREP(GENMASK(2, 
0), (p)))
+#define ST7571_SET_REGULATOR_REG(r)            (0x20 | FIELD_PREP(GENMASK(2, 
0), (r)))
+#define ST7571_SET_REVERSE(r)                  (0xa6 | FIELD_PREP(GENMASK(0, 
0), (r)))
+#define ST7571_SET_SEG_SCAN_DIR(d)             (0xa0 | FIELD_PREP(GENMASK(0, 
0), (d)))
+#define ST7571_SET_START_LINE_LSB(l)           (FIELD_PREP(GENMASK(6, 0), (l)))
+#define ST7571_SET_START_LINE_MSB              (0x40)
+
+/* Extension command set 3 */
+#define ST7571_COMMAND_SET_3                   (0x7b)
+#define ST7571_SET_COLOR_MODE(c)               (0x10 | FIELD_PREP(GENMASK(0, 
0), (c)))
+#define ST7571_COMMAND_SET_NORMAL              (0x00)
+
+/* ST7567 commands */
+#define ST7567_SET_LCD_BIAS(m) (0xa2 | FIELD_PREP(GENMASK(0, 0), (m)))
+
+#define ST7571_PAGE_HEIGHT 8
+
+#define DRIVER_NAME "st7571"
+#define DRIVER_DESC "ST7571 DRM driver"
+#define DRIVER_MAJOR 1
+#define DRIVER_MINOR 0
+
+static inline struct st7571_device *drm_to_st7571(struct drm_device *drm)
+{
+       return container_of(drm, struct st7571_device, drm);
+}
+
+static int st7571_send_command_list(struct st7571_device *st7571,
+                                   const u8 *cmd_list, size_t len)
+{
+       int ret;
+
+       for (int i = 0; i < len; i++) {
+               ret = regmap_write(st7571->regmap, ST7571_COMMAND_MODE, 
cmd_list[i]);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return ret;
+}
+
+static inline u8 st7571_transform_xy(const char *p, int x, int y, u8 bpp)
+{
+       int xrest = x % 8;
+       u8 result = 0;
+       u8 row_len = 16 * bpp;
+
+       /*
+        * 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 * row_len + x];
+               u8 bit = (byte >> xrest) & 1;
+
+               result |= (bit << i);
+       }
+
+       return result;
+}
+
+static int st7571_set_position(struct st7571_device *st7571, int x, int y)
+{
+       u8 cmd_list[] = {
+               ST7571_SET_COLUMN_LSB(x),
+               ST7571_SET_COLUMN_MSB(x),
+               ST7571_SET_PAGE(y / ST7571_PAGE_HEIGHT),
+       };
+
+       return st7571_send_command_list(st7571, cmd_list, ARRAY_SIZE(cmd_list));
+}
+
+static int st7571_fb_clear_screen(struct st7571_device *st7571)
+{
+       u32 npixels = st7571->ncols * round_up(st7571->nlines, 
ST7571_PAGE_HEIGHT) * st7571->bpp;
+       char pixelvalue = 0x00;
+
+       st7571_set_position(st7571, 0, 0);
+       for (int i = 0; i < npixels; i++)
+               regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, 
&pixelvalue, 1);
+
+       return 0;
+}
+
+static void st7571_prepare_buffer_monochrome(struct st7571_device *st7571,
+                                            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;
+       u32 size;
+
+       switch (fb->format->format) {
+       case DRM_FORMAT_XRGB8888:
+               dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
+               iosys_map_set_vaddr(&dst, st7571->hwbuf);
+
+               drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect, 
fmtcnv_state);
+               break;
+
+       case DRM_FORMAT_R1:
+               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
+               memcpy(st7571->hwbuf, vmap->vaddr, size);
+               break;
+       }
+}
+
+static void st7571_prepare_buffer_grayscale(struct st7571_device *st7571,
+                                           const struct iosys_map *vmap,
+                                           struct drm_framebuffer *fb,
+                                           struct drm_rect *rect,
+                                           struct drm_format_conv_state 
*fmtcnv_state)
+{
+       u32 size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
+       unsigned int dst_pitch;
+       struct iosys_map dst;
+
+       switch (fb->format->format) {
+       case DRM_FORMAT_XRGB8888:
+               dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 4);
+               iosys_map_set_vaddr(&dst, st7571->hwbuf);
+
+               drm_fb_xrgb8888_to_gray2(&dst, &dst_pitch, vmap, fb, rect, 
fmtcnv_state);
+               break;
+
+       case DRM_FORMAT_R1:
+               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 8;
+               memcpy(st7571->hwbuf, vmap->vaddr, size);
+               break;
+
+       case DRM_FORMAT_R2:
+               size = (rect->x2 - rect->x1) * (rect->y2 - rect->y1) / 4;
+               memcpy(st7571->hwbuf, vmap->vaddr, size);
+               break;
+       }
+}
+
+static int st7571_fb_update_rect_monochrome(struct drm_framebuffer *fb, struct 
drm_rect *rect)
+{
+       struct st7571_device *st7571 = drm_to_st7571(fb->dev);
+       char *row = st7571->row;
+
+       /* Align y to display page boundaries */
+       rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
+       rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), 
st7571->nlines);
+
+       for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {
+               for (int x = rect->x1; x < rect->x2; x++)
+                       row[x] = st7571_transform_xy(st7571->hwbuf, x, y, 1);
+
+               st7571_set_position(st7571, rect->x1, y);
+
+               /* TODO: Investige why we can't write multiple bytes at once */
+               for (int x = rect->x1; x < rect->x2; x++)
+                       regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, row 
+ x, 1);
+       }
+
+       return 0;
+}
+
+static int st7571_fb_update_rect_grayscale(struct drm_framebuffer *fb, struct 
drm_rect *rect)
+{
+       struct st7571_device *st7571 = drm_to_st7571(fb->dev);
+       u32 format = fb->format->format;
+       char *row = st7571->row;
+       int x1;
+       int x2;
+
+       /* Align y to display page boundaries */
+       rect->y1 = round_down(rect->y1, ST7571_PAGE_HEIGHT);
+       rect->y2 = min_t(unsigned int, round_up(rect->y2, ST7571_PAGE_HEIGHT), 
st7571->nlines);
+
+       switch (format) {
+       case DRM_FORMAT_R1:
+               x1 = rect->x1 * 1;
+               x2 = rect->x2 * 1;
+               break;
+       case DRM_FORMAT_R2:
+               fallthrough;
+       case DRM_FORMAT_XRGB8888:
+               x1 = rect->x1 * 2;
+               x2 = rect->x2 * 2;
+               break;
+       }
+
+       for (int y = rect->y1; y < rect->y2; y += ST7571_PAGE_HEIGHT) {
+               for (int x = x1; x < x2; x++)
+                       row[x] = st7571_transform_xy(st7571->hwbuf, x, y, 2);
+
+               st7571_set_position(st7571, rect->x1, y);
+
+               /* TODO: Investige why we can't write multiple bytes at once */
+               for (int x = x1; x < x2; x++) {
+                       regmap_bulk_write(st7571->regmap, ST7571_DATA_MODE, row 
+ x, 1);
+
+                       /*
+                        * As the display supports grayscale, all pixels must 
be written as two bits
+                        * even if the format is monochrome.
+                        *
+                        * The bit values maps to the following grayscale:
+                        * 0 0 = Black
+                        * 0 1 = Dark gray
+                        * 1 0 = Light gray
+                        * 1 1 = White
+                        *
+                        * For monochrome formats, write the same value twice 
to get
+                        * either a black or white pixel.
+                        */
+                       if (format == DRM_FORMAT_R1)
+                               regmap_bulk_write(st7571->regmap, 
ST7571_DATA_MODE, row + x, 1);
+               }
+       }
+
+       return 0;
+}
+
+static int st7571_connector_get_modes(struct drm_connector *conn)
+{
+       struct st7571_device *st7571 = drm_to_st7571(conn->dev);
+
+       return drm_connector_helper_get_modes_fixed(conn, &st7571->mode);
+}
+
+static const struct drm_connector_helper_funcs st7571_connector_helper_funcs = 
{
+       .get_modes = st7571_connector_get_modes,
+};
+
+static const struct st7571_panel_format st7571_monochrome = {
+       .prepare_buffer = st7571_prepare_buffer_monochrome,
+       .update_rect = st7571_fb_update_rect_monochrome,
+       .mode = ST7571_COLOR_MODE_BLACKWHITE,
+       .formats = {
+               DRM_FORMAT_XRGB8888,
+               DRM_FORMAT_R1,
+       },
+       .nformats = 2,
+};
+
+static const struct st7571_panel_format st7571_grayscale = {
+       .prepare_buffer = st7571_prepare_buffer_grayscale,
+       .update_rect = st7571_fb_update_rect_grayscale,
+       .mode = ST7571_COLOR_MODE_GRAY,
+       .formats = {
+               DRM_FORMAT_XRGB8888,
+               DRM_FORMAT_R1,
+               DRM_FORMAT_R2,
+       },
+       .nformats = 3,
+};
+
+static const u64 st7571_primary_plane_fmtmods[] = {
+       DRM_FORMAT_MOD_LINEAR,
+       DRM_FORMAT_MOD_INVALID
+};
+
+static int st7571_primary_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;
+
+       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 st7571_primary_plane_helper_atomic_update(struct drm_plane *plane,
+                                                     struct drm_atomic_state 
*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 *drm = plane->dev;
+       struct drm_rect damage;
+       struct st7571_device *st7571 = drm_to_st7571(plane->dev);
+       int ret, idx;
+
+       if (!fb)
+               return; /* no framebuffer; plane is disabled */
+
+       ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+       if (ret)
+               return;
+
+       if (!drm_dev_enter(drm, &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) {
+               st7571->pformat->prepare_buffer(st7571,
+                                               &shadow_plane_state->data[0],
+                                               fb, &damage,
+                                               
&shadow_plane_state->fmtcnv_state);
+
+               st7571->pformat->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 st7571_primary_plane_helper_atomic_disable(struct drm_plane *plane,
+                                                      struct drm_atomic_state 
*state)
+{
+       struct drm_device *drm = plane->dev;
+       struct st7571_device *st7571 = drm_to_st7571(plane->dev);
+       int idx;
+
+       if (!drm_dev_enter(drm, &idx))
+               return;
+
+       st7571_fb_clear_screen(st7571);
+       drm_dev_exit(idx);
+}
+
+static const struct drm_plane_helper_funcs st7571_primary_plane_helper_funcs = 
{
+       DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
+       .atomic_check = st7571_primary_plane_helper_atomic_check,
+       .atomic_update = st7571_primary_plane_helper_atomic_update,
+       .atomic_disable = st7571_primary_plane_helper_atomic_disable,
+};
+
+static const struct drm_plane_funcs st7571_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,
+};
+
+/*
+ * CRTC
+ */
+
+static enum drm_mode_status st7571_crtc_mode_valid(struct drm_crtc *crtc,
+                                                  const struct 
drm_display_mode *mode)
+{
+       struct st7571_device *st7571 = drm_to_st7571(crtc->dev);
+
+       return drm_crtc_helper_mode_valid_fixed(crtc, mode, &st7571->mode);
+}
+
+static const struct drm_crtc_helper_funcs st7571_crtc_helper_funcs = {
+       .atomic_check = drm_crtc_helper_atomic_check,
+       .mode_valid = st7571_crtc_mode_valid,
+};
+
+static const struct drm_crtc_funcs st7571_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,
+};
+
+/*
+ * Encoder
+ */
+
+static void st7571_encoder_atomic_enable(struct drm_encoder *encoder,
+                                        struct drm_atomic_state *state)
+{
+       struct drm_device *drm = encoder->dev;
+       struct st7571_device *st7571 = drm_to_st7571(drm);
+       u8 command = ST7571_DISPLAY_ON;
+       int ret;
+
+       ret = st7571->pdata->init(st7571);
+       if (ret)
+               return;
+
+       st7571_send_command_list(st7571, &command, 1);
+}
+
+static void st7571_encoder_atomic_disable(struct drm_encoder *encoder,
+                                         struct drm_atomic_state *state)
+{
+       struct drm_device *drm = encoder->dev;
+       struct st7571_device *st7571 = drm_to_st7571(drm);
+       u8 command = ST7571_DISPLAY_OFF;
+
+       st7571_send_command_list(st7571, &command, 1);
+}
+
+static const struct drm_encoder_funcs st7571_encoder_funcs = {
+       .destroy = drm_encoder_cleanup,
+
+};
+
+static const struct drm_encoder_helper_funcs st7571_encoder_helper_funcs = {
+       .atomic_enable = st7571_encoder_atomic_enable,
+       .atomic_disable = st7571_encoder_atomic_disable,
+};
+
+/*
+ * Connector
+ */
+
+static const struct drm_connector_funcs st7571_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_mode_config_funcs st7571_mode_config_funcs = {
+       .fb_create = drm_gem_fb_create_with_dirty,
+       .atomic_check = drm_atomic_helper_check,
+       .atomic_commit = drm_atomic_helper_commit,
+};
+
+static struct drm_display_mode st7571_mode(struct st7571_device *st7571)
+{
+       struct drm_display_mode mode = {
+               DRM_SIMPLE_MODE(st7571->ncols, st7571->nlines,
+                               st7571->width_mm, st7571->height_mm),
+       };
+
+       return mode;
+}
+
+static int st7571_mode_config_init(struct st7571_device *st7571)
+{
+       struct drm_device *drm = &st7571->drm;
+       const struct st7571_panel_constraints *constraints = 
&st7571->pdata->constraints;
+       int ret;
+
+       ret = drmm_mode_config_init(drm);
+       if (ret)
+               return ret;
+
+       drm->mode_config.min_width = constraints->min_ncols;
+       drm->mode_config.min_height = constraints->min_nlines;
+       drm->mode_config.max_width = constraints->max_ncols;
+       drm->mode_config.max_height = constraints->max_nlines;
+       drm->mode_config.preferred_depth = 24;
+       drm->mode_config.funcs = &st7571_mode_config_funcs;
+
+       return 0;
+}
+
+static int st7571_plane_init(struct st7571_device *st7571,
+                            const struct st7571_panel_format *pformat)
+{
+       struct drm_plane *primary_plane = &st7571->primary_plane;
+       struct drm_device *drm = &st7571->drm;
+       int ret;
+
+       ret = drm_universal_plane_init(drm, primary_plane, 0,
+                                      &st7571_primary_plane_funcs,
+                                      pformat->formats,
+                                      pformat->nformats,
+                                      st7571_primary_plane_fmtmods,
+                                      DRM_PLANE_TYPE_PRIMARY, NULL);
+       if (ret)
+               return ret;
+
+       drm_plane_helper_add(primary_plane, &st7571_primary_plane_helper_funcs);
+       drm_plane_enable_fb_damage_clips(primary_plane);
+
+       return 0;
+}
+
+static int st7571_crtc_init(struct st7571_device *st7571)
+{
+       struct drm_plane *primary_plane = &st7571->primary_plane;
+       struct drm_crtc *crtc = &st7571->crtc;
+       struct drm_device *drm = &st7571->drm;
+       int ret;
+
+       ret = drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
+                                       &st7571_crtc_funcs, NULL);
+       if (ret)
+               return ret;
+
+       drm_crtc_helper_add(crtc, &st7571_crtc_helper_funcs);
+
+       return 0;
+}
+
+static int st7571_encoder_init(struct st7571_device *st7571)
+{
+       struct drm_encoder *encoder = &st7571->encoder;
+       struct drm_crtc *crtc = &st7571->crtc;
+       struct drm_device *drm = &st7571->drm;
+       int ret;
+
+       ret = drm_encoder_init(drm, encoder, &st7571_encoder_funcs, 
DRM_MODE_ENCODER_NONE, NULL);
+       if (ret)
+               return ret;
+
+       drm_encoder_helper_add(encoder, &st7571_encoder_helper_funcs);
+
+       encoder->possible_crtcs = drm_crtc_mask(crtc);
+
+       return 0;
+}
+
+static int st7571_connector_init(struct st7571_device *st7571)
+{
+       struct drm_connector *connector = &st7571->connector;
+       struct drm_encoder *encoder = &st7571->encoder;
+       struct drm_device *drm = &st7571->drm;
+       int ret;
+
+       ret = drm_connector_init(drm, connector, &st7571_connector_funcs,
+                                DRM_MODE_CONNECTOR_Unknown);
+       if (ret)
+               return ret;
+
+       drm_connector_helper_add(connector, &st7571_connector_helper_funcs);
+
+       return drm_connector_attach_encoder(connector, encoder);
+}
+
+DEFINE_DRM_GEM_FOPS(st7571_fops);
+
+static const struct drm_driver st7571_driver = {
+       .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+
+       .name            = DRIVER_NAME,
+       .desc            = DRIVER_DESC,
+       .major           = DRIVER_MAJOR,
+       .minor           = DRIVER_MINOR,
+
+       .fops            = &st7571_fops,
+       DRM_GEM_SHMEM_DRIVER_OPS,
+       DRM_FBDEV_SHMEM_DRIVER_OPS,
+};
+
+static int st7571_validate_parameters(struct st7571_device *st7571)
+{
+       struct device *dev = st7571->dev;
+       const struct st7571_panel_constraints *constraints = 
&st7571->pdata->constraints;
+
+       if (st7571->width_mm  == 0) {
+               dev_err(dev, "Invalid panel width\n");
+               return -EINVAL;
+       }
+
+       if (st7571->height_mm == 0) {
+               dev_err(dev, "Invalid panel height\n");
+               return -EINVAL;
+       }
+
+       if (st7571->nlines < constraints->min_nlines ||
+           st7571->nlines > constraints->max_nlines) {
+               dev_err(dev, "Invalid timing configuration.\n");
+               return -EINVAL;
+       }
+
+       if (st7571->startline + st7571->nlines > constraints->max_nlines) {
+               dev_err(dev, "Invalid timing configuration.\n");
+               return -EINVAL;
+       }
+
+       if (st7571->ncols < constraints->min_ncols ||
+           st7571->ncols > constraints->max_ncols) {
+               dev_err(dev, "Invalid timing configuration.\n");
+               return -EINVAL;
+       }
+
+       if (st7571->grayscale && !constraints->support_grayscale) {
+               dev_err(dev, "Grayscale not supported\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int st7567_parse_dt(struct st7571_device *st7567)
+{
+       struct device *dev = st7567->dev;
+       struct device_node *np = dev->of_node;
+       struct display_timing dt;
+       int ret;
+
+       ret = of_get_display_timing(np, "panel-timing", &dt);
+       if (ret) {
+               dev_err(dev, "Failed to get display timing from DT\n");
+               return ret;
+       }
+
+       of_property_read_u32(np, "width-mm", &st7567->width_mm);
+       of_property_read_u32(np, "height-mm", &st7567->height_mm);
+       st7567->inverted = of_property_read_bool(np, "sitronix,inverted");
+
+       st7567->pformat = &st7571_monochrome;
+       st7567->bpp = 1;
+
+       st7567->startline = dt.vfront_porch.typ;
+       st7567->nlines = dt.vactive.typ;
+       st7567->ncols = dt.hactive.typ;
+
+       return 0;
+}
+
+static int st7571_parse_dt(struct st7571_device *st7571)
+{
+       struct device *dev = st7571->dev;
+       struct device_node *np = dev->of_node;
+       struct display_timing dt;
+       int ret;
+
+       ret = of_get_display_timing(np, "panel-timing", &dt);
+       if (ret) {
+               dev_err(dev, "Failed to get display timing from DT\n");
+               return ret;
+       }
+
+       of_property_read_u32(np, "width-mm", &st7571->width_mm);
+       of_property_read_u32(np, "height-mm", &st7571->height_mm);
+       st7571->grayscale = of_property_read_bool(np, "sitronix,grayscale");
+       st7571->inverted = of_property_read_bool(np, "sitronix,inverted");
+
+       if (st7571->grayscale) {
+               st7571->pformat = &st7571_grayscale;
+               st7571->bpp = 2;
+       } else {
+               st7571->pformat = &st7571_monochrome;
+               st7571->bpp = 1;
+       }
+
+       st7571->startline = dt.vfront_porch.typ;
+       st7571->nlines = dt.vactive.typ;
+       st7571->ncols = dt.hactive.typ;
+
+       st7571->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+       if (IS_ERR(st7571->reset))
+               return dev_err_probe(dev, PTR_ERR(st7571->reset),
+                                    "Failed to get reset gpio\n");
+
+       return 0;
+}
+
+static void st7571_reset(struct st7571_device *st7571)
+{
+       gpiod_set_value_cansleep(st7571->reset, 1);
+       fsleep(20);
+       gpiod_set_value_cansleep(st7571->reset, 0);
+}
+
+static int st7567_lcd_init(struct st7571_device *st7567)
+{
+       /*
+        * Most of the initialization sequence is taken directly from the
+        * referential initial code in the ST7567 datasheet.
+        */
+       u8 commands[] = {
+               ST7571_DISPLAY_OFF,
+
+               ST7567_SET_LCD_BIAS(1),
+
+               ST7571_SET_SEG_SCAN_DIR(0),
+               ST7571_SET_COM_SCAN_DIR(1),
+
+               ST7571_SET_REGULATOR_REG(4),
+               ST7571_SET_CONTRAST_MSB,
+               ST7571_SET_CONTRAST_LSB(0x20),
+
+               ST7571_SET_START_LINE_MSB,
+               ST7571_SET_START_LINE_LSB(st7567->startline),
+
+               ST7571_SET_POWER(0x4),  /* Power Control, VC: ON, VR: OFF, VF: 
OFF */
+               ST7571_SET_POWER(0x6),  /* Power Control, VC: ON, VR: ON, VF: 
OFF */
+               ST7571_SET_POWER(0x7),  /* Power Control, VC: ON, VR: ON, VF: 
ON */
+
+               ST7571_SET_REVERSE(st7567->inverted ? 1 : 0),
+               ST7571_SET_ENTIRE_DISPLAY_ON(0),
+       };
+
+       return st7571_send_command_list(st7567, commands, ARRAY_SIZE(commands));
+}
+
+static int st7571_lcd_init(struct st7571_device *st7571)
+{
+       /*
+        * Most of the initialization sequence is taken directly from the
+        * referential initial code in the ST7571 datasheet.
+        */
+       u8 commands[] = {
+               ST7571_DISPLAY_OFF,
+
+               ST7571_SET_MODE_MSB,
+               ST7571_SET_MODE_LSB(0x2e),
+
+               ST7571_SET_SEG_SCAN_DIR(0),
+               ST7571_SET_COM_SCAN_DIR(1),
+
+               ST7571_SET_COM0_MSB,
+               ST7571_SET_COM0_LSB(0x00),
+
+               ST7571_SET_START_LINE_MSB,
+               ST7571_SET_START_LINE_LSB(st7571->startline),
+
+               ST7571_OSC_ON,
+               ST7571_SET_REGULATOR_REG(5),
+               ST7571_SET_CONTRAST_MSB,
+               ST7571_SET_CONTRAST_LSB(0x33),
+               ST7571_SET_LCD_BIAS(0x04),
+               ST7571_SET_DISPLAY_DUTY_MSB,
+               ST7571_SET_DISPLAY_DUTY_LSB(st7571->nlines),
+
+               ST7571_SET_POWER(0x4),  /* Power Control, VC: ON, VR: OFF, VF: 
OFF */
+               ST7571_SET_POWER(0x6),  /* Power Control, VC: ON, VR: ON, VF: 
OFF */
+               ST7571_SET_POWER(0x7),  /* Power Control, VC: ON, VR: ON, VF: 
ON */
+
+               ST7571_COMMAND_SET_3,
+               ST7571_SET_COLOR_MODE(st7571->pformat->mode),
+               ST7571_COMMAND_SET_NORMAL,
+
+               ST7571_SET_REVERSE(st7571->inverted ? 1 : 0),
+               ST7571_SET_ENTIRE_DISPLAY_ON(0),
+       };
+
+       /* Perform a reset before initializing the controller */
+       st7571_reset(st7571);
+
+       return st7571_send_command_list(st7571, commands, ARRAY_SIZE(commands));
+}
+
+struct st7571_device *st7571_probe(struct device *dev,
+                                  struct regmap *regmap)
+{
+       struct st7571_device *st7571;
+       struct drm_device *drm;
+       int ret;
+
+       st7571 = devm_drm_dev_alloc(dev, &st7571_driver,
+                                   struct st7571_device, drm);
+       if (IS_ERR(st7571))
+               return st7571;
+
+       drm = &st7571->drm;
+       st7571->dev = dev;
+       st7571->pdata = device_get_match_data(st7571->dev);
+
+       ret = st7571->pdata->parse_dt(st7571);
+       if (ret)
+               return ERR_PTR(ret);
+
+       ret = st7571_validate_parameters(st7571);
+       if (ret)
+               return ERR_PTR(ret);
+
+       st7571->mode = st7571_mode(st7571);
+       st7571->regmap = regmap;
+
+       st7571->hwbuf = devm_kzalloc(st7571->dev,
+                                    (st7571->nlines * st7571->ncols * 
st7571->bpp) / 8,
+                                    GFP_KERNEL);
+       if (!st7571->hwbuf)
+               return ERR_PTR(-ENOMEM);
+
+       st7571->row = devm_kzalloc(st7571->dev,
+                                  (st7571->ncols * st7571->bpp),
+                                  GFP_KERNEL);
+       if (!st7571->row)
+               return ERR_PTR(-ENOMEM);
+
+       ret = st7571_mode_config_init(st7571);
+       if (ret) {
+               dev_err(st7571->dev, "Failed to initialize mode config\n");
+               return ERR_PTR(ret);
+       }
+
+       ret = st7571_plane_init(st7571, st7571->pformat);
+       if (ret) {
+               dev_err(st7571->dev, "Failed to initialize primary plane\n");
+               return ERR_PTR(ret);
+       }
+
+       ret = st7571_crtc_init(st7571);
+       if (ret < 0) {
+               dev_err(st7571->dev, "Failed to initialize CRTC\n");
+               return ERR_PTR(ret);
+       }
+
+       ret = st7571_encoder_init(st7571);
+       if (ret < 0) {
+               dev_err(st7571->dev, "Failed to initialize encoder\n");
+               return ERR_PTR(ret);
+       }
+
+       ret = st7571_connector_init(st7571);
+       if (ret < 0) {
+               dev_err(st7571->dev, "Failed to initialize connector\n");
+               return ERR_PTR(ret);
+       }
+
+       drm_mode_config_reset(drm);
+
+       ret = drm_dev_register(drm, 0);
+       if (ret) {
+               dev_err(st7571->dev, "Failed to register DRM device\n");
+               return ERR_PTR(ret);
+       }
+
+       drm_client_setup(drm, NULL);
+       return st7571;
+}
+EXPORT_SYMBOL_GPL(st7571_probe);
+
+void st7571_remove(struct st7571_device *st7571)
+{
+       drm_dev_unplug(&st7571->drm);
+}
+EXPORT_SYMBOL_GPL(st7571_remove);
+
+const struct st7571_panel_data st7567_config = {
+       .init = st7567_lcd_init,
+       .parse_dt = st7567_parse_dt,
+       .constraints = {
+               .min_nlines = 1,
+               .max_nlines = 64,
+               .min_ncols = 128,
+               .max_ncols = 128,
+               .support_grayscale = false,
+       },
+};
+EXPORT_SYMBOL_NS_GPL(st7567_config, "DRM_ST7571");
+
+const struct st7571_panel_data st7571_config = {
+       .init = st7571_lcd_init,
+       .parse_dt = st7571_parse_dt,
+       .constraints = {
+               .min_nlines = 1,
+               .max_nlines = 128,
+               .min_ncols = 128,
+               .max_ncols = 128,
+               .support_grayscale = true,
+       },
+};
+EXPORT_SYMBOL_NS_GPL(st7571_config, "DRM_ST7571");
+
+MODULE_AUTHOR("Marcus Folkesson <[email protected]>");
+MODULE_DESCRIPTION("DRM Driver for Sitronix ST7571 LCD controller");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/sitronix/st7571.h 
b/drivers/gpu/drm/sitronix/st7571.h
index 
f62c57ddb99ebe82f63048cc2ccf75a81518d717..af264f2e2ea47e7813067733e7051db9529ca1f1
 100644
--- a/drivers/gpu/drm/sitronix/st7571.h
+++ b/drivers/gpu/drm/sitronix/st7571.h
@@ -82,4 +82,10 @@ struct st7571_device {
        u8 *row;
 };
 
+extern const struct st7571_panel_data st7567_config;
+extern const struct st7571_panel_data st7571_config;
+
+struct st7571_device *st7571_probe(struct device *dev, struct regmap *regmap);
+void st7571_remove(struct st7571_device *st7571);
+
 #endif /* __ST7571_H__ */

-- 
2.50.1

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