Am 14.07.25 um 12:44 schrieb Javier Martinez Canillas:
The Sitronix ST7567 is a monochrome Dot Matrix LCD Controller that has SPI,
I2C and parallel interfaces. The st7571-i2c driver only has support for I2C
so displays using other transport interfaces are currently not supported.

The DRM_FORMAT_R1 pixel format and data commands are the same than what
is used by the ST7571 controller, so only is needed a different callback
that implements the expected initialization sequence for the ST7567 chip.

Signed-off-by: Javier Martinez Canillas <javi...@redhat.com>
Reviewed-by: Marcus Folkesson <marcus.folkes...@gmail.com>

Reviewed-by: Thomas Zimmermann <tzimmerm...@suse.de>

---

Changes in v2:
- Use a different parse DT function (Thomas Zimmermann).

  drivers/gpu/drm/sitronix/st7571-i2c.c | 74 +++++++++++++++++++++++++++
  1 file changed, 74 insertions(+)

diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c 
b/drivers/gpu/drm/sitronix/st7571-i2c.c
index f9c4fedb3cca..1b820ff6a9dd 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -68,6 +68,9 @@
  #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"
@@ -774,6 +777,32 @@ static int st7571_validate_parameters(struct st7571_device 
*st7571)
        return 0;
  }
+static int st7567_parse_dt(struct st7571_device *st7567)
+{
+       struct device *dev = &st7567->client->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->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->client->dev;
@@ -819,6 +848,37 @@ static void st7571_reset(struct st7571_device *st7571)
        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_ENTIRE_DISPLAY_ON(0),
+       };
+
+       return st7571_send_command_list(st7567, commands, ARRAY_SIZE(commands));
+}
+
  static int st7571_lcd_init(struct st7571_device *st7571)
  {
        /*
@@ -963,6 +1023,18 @@ static void st7571_remove(struct i2c_client *client)
        drm_dev_unplug(&st7571->dev);
  }
+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,
+       },
+};
+
  struct st7571_panel_data st7571_config = {
        .init = st7571_lcd_init,
        .parse_dt = st7571_parse_dt,
@@ -976,12 +1048,14 @@ struct st7571_panel_data st7571_config = {
  };
static const struct of_device_id st7571_of_match[] = {
+       { .compatible = "sitronix,st7567", .data = &st7567_config },
        { .compatible = "sitronix,st7571", .data = &st7571_config },
        {},
  };
  MODULE_DEVICE_TABLE(of, st7571_of_match);
static const struct i2c_device_id st7571_id[] = {
+       { "st7567", 0 },
        { "st7571", 0 },
        { }
  };

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

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