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>
---
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 },
{ }
};
--
2.49.0
