video: dw_hdmi: Add support for ddc-i2c-bus property
Add support for the ddc-i2c-bus device tree property which allows
for using an external i2c master for reading the display's EDID.
Signed-off-by: Niklas Schulze <me@jns.io>
diff --git a/drivers/video/dw_hdmi.c b/drivers/video/dw_hdmi.c
index 463436e..bf74d6a 100644
--- a/drivers/video/dw_hdmi.c
+++ b/drivers/video/dw_hdmi.c
@@ -8,6 +8,7 @@
#include <common.h>
#include <fdtdec.h>
#include <asm/io.h>
+#include <i2c.h>
#include <media_bus_format.h>
#include "dw_hdmi.h"
@@ -812,6 +813,18 @@
u32 trytime = 5;
u32 n;
+ if (CONFIG_IS_ENABLED(DM_I2C) && hdmi->ddc_bus) {
+ struct udevice *chip;
+
+ edid_read_err = i2c_get_chip(hdmi->ddc_bus,
+ HDMI_I2CM_SLAVE_DDC_ADDR,
+ 1, &chip);
+ if (edid_read_err)
+ return edid_read_err;
+
+ return dm_i2c_read(chip, shift, buff, HDMI_EDID_BLOCK_SIZE);
+ }
+
/* set ddc i2c clk which devided from ddc_clk to 100khz */
hdmi_write(hdmi, hdmi->i2c_clk_high, HDMI_I2CM_SS_SCL_HCNT_0_ADDR);
hdmi_write(hdmi, hdmi->i2c_clk_low, HDMI_I2CM_SS_SCL_LCNT_0_ADDR);