Add i2c_bus_num field to panel_generic_dpi_data, and use it in the
panel-generic-dpi.c to detect if a panel is connected and to read EDID
from the panel.
Original by: Ricardo Salveti de Araujo <ricardo.salv...@canonical.com>
Signed-off-by: Tomi Valkeinen <tomi.valkei...@ti.com>
---
drivers/video/omap2/displays/panel-generic-dpi.c | 92 ++++++++++++++++++++++
include/video/omap-panel-generic-dpi.h | 2 +
2 files changed, 94 insertions(+), 0 deletions(-)
diff --git a/drivers/video/omap2/displays/panel-generic-dpi.c
b/drivers/video/omap2/displays/panel-generic-dpi.c
index 9c90f75..6ef36ad 100644
--- a/drivers/video/omap2/displays/panel-generic-dpi.c
+++ b/drivers/video/omap2/displays/panel-generic-dpi.c
@@ -34,6 +34,8 @@
#include <linux/delay.h>
#include <linux/slab.h>
#include <video/omapdss.h>
+#include <linux/i2c.h>
+#include <drm/drm_edid.h>
#include <video/omap-panel-generic-dpi.h>
@@ -407,6 +409,93 @@ static int generic_dpi_panel_check_timings(struct
omap_dss_device *dssdev,
return dpi_check_timings(dssdev, timings);
}
+
+static int generic_dpi_ddc_read(struct i2c_adapter *adapter,
+ unsigned char *buf, u16 count, u8 offset)
+{
+ int r, retries;
+
+ for (retries = 3; retries > 0; retries--) {
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &offset,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len = count,
+ .buf = buf,
+ }
+ };
+
+ r = i2c_transfer(adapter, msgs, 2);
+ if (r == 2)
+ return 0;
+
+ if (r != -EAGAIN)
+ break;
+ }
+
+ return r < 0 ? r : -EIO;
+}
+
+static int generic_dpi_panel_read_edid(struct omap_dss_device *dssdev,
+ u8 *edid, int len)
+{
+ struct panel_generic_dpi_data *panel_data = get_panel_data(dssdev);
+ struct i2c_adapter *adapter;
+ int r, l, bytes_read;
+
+ if (panel_data->i2c_bus_num == 0)
+ return -ENODEV;
+
+ adapter = i2c_get_adapter(panel_data->i2c_bus_num);
+ if (!adapter) {
+ dev_err(&dssdev->dev, "Failed to get I2C adapter, bus %d\n",
+ panel_data->i2c_bus_num);
+ return -EINVAL;
+ }
+
+ l = min(EDID_LENGTH, len);
+ r = generic_dpi_ddc_read(adapter, edid, l, 0);
+ if (r)
+ return r;
+
+ bytes_read = l;
+
+ /* if there are extensions, read second block */
+ if (len > EDID_LENGTH && edid[0x7e] > 0) {
+ l = min(EDID_LENGTH, len - EDID_LENGTH);
+
+ r = generic_dpi_ddc_read(adapter, edid + EDID_LENGTH,
+ l, EDID_LENGTH);
+ if (r)
+ return r;
+
+ bytes_read += l;
+ }
+
+ return bytes_read;
+}
+
+static bool generic_dpi_panel_detect(struct omap_dss_device *dssdev)
+{
+ struct panel_generic_dpi_data *panel_data = get_panel_data(dssdev);
+ struct i2c_adapter *adapter;
+ unsigned char out;
+
+ if (panel_data->i2c_bus_num == 0)
+ return true;
+
+ adapter = i2c_get_adapter(panel_data->i2c_bus_num);
+ if (!adapter)
+ return true;
+
+ return generic_dpi_ddc_read(adapter, &out, 1, 0) == 0;
+}
+
static struct omap_dss_driver dpi_driver = {
.probe = generic_dpi_panel_probe,
.remove = __exit_p(generic_dpi_panel_remove),
@@ -420,6 +509,9 @@ static struct omap_dss_driver dpi_driver = {
.get_timings = generic_dpi_panel_get_timings,
.check_timings = generic_dpi_panel_check_timings,
+ .read_edid = generic_dpi_panel_read_edid,
+ .detect = generic_dpi_panel_detect,
+
.driver = {
.name = "generic_dpi_panel",
.owner = THIS_MODULE,
diff --git a/include/video/omap-panel-generic-dpi.h
b/include/video/omap-panel-generic-dpi.h
index 127e3f2..3ab023a 100644
--- a/include/video/omap-panel-generic-dpi.h
+++ b/include/video/omap-panel-generic-dpi.h
@@ -27,11 +27,13 @@ struct omap_dss_device;
* @name: panel name
* @platform_enable: platform specific panel enable function
* @platform_disable: platform specific panel disable function
+ * @i2c_bus_num: i2c bus id for the panel
*/
struct panel_generic_dpi_data {
const char *name;
int (*platform_enable)(struct omap_dss_device *dssdev);
void (*platform_disable)(struct omap_dss_device *dssdev);
+ u16 i2c_bus_num;
};
#endif /* __OMAP_PANEL_GENERIC_DPI_H */
--
1.7.4.1
--
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