@@ -196,6 +196,7 @@ struct rpi_touchscreen {
struct drm_panel base;
struct mipi_dsi_device *dsi;
struct i2c_client *i2c;
+ bool connected;
};
static const struct drm_display_mode rpi_touchscreen_modes[] = {
@@ -255,6 +256,9 @@ static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg));
#else
+ if (!ts->connected)
+ return 0;
+
rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8);
rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg);
rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8);
@@ -268,6 +272,9 @@ static int rpi_touchscreen_disable(struct drm_panel *panel)
{
struct rpi_touchscreen *ts = panel_to_ts(panel);
+ if (!ts->connected)
+ return 0;
+
rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
@@ -286,6 +293,9 @@ static int rpi_touchscreen_enable(struct drm_panel *panel)
struct rpi_touchscreen *ts = panel_to_ts(panel);
int i;
+ if (!ts->connected)
+ return 0;
+
rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
/* Wait for nPWRDWN to go low to indicate poweron is done. */
for (i = 0; i < 100; i++) {
@@ -330,6 +340,10 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel)
struct drm_device *drm = panel->drm;
unsigned int i, num = 0;
static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+ if (!ts->connected)
+ return 0;
for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
@@ -362,7 +376,34 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel)
return num;
}
+static int rpi_touchscreen_detect(struct drm_panel *panel)
+{
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+ int ver;
+
+ if (ts->connected)
+ return connector_status_connected;
+
+ ver = rpi_touchscreen_i2c_read(ts, REG_ID);
+ switch (ver) {
+ case 0xde: /* ver 1 */
+ case 0xc3: /* ver 2 */
+ ts->connected = true;
+
+ /* Turn off at boot, so we can cleanly sequence powering on. */
+ rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
+
+ return connector_status_connected;
+
+ default:
+ break;
+ }
+
+ return connector_status_disconnected;
+}
+
static const struct drm_panel_funcs rpi_touchscreen_funcs = {
+ .detect = rpi_touchscreen_detect,
.disable = rpi_touchscreen_disable,
.unprepare = rpi_touchscreen_noop,
.prepare = rpi_touchscreen_noop,
@@ -393,22 +434,24 @@ static int rpi_touchscreen_probe(struct i2c_client *i2c,
ts->i2c = i2c;
ver = rpi_touchscreen_i2c_read(ts, REG_ID);
- if (ver < 0) {
- dev_err(dev, "Atmel I2C read failed: %d\n", ver);
- return -ENODEV;
- }
-
switch (ver) {
case 0xde: /* ver 1 */
case 0xc3: /* ver 2 */
+ ts->connected = true;
+
+ /* Turn off at boot, so we can cleanly sequence powering on. */
+ rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
break;
default:
- dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
- return -ENODEV;
+ if (ver < 0)
+ dev_err(dev, "Atmel I2C read failed: %d\n", ver);
+ else
+ dev_err(dev,
+ "Unknown Atmel firmware revision: 0x%02x\n",
+ ver);
+ break;
}
- /* Turn off at boot, so we can cleanly sequence powering on. */
- rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
/* Look up the DSI host. It needs to probe before we do. */
endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
@@ -432,6 +475,7 @@ static int rpi_touchscreen_probe(struct i2c_client *i2c,
ts->base.dev = dev;
ts->base.funcs = &rpi_touchscreen_funcs;
+ ts->base.polled = DRM_CONNECTOR_POLL_CONNECT;
/* This appears last, as it's what will unblock the DSI host
* driver's component bind function.
Implement a way to determine when the panel is connected. This is done by reading REG_ID through I2C. We consider the panel as disconnect until we retrieve a valid ID. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> --- .../gpu/drm/panel/panel-raspberrypi-touchscreen.c | 62 ++++++++++++++++++---- 1 file changed, 53 insertions(+), 9 deletions(-)