[PATCH v8 9/9] drm/bridge: it6505: Register Type C mode switches

From: Pin-yen Lin
Date: Sat Jan 07 2023 - 05:25:59 EST


Register USB Type-C mode switches when the "mode-switch" property and
relevant port are available in Device Tree. Configure the "lane_swap"
state based on the entered alternate mode for a specific Type-C
connector, which ends up updating the lane swap registers of the it6505
chip.

Signed-off-by: Pin-yen Lin <treapking@xxxxxxxxxxxx>

---

(no changes since v7)

Changes in v7:
- Fixed style issues in it6505 driver
- Removed the redundant sleep in it6505 driver
- Removed DT property validation in it6505 driver
- Rebased to drm-misc-next
- Extracted common codes to another commit

Changes in v6:
- Changed it6505_typec_mux_set callback function to accommodate with
the latest drm-misc patches
- Changed the driver implementation to accommodate with the new binding
- Squashed to a single patch

drivers/gpu/drm/bridge/Kconfig | 1 +
drivers/gpu/drm/bridge/ite-it6505.c | 119 +++++++++++++++++++++++++++-
2 files changed, 116 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 737578dd57ed..33803f581562 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -87,6 +87,7 @@ config DRM_FSL_LDB
config DRM_ITE_IT6505
tristate "ITE IT6505 DisplayPort bridge"
depends on OF
+ depends on TYPEC || TYPEC=n
select DRM_DISPLAY_DP_HELPER
select DRM_DISPLAY_HDCP_HELPER
select DRM_DISPLAY_HELPER
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 9cda2df21b88..d9be09e889e2 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -17,6 +17,8 @@
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/types.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
#include <linux/wait.h>

#include <crypto/hash.h>
@@ -28,6 +30,7 @@
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

@@ -455,6 +458,7 @@ struct it6505 {
struct delayed_work delayed_audio;
struct it6505_audio_data audio;
struct dentry *debugfs;
+ struct drm_dp_typec_switch_desc switch_desc;

/* it6505 driver hold option */
bool enable_drv_hold;
@@ -3346,12 +3350,105 @@ static void it6505_shutdown(struct i2c_client *client)
it6505_lane_off(it6505);
}

+static void it6505_typec_ports_update(struct it6505 *it6505)
+{
+ struct drm_dp_typec_switch_desc switch_desc = it6505->switch_desc;
+
+ /* Check if both ports available and do nothing to retain the current one */
+ if (switch_desc.typec_ports[0].dp_connected && switch_desc.typec_ports[1].dp_connected)
+ return;
+
+ if (switch_desc.typec_ports[0].dp_connected)
+ it6505->lane_swap = false;
+ else if (switch_desc.typec_ports[1].dp_connected)
+ it6505->lane_swap = true;
+}
+
+static int it6505_typec_mux_set(struct typec_mux_dev *mux,
+ struct typec_mux_state *state)
+{
+ struct drm_dp_typec_port_data *port_data = typec_mux_get_drvdata(mux);
+ struct it6505 *it6505 = (struct it6505 *) port_data->data;
+ struct device *dev = &it6505->client->dev;
+ struct drm_dp_typec_switch_desc switch_desc = it6505->switch_desc;
+ bool old_dp_connected, new_dp_connected;
+
+ if (switch_desc.num_typec_switches == 1)
+ return 0;
+
+ mutex_lock(&it6505->extcon_lock);
+
+ old_dp_connected = switch_desc.typec_ports[0].dp_connected ||
+ switch_desc.typec_ports[1].dp_connected;
+
+ port_data->dp_connected = state->alt &&
+ state->alt->svid == USB_TYPEC_DP_SID &&
+ state->alt->mode == USB_TYPEC_DP_MODE;
+
+ dev_dbg(dev, "mux_set dp_connected: c0=%d, c1=%d\n",
+ switch_desc.typec_ports[0].dp_connected, switch_desc.typec_ports[1].dp_connected);
+
+ new_dp_connected = switch_desc.typec_ports[0].dp_connected ||
+ switch_desc.typec_ports[1].dp_connected;
+
+ if (it6505->enable_drv_hold) {
+ dev_dbg(dev, "enable driver hold\n");
+ goto unlock;
+ }
+
+ it6505_typec_ports_update(it6505);
+
+ if (!old_dp_connected && new_dp_connected) {
+ int ret = pm_runtime_get_sync(dev);
+
+ /*
+ * pm_runtime_force_suspend() disables runtime PM when the
+ * system enters suspend state. But on system resume, mux_set
+ * can be triggered before pm_runtime_force_resume() re-enables
+ * runtime PM. This makes the bridge stay powered off if the
+ * downstream display is connected when the system is suspended.
+ * Handling the error here to make sure the bridge is powered
+ * on, and leave the PM runtime usage count incremented so
+ * the future runtime PM calls is balanced.
+ */
+ if (ret < 0)
+ it6505_poweron(it6505);
+
+ complete_all(&it6505->extcon_completion);
+ }
+
+ if (old_dp_connected && !new_dp_connected) {
+ reinit_completion(&it6505->extcon_completion);
+ pm_runtime_put_sync(dev);
+ if (it6505->bridge.dev)
+ drm_helper_hpd_irq_event(it6505->bridge.dev);
+ memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+ }
+
+unlock:
+ mutex_unlock(&it6505->extcon_lock);
+ return 0;
+}
+
+static void it6505_unregister_typec_switches(struct it6505 *it6505)
+{
+ drm_dp_unregister_typec_switches(&it6505->switch_desc);
+}
+
+static int it6505_register_typec_switches(struct device *dev, struct it6505 *it6505)
+{
+ struct device_node *port = of_graph_get_port_by_id(dev->of_node, 1);
+
+ return drm_dp_register_typec_switches(dev, port, &it6505->switch_desc,
+ it6505, it6505_typec_mux_set);
+}
+
static int it6505_i2c_probe(struct i2c_client *client)
{
struct it6505 *it6505;
struct device *dev = &client->dev;
struct extcon_dev *extcon;
- int err, intp_irq;
+ int err, intp_irq, ret;

it6505 = devm_kzalloc(&client->dev, sizeof(*it6505), GFP_KERNEL);
if (!it6505)
@@ -3371,11 +3468,24 @@ static int it6505_i2c_probe(struct i2c_client *client)
if (PTR_ERR(extcon) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (IS_ERR(extcon)) {
- dev_err(dev, "can not get extcon device!");
- return PTR_ERR(extcon);
+ if (PTR_ERR(extcon) != -ENODEV)
+ dev_warn(dev, "Cannot get extcon device: %ld\n",
+ PTR_ERR(extcon));
+ it6505->extcon = NULL;
+ } else {
+ it6505->extcon = extcon;
}

- it6505->extcon = extcon;
+ ret = it6505_register_typec_switches(dev, it6505);
+ if (ret) {
+ if (ret != -ENODEV)
+ dev_warn(dev, "Didn't register Type-C switches, err: %d\n",
+ ret);
+ if (!it6505->extcon) {
+ dev_err(dev, "Both extcon and typec-switch are not registered.\n");
+ return -EINVAL;
+ }
+ }

it6505->regmap = devm_regmap_init_i2c(client, &it6505_regmap_config);
if (IS_ERR(it6505->regmap)) {
@@ -3447,6 +3557,7 @@ static void it6505_i2c_remove(struct i2c_client *client)
it6505_debugfs_remove(it6505);
it6505_poweroff(it6505);
it6505_remove_edid(it6505);
+ it6505_unregister_typec_switches(it6505);
}

static const struct i2c_device_id it6505_id[] = {
--
2.39.0.314.g84b9a713c41-goog