[PATCH v12 10/10] drm/bridge: it6505: Register Type C mode switches

Pin-yen Lin
2023-02-21T09:53:11Z

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@chromium.org>

---

Changes in v12:
- Fixes style issues in it6505 driver
- Replaced &it6505->client->dev with it6505->dev
- Updated the error logs when parsing data-lanes property

Changes in v11:
- Added back "data-lanes" parsing logics
- Removed Kconfig dependency
- Updated the usage of the private data

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/ite-it6505.c | 186 +++++++++++++++++++++++++++-
1 file changed, 182 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index d4bc388b68ac..6c03a853a876 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>
@@ -27,6 +29,7 @@
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

@@ -401,6 +404,11 @@ struct debugfs_entries {
const struct file_operations *fops;
};

+struct it6505_typec_port_data {
+ bool dp_connected;
+ bool lane_swap;
+};
+
struct it6505 {
struct drm_dp_aux aux;
struct drm_bridge bridge;
@@ -454,6 +462,9 @@ struct it6505 {
struct delayed_work delayed_audio;
struct it6505_audio_data audio;
struct dentry *debugfs;
+ struct completion mux_register;
+ struct drm_dp_typec_switch_desc switch_desc;
+ struct it6505_typec_port_data *port_data;

/* it6505 driver hold option */
bool enable_drv_hold;
@@ -3345,12 +3356,164 @@ static void it6505_shutdown(struct i2c_client *client)
it6505_lane_off(it6505);
}

+static void it6505_typec_ports_update(struct it6505 *it6505)
+{
+ int i;
+
+ /* Check if both ports available and do nothing to retain the current one */
+ if (it6505->port_data[0].dp_connected && it6505->port_data[1].dp_connected)
+ return;
+
+ for (i = 0; i < 2; i++) {
+ if (it6505->port_data[i].dp_connected)
+ it6505->lane_swap = it6505->port_data[i].lane_swap;
+ }
+}
+
+static int it6505_typec_mux_set(struct typec_mux_dev *mux,
+ struct typec_mux_state *state)
+{
+ struct drm_dp_typec_port_data *port = typec_mux_get_drvdata(mux);
+ struct it6505 *it6505 = port->data;
+ struct device *dev = it6505->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);
+ wait_for_completion(&it6505->mux_register);
+
+ old_dp_connected = it6505->port_data[0].dp_connected ||
+ it6505->port_data[1].dp_connected;
+
+ it6505->port_data[port->port_num].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",
+ it6505->port_data[0].dp_connected, it6505->port_data[1].dp_connected);
+
+ new_dp_connected = it6505->port_data[0].dp_connected ||
+ it6505->port_data[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_node = of_graph_get_port_by_id(dev->of_node, 1);
+ struct drm_dp_typec_switch_desc *switch_desc = &it6505->switch_desc;
+ int ret;
+ u32 dp_lanes[4];
+ unsigned int i, num_lanes;
+
+ ret = drm_dp_register_typec_switches(dev, &port_node->fwnode,
+ &it6505->switch_desc, it6505,
+ it6505_typec_mux_set);
+ if (ret)
+ return ret;
+
+ it6505->port_data = devm_kcalloc(
+ dev, switch_desc->num_typec_switches,
+ sizeof(struct it6505_typec_port_data), GFP_KERNEL);
+
+ if (!it6505->port_data) {
+ ret = -ENOMEM;
+ goto unregister_mux;
+ }
+
+ for (i = 0; i < switch_desc->num_typec_switches; i++) {
+ struct drm_dp_typec_port_data *port = &switch_desc->typec_ports[i];
+ struct fwnode_handle *fwnode = port->fwnode;
+
+ num_lanes = fwnode_property_count_u32(fwnode, "data-lanes");
+
+ if (num_lanes < 0) {
+ dev_err(dev,
+ "Error on getting data lanes count from %pfwP: %d\n",
+ fwnode, num_lanes);
+ ret = num_lanes;
+ goto unregister_mux;
+ }
+
+ if (num_lanes > 2) {
+ dev_err(dev,
+ "Invalid data lanes count for mode switches from %pfwP: %d\n",
+ fwnode, num_lanes);
+ ret = -EINVAL;
+ goto unregister_mux;
+ }
+
+ ret = fwnode_property_read_u32_array(fwnode, "data-lanes",
+ dp_lanes, num_lanes);
+ if (ret) {
+ dev_err(dev,
+ "Failed to read the data-lanes variable: %d\n",
+ ret);
+ goto unregister_mux;
+ }
+
+ it6505->port_data[i].lane_swap = (dp_lanes[0] / 2 == 1);
+ }
+ complete_all(&it6505->mux_register);
+
+ return 0;
+
+unregister_mux:
+ complete_all(&it6505->mux_register);
+ it6505_unregister_typec_switches(it6505);
+ return ret;
+}
+
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)
@@ -3370,11 +3533,25 @@ 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;
+ init_completion(&it6505->mux_register);
+ 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)) {
@@ -3446,6 +3623,7 @@ 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[] = {
--
2.39.2.637.g21b0678d19-goog