[PATCH v6 7/7] drm/bridge: it6505: Register Type C mode switches

From: Pin-yen Lin
Date: Thu Nov 24 2022 - 05:22:59 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>

---

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 | 205 +++++++++++++++++++++++++++-
2 files changed, 202 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 57946d80b02d..9b1240ef3981 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 21a9b8422bda..37e2bd8d8d79 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>
@@ -30,6 +32,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
+#include <drm/drm_of.h>

#include <sound/hdmi-codec.h>

@@ -402,6 +405,12 @@ struct debugfs_entries {
const struct file_operations *fops;
};

+struct it6505_port_data {
+ bool dp_connected;
+ struct typec_mux_dev *typec_mux;
+ struct it6505 *it6505;
+};
+
struct it6505 {
struct drm_dp_aux aux;
struct drm_bridge bridge;
@@ -454,6 +463,8 @@ struct it6505 {
struct delayed_work delayed_audio;
struct it6505_audio_data audio;
struct dentry *debugfs;
+ int num_typec_switches;
+ struct it6505_port_data *typec_ports;

/* it6505 driver hold option */
bool enable_drv_hold;
@@ -3265,13 +3276,185 @@ static void it6505_shutdown(struct i2c_client *client)
it6505_lane_off(it6505);
}

+static void it6505_typec_ports_update(struct it6505 *it6505)
+{
+ usleep_range(3000, 4000);
+
+ if (it6505->typec_ports[0].dp_connected && it6505->typec_ports[1].dp_connected)
+ /* Both ports available, do nothing to retain the current one. */
+ return;
+ else if (it6505->typec_ports[0].dp_connected)
+ it6505->lane_swap = false;
+ else if (it6505->typec_ports[1].dp_connected)
+ it6505->lane_swap = true;
+
+ usleep_range(3000, 4000);
+}
+
+static int it6505_typec_mux_set(struct typec_mux_dev *mux,
+ struct typec_mux_state *state)
+{
+ struct it6505_port_data *data = typec_mux_get_drvdata(mux);
+ struct it6505 *it6505 = data->it6505;
+ struct device *dev = &it6505->client->dev;
+ bool old_dp_connected, new_dp_connected;
+
+ if (it6505->num_typec_switches == 1)
+ return 0;
+
+ mutex_lock(&it6505->extcon_lock);
+
+ old_dp_connected = it6505->typec_ports[0].dp_connected ||
+ it6505->typec_ports[1].dp_connected;
+
+ 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",
+ it6505->typec_ports[0].dp_connected, it6505->typec_ports[1].dp_connected);
+
+ new_dp_connected = it6505->typec_ports[0].dp_connected ||
+ it6505->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);
+
+ /*
+ * On system resume, mux_set can be triggered before
+ * pm_runtime_force_resume re-enables runtime power management.
+ * Handling the error here to make sure the bridge is powered on.
+ */
+ 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 int it6505_register_mode_switch(struct device *dev, struct device_node *node,
+ struct it6505 *it6505)
+{
+ struct it6505_port_data *port_data;
+ struct typec_mux_desc mux_desc = {};
+ char name[32];
+ u32 dp_lanes[2];
+ int ret, num_lanes, i, port_num = -1;
+
+ num_lanes = drm_of_get_data_lanes_count(node, 0, 2);
+ if (num_lanes <= 0) {
+ dev_err(dev, "Error on getting data lanes count: %d\n",
+ num_lanes);
+ return num_lanes;
+ }
+
+ ret = of_property_read_u32_array(node, "data-lanes", dp_lanes, num_lanes);
+ if (ret) {
+ dev_err(dev, "Failed to read the data-lanes variable: %d\n",
+ ret);
+ return ret;
+ }
+
+ for (i = 0; i < num_lanes; i++) {
+ if (port_num != -1 && port_num != dp_lanes[i] / 2) {
+ dev_err(dev, "Invalid data lane numbers\n");
+ return -EINVAL;
+ }
+ port_num = dp_lanes[i] / 2;
+ }
+
+ port_data = &it6505->typec_ports[port_num];
+ port_data->it6505 = it6505;
+ mux_desc.fwnode = &node->fwnode;
+ mux_desc.drvdata = port_data;
+ snprintf(name, sizeof(name), "%s-%u", node->name, port_num);
+ mux_desc.name = name;
+ mux_desc.set = it6505_typec_mux_set;
+
+ port_data->typec_mux = typec_mux_register(dev, &mux_desc);
+ if (IS_ERR(port_data->typec_mux)) {
+ ret = PTR_ERR(port_data->typec_mux);
+ dev_err(dev, "Mode switch register for port %d failed: %d\n",
+ port_num, ret);
+ }
+
+ return ret;
+}
+
+static void it6505_unregister_typec_switches(struct it6505 *it6505)
+{
+ int i;
+
+ for (i = 0; i < it6505->num_typec_switches; i++)
+ typec_mux_unregister(it6505->typec_ports[i].typec_mux);
+}
+
+static int it6505_register_typec_switches(struct device *dev, struct it6505 *it6505)
+{
+ struct device_node *port, *sw;
+ int ret = 0;
+
+ port = of_graph_get_port_by_id(dev->of_node, 1);
+
+ for_each_child_of_node(port, sw) {
+ if (of_property_read_bool(sw, "mode-switch"))
+ it6505->num_typec_switches++;
+ }
+
+ if (!it6505->num_typec_switches) {
+ dev_warn(dev, "No Type-C switches node found\n");
+ return ret;
+ }
+
+ it6505->typec_ports = devm_kzalloc(
+ dev, it6505->num_typec_switches * sizeof(struct it6505_port_data),
+ GFP_KERNEL);
+ if (!it6505->typec_ports)
+ return -ENOMEM;
+
+ /* Register switches for each connector. */
+ for_each_child_of_node(port, sw) {
+ if (!of_property_read_bool(sw, "mode-switch"))
+ continue;
+ ret = it6505_register_mode_switch(dev, sw, it6505);
+ if (ret) {
+ dev_err(dev, "Failed to register mode switch: %d\n", ret);
+ of_node_put(sw);
+ break;
+ }
+ }
+
+ if (ret)
+ it6505_unregister_typec_switches(it6505);
+
+ return ret;
+}
+
static int it6505_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
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)
@@ -3292,11 +3475,24 @@ 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)) {
@@ -3367,6 +3563,7 @@ static void it6505_i2c_remove(struct i2c_client *client)
drm_dp_aux_unregister(&it6505->aux);
it6505_debugfs_remove(it6505);
it6505_poweroff(it6505);
+ it6505_unregister_typec_switches(it6505);
}

static const struct i2c_device_id it6505_id[] = {
--
2.38.1.584.g0f3c55d4c2-goog