On 16/07/2026 13:31, [email protected] wrote:
> From: Sunyun Yang <[email protected]>
>
> LT9611C(EX/UXD) is an I2C-controlled chip that Receiver signal/dual port
> mipi dsi and output hdmi, differences in hardware features:
> - LT9611C: supports 1-port mipi dsi to hdmi 1.4
> - LT9611EX: supports 2-port mipi dsi to hdmi 1.4
> - LT9611UXD: supports 2-port mipi dsi to hdmi 1.4/2.0
>
> Signed-off-by: Sunyun Yang <[email protected]>
> Co-developed-by: Mohit Dsor <[email protected]>
> Signed-off-by: Mohit Dsor <[email protected]>
> ---
> MAINTAINERS | 7 +
> drivers/gpu/drm/bridge/Kconfig | 18 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/lontium-lt9611c.c | 1293
> ++++++++++++++++++++++++++++++
> 4 files changed, 1319 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6dea93a41962..30be2eaf2bec 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15184,6 +15184,13 @@ S: Maintained
> F: Documentation/devicetree/bindings/display/bridge/lontium,lt8912b.yaml
> F: drivers/gpu/drm/bridge/lontium-lt8912b.c
>
> +LONTIUM LT9611C MIPI DSI TO HDMI BRIDGE
> +M: Sunyun Yang <[email protected]>
> +M: Mohit Dsor <[email protected]>
> +S: Maintained
> +F: Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> +F: drivers/gpu/drm/bridge/lontium-lt9611c.c
> +
> LOONGARCH
> M: Huacai Chen <[email protected]>
> R: WANG Xuerui <[email protected]>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 4a57d49b4c6d..b8959b8e2ad0 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -177,6 +177,24 @@ config DRM_LONTIUM_LT9611
> HDMI signals
> Please say Y if you have such hardware.
>
> +config DRM_LONTIUM_LT9611C
> + tristate "Lontium LT9611C DSI/HDMI bridge"
> + select SND_SOC_HDMI_CODEC if SND_SOC
> + depends on OF
> + select CRC8
> + select FW_LOADER
> + select DRM_PANEL_BRIDGE
> + select DRM_KMS_HELPER
> + select DRM_MIPI_DSI
> + select DRM_DISPLAY_HELPER
> + select DRM_DISPLAY_HDMI_STATE_HELPER
> + select REGMAP_I2C
> + help
> + Driver for Lontium DSI to HDMI bridge
> + chip driver that converts dual DSI and I2S to
> + HDMI signals
> + Please say Y if you have such hardware.
Please wrap the code to appropriate limits.
...
> +
> +static void lt9611c_reset(struct lt9611c *lt9611c)
> +{
> + gpiod_set_value_cansleep(lt9611c->reset_gpio, 1);
> + usleep_range(10000, 12000);
> +
> + gpiod_set_value_cansleep(lt9611c->reset_gpio, 0);
> + msleep(400);
> +
> + dev_dbg(lt9611c->dev, "lt9611c reset");
Same comment as before.
> +}
> +
> +static int lt9611c_upgrade_result(struct lt9611c *lt9611c, u8 fw_crc)
> +{
> + struct device *dev = lt9611c->dev;
> + unsigned int crc_result;
> +
> + regmap_write(lt9611c->regmap, 0xe0ee, 0x01);
> + regmap_read(lt9611c->regmap, 0xe021, &crc_result);
> +
> + if (crc_result != fw_crc) {
> + dev_err(dev, "lt9611c fw upgrade failed, expected crc=0x%02x,
> read crc=0x%02x\n",
> + fw_crc, crc_result);
> + return -1;
> + }
> +
> + dev_dbg(dev, "lt9611c firmware upgrade success, crc=0x%02x\n",
> crc_result);
> + return 0;
> +}
...
> +
> +static ssize_t lt9611c_firmware_show(struct device *dev, struct
> device_attribute *attr, char *buf)
> +{
> + struct lt9611c *lt9611c = dev_get_drvdata(dev);
> +
> + return sysfs_emit(buf, "0x%04x\n", lt9611c->fw_version);
> +}
> +
> +static DEVICE_ATTR_RW(lt9611c_firmware);
Where is this ABI documented?
> +
> +static struct attribute *lt9611c_attrs[] = {
> + &dev_attr_lt9611c_firmware.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group lt9611c_attr_group = {
> + .attrs = lt9611c_attrs,
> +};
> +
> +static const struct attribute_group *lt9611c_attr_groups[] = {
> + <9611c_attr_group,
> + NULL,
> +};
> +
> +static int lt9611c_probe(struct i2c_client *client)
> +{
> + struct lt9611c *lt9611c;
> + struct device *dev = &client->dev;
> + bool fw_updated = false;
> + int ret;
> +
> + crc8_populate_msb(lt9611c_crc8_table, LT9611C_CRC_POLYNOMIAL);
> +
> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
> + return dev_err_probe(dev, -ENODEV, "device doesn't support
> I2C\n");
> +
> + lt9611c = devm_drm_bridge_alloc(dev, struct lt9611c, bridge,
> <9611c_bridge_funcs);
> + if (IS_ERR(lt9611c))
> + return dev_err_probe(dev, PTR_ERR(lt9611c), "drm bridge alloc
> failed.\n");
> +
> + lt9611c->dev = dev;
> + lt9611c->client = client;
> + lt9611c->chip_type = (uintptr_t)i2c_get_match_data(client);
uintptr_t is not for kernel, use unsigned long.
> +
> + ret = devm_mutex_init(dev, <9611c->ocm_lock);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to init mutex\n");
> +
> + lt9611c->regmap = devm_regmap_init_i2c(client, <9611c_regmap_config);
> + if (IS_ERR(lt9611c->regmap))
> + return dev_err_probe(dev, PTR_ERR(lt9611c->regmap), "regmap i2c
> init failed\n");
> +
> + ret = lt9611c_parse_dt(dev, lt9611c);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to parse device tree\n");
> +
> + ret = lt9611c_gpio_init(lt9611c);
> + if (ret < 0)
> + goto err_of_put;
> +
> + ret = lt9611c_regulator_init(lt9611c);
> + if (ret < 0)
> + goto err_of_put;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(lt9611c->supplies),
> lt9611c->supplies);
> + if (ret)
> + goto err_of_put;
> +
> + lt9611c_reset(lt9611c);
> +
> + lt9611c_lock(lt9611c);
> +
> + ret = lt9611c_read_chipid(lt9611c);
> + if (ret < 0) {
> + dev_err(dev, "failed to read chip id.\n");
> + lt9611c_unlock(lt9611c);
> + goto err_disable_regulators;
> + }
> +
> +retry:
> + lt9611c->fw_version = lt9611c_read_version(lt9611c);
> + if (lt9611c->fw_version < 0) {
> + dev_err(dev, "failed to read fw version\n");
> + ret = -EOPNOTSUPP;
> + lt9611c_unlock(lt9611c);
> + goto err_disable_regulators;
> +
> + } else if (lt9611c->fw_version == 0) {
> + if (!fw_updated) {
> + fw_updated = true;
> + ret = lt9611c_firmware_upgrade(lt9611c);
> + if (ret < 0) {
> + lt9611c_unlock(lt9611c);
> + goto err_disable_regulators;
> + }
> +
> + goto retry;
> +
> + } else {
> + dev_err(dev, "fw version 0x%04x, update failed\n",
> lt9611c->fw_version);
> + ret = -EOPNOTSUPP;
> + lt9611c_unlock(lt9611c);
> + goto err_disable_regulators;
> + }
> + }
> +
> + lt9611c_unlock(lt9611c);
> + dev_dbg(dev, "current version:0x%04x", lt9611c->fw_version);
> +
> + INIT_WORK(<9611c->work, lt9611c_hpd_work);
> +
> + ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + lt9611c_irq_thread_handler,
> + IRQF_TRIGGER_FALLING |
> + IRQF_ONESHOT |
> + IRQF_NO_AUTOEN,
> + "lt9611c", lt9611c);
> + if (ret) {
> + dev_err(dev, "failed to request irq\n");
> + goto err_disable_regulators;
> + }
> +
> + lt9611c->bridge.of_node = client->dev.of_node;
> + lt9611c->bridge.ops = DRM_BRIDGE_OP_DETECT |
> + DRM_BRIDGE_OP_EDID |
> + DRM_BRIDGE_OP_HPD |
> + DRM_BRIDGE_OP_HDMI |
> + DRM_BRIDGE_OP_HDMI_AUDIO;
> + lt9611c->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
> +
> + lt9611c->bridge.vendor = "Lontium";
> + lt9611c->bridge.product = "LT9611C";
> +
> + lt9611c->bridge.hdmi_audio_dev = dev;
> + lt9611c->bridge.hdmi_audio_max_i2s_playback_channels = 8;
> + lt9611c->bridge.hdmi_audio_dai_port = 2;
> +
> + devm_drm_bridge_add(dev, <9611c->bridge);
> +
> + /* Attach primary DSI */
> + lt9611c->dsi0 = lt9611c_attach_dsi(lt9611c, lt9611c->dsi0_node);
> + if (IS_ERR(lt9611c->dsi0)) {
> + ret = PTR_ERR(lt9611c->dsi0);
> + goto err_remove_bridge;
> + }
> +
> + /* Attach secondary DSI, if specified */
> + if (lt9611c->dsi1_node) {
> + lt9611c->dsi1 = lt9611c_attach_dsi(lt9611c, lt9611c->dsi1_node);
> + if (IS_ERR(lt9611c->dsi1)) {
> + ret = PTR_ERR(lt9611c->dsi1);
> + goto err_remove_bridge;
> + }
> + }
> +
> + lt9611c->hdmi_connected = false;
> + i2c_set_clientdata(client, lt9611c);
> + enable_irq(client->irq);
> +
> + lt9611c_reset(lt9611c);
> + return 0;
> +
> +err_remove_bridge:
> + cancel_work_sync(<9611c->work);
> +
> +err_disable_regulators:
> + regulator_bulk_disable(ARRAY_SIZE(lt9611c->supplies),
> lt9611c->supplies);
> +
> +err_of_put:
> + of_node_put(lt9611c->dsi1_node);
> + of_node_put(lt9611c->dsi0_node);
> +
> + return ret;
> +}
> +
> +static void lt9611c_remove(struct i2c_client *client)
> +{
> + struct lt9611c *lt9611c = i2c_get_clientdata(client);
> +
> + cancel_work_sync(<9611c->work);
> + regulator_bulk_disable(ARRAY_SIZE(lt9611c->supplies),
> lt9611c->supplies);
> + of_node_put(lt9611c->dsi1_node);
> + of_node_put(lt9611c->dsi0_node);
> +}
> +
> +static int lt9611c_bridge_suspend(struct device *dev)
> +{
> + struct lt9611c *lt9611c = dev_get_drvdata(dev);
> + int ret;
> +
> + dev_dbg(lt9611c->dev, "suspend\n");
Same comments.
This does not look like useful printk message. Drivers should be silent
on success:
https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/coding-style.rst#L913
https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/debugging/driver_development_debugging_guide.rst#L79
Best regards,
Krzysztof
