Re: [PATCH 2/2] drm/bridge: Add LT7911EXC edp to mipi bridge driver

[杨孙运 <yangsunyun1993@gmail.com>]

Quentin Freimanis <quentin@q-lab.dev> 于2026年4月20日周一 13:06写道：
>
> On 2026-04-19 7:33 p.m., syyang@lontium.com wrote:
> > From: Sunyun Yang <syyang@lontium.com>
> >
> > LT7911EXC is a high performance  eDP1.4 to MIPI chip for
> > VR/Display application.
> >
> > -eDP1.4Receiver
> >   1.Support SSC
>
> s/1.Support/1. Supports/
>
it will be fixed  in the next version.

> >   2.Support 1/2/4 lanes
> >   3.Support up to 4K@60HzRGB/YCbCr4:4:48bpc
> >   4.Support lane swap and PN swap
>
> Same for these
>
it will be fixed  in the next version.

> >
> > -MIPI Transmitter
> >   1.CompliantwithD-PHY1.2&DSI1.1&CSI-22.0；1 clock lane,
> >     and1/2/3/4 configurable data lanes:2.5Gbpsperdatalane
> >   2.CompliantwithC-PHY1.0&DSI-21.0&CSI-22.0;
> >     1/2/3 configurable data trio；2.5Gsps perdatatrio
> >   3.Support1/2configurable ports
> >   4.DSISupport16/20/24-bit YCbCr4:2:2,16/18/24/30-bit RGB
>
> Missing spaces, this is hard to read and needs to be cleaned up
>
it will be fixed  in the next version.

> >
> > Signed-off-by: Sunyun Yang <syyang@lontium.com>
> > ---
> >   drivers/gpu/drm/bridge/Kconfig             |  18 +
> >   drivers/gpu/drm/bridge/Makefile            |   1 +
> >   drivers/gpu/drm/bridge/lontium-lt7911exc.c | 571 +++++++++++++++++++++
> >   3 files changed, 590 insertions(+)
> >   create mode 100644 drivers/gpu/drm/bridge/lontium-lt7911exc.c
> >
> > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > index c3209b0f4678..bae8cdaea666 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -202,6 +202,24 @@ config DRM_LONTIUM_LT8713SX
> >         to 3 configurable Type-C/DP1.4/HDMI2.0 outputs
> >         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.
> > +
> >   config DRM_ITE_IT66121
> >       tristate "ITE IT66121 HDMI bridge"
> >       depends on OF
> > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> > index beab5b695a6e..54b293d1663e 100644
> > --- a/drivers/gpu/drm/bridge/Makefile
> > +++ b/drivers/gpu/drm/bridge/Makefile
> > @@ -18,6 +18,7 @@ obj-$(CONFIG_DRM_LONTIUM_LT9211) += lontium-lt9211.o
> >   obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
> >   obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o
> >   obj-$(CONFIG_DRM_LONTIUM_LT8713SX) += lontium-lt8713sx.o
> > +obj-$(CONFIG_DRM_LONTIUM_LT7911EXC) += lontium-lt7911exc.o
> >   obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
> >   obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> >   obj-$(CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER) += microchip-lvds.o
> > diff --git a/drivers/gpu/drm/bridge/lontium-lt7911exc.c b/drivers/gpu/drm/bridge/lontium-lt7911exc.c
> > new file mode 100644
> > index 000000000000..d1c1d9e073ef
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/lontium-lt7911exc.c
> > @@ -0,0 +1,571 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2026 Lontium Semiconductor, Inc.
> > + */
> > +
> > +#include <linux/crc32.h>
> > +#include <linux/firmware.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/regmap.h>
> > +#include <drm/drm_of.h>
> > +
> > +#define FW_SIZE (64 * 1024)
> > +#define LT_PAGE_SIZE 32
> > +#define FW_FILE  "LT7911EXC.bin"
>
> Other lontium bridge chips use lowercase and a _fw.bin suffix, such as
> "lt9611uxc_fw.bin". Rename to be consistent
>
it will be fixed  in the next version.

> > +#define LT7911EXC_PAGE_CONTROL 0xff
> > +
> > +struct lt7911exc {
> > +     struct device *dev;
> > +     struct i2c_client *client;
> > +     struct drm_bridge bridge;
> > +     struct drm_bridge *panel_bridge;
> > +     struct regmap *regmap;
> > +     /* Protects all accesses to registers by stopping the on-chip MCU */
> > +     struct mutex ocm_lock;
> > +     struct regulator_bulk_data supplies[2];
> > +
> > +     struct gpio_desc *reset_gpio;
> > +     const struct firmware *fw;
> > +     int fw_version;
> > +     u32 fw_crc;
> > +
> > +     bool enabled;
> > +};
> > +
> > +static const struct regmap_range_cfg lt7911exc_ranges[] = {
> > +     {
> > +             .name = "register_range",
> > +             .range_min =  0,
> > +             .range_max = 0xffff,
> > +             .selector_reg = LT7911EXC_PAGE_CONTROL,
> > +             .selector_mask = 0xff,
> > +             .selector_shift = 0,
> > +             .window_start = 0,
> > +             .window_len = 0x100,
> > +     },
> > +};
> > +
> > +static const struct regmap_config lt7911exc_regmap_config = {
> > +     .reg_bits = 8,
> > +     .val_bits = 8,
> > +     .max_register = 0xffff,
> > +     .ranges = lt7911exc_ranges,
> > +     .num_ranges = ARRAY_SIZE(lt7911exc_ranges),
> > +};
> > +
> > +static u32 cal_crc32_custom(const u8 *data, u64 length)
> > +{
> > +     u32 crc = 0xffffffff;
> > +     u8 buf[4];
> > +     u64 i;
> > +
> > +     for (i = 0; i < length; i += 4) {
> > +             buf[0] = data[i + 3];
> > +             buf[1] = data[i + 2];
> > +             buf[2] = data[i + 1];
> > +             buf[3] = data[i + 0];
> > +             crc = crc32_be(crc, buf, 4);
> > +             }
> > +
> > +     return crc;
> > +}
> > +
> > +static inline struct lt7911exc *
> > +             bridge_to_lt7911exc(struct drm_bridge *bridge)
> > +{
> > +     return container_of(bridge, struct lt7911exc, bridge);
> > +}
> > +
> > +static int lt7911exc_regulator_enable(struct lt7911exc *lt7911exc)
> > +{
> > +     int ret;
> > +
> > +     ret = regulator_enable(lt7911exc->supplies[0].consumer);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     usleep_range(5000, 10000);
> > +
> > +     ret = regulator_enable(lt7911exc->supplies[1].consumer);
> > +     if (ret < 0) {
> > +             regulator_disable(lt7911exc->supplies[0].consumer);
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int lt7911exc_regulator_disable(struct lt7911exc *lt7911exc)
> > +{
> > +     int ret;
> > +
> > +     ret = regulator_disable(lt7911exc->supplies[1].consumer);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     ret = regulator_disable(lt7911exc->supplies[0].consumer);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     return 0;
> > +}
> > +
> > +static void lt7911exc_reset(struct lt7911exc *lt7911exc)
> > +{
> > +     gpiod_set_value_cansleep(lt7911exc->reset_gpio, 1);
> > +     msleep(20);
> > +
> > +     gpiod_set_value_cansleep(lt7911exc->reset_gpio, 0);
> > +     msleep(20);
> > +
> > +     gpiod_set_value_cansleep(lt7911exc->reset_gpio, 1);
> > +     msleep(400);
> > +
> > +     dev_dbg(lt7911exc->dev, "lt7911exc reset");
>
> missing newline in dev_dbg(), all other calls have it.
>
it will be fixed  in the next version.
dev_dbg(lt7911exc->dev, "lt7911exc reset\n");

> > +}
> > +
> > +static int lt7911exc_parse_dt(struct lt7911exc *lt7911exc)
> > +{
> > +     int ret;
> > +
> > +     lt7911exc->supplies[0].supply = "vcc";
> > +     lt7911exc->supplies[1].supply = "vdd";
> > +
> > +     ret = devm_regulator_bulk_get(lt7911exc->dev, 2, lt7911exc->supplies);
> > +     if (ret) {
> > +             dev_err(lt7911exc->dev, "failed get regulator\n");
> > +             return ret;
> > +     }
> > +
> > +     lt7911exc->reset_gpio = devm_gpiod_get(lt7911exc->dev, "reset", GPIOD_OUT_LOW);
> > +     if (IS_ERR(lt7911exc->reset_gpio)) {
> > +             dev_err(lt7911exc->dev, "failed to acquire reset gpio\n");
> > +             return PTR_ERR(lt7911exc->reset_gpio);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int lt7911exc_read_version(struct lt7911exc *lt7911exc)
> > +{
> > +     u8 buf[2];
> > +     int ret;
> > +
> > +     ret = regmap_bulk_read(lt7911exc->regmap, 0xe081, buf, 3);
> > +     if (ret)
> > +             return ret;
> > +
> > +     return (buf[0] << 16) | (buf[1] << 8) | buf[2];
> > +}
> > +
> > +static void lt7911exc_lock(struct lt7911exc *lt7911exc)
> > +{
> > +     mutex_lock(&lt7911exc->ocm_lock);
> > +     regmap_write(lt7911exc->regmap, 0xe0ee, 0x01);
> > +}
> > +
> > +static void lt7911exc_unlock(struct lt7911exc *lt7911exc)
> > +{
> > +     regmap_write(lt7911exc->regmap, 0xe0ee, 0x00);
> > +     mutex_unlock(&lt7911exc->ocm_lock);
> > +}
> > +
> > +static int lt7911exc_prepare_firmware_data(struct lt7911exc *lt7911exc)
> > +{
> > +     struct device *dev = lt7911exc->dev;
> > +     int ret;
> > +     u8 *buffer;
> > +     size_t total_size = FW_SIZE - 4;
> > +
> > +     ret = request_firmware(&lt7911exc->fw, FW_FILE, dev);
> > +     if (ret) {
> > +             dev_err(dev, "failed load file '%s', error type %d\n", FW_FILE, ret);
> > +             return ret;
> > +     }
> > +
> > +     if (lt7911exc->fw->size > total_size) {
> > +             dev_err(dev, "firmware too large (%zu > %zu)\n", lt7911exc->fw->size, total_size);
> > +             release_firmware(lt7911exc->fw);
> > +             lt7911exc->fw = NULL;
> > +             return -EINVAL;
> > +     }
> > +
> > +     dev_dbg(dev, "firmware size: %zu bytes\n", lt7911exc->fw->size);
> > +
> > +     buffer = kzalloc(total_size, GFP_KERNEL);
> > +     if (!buffer) {
> > +             release_firmware(lt7911exc->fw);
> > +             lt7911exc->fw = NULL;
> > +             return -ENOMEM;
> > +     }
> > +
> > +     memset(buffer, 0xff, total_size);
> > +     memcpy(buffer, lt7911exc->fw->data, lt7911exc->fw->size);
> > +
> > +     lt7911exc->fw_crc = cal_crc32_custom(buffer, total_size);
> > +     dev_dbg(dev, "firmware crc: 0x%08x\n", lt7911exc->fw_crc);
> > +
> > +     kfree(buffer);
> > +     return 0;
> > +}
> > +
> > +static void lt7911exc_block_erase(struct lt7911exc *lt7911exc)
> > +{
> > +     struct device *dev = lt7911exc->dev;
> > +     const u32 addr = 0x00;
> > +
> > +     const struct reg_sequence seq_write[] = {
> > +             REG_SEQ0(0xe0ee, 0x01),
> > +             REG_SEQ0(0xe054, 0x01),
> > +             REG_SEQ0(0xe055, 0x06),
> > +             REG_SEQ0(0xe051, 0x01),
> > +             REG_SEQ0(0xe051, 0x00),
> > +             REG_SEQ0(0xe054, 0x05),
> > +             REG_SEQ0(0xe055, 0xd8),
> > +             REG_SEQ0(0xe05a, (addr >> 16) & 0xff),
> > +             REG_SEQ0(0xe05b, (addr >> 8) & 0xff),
> > +             REG_SEQ0(0xe05c, addr & 0xff),
> > +             REG_SEQ0(0xe051, 0x01),
> > +             REG_SEQ0(0xe050, 0x00),
> > +     };
> > +
> > +     regmap_multi_reg_write(lt7911exc->regmap, seq_write, ARRAY_SIZE(seq_write));
> > +
> > +     msleep(200);
> > +     dev_dbg(dev, "erase flash done.\n");
> > +}
> > +
> > +static void lt7911exc_prog_init(struct lt7911exc *lt7911exc, u64 addr)
> > +{
> > +     const struct reg_sequence seq_write[] = {
> > +             REG_SEQ0(0xe0ee, 0x01),
> > +             REG_SEQ0(0xe05f, 0x01),
> > +             REG_SEQ0(0xe05a, (addr >> 16) & 0xff),
> > +             REG_SEQ0(0xe05b, (addr >> 8) & 0xff),
> > +             REG_SEQ0(0xe05c, addr & 0xff),
> > +     };
> > +
> > +     regmap_multi_reg_write(lt7911exc->regmap, seq_write, ARRAY_SIZE(seq_write));
> > +}
> > +
> > +static int lt7911exc_write_data(struct lt7911exc *lt7911exc, u64 addr)
> > +{
> > +     struct device *dev = lt7911exc->dev;
> > +     int ret;
> > +     int page = 0, num = 0, page_len = 0;
> > +     u64 size, offset;
> > +     const u8 *data;
> > +
> > +     data = lt7911exc->fw->data;
> > +     size = lt7911exc->fw->size;
> > +     page = (size + LT_PAGE_SIZE - 1) / LT_PAGE_SIZE;
> > +     if (page * LT_PAGE_SIZE > FW_SIZE) {
> > +             dev_err(dev, "firmware size out of range\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     dev_dbg(dev, "%u pages, total size %llu byte\n", page, size);
> > +
> > +     for (num = 0; num < page; num++) {
> > +             offset = num * LT_PAGE_SIZE;
> > +             page_len = (offset + LT_PAGE_SIZE <= size) ? LT_PAGE_SIZE : (size - offset);
> > +             lt7911exc_prog_init(lt7911exc, addr);
> > +
> > +             ret = regmap_raw_write(lt7911exc->regmap, 0xe05d, &data[offset], page_len);
> > +             if (ret) {
> > +                     dev_err(dev, "write error at page %d\n", num);
> > +                     return ret;
> > +             }
> > +
> > +             if (page_len < LT_PAGE_SIZE) {
> > +                     regmap_write(lt7911exc->regmap, 0xe05f, 0x05);
> > +                     regmap_write(lt7911exc->regmap, 0xe05f, 0x01);
> > +                     //hardware requires delay
> > +                     usleep_range(1000, 2000);
> > +             }
> > +
> > +             regmap_write(lt7911exc->regmap, 0xe05f, 0x00);
> > +             addr += LT_PAGE_SIZE;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int lt7911exc_write_crc(struct lt7911exc *lt7911exc, u64 addr)
> > +{
> > +     u8 crc[4];
> > +     int ret;
> > +
> > +     crc[0] = lt7911exc->fw_crc & 0xff;
> > +     crc[1] = (lt7911exc->fw_crc >> 8) & 0xff;
> > +     crc[2] = (lt7911exc->fw_crc >> 16) & 0xff;
> > +     crc[3] = (lt7911exc->fw_crc >> 24) & 0xff;
> > +
> > +     regmap_write(lt7911exc->regmap, 0xe05f, 0x01);
> > +     regmap_write(lt7911exc->regmap, 0xe05a, (addr >> 16) & 0xff);
> > +     regmap_write(lt7911exc->regmap, 0xe05b, (addr >> 8) & 0xff);
> > +     regmap_write(lt7911exc->regmap, 0xe05c, addr & 0xff);
> > +
> > +     ret = regmap_raw_write(lt7911exc->regmap, 0xe05d, crc, 4);
> > +     if (ret)
> > +             return ret;
>
> nit: Newline here makes it more readable
>
it will be fixed  in the next version.

> > +     regmap_write(lt7911exc->regmap, 0xe05f, 0x05);
> > +     regmap_write(lt7911exc->regmap, 0xe05f, 0x01);
> > +     usleep_range(1000, 2000);
> > +     regmap_write(lt7911exc->regmap, 0xe05f, 0x00);
> > +
> > +     return 0;
> > +}
> > +
> > +static int lt7911exc_firmware_upgrade(struct lt7911exc *lt7911exc)
> > +{
> > +     struct device *dev = lt7911exc->dev;
> > +     int ret;
> > +
> > +     ret = lt7911exc_prepare_firmware_data(lt7911exc);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     dev_dbg(dev, "starting firmware upgrade, size: %zu bytes\n", lt7911exc->fw->size);
> > +
> > +     lt7911exc_block_erase(lt7911exc);
> > +
> > +     ret = lt7911exc_write_data(lt7911exc, 0);
> > +     if (ret < 0) {
> > +             dev_err(dev, "failed to write firmware data\n");
> > +             return ret;
> > +     }
> > +
> > +     release_firmware(lt7911exc->fw);
> > +     lt7911exc->fw = NULL;
> > +
> > +     ret = lt7911exc_write_crc(lt7911exc, FW_SIZE - 4);
> > +     if (ret < 0) {
> > +             dev_err(dev, "failed to write firmware crc\n");
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int lt7911exc_upgrade_result(struct lt7911exc *lt7911exc)
> > +{
> > +     struct device *dev = lt7911exc->dev;
> > +     u32 read_hw_crc = 0;
> > +     u8 crc_tmp[4];
> > +     int ret;
> > +
> > +     regmap_write(lt7911exc->regmap, 0xe0ee, 0x01);
> > +     regmap_write(lt7911exc->regmap, 0xe07b, 0x60);
> > +     regmap_write(lt7911exc->regmap, 0xe07b, 0x40);
> > +     msleep(150);
> > +     ret = regmap_bulk_read(lt7911exc->regmap, 0x22, crc_tmp, 4);
> > +     if (ret) {
> > +             dev_err(lt7911exc->dev, "Failed to read CRC: %d\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     read_hw_crc = crc_tmp[0] << 24 | crc_tmp[1] << 16 |
> > +                             crc_tmp[2] << 8 | crc_tmp[3];
> > +
> > +     if (read_hw_crc != lt7911exc->fw_crc) {
> > +             dev_err(dev, "lt7911exc firmware upgrade failed, expected CRC=0x%08x, read CRC=0x%08x\n",
> > +                     lt7911exc->fw_crc, read_hw_crc);
> > +             return -EIO;
> > +     }
> > +
> > +     dev_dbg(dev, "lt7911exc firmware upgrade success, CRC=0x%08x\n", read_hw_crc);
> > +     return 0;
> > +}
> > +
> > +static void lt7911exc_pre_enable(struct drm_bridge *bridge)
> > +{
> > +     struct lt7911exc *lt7911exc = bridge_to_lt7911exc(bridge);
> > +     int ret;
> > +
> > +     if (lt7911exc->enabled)
> > +             return;
> > +
> > +     ret = lt7911exc_regulator_enable(lt7911exc);
> > +     if (ret)
> > +             return;
> > +
> > +     lt7911exc_reset(lt7911exc);
> > +
> > +     lt7911exc->enabled = true;
> > +}
> > +
> > +static void lt7911exc_disable(struct drm_bridge *bridge)
> > +{
> > +     /* Delay after panel is disabled */
> > +     msleep(20);
> > +}
> > +
> > +static void lt7911exc_post_disable(struct drm_bridge *bridge)
> > +{
> > +     struct lt7911exc *lt7911exc = bridge_to_lt7911exc(bridge);
> > +     int ret;
> > +
> > +     if (!lt7911exc->enabled)
> > +             return;
> > +
> > +     lt7911exc->enabled = false;
> > +
> > +     ret = lt7911exc_regulator_disable(lt7911exc);
> > +     if (ret)
> > +             return;
> > +
> > +     gpiod_set_value_cansleep(lt7911exc->reset_gpio, 0);
> > +}
> > +
> > +static int lt7911exc_attach(struct drm_bridge *bridge,
> > +                         struct drm_encoder *encoder,
> > +                         enum drm_bridge_attach_flags flags)
> > +{
> > +     struct lt7911exc *lt7911exc = bridge_to_lt7911exc(bridge);
> > +
> > +     return drm_bridge_attach(lt7911exc->bridge.encoder, lt7911exc->panel_bridge,
> > +                              &lt7911exc->bridge, flags);
> > +}
> > +
> > +static const struct drm_bridge_funcs lt7911exc_bridge_funcs = {
> > +     .pre_enable = lt7911exc_pre_enable,
> > +     .disable = lt7911exc_disable,
> > +     .post_disable = lt7911exc_post_disable,
>
> These are all deprecated, is there any reason to use them and not the
> atomic_* callbacks?
>
it will be fixed  in the next version.

> > +     .attach = lt7911exc_attach,
> > +};
> > +
> > +static int lt7911exc_probe(struct i2c_client *client)
> > +{
> > +     struct device *dev = &client->dev;
> > +     struct lt7911exc *lt7911exc;
> > +     struct drm_bridge *panel_bridge;
> > +     bool fw_updated = false;
> > +     int ret;
> > +
> > +     if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> > +             dev_err(dev, "device doesn't support I2C\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     lt7911exc = devm_drm_bridge_alloc(dev, struct lt7911exc, bridge,
> > +                                       &lt7911exc_bridge_funcs);
> > +     if (IS_ERR(lt7911exc))
> > +             return PTR_ERR(lt7911exc);
> > +
> > +     panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
> > +     if (IS_ERR(panel_bridge))
> > +             return PTR_ERR(panel_bridge);
> > +
> > +     lt7911exc->panel_bridge = panel_bridge;
> > +     lt7911exc->client = client;
> > +     lt7911exc->dev = dev;
> > +     i2c_set_clientdata(client, lt7911exc);
> > +     mutex_init(&lt7911exc->ocm_lock);
> > +
> > +     lt7911exc->regmap = devm_regmap_init_i2c(client, &lt7911exc_regmap_config);
> > +     if (IS_ERR(lt7911exc->regmap)) {
> > +             dev_err(dev, "regmap i2c init failed\n");
> > +             return PTR_ERR(lt7911exc->regmap);
> > +     }
> > +
> > +     ret = lt7911exc_parse_dt(lt7911exc);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = lt7911exc_regulator_enable(lt7911exc);
> > +     if (ret)
> > +             return ret;
> > +
> > +     lt7911exc_reset(lt7911exc);
> > +     lt7911exc->enabled = true;
> > +     lt7911exc_lock(lt7911exc);
> > +
> > +retry:
> > +     lt7911exc->fw_version = lt7911exc_read_version(lt7911exc);
> > +     if (lt7911exc->fw_version < 0) {
> > +             dev_err(dev, "failed to read FW version\n");
> > +             lt7911exc_unlock(lt7911exc);
> > +             goto err_disable_regulators;
> > +
> > +     } else if (lt7911exc->fw_version == 0) {
> > +             if (!fw_updated) {
> > +                     fw_updated = true;
> > +                     ret = lt7911exc_firmware_upgrade(lt7911exc);
> > +                     if (ret < 0) {
> > +                             lt7911exc_unlock(lt7911exc);
> > +                             goto err_disable_regulators;
> > +                     }
> > +
> > +                     lt7911exc_reset(lt7911exc);
> > +
> > +                     ret = lt7911exc_upgrade_result(lt7911exc);
> > +                     if (ret < 0) {
> > +                             lt7911exc_unlock(lt7911exc);
> > +                             goto err_disable_regulators;
> > +                     }
> > +
> > +                     goto retry;
> > +
> > +             } else {
> > +                     dev_err(dev, "fw version 0x%04x, update failed\n", lt7911exc->fw_version);
> > +                     ret = -EOPNOTSUPP;
> > +                     lt7911exc_unlock(lt7911exc);
> > +                     goto err_disable_regulators;
> > +             }
> > +     }
> > +
> > +     lt7911exc_unlock(lt7911exc);
> > +
> > +     lt7911exc->bridge.type = DRM_MODE_CONNECTOR_DSI;
> > +     lt7911exc->bridge.of_node = dev->of_node;
> > +     drm_bridge_add(&lt7911exc->bridge);
> > +
> > +     return 0;
> > +
> > +err_disable_regulators:
> > +     regulator_bulk_disable(ARRAY_SIZE(lt7911exc->supplies), lt7911exc->supplies);
> > +     if (lt7911exc->fw) {
> > +             release_firmware(lt7911exc->fw);
> > +             lt7911exc->fw = NULL;
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> > +static void lt7911exc_remove(struct i2c_client *client)
> > +{
> > +     struct lt7911exc *lt7911exc = i2c_get_clientdata(client);
> > +
> > +     drm_bridge_remove(&lt7911exc->bridge);
> > +     mutex_destroy(&lt7911exc->ocm_lock);
> > +}
> > +
> > +static const struct i2c_device_id lt7911exc_i2c_table[] = {
> > +     {"lontium, lt7911exc", 0},
>
> Extra space here in the device id
>
  it will be fixed  in the next version.   {"lontium, lt7911exc"},

> > +     { /* sentinel */ }
> > +};
> > +
> > +MODULE_DEVICE_TABLE(i2c, lt7911exc_i2c_table);
> > +
> > +static const struct of_device_id lt7911exc_devices[] = {
> > +     {.compatible = "lontium,lt7911exc",},
> > +     {}
> > +};
> > +MODULE_DEVICE_TABLE(of, lt7911exc_devices);
> > +
> > +static struct i2c_driver lt7911exc_driver = {
> > +     .id_table       = lt7911exc_i2c_table,
> > +     .probe          = lt7911exc_probe,
> > +     .remove         = lt7911exc_remove,
> > +     .driver         = {
> > +             .name   = "lt7911exc",
> > +             .of_match_table = lt7911exc_devices,
> > +     },
> > +};
> > +module_i2c_driver(lt7911exc_driver);
> > +
> > +MODULE_AUTHOR("SunYun Yang <syyang@lontium.com>");
> > +MODULE_DESCRIPTION("Lontium lt7911exc edp to mipi dsi bridge driver");
> > +MODULE_LICENSE("GPL v2");
>