The lt8713sx is a Type-C/DP1.4 to Type-C/DP1.4/HDMI2.0 converter,
with three configurable DP1.4/HDMI2.0/DP++ output interfaces and
audio output interface.

Driver is required for firmware upgrade in the bridge chip.

Co-developed-by: Prahlad Valluru <[email protected]>
Signed-off-by: Prahlad Valluru <[email protected]>
Signed-off-by: Vishnu Saini <[email protected]>
---
 drivers/gpu/drm/bridge/Kconfig            |  10 ++
 drivers/gpu/drm/bridge/Makefile           |   1 +
 drivers/gpu/drm/bridge/lontium-lt8713sx.c | 713 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 724 insertions(+)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index a250afd8d662..7fef383ed7cb 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -184,6 +184,16 @@ config DRM_LONTIUM_LT9611UXC
          HDMI signals
          Please say Y if you have such hardware.
 
+config DRM_LONTIUM_LT8713SX
+       tristate "Lontium LT8713SX DP MST bridge"
+       depends on OF
+       select REGMAP_I2C
+       help
+         Driver for Lontium LT8713SX DP MST bridge
+         chip firmware upgrade, which converts Type-C/DP1.4
+         to 3 configurable Type-C/DP1.4/HDMI2.0 outputs
+         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 c7dc03182e59..07eeb13fa497 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o
 obj-$(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_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-lt8713sx.c 
b/drivers/gpu/drm/bridge/lontium-lt8713sx.c
new file mode 100644
index 000000000000..a5aed2474a2e
--- /dev/null
+++ b/drivers/gpu/drm/bridge/lontium-lt8713sx.c
@@ -0,0 +1,713 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#define FW_FILE "lt8713sx_fw.bin"
+
+#define LT8713SX_PAGE_SIZE 256
+#define FW_12K_SIZE        (12  * 1024)
+#define FW_64K_SIZE        (64  * 1024)
+#define FW_256K_SIZE       (256 * 1024)
+
+struct crc_config {
+       u8 width;
+       u32 poly;
+       u32 crc_init;
+       u32 xor_out;
+       bool ref_in;
+       bool ref_out;
+};
+
+struct lt8713sx {
+       struct device *dev;
+
+       struct regmap *regmap;
+       /* Protects all accesses to registers by stopping the on-chip MCU */
+       struct mutex ocm_lock;
+
+       struct gpio_desc *reset_gpio;
+       struct gpio_desc *enable_gpio;
+
+       struct regulator_bulk_data supplies[2];
+
+       struct i2c_client *client;
+       const struct firmware *fw;
+
+       u8 *fw_buffer;
+
+       u32 main_crc_value;
+       u32 bank_crc_value[17];
+
+       int bank_num;
+};
+
+static void lt8713sx_reset(struct lt8713sx *lt8713sx);
+
+static const struct regmap_range lt8713sx_ranges[] = {
+       {
+               .range_min = 0,
+               .range_max = 0xffff
+       },
+};
+
+static const struct regmap_access_table lt8713sx_table = {
+       .yes_ranges = lt8713sx_ranges,
+       .n_yes_ranges = ARRAY_SIZE(lt8713sx_ranges),
+};
+
+static const struct regmap_config lt8713sx_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .volatile_table = &lt8713sx_table,
+       .cache_type = REGCACHE_NONE,
+};
+
+static void lt8713sx_i2c_enable(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0xee, 0x01);
+}
+
+static void lt8713sx_i2c_disable(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0xee, 0x00);
+}
+
+static unsigned int bits_reverse(u32 in_val, u8 bits)
+{
+       u32 out_val = 0;
+       u8 i;
+
+       for (i = 0; i < bits; i++) {
+               if (in_val & (1 << i))
+                       out_val |= 1 << (bits - 1 - i);
+       }
+
+       return out_val;
+}
+
+static unsigned int get_crc(struct crc_config crc_cfg, const  u8 *buf, u64 
buf_len)
+{
+       u8 width    = crc_cfg.width;
+       u32  poly   = crc_cfg.poly;
+       u32  crc    = crc_cfg.crc_init;
+       u32  xorout = crc_cfg.xor_out;
+       bool refin  = crc_cfg.ref_in;
+       bool refout = crc_cfg.ref_out;
+       u8 n;
+       u32  bits;
+       u32  data;
+       u8 i;
+
+       n    =  (width < 8) ? 0 : (width - 8);
+       crc  =  (width < 8) ? (crc << (8 - width)) : crc;
+       bits =  (width < 8) ? 0x80 : (1 << (width - 1));
+       poly =  (width < 8) ? (poly << (8 - width)) : poly;
+
+       while (buf_len--) {
+               data = *(buf++);
+               if (refin)
+                       data = bits_reverse(data, 8);
+               crc ^= (data << n);
+               for (i = 0; i < 8; i++) {
+                       if (crc & bits)
+                               crc = (crc << 1) ^ poly;
+                       else
+                               crc = crc << 1;
+               }
+       }
+       crc = (width < 8) ? (crc >> (8 - width)) : crc;
+       if (refout)
+               crc = bits_reverse(crc, width);
+       crc ^= xorout;
+
+       return (crc & ((2 << (width - 1)) - 1));
+}
+
+static u32 calculate_64K_crc(const u8 *upgrade_data, u64 len)
+{
+       struct crc_config crc_cfg = {
+               .width = 8,
+               .poly  = 0x31,
+               .crc_init = 0,
+               .xor_out = 0,
+               .ref_out = false,
+               .ref_in = false,
+       };
+       u64 crc_size = FW_64K_SIZE - 1;
+       u8 default_val = 0xFF;
+
+       crc_cfg.crc_init = get_crc(crc_cfg, upgrade_data, len);
+
+       crc_size -= len;
+       while (crc_size--)
+               crc_cfg.crc_init = get_crc(crc_cfg, &default_val, 1);
+
+       return crc_cfg.crc_init;
+}
+
+static u32 calculate_12K_crc(const u8 *upgrade_data, u64 len)
+{
+       struct crc_config crc_cfg = {
+               .width = 8,
+               .poly  = 0x31,
+               .crc_init = 0,
+               .xor_out = 0,
+               .ref_out = false,
+               .ref_in = false,
+       };
+       u64 crc_size = FW_12K_SIZE;
+       u8 default_val = 0xFF;
+
+       crc_cfg.crc_init = get_crc(crc_cfg, upgrade_data, len);
+
+       crc_size -= len;
+       while (crc_size--)
+               crc_cfg.crc_init = get_crc(crc_cfg, &default_val, 1);
+
+       return crc_cfg.crc_init;
+}
+
+static int lt8713sx_prepare_firmware_data(struct lt8713sx *lt8713sx)
+{
+       int ret = 0;
+
+       ret = request_firmware(&lt8713sx->fw, FW_FILE, lt8713sx->dev);
+       if (ret < 0) {
+               pr_err("request firmware failed\n");
+               return ret;
+       }
+
+       pr_debug("Firmware size: %zu bytes\n", lt8713sx->fw->size);
+
+       if (lt8713sx->fw->size > FW_256K_SIZE - 1) {
+               pr_err("Firmware size exceeds 256KB limit\n");
+               release_firmware(lt8713sx->fw);
+               return -EINVAL;
+       }
+
+       lt8713sx->fw_buffer = kzalloc(FW_256K_SIZE, GFP_KERNEL);
+       if (!lt8713sx->fw_buffer) {
+               release_firmware(lt8713sx->fw);
+               return -ENOMEM;
+       }
+
+       memset(lt8713sx->fw_buffer, 0xFF, FW_256K_SIZE);
+
+       if (lt8713sx->fw->size < FW_64K_SIZE) {
+               /*TODO: CRC should be calculated with 0xff also */
+               memcpy(lt8713sx->fw_buffer, lt8713sx->fw->data, 
lt8713sx->fw->size);
+               lt8713sx->fw_buffer[FW_64K_SIZE - 1] =
+                               calculate_64K_crc(lt8713sx->fw->data, 
lt8713sx->fw->size);
+               lt8713sx->main_crc_value = lt8713sx->fw_buffer[FW_64K_SIZE - 1];
+               pr_debug("Main Firmware Data  Crc=0x%02X\n", 
lt8713sx->main_crc_value);
+
+       } else {
+               //main firmware
+               memcpy(lt8713sx->fw_buffer, lt8713sx->fw->data, FW_64K_SIZE - 
1);
+               lt8713sx->fw_buffer[FW_64K_SIZE - 1] =
+                               calculate_64K_crc(lt8713sx->fw_buffer, 
FW_64K_SIZE - 1);
+               lt8713sx->main_crc_value = lt8713sx->fw_buffer[FW_64K_SIZE - 1];
+               pr_debug("Main Firmware Data  Crc=0x%02X\n", 
lt8713sx->main_crc_value);
+
+               //bank firmware
+               memcpy(lt8713sx->fw_buffer + FW_64K_SIZE,
+                      lt8713sx->fw->data + FW_64K_SIZE,
+                      lt8713sx->fw->size - FW_64K_SIZE);
+
+               lt8713sx->bank_num = (lt8713sx->fw->size - FW_64K_SIZE + 
FW_12K_SIZE - 1) /
+                                       FW_12K_SIZE;
+               pr_debug("Bank Number Total is %d.\n", lt8713sx->bank_num);
+
+               for (int i = 0; i < lt8713sx->bank_num; i++) {
+                       lt8713sx->bank_crc_value[i] =
+                               calculate_12K_crc(lt8713sx->fw_buffer + 
FW_64K_SIZE +
+                                                 i * FW_12K_SIZE,
+                                                 FW_12K_SIZE);
+                       pr_debug("Bank number:%d; Firmware Data  Crc:0x%02X\n",
+                                i, lt8713sx->bank_crc_value[i]);
+               }
+       }
+       return 0;
+}
+
+static void lt8713sx_config_parameters(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xFF, 0xE0);
+       regmap_write(lt8713sx->regmap, 0xEE, 0x01);
+       regmap_write(lt8713sx->regmap, 0x5E, 0xC1);
+       regmap_write(lt8713sx->regmap, 0x58, 0x00);
+       regmap_write(lt8713sx->regmap, 0x59, 0x50);
+       regmap_write(lt8713sx->regmap, 0x5A, 0x10);
+       regmap_write(lt8713sx->regmap, 0x5A, 0x00);
+       regmap_write(lt8713sx->regmap, 0x58, 0x21);
+}
+
+static void lt8713sx_wren(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe1);
+       regmap_write(lt8713sx->regmap, 0x03, 0xbf);
+       regmap_write(lt8713sx->regmap, 0x03, 0xff);
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0x5a, 0x04);
+       regmap_write(lt8713sx->regmap, 0x5a, 0x00);
+}
+
+static void lt8713sx_wrdi(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0x5A, 0x08);
+       regmap_write(lt8713sx->regmap, 0x5A, 0x00);
+}
+
+static void lt8713sx_fifo_reset(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe1);
+       regmap_write(lt8713sx->regmap, 0x03, 0xbf);
+       regmap_write(lt8713sx->regmap, 0x03, 0xff);
+}
+
+static void lt8713sx_disable_sram_write(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0x55, 0x00);
+}
+
+static void lt8713sx_sram_to_flash(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0x5a, 0x30);
+       regmap_write(lt8713sx->regmap, 0x5a, 0x00);
+}
+
+static void lt8713sx_i2c_to_sram(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0x55, 0x80);
+       regmap_write(lt8713sx->regmap, 0x5e, 0xc0);
+       regmap_write(lt8713sx->regmap, 0x58, 0x21);
+}
+
+static u8 lt8713sx_read_flash_status(struct lt8713sx *lt8713sx)
+{
+       u32 flash_status = 0;
+
+       regmap_write(lt8713sx->regmap,  0xFF, 0xE1);//fifo_rst_n
+       regmap_write(lt8713sx->regmap,  0x03, 0x3F);
+       regmap_write(lt8713sx->regmap,  0x03, 0xFF);
+
+       regmap_write(lt8713sx->regmap,  0xFF, 0xE0);
+       regmap_write(lt8713sx->regmap,  0x5e, 0x40);
+       regmap_write(lt8713sx->regmap,  0x56, 0x05);//opcode=read status 
register
+       regmap_write(lt8713sx->regmap,  0x55, 0x25);
+       regmap_write(lt8713sx->regmap,  0x55, 0x01);
+       regmap_write(lt8713sx->regmap,  0x58, 0x21);
+
+       regmap_read(lt8713sx->regmap, 0x5f, &flash_status);
+       pr_debug("flash_status:%x\n", flash_status);
+
+       return flash_status;
+}
+
+static void lt8713sx_block_erase(struct lt8713sx *lt8713sx)
+{
+       u32 i = 0;
+       u8 flash_status = 0;
+       u8 blocknum = 0x00;
+       u32 flashaddr = 0x00;
+
+       for (blocknum = 0; blocknum < 8; blocknum++) {
+               flashaddr = blocknum * 0x008000;
+               regmap_write(lt8713sx->regmap,  0xFF, 0xE0);
+               regmap_write(lt8713sx->regmap,  0xEE, 0x01);
+               regmap_write(lt8713sx->regmap,  0x5A, 0x04);
+               regmap_write(lt8713sx->regmap,  0x5A, 0x00);
+               regmap_write(lt8713sx->regmap,  0x5B, flashaddr >> 16);//set 
flash address[23:16]
+               regmap_write(lt8713sx->regmap,  0x5C, flashaddr >> 8);//set 
flash address[15:8]
+               regmap_write(lt8713sx->regmap,  0x5D, flashaddr);//set flash 
address[7:0]
+               regmap_write(lt8713sx->regmap,  0x5A, 0x01);
+               regmap_write(lt8713sx->regmap,  0x5A, 0x00);
+               msleep(100); //delay 100ms
+               i = 0;
+               while (1) {
+                       flash_status = lt8713sx_read_flash_status(lt8713sx); 
//wait erase finish
+                       if ((flash_status & 0x01) == 0)
+                               break;
+
+                       if (i > 50)
+                               break;
+
+                       i++;
+                       msleep(50); //delay 50ms
+               }
+       }
+       pr_debug("erase flash done.\n");
+}
+
+static void lt8713sx_load_main_fw_to_sram(struct lt8713sx *lt8713sx)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0xee, 0x01);
+       regmap_write(lt8713sx->regmap, 0x68, 0x00);
+       regmap_write(lt8713sx->regmap, 0x69, 0x00);
+       regmap_write(lt8713sx->regmap, 0x6a, 0x00);
+       regmap_write(lt8713sx->regmap, 0x65, 0x00);
+       regmap_write(lt8713sx->regmap, 0x66, 0xff);
+       regmap_write(lt8713sx->regmap, 0x67, 0xff);
+       regmap_write(lt8713sx->regmap, 0x6b, 0x00);
+       regmap_write(lt8713sx->regmap, 0x6c, 0x00);
+       regmap_write(lt8713sx->regmap, 0x60, 0x01);
+       msleep(200);
+       regmap_write(lt8713sx->regmap, 0x60, 0x00);
+}
+
+static void lt8713sx_load_bank_fw_to_sram(struct lt8713sx *lt8713sx, u64 addr)
+{
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_write(lt8713sx->regmap, 0xee, 0x01);
+       regmap_write(lt8713sx->regmap, 0x68, ((addr & 0xFF0000) >> 16));
+       regmap_write(lt8713sx->regmap, 0x69, ((addr & 0x00FF00) >> 8));
+       regmap_write(lt8713sx->regmap, 0x6a, (addr & 0x0000FF));
+       regmap_write(lt8713sx->regmap, 0x65, 0x00);
+       regmap_write(lt8713sx->regmap, 0x66, 0x30);
+       regmap_write(lt8713sx->regmap, 0x67, 0x00);
+       regmap_write(lt8713sx->regmap, 0x6b, 0x00);
+       regmap_write(lt8713sx->regmap, 0x6c, 0x00);
+       regmap_write(lt8713sx->regmap, 0x60, 0x01);
+       msleep(50);
+       regmap_write(lt8713sx->regmap, 0x60, 0x00);
+}
+
+static int lt8713sx_write_data(struct lt8713sx *lt8713sx, const u8 *data, u64 
filesize)
+{
+       int page = 0, num = 0, i = 0, val;
+
+       page = (filesize % LT8713SX_PAGE_SIZE) ?
+                       ((filesize / LT8713SX_PAGE_SIZE) + 1) : (filesize / 
LT8713SX_PAGE_SIZE);
+
+       pr_debug("Writing to Sram=%u pages, total size = %llu bytes\n", page, 
filesize);
+
+       for (num = 0; num < page; num++) {
+               pr_debug("page[%d]\n", num);
+               lt8713sx_i2c_to_sram(lt8713sx);
+
+               for (i = 0; i < LT8713SX_PAGE_SIZE; i++) {
+                       if ((num * LT8713SX_PAGE_SIZE + i) < filesize)
+                               val = *(data + (num * LT8713SX_PAGE_SIZE + i));
+                       else
+                               val = 0xFF;
+                       regmap_write(lt8713sx->regmap, 0x59, val);
+               }
+
+               lt8713sx_wren(lt8713sx);
+               lt8713sx_sram_to_flash(lt8713sx);
+       }
+
+       lt8713sx_wrdi(lt8713sx);
+       lt8713sx_disable_sram_write(lt8713sx);
+
+       return 0;
+}
+
+static void lt8713sx_main_upgrade_result(struct lt8713sx *lt8713sx)
+{
+       u32 main_crc_result;
+
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+       regmap_read(lt8713sx->regmap, 0x23, &main_crc_result);
+
+       pr_debug("Main CRC HW: 0x%02X\n", main_crc_result);
+       pr_debug("Main CRC FW: 0x%02X\n", lt8713sx->main_crc_value);
+
+       if (main_crc_result == lt8713sx->main_crc_value)
+               pr_debug("Main Firmware Upgrade Success.\n");
+       else
+               pr_err("Main Firmware Upgrade Failed.\n");
+}
+
+static void lt8713sx_bank_upgrade_result(struct lt8713sx *lt8713sx, u8 banknum)
+{
+       u32 bank_crc_result;
+
+       regmap_write(lt8713sx->regmap, 0xff, 0xe0);
+
+       regmap_read(lt8713sx->regmap, 0x23, &bank_crc_result);
+
+       pr_debug("Bank %d CRC Result: 0x%02X\n", banknum, bank_crc_result);
+
+       if (bank_crc_result == lt8713sx->bank_crc_value[banknum])
+               pr_debug("Bank %d Firmware Upgrade Success.\n", banknum);
+       else
+               pr_err("Bank %d Firmware Upgrade Failed.\n", banknum);
+}
+
+static void lt8713sx_bank_result_check(struct lt8713sx *lt8713sx)
+{
+       int i;
+       u64 addr = 0x010000;
+
+       for (i = 0; i < lt8713sx->bank_num; i++) {
+               lt8713sx_load_bank_fw_to_sram(lt8713sx, addr);
+               lt8713sx_bank_upgrade_result(lt8713sx, i);
+               addr += 0x3000;
+       }
+}
+
+static int lt8713sx_firmware_upgrade(struct lt8713sx *lt8713sx)
+{
+       int ret;
+
+       lt8713sx_config_parameters(lt8713sx);
+
+       lt8713sx_block_erase(lt8713sx);
+
+       if (lt8713sx->fw->size < FW_64K_SIZE) {
+               ret = lt8713sx_write_data(lt8713sx, lt8713sx->fw_buffer, 
FW_64K_SIZE);
+               if (ret < 0) {
+                       pr_err("Failed to write firmware data: %d\n", ret);
+                       return ret;
+               }
+       } else {
+               ret = lt8713sx_write_data(lt8713sx, lt8713sx->fw_buffer, 
lt8713sx->fw->size);
+               if (ret < 0) {
+                       pr_err("Failed to write firmware data: %d\n", ret);
+                       return ret;
+               }
+       }
+
+       pr_debug("Write Data done.\n");
+
+       return 0;
+}
+
+static int lt8713sx_firmware_update(struct lt8713sx *lt8713sx)
+{
+       int ret = 0;
+
+       mutex_lock(&lt8713sx->ocm_lock);
+       lt8713sx_i2c_enable(lt8713sx);
+
+       ret = lt8713sx_prepare_firmware_data(lt8713sx);
+       if (ret < 0) {
+               pr_err("Failed to prepare firmware data: %d\n", ret);
+               goto error;
+       }
+
+       ret = lt8713sx_firmware_upgrade(lt8713sx);
+       if (ret < 0) {
+               pr_err("Upgrade failure.\n");
+               goto error;
+       } else {
+               /* Validate CRC */
+               lt8713sx_load_main_fw_to_sram(lt8713sx);
+               lt8713sx_main_upgrade_result(lt8713sx);
+               lt8713sx_wrdi(lt8713sx);
+               lt8713sx_fifo_reset(lt8713sx);
+               lt8713sx_bank_result_check(lt8713sx);
+               lt8713sx_wrdi(lt8713sx);
+       }
+
+error:
+       lt8713sx_i2c_disable(lt8713sx);
+       if (!ret)
+               lt8713sx_reset(lt8713sx);
+
+       kfree(lt8713sx->fw_buffer);
+       lt8713sx->fw_buffer = NULL;
+
+       if (lt8713sx->fw) {
+               release_firmware(lt8713sx->fw);
+               lt8713sx->fw = NULL;
+       }
+       mutex_unlock(&lt8713sx->ocm_lock);
+
+       return ret;
+}
+
+static void lt8713sx_reset(struct lt8713sx *lt8713sx)
+{
+       pr_debug("reset bridge.\n");
+       gpiod_set_value_cansleep(lt8713sx->reset_gpio, 1);
+       msleep(20);
+
+       gpiod_set_value_cansleep(lt8713sx->reset_gpio, 0);
+       msleep(20);
+
+       gpiod_set_value_cansleep(lt8713sx->reset_gpio, 1);
+       msleep(20);
+       pr_debug("reset done.\n");
+}
+
+static int lt8713sx_regulator_init(struct lt8713sx *lt8713sx)
+{
+       int ret;
+
+       lt8713sx->supplies[0].supply = "vdd";
+       lt8713sx->supplies[1].supply = "vcc";
+
+       ret = devm_regulator_bulk_get(lt8713sx->dev, 2, lt8713sx->supplies);
+       if (ret < 0)
+               return dev_err_probe(lt8713sx->dev, ret, "failed to get 
regulators\n");
+
+       ret = regulator_set_load(lt8713sx->supplies[0].consumer, 200000);
+       if (ret < 0)
+               return dev_err_probe(lt8713sx->dev, ret, "failed to set 
regulator load\n");
+
+       return 0;
+}
+
+static int lt8713sx_regulator_enable(struct lt8713sx *lt8713sx)
+{
+       int ret;
+
+       ret = regulator_enable(lt8713sx->supplies[0].consumer);
+       if (ret < 0)
+               return dev_err_probe(lt8713sx->dev, ret, "failed to enable vdd 
regulator\n");
+
+       usleep_range(1000, 10000);
+
+       ret = regulator_enable(lt8713sx->supplies[1].consumer);
+       if (ret < 0) {
+               regulator_disable(lt8713sx->supplies[0].consumer);
+               return dev_err_probe(lt8713sx->dev, ret, "failed to enable vcc 
regulator\n");
+       }
+       return 0;
+}
+
+static int lt8713sx_gpio_init(struct lt8713sx *lt8713sx)
+{
+       struct device *dev = lt8713sx->dev;
+
+       lt8713sx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+       if (IS_ERR(lt8713sx->reset_gpio))
+               return dev_err_probe(dev, PTR_ERR(lt8713sx->reset_gpio),
+                                    "failed to acquire reset gpio\n");
+
+       /* power enable gpio */
+       lt8713sx->enable_gpio = devm_gpiod_get_optional(dev, "enable", 
GPIOD_OUT_HIGH);
+       if (IS_ERR(lt8713sx->enable_gpio))
+               return dev_err_probe(dev, PTR_ERR(lt8713sx->enable_gpio),
+                                    "failed to acquire enable gpio\n");
+       return 0;
+}
+
+static ssize_t lt8713sx_firmware_store(struct device *dev,
+                                      struct device_attribute *attr,
+                                      const char *buf, size_t len)
+{
+       struct lt8713sx *lt8713sx = dev_get_drvdata(dev);
+       int ret;
+
+       ret = lt8713sx_firmware_update(lt8713sx);
+       if (ret < 0)
+               return ret;
+       return len;
+}
+
+static DEVICE_ATTR_WO(lt8713sx_firmware);
+
+static struct attribute *lt8713sx_attrs[] = {
+       &dev_attr_lt8713sx_firmware.attr,
+       NULL,
+};
+
+static const struct attribute_group lt8713sx_attr_group = {
+       .attrs = lt8713sx_attrs,
+};
+
+static const struct attribute_group *lt8713sx_attr_groups[] = {
+       &lt8713sx_attr_group,
+       NULL,
+};
+
+static int lt8713sx_probe(struct i2c_client *client)
+{
+       struct lt8713sx *lt8713sx;
+       struct device *dev = &client->dev;
+       int ret;
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+               return dev_err_probe(dev, -ENODEV, "device doesn't support 
I2C\n");
+
+       lt8713sx = devm_kzalloc(dev, sizeof(*lt8713sx), GFP_KERNEL);
+       if (!lt8713sx)
+               return dev_err_probe(dev, -ENOMEM, "failed to allocate lt8713sx 
struct\n");
+
+       lt8713sx->dev = dev;
+       lt8713sx->client = client;
+       i2c_set_clientdata(client, lt8713sx);
+
+       mutex_init(&lt8713sx->ocm_lock);
+
+       lt8713sx->regmap = devm_regmap_init_i2c(client, 
&lt8713sx_regmap_config);
+       if (IS_ERR(lt8713sx->regmap))
+               return dev_err_probe(dev, PTR_ERR(lt8713sx->regmap), "regmap 
i2c init failed\n");
+
+       ret = lt8713sx_gpio_init(lt8713sx);
+       if (ret < 0)
+               goto err_of_put;
+
+       ret = lt8713sx_regulator_init(lt8713sx);
+       if (ret < 0)
+               goto err_of_put;
+
+       ret = lt8713sx_regulator_enable(lt8713sx);
+       if (ret)
+               goto err_of_put;
+
+       lt8713sx_reset(lt8713sx);
+
+       return 0;
+
+err_of_put:
+       return ret;
+}
+
+static void lt8713sx_remove(struct i2c_client *client)
+{
+       struct lt8713sx *lt8713sx = i2c_get_clientdata(client);
+
+       mutex_destroy(&lt8713sx->ocm_lock);
+
+       regulator_bulk_disable(ARRAY_SIZE(lt8713sx->supplies), 
lt8713sx->supplies);
+}
+
+static struct i2c_device_id lt8713sx_id[] = {
+       { "lontium,lt8713sx", 0 },
+       { /* sentinel */ }
+};
+
+static const struct of_device_id lt8713sx_match_table[] = {
+       { .compatible = "lontium,lt8713sx" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lt8713sx_match_table);
+
+static struct i2c_driver lt8713sx_driver = {
+       .driver = {
+               .name = "lt8713sx",
+               .of_match_table = lt8713sx_match_table,
+               .dev_groups = lt8713sx_attr_groups,
+       },
+       .probe = lt8713sx_probe,
+       .remove = lt8713sx_remove,
+       .id_table = lt8713sx_id,
+};
+
+module_i2c_driver(lt8713sx_driver);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("lt8713sx drm bridge driver");
+MODULE_AUTHOR("Tony <[email protected]>");
+MODULE_FIRMWARE(FW_FILE);

-- 
2.34.1

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