[PATCH 0/2] Add lontium lt8713sx bridge driver

[PATCH 0/2] Add lontium lt8713sx bridge driver

[Vishnu Saini]

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.

This series provides bridge driver and dt bindings for lt8713sx.
The driver is required for firmware upgrade in the bridge chip.

Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>
---
Vishnu Saini (2):
      dt-bindings: bridge: lt8713sx: Add bindings
      drm/bridge: add support for lontium lt8713sx bridge driver

 Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml |  47 ++++
 drivers/gpu/drm/bridge/Kconfig                                         |  10 +
 drivers/gpu/drm/bridge/Makefile                                        |   1 +
 drivers/gpu/drm/bridge/lontium-lt8713sx.c                              | 717 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 775 insertions(+)
---
base-commit: de0d6e19d2ef33ba34be2467ffdf3595da5f5326
change-id: 20251115-lt8713sx-bridge-driver-32704455bc9a

Best regards,
-- 
Vishnu Saini <vishnu.saini@oss.qualcomm.com>

[PATCH 1/2] dt-bindings: bridge: lt8713sx: Add bindings

[Vishnu Saini]

Add bindings for lt8713sx.

Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>
Co-developed-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
Signed-off-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
---
 Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml
new file mode 100644
index 000000000000..3292e149706c
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/lontium,lt8713sx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Lontium LT8713SX Type-C/DP1.4 to Type-C/DP1.4/HDMI2.0/DP++ bridge-hub
+
+maintainers:
+  - Tony <syyang@lontium.com>
+
+description: |
+  The Lontium LT8713SX is a Type-C/DP1.4 to Type-C/DP1.4/HDMI2.0 converter
+  that integrates one DP input and up to three configurable output interfaces
+  (DP1.4 / HDMI2.0 / DP++), with SST/MST functionality and audio support.
+
+properties:
+  compatible:
+    enum:
+      - lontium,lt8713sx
+
+  reg:
+    maxItems: 1
+    description: I2C address of the device.
+
+  reset-gpios:
+    description: GPIO connected to active high RESET pin.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        bridge@4f {
+            compatible = "lontium,lt8713sx";
+            reg = <0x4f>;
+            reset-gpios = <&tlmm 6 GPIO_ACTIVE_HIGH>;
+        };
+    };

-- 
2.34.1

[PATCH 2/2] drm/bridge: add support for lontium lt8713sx bridge driver

[Vishnu Saini]

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.

Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>
Co-developed-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
Signed-off-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
---
 drivers/gpu/drm/bridge/Kconfig            |  10 ++
 drivers/gpu/drm/bridge/Makefile           |   1 +
 drivers/gpu/drm/bridge/lontium-lt8713sx.c | 717 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 728 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..7e8d60586e28
--- /dev/null
+++ b/drivers/gpu/drm/bridge/lontium-lt8713sx.c
@@ -0,0 +1,717 @@
+// 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 ret;
+
+	return regulator_set_load(lt8713sx->supplies[0].consumer, 200000);
+}
+
+static int lt8713sx_regulator_enable(struct lt8713sx *lt8713sx)
+{
+	int ret;
+
+	ret = regulator_enable(lt8713sx->supplies[0].consumer);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(1000, 10000);
+
+	ret = regulator_enable(lt8713sx->supplies[1].consumer);
+	if (ret < 0) {
+		regulator_disable(lt8713sx->supplies[0].consumer);
+		return ret;
+	}
+
+	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)) {
+		dev_err(dev, "failed to acquire reset gpio\n");
+		return PTR_ERR(lt8713sx->reset_gpio);
+	}
+
+	/* power enable gpio */
+	lt8713sx->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(lt8713sx->enable_gpio)) {
+		dev_err(dev, "failed to acquire enable gpio\n");
+		return PTR_ERR(lt8713sx->enable_gpio);
+	}
+
+	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)) {
+		dev_err(dev, "device doesn't support I2C\n");
+		return -ENODEV;
+	}
+
+	lt8713sx = devm_kzalloc(dev, sizeof(*lt8713sx), GFP_KERNEL);
+	if (!lt8713sx)
+		return -ENOMEM;
+
+	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)) {
+		dev_err(lt8713sx->dev, "regmap i2c init failed\n");
+		return PTR_ERR(lt8713sx->regmap);
+	}
+
+	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 <syyang@lontium.com>");
+MODULE_FIRMWARE(FW_FILE);

-- 
2.34.1

Re: [PATCH 1/2] dt-bindings: bridge: lt8713sx: Add bindings

[Krzysztof Kozlowski]

On 15/11/2025 02:03, Vishnu Saini wrote:
> Add bindings for lt8713sx.
> 
> Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>
> Co-developed-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
> Signed-off-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>

Incomplete or incorrectly ordered DCO chain. Please read submitting
patches so you understand what you have to certify.

> ---
>  Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml | 47 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml
> new file mode 100644
> index 000000000000..3292e149706c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt8713sx.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/lontium,lt8713sx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Lontium LT8713SX Type-C/DP1.4 to Type-C/DP1.4/HDMI2.0/DP++ bridge-hub
> +
> +maintainers:
> +  - Tony <syyang@lontium.com>
> +
> +description: |

Do not need '|' unless you need to preserve formatting.

> +  The Lontium LT8713SX is a Type-C/DP1.4 to Type-C/DP1.4/HDMI2.0 converter
> +  that integrates one DP input and up to three configurable output interfaces
> +  (DP1.4 / HDMI2.0 / DP++), with SST/MST functionality and audio support.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - lontium,lt8713sx
> +
> +  reg:
> +    maxItems: 1
> +    description: I2C address of the device.

Drop description, obvious thus redundant.

> +
> +  reset-gpios:
> +    description: GPIO connected to active high RESET pin.
> +

Missing ports, supply.

> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    i2c0 {

i2c

> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        bridge@4f {
> +            compatible = "lontium,lt8713sx";
> +            reg = <0x4f>;
> +            reset-gpios = <&tlmm 6 GPIO_ACTIVE_HIGH>;
> +        };
> +    };
> 


Best regards,
Krzysztof

Re: [PATCH 2/2] drm/bridge: add support for lontium lt8713sx bridge driver

[Krzysztof Kozlowski]

On 15/11/2025 02:03, Vishnu Saini wrote:
> 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.
> 
> Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>
> Co-developed-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
> Signed-off-by: Prahlad Valluru <vvalluru@qti.qualcomm.com>
> ---



> +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)) {
> +		dev_err(dev, "failed to acquire reset gpio\n");
> +		return PTR_ERR(lt8713sx->reset_gpio);
> +	}
> +
> +	/* power enable gpio */
> +	lt8713sx->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
> +	if (IS_ERR(lt8713sx->enable_gpio)) {
> +		dev_err(dev, "failed to acquire enable gpio\n");

Syntax is return dev_err_probe. In multiple other places as well. You
need to handle deferred probe.

Best regards,
Krzysztof

Re: [PATCH 0/2] Add lontium lt8713sx bridge driver

[Krzysztof Kozlowski]

On 15/11/2025 02:03, Vishnu Saini wrote:
> 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.
> 
> This series provides bridge driver and dt bindings for lt8713sx.
> The driver is required for firmware upgrade in the bridge chip.
> 
> Signed-off-by: Vishnu Saini <vishnu.saini@oss.qualcomm.com>


There are bounces here from qc-display-maintainer@oss.qualcomm.com.
Please do not Cc fake addresses or internal stuff, because we do not
care about them and I really should have to deal with bounces from your
internal stuff.

Best regards,
Krzysztof