i2c_master: extend i2c_xfer_no_retry to also support large writestabilize-13605.B-master

This CL extends CONFIG_I2C_XFER_LARGE_READ to also support large
(greater than 255 bytes) write.
Related config name is also updated to reflect the behavior change,

BUG=b:169651794
TEST=flash fw successfully on Zed.
BRANCH=none

Signed-off-by: Ting Shen <phoenixshen@google.com>
Change-Id: Icb889013da01f48708cd0227207561b8186bac63
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2537412
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: Ting Shen <phoenixshen@chromium.org>

8 files changed, 51 insertions, 40 deletions

diff --git a/board/c2d2/board.h b/board/c2d2/board.h
index 770851332c..d3a8a35bdb 100644
--- a/board/c2d2/board.h
+++ b/board/c2d2/board.h
@@ -84,7 +84,7 @@
 
 /* See i2c_ite_flash_support.c for more information about these values */
 #define CONFIG_ITE_FLASH_SUPPORT
-#define CONFIG_I2C_XFER_LARGE_READ
+#define CONFIG_I2C_XFER_LARGE_TRANSFER
 #undef CONFIG_USB_I2C_MAX_WRITE_COUNT
 #undef CONFIG_USB_I2C_MAX_READ_COUNT
 #define CONFIG_USB_I2C_MAX_WRITE_COUNT ((1<<9) - 4)
diff --git a/board/hammer/board.h b/board/hammer/board.h
index 5903abe1df..60ec82eae7 100644
--- a/board/hammer/board.h
+++ b/board/hammer/board.h
@@ -180,7 +180,7 @@
 #undef CONFIG_USB_I2C_MAX_READ_COUNT
 #define CONFIG_USB_I2C_MAX_READ_COUNT (1024 - 6) /* 6 is maximum header size */
 
-#define CONFIG_I2C_XFER_LARGE_READ
+#define CONFIG_I2C_XFER_LARGE_TRANSFER
 
 /* No lid switch */
 #undef CONFIG_LID_SWITCH
diff --git a/board/servo_micro/board.h b/board/servo_micro/board.h
index 1565a63f9a..c597861242 100644
--- a/board/servo_micro/board.h
+++ b/board/servo_micro/board.h
@@ -90,7 +90,7 @@
 
 /* See i2c_ite_flash_support.c for more information about these values */
 #define CONFIG_ITE_FLASH_SUPPORT
-#define CONFIG_I2C_XFER_LARGE_READ
+#define CONFIG_I2C_XFER_LARGE_TRANSFER
 #undef CONFIG_USB_I2C_MAX_WRITE_COUNT
 #undef CONFIG_USB_I2C_MAX_READ_COUNT
 #define CONFIG_USB_I2C_MAX_WRITE_COUNT ((1<<9) - 4)
diff --git a/chip/stm32/i2c_ite_flash_support.c b/chip/stm32/i2c_ite_flash_support.c
index eca3c999af..916a8c364c 100644
--- a/chip/stm32/i2c_ite_flash_support.c
+++ b/chip/stm32/i2c_ite_flash_support.c
@@ -42,11 +42,11 @@
 
 /*
  * iteflash requires 256 byte reads for verifying ITE EC firmware.  Without this
- * the limit is CONFIG_I2C_CHIP_MAX_READ_SIZE which is 255 for STM32F0 due to an
- * 8 bit field, per src/platform/ec/include/config.h comment.
+ * the limit is CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE which is 255 for STM32F0 due
+ * to an 8 bit field, per src/platform/ec/include/config.h comment.
  */
-#ifndef CONFIG_I2C_XFER_LARGE_READ
-#error Must define CONFIG_I2C_XFER_LARGE_READ
+#ifndef CONFIG_I2C_XFER_LARGE_TRANSFER
+#error Must define CONFIG_I2C_XFER_LARGE_TRANSFER
 #endif
 
 #define KHz 1000
diff --git a/common/i2c_master.c b/common/i2c_master.c
index 7702beebb3..ee54468dea 100644
--- a/common/i2c_master.c
+++ b/common/i2c_master.c
@@ -142,37 +142,48 @@ __maybe_unused static int chip_i2c_xfer_with_notify(
 	return ret;
 }
 
-#ifdef CONFIG_I2C_XFER_LARGE_READ
+#ifdef CONFIG_I2C_XFER_LARGE_TRANSFER
 /*
- * Internal function that splits reading into multiple chip_i2c_xfer() calls
- * if in_size exceeds CONFIG_I2C_CHIP_MAX_READ_SIZE.
+ * Internal function that splits transfer into multiple chip_i2c_xfer() calls
+ * if in_size or out_size exceeds CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE.
  */
 static int i2c_xfer_no_retry(const int port,
 			     const uint16_t slave_addr_flags,
 			     const uint8_t *out, int out_size,
 			     uint8_t *in, int in_size, int flags)
 {
-	int ret;
-	int out_flags = flags & I2C_XFER_START;
-	int in_chunk_size = MIN(in_size, CONFIG_I2C_CHIP_MAX_READ_SIZE);
-
-	in_size -= in_chunk_size;
-	out_flags |= !in_size ? (flags & I2C_XFER_STOP) : 0;
-	ret = chip_i2c_xfer_with_notify(port, slave_addr_flags,
-					out, out_size, in,
-					in_chunk_size, out_flags);
-	in += in_chunk_size;
-	while (in_size && ret == EC_SUCCESS) {
-		in_chunk_size = MIN(in_size, CONFIG_I2C_CHIP_MAX_READ_SIZE);
-		in_size -= in_chunk_size;
-		ret = chip_i2c_xfer_with_notify(port, slave_addr_flags,
-			NULL, 0, in,
-			in_chunk_size, !in_size ? (flags & I2C_XFER_STOP) : 0);
-		in += in_chunk_size;
+	for (int offset = 0; offset < out_size; ) {
+		int chunk_size = MIN(out_size - offset,
+				CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE);
+		int out_flags = 0;
+
+		if (offset == 0)
+			out_flags |= flags & I2C_XFER_START;
+		if (in_size == 0 && offset + chunk_size == out_size)
+			out_flags |= flags & I2C_XFER_STOP;
+
+		RETURN_ERROR(chip_i2c_xfer_with_notify(port, slave_addr_flags,
+				out + offset, chunk_size, NULL, 0,
+				out_flags));
+		offset += chunk_size;
 	}
-	return ret;
+	for (int offset = 0; offset < in_size; ) {
+		int chunk_size = MIN(in_size - offset,
+				CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE);
+		int in_flags = 0;
+
+		if (offset == 0)
+			in_flags |= flags & I2C_XFER_START;
+		if (offset + chunk_size == in_size)
+			in_flags |= flags & I2C_XFER_STOP;
+
+		RETURN_ERROR(chip_i2c_xfer_with_notify(port, slave_addr_flags,
+				NULL, 0, in + offset, chunk_size, in_flags));
+		offset += chunk_size;
+	}
+	return EC_SUCCESS;
 }
-#endif /* CONFIG_I2C_XFER_LARGE_READ */
+#endif /* CONFIG_I2C_XFER_LARGE_TRANSFER */
 
 int i2c_xfer_unlocked(const int port,
 		      const uint16_t slave_addr_flags,
@@ -192,7 +203,7 @@ int i2c_xfer_unlocked(const int port,
 #ifdef CONFIG_ZEPHYR
 		ret = i2c_write_read(i2c_get_device_for_port(port), addr_flags,
 				     out, out_size, in, in_size);
-#elif defined(CONFIG_I2C_XFER_LARGE_READ)
+#elif defined(CONFIG_I2C_XFER_LARGE_TRANSFER)
 		ret = i2c_xfer_no_retry(port, addr_flags,
 					    out, out_size, in,
 					    in_size, flags);
@@ -200,7 +211,7 @@ int i2c_xfer_unlocked(const int port,
 		ret = chip_i2c_xfer_with_notify(port, addr_flags,
 						    out, out_size,
 						    in, in_size, flags);
-#endif /* CONFIG_I2C_XFER_LARGE_READ */
+#endif /* CONFIG_I2C_XFER_LARGE_TRANSFER */
 		if (ret != EC_ERROR_BUSY)
 			break;
 	}
diff --git a/docs/configuration/i2c.md b/docs/configuration/i2c.md
index f258b3cca3..7a6241e349 100644
--- a/docs/configuration/i2c.md
+++ b/docs/configuration/i2c.md
@@ -14,7 +14,7 @@ The following parameters control the behavior of the I2C library. [config.h]
 defines a reasonable default value, but you may need to change the default value
 for your board.
 
-- `CONFIG_I2C_CHIP_MAX_READ_SIZE <bytes>`
+- `CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE <bytes>`
 - `CONFIG_I2C_NACK_RETRY_COUNT <count>`
 - `CONFIG_I2C_EXTRA_PACKET_SIZE <bytes>` - Only used on STM32 EC's if
   `CONFIG_HOSTCMD_I2C_ADDR_FLAGS` is defined.
diff --git a/include/config.h b/include/config.h
index 4891b36617..5d67079d9a 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2313,16 +2313,16 @@
 #undef CONFIG_I2C_BUS_MAY_BE_UNPOWERED
 
 /*
- * Conservative I2C reading size per single transaction. For example, register
- * of stm32f0 and stm32l4 are limited to be 8 bits for this field.
+ * Conservative I2C transmission size per single transaction. For example,
+ * register of stm32f0 and stm32l4 are limited to be 8 bits for this field.
  */
-#define CONFIG_I2C_CHIP_MAX_READ_SIZE 255
+#define CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE 255
 
 /*
  * Enable i2c_xfer() for receiving request larger than
- * CONFIG_I2C_CHIP_MAX_READ_SIZE.
+ * CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE.
  */
-#undef CONFIG_I2C_XFER_LARGE_READ
+#undef CONFIG_I2C_XFER_LARGE_TRANSFER
 
 /*
  * If defined, makes i2c_xfer callback into board-provided functions before the
diff --git a/include/i2c.h b/include/i2c.h
index 4022976dcb..8b53f5e836 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -167,9 +167,9 @@ extern const int i2c_test_dev_used;
 
 /**
  * Transmit one block of raw data, then receive one block of raw data. However,
- * received data might be capped at CONFIG_I2C_CHIP_MAX_READ_SIZE if
- * CONFIG_I2C_XFER_LARGE_READ is not defined.  The transfer is strictly atomic,
- * by locking the I2C port and performing an I2C_XFER_SINGLE transfer.
+ * transferred data might be capped at CONFIG_I2C_CHIP_MAX_TRANSFER_SIZE if
+ * CONFIG_I2C_XFER_LARGE_TRANSFER is not defined.  The transfer is strictly
+ * atomic, by locking the I2C port and performing an I2C_XFER_SINGLE transfer.
  *
  * @param port		Port to access
  * @param slave_addr	Slave device address