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-rw-r--r--src/southbridge/intel/common/smbus.c58
1 files changed, 43 insertions, 15 deletions
diff --git a/src/southbridge/intel/common/smbus.c b/src/southbridge/intel/common/smbus.c
index cac9ba7943..ee58aab995 100644
--- a/src/southbridge/intel/common/smbus.c
+++ b/src/southbridge/intel/common/smbus.c
@@ -17,6 +17,7 @@
#include <arch/io.h>
#include <device/smbus_def.h>
+#include <stdlib.h>
#include "smbus.h"
@@ -193,14 +194,17 @@ int do_smbus_write_byte(unsigned int smbus_base, u8 device,
}
int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd,
- unsigned int bytes, u8 *buf)
+ unsigned int max_bytes, u8 *buf)
{
u8 status;
+ int slave_bytes;
int bytes_read = 0;
unsigned int loops = SMBUS_TIMEOUT;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
+ max_bytes = MIN(32, max_bytes);
+
/* Set up transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & ~SMBHSTCNT_INTREN,
@@ -210,11 +214,15 @@ int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd,
/* Set the command/address... */
outb(cmd & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a block data read */
- outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BLOCK_DATA,
+ outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
+ /* Reset number of bytes to transfer so we notice later it
+ * was really updated with the transaction. */
+ outb(0, smbus_base + SMBHSTDAT0);
+
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
smbus_base + SMBHSTCTL);
@@ -233,28 +241,39 @@ int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd,
return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */
- *buf = inb(smbus_base + SMBBLKDAT);
- buf++;
- bytes_read++;
- if (--bytes == 1) {
- /* indicate that next byte is the last one */
- outb(inb(smbus_base + SMBHSTCTL)
- | SMBHSTCNT_LAST_BYTE,
- smbus_base + SMBHSTCTL);
+
+ if (bytes_read < max_bytes) {
+ *buf = inb(smbus_base + SMBBLKDAT);
+ buf++;
+ bytes_read++;
}
+
+ /* Engine internally completes the transaction
+ * and clears HOST_BUSY flag once the byte count
+ * from slave is reached.
+ */
outb(status, smbus_base + SMBHSTSTAT);
}
} while ((status & SMBHSTSTS_HOST_BUSY) && loops);
+ /* Post-check we received complete message. */
+ slave_bytes = inb(smbus_base + SMBHSTDAT0);
+ if (bytes_read < slave_bytes)
+ return SMBUS_ERROR;
+
return bytes_read;
}
int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd,
- unsigned int bytes, const u8 *buf)
+ const unsigned int bytes, const u8 *buf)
{
u8 status;
+ int bytes_sent = 0;
unsigned int loops = SMBUS_TIMEOUT;
+ if (bytes > 32)
+ return SMBUS_ERROR;
+
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
@@ -267,7 +286,7 @@ int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd,
/* Set the command/address... */
outb(cmd & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a block data write */
- outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | I801_BLOCK_DATA,
+ outb((inb(smbus_base + SMBHSTCTL) & 0xc3) | I801_BLOCK_DATA,
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
@@ -275,8 +294,10 @@ int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd,
/* set number of bytes to transfer */
outb(bytes, smbus_base + SMBHSTDAT0);
+ /* Send first byte from buffer, bytes_sent increments after
+ * hardware acknowledges it.
+ */
outb(*buf++, smbus_base + SMBBLKDAT);
- bytes--;
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | SMBHSTCNT_START),
@@ -296,12 +317,19 @@ int do_smbus_block_write(unsigned int smbus_base, u8 device, u8 cmd,
return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) {
- outb(*buf++, smbus_base + SMBBLKDAT);
+ bytes_sent++;
+ if (bytes_sent < bytes)
+ outb(*buf++, smbus_base + SMBBLKDAT);
+
+ /* Engine internally completes the transaction
+ * and clears HOST_BUSY flag once the byte count
+ * has been reached.
+ */
outb(status, smbus_base + SMBHSTSTAT);
}
} while ((status & SMBHSTSTS_HOST_BUSY) && loops);
- return 0;
+ return bytes_sent;
}
/* Only since ICH5 */