sb/intel/common: SMBus complete_command()
Adds helper to test for SMBHSTSTAT flags for
hardware having finished or failed a transaction.
Change-Id: Idea15e03edde7aeedf198c1529f09c24a5bc0b06
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/21120
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/southbridge/intel/common/smbus.c b/src/southbridge/intel/common/smbus.c
index fb7f8e5..1302798 100644
--- a/src/southbridge/intel/common/smbus.c
+++ b/src/southbridge/intel/common/smbus.c
@@ -65,6 +65,14 @@
inb(0x80);
}
+static int host_completed(u8 status)
+{
+ if (status & SMBHSTSTS_HOST_BUSY)
+ return 0;
+ status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
+ return status != 0;
+}
+
static int recover_master(int smbus_base, int ret)
{
/* TODO: Depending of the failure, drive KILL transaction
@@ -74,6 +82,17 @@
return ret;
}
+static int cb_err_from_stat(u8 status)
+{
+ /* Ignore the "In Use" status... */
+ status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
+
+ if (status == SMBHSTSTS_INTR)
+ return 0;
+
+ return SMBUS_ERROR;
+}
+
static int setup_command(unsigned int smbus_base, u8 ctrl, u8 xmitadd)
{
unsigned int loops = SMBUS_TIMEOUT;
@@ -128,26 +147,28 @@
return 0;
}
-static int smbus_wait_until_done(u16 smbus_base)
+static int complete_command(unsigned int smbus_base)
{
unsigned int loops = SMBUS_TIMEOUT;
- unsigned char byte;
+ u8 status;
+
do {
smbus_delay();
- if (--loops == 0)
- break;
- byte = inb(smbus_base + SMBHSTSTAT);
- } while ((byte & SMBHSTSTS_HOST_BUSY)
- || (byte & ~(SMBHSTSTS_INUSE_STS | SMBHSTSTS_HOST_BUSY)) == 0);
- return loops ? 0 : -1;
+ status = inb(smbus_base + SMBHSTSTAT);
+ } while (--loops && !host_completed(status));
+
+ if (loops == 0)
+ return recover_master(smbus_base,
+ SMBUS_WAIT_UNTIL_DONE_TIMEOUT);
+
+ return cb_err_from_stat(status);
}
int do_smbus_read_byte(unsigned int smbus_base, u8 device,
unsigned int address)
{
int ret;
- unsigned char status;
- unsigned char byte;
+ u8 byte;
/* Set up for a byte data read. */
ret = setup_command(smbus_base, I801_BYTE_DATA, XMIT_READ(device));
@@ -166,25 +187,18 @@
return ret;
/* Poll for transaction completion */
- if (smbus_wait_until_done(smbus_base) < 0)
- return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
-
- status = inb(smbus_base + SMBHSTSTAT);
-
- /* Ignore the "In Use" status... */
- status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
+ ret = complete_command(smbus_base);
+ if (ret < 0)
+ return ret;
/* Read results of transaction */
byte = inb(smbus_base + SMBHSTDAT0);
- if (status != SMBHSTSTS_INTR)
- return SMBUS_ERROR;
return byte;
}
int do_smbus_write_byte(unsigned int smbus_base, u8 device,
unsigned int address, unsigned int data)
{
- unsigned char status;
int ret;
/* Set up for a byte data write. */
@@ -204,19 +218,7 @@
return ret;
/* Poll for transaction completion */
- if (smbus_wait_until_done(smbus_base) < 0)
- return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
-
- status = inb(smbus_base + SMBHSTSTAT);
-
- /* Ignore the "In Use" status... */
- status &= ~(SMBHSTSTS_SMBALERT_STS | SMBHSTSTS_INUSE_STS);
-
- /* Read results of transaction */
- if (status != SMBHSTSTS_INTR)
- return SMBUS_ERROR;
-
- return 0;
+ return complete_command(smbus_base);
}
int do_smbus_block_read(unsigned int smbus_base, u8 device, u8 cmd,
@@ -248,12 +250,7 @@
/* Poll for transaction completion */
do {
- loops--;
status = inb(smbus_base + SMBHSTSTAT);
- if (status & (SMBHSTSTS_FAILED | /* FAILED */
- SMBHSTSTS_BUS_ERR | /* BUS ERR */
- SMBHSTSTS_DEV_ERR)) /* DEV ERR */
- return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) { /* Byte done */
@@ -266,9 +263,9 @@
* and clears HOST_BUSY flag once the byte count
* from slave is reached.
*/
- outb(status, smbus_base + SMBHSTSTAT);
+ outb(SMBHSTSTS_BYTE_DONE, smbus_base + SMBHSTSTAT);
}
- } while ((status & SMBHSTSTS_HOST_BUSY) && loops);
+ } while (--loops && !host_completed(status));
/* Post-check we received complete message. */
slave_bytes = inb(smbus_base + SMBHSTDAT0);
@@ -276,6 +273,14 @@
dprintk("%s: status = %02x, len = %d / %d, loops = %d\n",
__func__, status, bytes_read, slave_bytes, loops);
+ if (loops == 0)
+ return recover_master(smbus_base,
+ SMBUS_WAIT_UNTIL_DONE_TIMEOUT);
+
+ ret = cb_err_from_stat(status);
+ if (ret < 0)
+ return ret;
+
if (bytes_read < slave_bytes)
return SMBUS_ERROR;
@@ -315,12 +320,7 @@
/* Poll for transaction completion */
do {
- loops--;
status = inb(smbus_base + SMBHSTSTAT);
- if (status & (SMBHSTSTS_FAILED | /* FAILED */
- SMBHSTSTS_BUS_ERR | /* BUS ERR */
- SMBHSTSTS_DEV_ERR)) /* DEV ERR */
- return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) {
bytes_sent++;
@@ -331,13 +331,21 @@
* and clears HOST_BUSY flag once the byte count
* has been reached.
*/
- outb(status, smbus_base + SMBHSTSTAT);
+ outb(SMBHSTSTS_BYTE_DONE, smbus_base + SMBHSTSTAT);
}
- } while ((status & SMBHSTSTS_HOST_BUSY) && loops);
+ } while (--loops && !host_completed(status));
dprintk("%s: status = %02x, len = %d / %d, loops = %d\n",
__func__, status, bytes_sent, bytes, loops);
+ if (loops == 0)
+ return recover_master(smbus_base,
+ SMBUS_WAIT_UNTIL_DONE_TIMEOUT);
+
+ ret = cb_err_from_stat(status);
+ if (ret < 0)
+ return ret;
+
if (bytes_sent < bytes)
return SMBUS_ERROR;
@@ -373,12 +381,7 @@
/* Poll for transaction completion */
do {
- loops--;
status = inb(smbus_base + SMBHSTSTAT);
- if (status & (SMBHSTSTS_FAILED | /* FAILED */
- SMBHSTSTS_BUS_ERR | /* BUS ERR */
- SMBHSTSTS_DEV_ERR)) /* DEV ERR */
- return SMBUS_ERROR;
if (status & SMBHSTSTS_BYTE_DONE) {
@@ -394,13 +397,21 @@
smbus_base + SMBHSTCTL);
}
- outb(status, smbus_base + SMBHSTSTAT);
+ outb(SMBHSTSTS_BYTE_DONE, smbus_base + SMBHSTSTAT);
}
- } while ((status & SMBHSTSTS_HOST_BUSY) && loops);
+ } while (--loops && !host_completed(status));
dprintk("%s: status = %02x, len = %d / %d, loops = %d\n",
__func__, status, bytes_read, bytes, loops);
+ if (loops == 0)
+ return recover_master(smbus_base,
+ SMBUS_WAIT_UNTIL_DONE_TIMEOUT);
+
+ ret = cb_err_from_stat(status);
+ if (ret < 0)
+ return ret;
+
if (bytes_read < bytes)
return SMBUS_ERROR;