Module Name: src
Committed By: thorpej
Date: Tue Jun 12 13:18:48 UTC 2018
Modified Files:
src/sys/dev/i2c: gttwsi_core.c
Log Message:
When initiating a transfer, if a device isn't present, we won't
get an ACK after sending the address. Check for this alternate
state and suppress the error message when it occurs.
Fixes PR kern/53356.
To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/sys/dev/i2c/gttwsi_core.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/i2c/gttwsi_core.c
diff -u src/sys/dev/i2c/gttwsi_core.c:1.5 src/sys/dev/i2c/gttwsi_core.c:1.6
--- src/sys/dev/i2c/gttwsi_core.c:1.5 Mon May 7 15:03:19 2018
+++ src/sys/dev/i2c/gttwsi_core.c Tue Jun 12 13:18:48 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: gttwsi_core.c,v 1.5 2018/05/07 15:03:19 jmcneill Exp $ */
+/* $NetBSD: gttwsi_core.c,v 1.6 2018/06/12 13:18:48 thorpej Exp $ */
/*
* Copyright (c) 2008 Eiji Kawauchi.
* All rights reserved.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.5 2018/05/07 15:03:19 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.6 2018/06/12 13:18:48 thorpej Exp $");
#include "locators.h"
#include <sys/param.h>
@@ -91,7 +91,8 @@ static int gttwsi_initiate_xfer(void *v,
static int gttwsi_read_byte(void *v, uint8_t *valp, int flags);
static int gttwsi_write_byte(void *v, uint8_t val, int flags);
-static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t, int);
+static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t,
+ uint32_t, int);
static inline uint32_t
gttwsi_default_read_4(struct gttwsi_softc *sc, uint32_t reg)
@@ -243,7 +244,7 @@ gttwsi_send_start(void *v, int flags)
else
expect = STAT_SCT;
sc->sc_started = true;
- return gttwsi_wait(sc, CONTROL_START, expect, flags);
+ return gttwsi_wait(sc, CONTROL_START, expect, 0, flags);
}
static int
@@ -277,7 +278,7 @@ static int
gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags)
{
struct gttwsi_softc *sc = v;
- uint32_t data, expect;
+ uint32_t data, expect, alt;
int error, read;
KASSERT(sc->sc_inuse);
@@ -285,10 +286,13 @@ gttwsi_initiate_xfer(void *v, i2c_addr_t
gttwsi_send_start(v, flags);
read = (flags & I2C_F_READ) != 0;
- if (read)
+ if (read) {
expect = STAT_ARBT_AR;
- else
+ alt = STAT_ARBT_ANR;
+ } else {
expect = STAT_AWBT_AR;
+ alt = STAT_AWBT_ANR;
+ }
/*
* First byte contains whether this xfer is a read or write.
@@ -301,23 +305,26 @@ gttwsi_initiate_xfer(void *v, i2c_addr_t
*/
data |= 0xf0 | ((addr & 0x300) >> 7);
gttwsi_write_4(sc, TWSI_DATA, data);
- error = gttwsi_wait(sc, 0, expect, flags);
+ error = gttwsi_wait(sc, 0, expect, alt, flags);
if (error)
return error;
/*
* The first address byte has been sent, now to send
* the second one.
*/
- if (read)
+ if (read) {
expect = STAT_SARBT_AR;
- else
+ alt = STAT_SARBT_ANR;
+ } else {
expect = STAT_SAWBT_AR;
+ alt = STAT_SAWBT_ANR;
+ }
data = (uint8_t)addr;
} else
data |= (addr << 1);
gttwsi_write_4(sc, TWSI_DATA, data);
- return gttwsi_wait(sc, 0, expect, flags);
+ return gttwsi_wait(sc, 0, expect, alt, flags);
}
static int
@@ -329,9 +336,9 @@ gttwsi_read_byte(void *v, uint8_t *valp,
KASSERT(sc->sc_inuse);
if (flags & I2C_F_LAST)
- error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, flags);
+ error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, 0, flags);
else
- error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, flags);
+ error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, 0, flags);
if (!error)
*valp = gttwsi_read_4(sc, TWSI_DATA);
if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP))
@@ -348,7 +355,7 @@ gttwsi_write_byte(void *v, uint8_t val,
KASSERT(sc->sc_inuse);
gttwsi_write_4(sc, TWSI_DATA, val);
- error = gttwsi_wait(sc, 0, STAT_MTDB_AR, flags);
+ error = gttwsi_wait(sc, 0, STAT_MTDB_AR, 0, flags);
if (flags & I2C_F_STOP)
gttwsi_send_stop(sc, flags);
return error;
@@ -356,7 +363,7 @@ gttwsi_write_byte(void *v, uint8_t val,
static int
gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect,
- int flags)
+ uint32_t alt, int flags)
{
uint32_t status;
int timo, error = 0;
@@ -389,8 +396,16 @@ gttwsi_wait(struct gttwsi_softc *sc, uin
status = gttwsi_read_4(sc, TWSI_STATUS);
if (status != expect) {
- aprint_error_dev(sc->sc_dev,
- "unexpected status 0x%x: expect 0x%x\n", status, expect);
+ /*
+ * In the case of probing for a device, we are expecting
+ * 2 different status codes: the ACK case (device exists),
+ * or the NACK case (device does not exist). We don't
+ * need to report an error in the later case.
+ */
+ if (alt != 0 && status != alt)
+ aprint_error_dev(sc->sc_dev,
+ "unexpected status 0x%x: expect 0x%x\n", status,
+ expect);
return EIO;
}
return error;
