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-rw-r--r--Documentation/i2c/functionality9
-rw-r--r--Documentation/i2c/i2c-protocol9
-rw-r--r--drivers/base/regmap/regmap-i2c.c2
-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c2
-rw-r--r--drivers/i2c/busses/i2c-nuc900.c3
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c3
-rw-r--r--drivers/i2c/i2c-dev.c30
-rw-r--r--drivers/input/joystick/as5011.c1
-rw-r--r--drivers/video/matrox/matroxfb_maven.c1
-rw-r--r--include/linux/i2c.h5
10 files changed, 51 insertions, 14 deletions
diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
index 42c17c1fb3cd..b0ff2ab596ce 100644
--- a/Documentation/i2c/functionality
+++ b/Documentation/i2c/functionality
@@ -18,9 +18,9 @@ For the most up-to-date list of functionality constants, please check
adapters typically can not do these)
I2C_FUNC_10BIT_ADDR Handles the 10-bit address extensions
I2C_FUNC_PROTOCOL_MANGLING Knows about the I2C_M_IGNORE_NAK,
- I2C_M_REV_DIR_ADDR, I2C_M_NOSTART and
- I2C_M_NO_RD_ACK flags (which modify the
- I2C protocol!)
+ I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK
+ flags (which modify the I2C protocol!)
+ I2C_FUNC_NOSTART Can skip repeated start sequence
I2C_FUNC_SMBUS_QUICK Handles the SMBus write_quick command
I2C_FUNC_SMBUS_READ_BYTE Handles the SMBus read_byte command
I2C_FUNC_SMBUS_WRITE_BYTE Handles the SMBus write_byte command
@@ -50,6 +50,9 @@ A few combinations of the above flags are also defined for your convenience:
emulated by a real I2C adapter (using
the transparent emulation layer)
+In kernel versions prior to 3.5 I2C_FUNC_NOSTART was implemented as
+part of I2C_FUNC_PROTOCOL_MANGLING.
+
ADAPTER IMPLEMENTATION
----------------------
diff --git a/Documentation/i2c/i2c-protocol b/Documentation/i2c/i2c-protocol
index 10518dd58814..0b3e62d1f77a 100644
--- a/Documentation/i2c/i2c-protocol
+++ b/Documentation/i2c/i2c-protocol
@@ -49,7 +49,9 @@ a byte read, followed by a byte write:
Modified transactions
=====================
-We have found some I2C devices that needs the following modifications:
+The following modifications to the I2C protocol can also be generated,
+with the exception of I2C_M_NOSTART these are usually only needed to
+work around device issues:
Flag I2C_M_NOSTART:
In a combined transaction, no 'S Addr Wr/Rd [A]' is generated at some
@@ -60,6 +62,11 @@ We have found some I2C devices that needs the following modifications:
we do not generate Addr, but we do generate the startbit S. This will
probably confuse all other clients on your bus, so don't try this.
+ This is often used to gather transmits from multiple data buffers in
+ system memory into something that appears as a single transfer to the
+ I2C device but may also be used between direction changes by some
+ rare devices.
+
Flags I2C_M_REV_DIR_ADDR
This toggles the Rd/Wr flag. That is, if you want to do a write, but
need to emit an Rd instead of a Wr, or vice versa, you set this
diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
index 5f6b2478bf17..fa6bf5279d28 100644
--- a/drivers/base/regmap/regmap-i2c.c
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -42,7 +42,7 @@ static int regmap_i2c_gather_write(void *context,
/* If the I2C controller can't do a gather tell the core, it
* will substitute in a linear write for us.
*/
- if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING))
+ if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART))
return -ENOTSUPP;
xfer[0].addr = i2c->addr;
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 7f0b83219744..fad22b0bb5b0 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -608,7 +608,7 @@ bailout:
static u32 bit_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c
index 03b615778887..a26dfb8cd586 100644
--- a/drivers/i2c/busses/i2c-nuc900.c
+++ b/drivers/i2c/busses/i2c-nuc900.c
@@ -502,7 +502,8 @@ static int nuc900_i2c_xfer(struct i2c_adapter *adap,
/* declare our i2c functionality */
static u32 nuc900_i2c_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART |
+ I2C_FUNC_PROTOCOL_MANGLING;
}
/* i2c bus registration info */
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index fa0b13490873..01959154572d 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -626,7 +626,8 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
/* declare our i2c functionality */
static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART |
+ I2C_FUNC_PROTOCOL_MANGLING;
}
/* i2c bus registration info */
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 45048323b75e..5ec2261574ec 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -265,19 +265,41 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
res = 0;
for (i = 0; i < rdwr_arg.nmsgs; i++) {
- /* Limit the size of the message to a sane amount;
- * and don't let length change either. */
- if ((rdwr_pa[i].len > 8192) ||
- (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
+ /* Limit the size of the message to a sane amount */
+ if (rdwr_pa[i].len > 8192) {
res = -EINVAL;
break;
}
+
data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
if (IS_ERR(rdwr_pa[i].buf)) {
res = PTR_ERR(rdwr_pa[i].buf);
break;
}
+
+ /*
+ * If the message length is received from the slave (similar
+ * to SMBus block read), we must ensure that the buffer will
+ * be large enough to cope with a message length of
+ * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
+ * drivers allow. The first byte in the buffer must be
+ * pre-filled with the number of extra bytes, which must be
+ * at least one to hold the message length, but can be
+ * greater (for example to account for a checksum byte at
+ * the end of the message.)
+ */
+ if (rdwr_pa[i].flags & I2C_M_RECV_LEN) {
+ if (!(rdwr_pa[i].flags & I2C_M_RD) ||
+ rdwr_pa[i].buf[0] < 1 ||
+ rdwr_pa[i].len < rdwr_pa[i].buf[0] +
+ I2C_SMBUS_BLOCK_MAX) {
+ res = -EINVAL;
+ break;
+ }
+
+ rdwr_pa[i].len = rdwr_pa[i].buf[0];
+ }
}
if (res < 0) {
int j;
diff --git a/drivers/input/joystick/as5011.c b/drivers/input/joystick/as5011.c
index 3063464474bf..57d19d4e0a2d 100644
--- a/drivers/input/joystick/as5011.c
+++ b/drivers/input/joystick/as5011.c
@@ -231,6 +231,7 @@ static int __devinit as5011_probe(struct i2c_client *client,
}
if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_NOSTART |
I2C_FUNC_PROTOCOL_MANGLING)) {
dev_err(&client->dev,
"need i2c bus that supports protocol mangling\n");
diff --git a/drivers/video/matrox/matroxfb_maven.c b/drivers/video/matrox/matroxfb_maven.c
index 31b8f67477b7..217678e0b983 100644
--- a/drivers/video/matrox/matroxfb_maven.c
+++ b/drivers/video/matrox/matroxfb_maven.c
@@ -1243,6 +1243,7 @@ static int maven_probe(struct i2c_client *client,
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_WORD_DATA |
I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_NOSTART |
I2C_FUNC_PROTOCOL_MANGLING))
goto ERROR0;
if (!(data = kzalloc(sizeof(*data), GFP_KERNEL))) {
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index b66cb601435f..ddfa04108baf 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -541,7 +541,7 @@ struct i2c_msg {
__u16 flags;
#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
#define I2C_M_RD 0x0001 /* read data, from slave to master */
-#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */
+#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */
#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
@@ -554,8 +554,9 @@ struct i2c_msg {
#define I2C_FUNC_I2C 0x00000001
#define I2C_FUNC_10BIT_ADDR 0x00000002
-#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */
+#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_IGNORE_NAK etc. */
#define I2C_FUNC_SMBUS_PEC 0x00000008
+#define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
#define I2C_FUNC_SMBUS_QUICK 0x00010000
#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 03:31:51 +0000