On Thursday 20 September 2007, Jean Delvare wrote:
> > Right ... then your suggestion above would seem to be The Answer,
> > although rather than modify algo-bit etc I'd just add that flag
> > into I2C_FUNC_SMBUS_EMUL. Maybe that's what you meant.
>
> That's not what I meant, but this seems to be the right thing to do,
> yes. This should make the patch pretty simple.
>
> > The "rename" would presumably involve leaving the old symbol around
> > for a while, deprecated so gcc warns when it's used.
>
> Inside the kernel, we do not care. For the user-space interface through
> i2c-dev (i.e. lm-sensors' i2c-dev.h), well... I do not expect anyone to
> actually use this flag, except "i2cdetect -F". There's simply no
> real-world use case for the old semantic that bit had. So I think you
> can just rename it and be done with it.
Like this... which doesn't update "i2cdetect"
========= CUT HERE
Rename I2C_FUNC_SMBUS_HWPEC_CALC as I2C_FUNC_SMBUS_PEC, and list that
functionality as always available through the software implementation.
Update documentation accordingly (and list similar requirements).
The way it's currently packaged doesn't present the capability in a
useful way. Basically, it's always available -- except when the I2C
stack is running on SMBus hardware without PEC support in hardware.
Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
---
Documentation/i2c/dev-interface | 10 +++++++---
drivers/i2c/busses/i2c-amd8111.c | 2 +-
drivers/i2c/busses/i2c-i801.c | 2 +-
include/linux/i2c.h | 5 +++--
4 files changed, 12 insertions(+), 7 deletions(-)
--- g26.orig/Documentation/i2c/dev-interface 2007-09-21 09:15:36.000000000 -0700
+++ g26/Documentation/i2c/dev-interface 2007-09-21 09:21:29.000000000 -0700
@@ -90,12 +90,14 @@ ioctl(file,I2C_SLAVE,long addr)
ioctl(file,I2C_TENBIT,long select)
Selects ten bit addresses if select not equals 0, selects normal 7 bit
- addresses if select equals 0. Default 0.
+ addresses if select equals 0. Default 0. This request is only valid
+ if the adapter has I2C_FUNC_10BIT_ADDR.
ioctl(file,I2C_PEC,long select)
Selects SMBus PEC (packet error checking) generation and verification
if select not equals 0, disables if select equals 0. Default 0.
- Used only for SMBus transactions.
+ Used only for SMBus transactions; only valid if the adapter has
+ I2C_FUNC_SMBUS_PEC.
ioctl(file,I2C_FUNCS,unsigned long *funcs)
Gets the adapter functionality and puts it in *funcs.
@@ -103,8 +105,10 @@ ioctl(file,I2C_FUNCS,unsigned long *func
ioctl(file,I2C_RDWR,struct i2c_rdwr_ioctl_data *msgset)
Do combined read/write transaction without stop in between.
- The argument is a pointer to a struct i2c_rdwr_ioctl_data {
+ Only valid if the adapter has I2C_FUNC_I2C. The argument is
+ a pointer to a
+ struct i2c_rdwr_ioctl_data {
struct i2c_msg *msgs; /* ptr to array of simple messages */
int nmsgs; /* number of messages to exchange */
}
--- g26.orig/drivers/i2c/busses/i2c-amd8111.c 2007-09-21 09:10:09.000000000 -0700
+++ g26/drivers/i2c/busses/i2c-amd8111.c 2007-09-21 09:10:21.000000000 -0700
@@ -326,7 +326,7 @@ static u32 amd8111_func(struct i2c_adapt
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
- I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_HWPEC_CALC;
+ I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PEC;
}
static const struct i2c_algorithm smbus_algorithm = {
--- g26.orig/drivers/i2c/busses/i2c-i801.c 2007-09-21 09:10:09.000000000 -0700
+++ g26/drivers/i2c/busses/i2c-i801.c 2007-09-21 09:10:26.000000000 -0700
@@ -515,7 +515,7 @@ static u32 i801_func(struct i2c_adapter
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK
- | (isich4 ? I2C_FUNC_SMBUS_HWPEC_CALC : 0);
+ | (isich4 ? I2C_FUNC_SMBUS_PEC : 0);
}
static const struct i2c_algorithm smbus_algorithm = {
--- g26.orig/include/linux/i2c.h 2007-09-21 09:07:49.000000000 -0700
+++ g26/include/linux/i2c.h 2007-09-21 09:23:42.000000000 -0700
@@ -467,7 +467,7 @@ struct i2c_msg {
#define I2C_FUNC_I2C 0x00000001
#define I2C_FUNC_10BIT_ADDR 0x00000002
#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_{REV_DIR_ADDR,NOSTART,..} */
-#define I2C_FUNC_SMBUS_HWPEC_CALC 0x00000008 /* SMBus 2.0 */
+#define I2C_FUNC_SMBUS_PEC 0x00000008
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
#define I2C_FUNC_SMBUS_QUICK 0x00010000
#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
@@ -503,7 +503,8 @@ struct i2c_msg {
I2C_FUNC_SMBUS_WORD_DATA | \
I2C_FUNC_SMBUS_PROC_CALL | \
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
- I2C_FUNC_SMBUS_I2C_BLOCK)
+ I2C_FUNC_SMBUS_I2C_BLOCK | \
+ I2C_FUNC_SMBUS_PEC)
/*
* Data for SMBus Messages
