Re: [PATCH] kernel 2.6.11.6 - I2C adaptor for ColdFire 5282 CPU

["Randy.Dunlap" <rddunlap@osdl.org>]

Derek Cheung wrote:
> 
>> Below please find the patch file I "diff" against Linux 2.6.11.6. It
>> contains the I2C adaptor for ColdFire 5282 CPU. Since most ColdFire
> CPU
>> shares the same I2C register set, the code can be easily adopted for
>> other ColdFire CPUs for I2C operations.
>>
>> I have tested the code on a ColdFire 5282Lite CPU board
>> (http://www.axman.com/Pages/cml-5282LITE.html) running uClinux 2.6.9
>> with LM75 and DS1621 temperature sensor chips. As advised by David
>> McCullough, the code will be incorporated in the next uClinux
> release.
> 
>> The patch contains:
>>
>> linux/drivers/i2c/busses
>>  		i2c-mcf5282.c (new file)

Limit source code lines to 80 characters (including comment lines).

+static int mcf5282_read_data():

+	if (ackType == NACK)
+		*MCF5282_I2C_I2CR |= MCF5282_I2C_I2CR_TXAK;     // generate NA
+	else
+                *MCF5282_I2C_I2CR &= ~MCF5282_I2C_I2CR_TXAK;    // 
generate ACK

The 2 assignments above should begin in the same column.
Also, kernel comment style is C /* ... */, not C++ (or C99) // style.

+        if (timeout <= 0)
+                printk("%s - I2C IIF never set. Timeout is %d \n", 
__FUNCTION__, timeout);

All printk() calls should have a KERN_WARNING or KERN_ERR or
KERN_DEBUG level used in it...

+	if (timeout <= 0 )

No space before the closing ')'.

+static int mcf5282_write_data():

+        if (timeout <=0)
should be (add a space)
+        if (timeout <= 0)

+	if (timeout <= 0 )
Drop space before ')'

Drop the debugging printk's and DEREK_DEBUG blocks.

+        switch (size) {
+                case I2C_SMBUS_QUICK:
We usually don't indent the 'case' line to save one indent level.
It helps when using 8-space tabs.

+			// this is not yet ready!!!
Put blocks like this inside
#if 0
or
#if NOT_READY_YET
#endif
blocks.

+static u32 mcf5282_func(struct i2c_adapter *adapter)
+{
+	return(I2C_FUNC_SMBUS_QUICK |
+	       I2C_FUNC_SMBUS_BYTE |
+	       I2C_FUNC_SMBUS_PROC_CALL |
+	       I2C_FUNC_SMBUS_BYTE_DATA |
+	       I2C_FUNC_SMBUS_WORD_DATA |
+	       I2C_FUNC_SMBUS_BLOCK_DATA);
+};
Don't use parens on return statements.


+static int __init i2c_mcf5282_init():
is not driver registration needed?  I don't know the I2C
subsystem, so maybe not...



Big Question:  does most Coldfire or I2C use volatile so heavily,
or is it just this one driver that does that?  Volatile here
semms very overused.


-- 
~Randy