On Sunday 14 June 2015 05:42 PM, Vaibhav Hiremath wrote:
On Friday 12 June 2015 05:11 AM, Wolfram Sang wrote:
Current implementation:
--------------------
Everyone probably does have their own custom implementation for this.
Or some other mechanism to achieve this (may be hardware support).
Do you have examples? It is easier to look at code.
As I mentioned in the "Problem Statement",
I2C interface for PMIC may need to be used at the end of poweroff
sequence where you cannot afford to sleep/schedule, as interrupt has
been disabled.
Earlier I was working on OMAP platform, where I remember we had
implemented something for such requirement, but as I am not in TI
anymore, I can not access the internal code.
Let me check whether I can share the current marvell codebase
outside.
/* We can also check i2c_check_functionality(adap,I2C_FUNC_PIO) */
if (msg->flags & I2C_M_PIO) {
/* PIO mode operation */
} else {
/* non-pio mode of operation */
}
I'd rather let the core decide. Like introduce a master_xfer_nosleep
callback and let the core use the standard or the nosleep one. We'd need
the same for smbus as well.
This leads to the question if we need a M_FLAG or expose the *_nosleep
functions directly?
I thought of it, but did not convince myself after looking at the usage
of this. This function would be used only when interrupt is disabled.
And I wonder about the demand for it. There are a number of SoCs with
designated I2C cores for the PMIC which do automated transfers.
This is exactly the same reason I did not propose it as a core change.
as I feel that the use of this is very minimal and with M_FLAG driver
can very well handle it.
Wolfram,
Any update on this?
If we could close on this, I can quickly change the code and submit the
patch for review.
Thanks,
Vaibhav
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
