On Tuesday 08 November 2016 08:38 PM, Arnd Bergmann wrote:
On Tuesday, November 8, 2016 7:16:30 PM CET Anurup M wrote:
If these are backwards compatible, just mark them as compatible in DT,
e.g. hip06 can use
compatible = "hisilicon,hip06-cpu-djtag-v1", "hisilicon,hip05-cpu-djtag-v1";
so you can tell the difference if you need to, but the driver only has to
list the oldest one here.
What is the difference between the cpu and io djtag interfaces?
On some chips like hip06, the djtag version is different for IO die.
In what way? The driver doesn't seem to care about the difference.
There is a difference in djtag version of CPU and IO die (in some chips).
For ex: in hip06 djtag for CPU is v1 and for IO is v2.
so they use different readwrite handlers djtag_readwrite_(v1/2).
+ /* for hip06(D03) cpu die */
+ { .compatible = "hisilicon,hip06-cpu-djtag-v1",
+ .data = (void *)djtag_readwrite_v1 },
+ /* for hip06(D03) io die */
+ { .compatible = "hisilicon,hip06-io-djtag-v2",
+ .data = (void *)djtag_readwrite_v2 },
For the same djtag version, there is no difference in handling in the
driver.
Right, but my point was about the compatibility with the older chips
using the same IP block, marking the ones as compatible that actually
use the same interface.
I also see that the compatible strings have the version included in
them, and you can probably drop them by requiring them only in the
fallback:
compatible = "hisilicon,hip05-cpu-djtag", "hisilicon,djtag-v1";
compatible = "hisilicon,hip05-io-djtag", "hisilicon,djtag-v1";
compatible = "hisilicon,hip06-cpu-djtag", "hisilicon,djtag-v1";
compatible = "hisilicon,hip06-io-djtag", "hisilicon,djtag-v2";
compatible = "hisilicon,hip07-cpu-djtag", "hisilicon,djtag-v2";
compatible = "hisilicon,hip07-io-djtag", "hisilicon,djtag-v2";
We want to have the first entry be as specific as possible, but
the last (second) entry is the one that can be used by the driver
for matching. When a future hip08/hip09/... chip uses an existing
interface, you then don't have to update the driver.
Thanks. I had a similar thought on this. So as I have the version string
in the
second entry "-v(1/2)".
I can use it in driver for matching. So i think I will change it as below.
Please correct me if my understanding is wrong.
static const struct of_device_id djtag_of_match[] = {
- /* for hip05(D02) cpu die */
- { .compatible = "hisilicon,hip05-cpu-djtag-v1",
+ /* for hisi djtag-v1 cpu die */
+ { .compatible = "hisilicon,hisi-cpu-djtag-v1",
.data = djtag_readwrite_v1 },
- /* for hip05(D02) io die */
- { .compatible = "hisilicon,hip05-io-djtag-v1",
+ /* for hisi djtag-v1 io die */
+ { .compatible = "hisilicon,hisi-io-djtag-v1",
.data = djtag_readwrite_v1 },
- /* for hip06(D03) cpu die */
- { .compatible = "hisilicon,hip06-cpu-djtag-v1",
- .data = djtag_readwrite_v1 },
- /* for hip06(D03) io die */
- { .compatible = "hisilicon,hip06-io-djtag-v2",
- .data = djtag_readwrite_v2 },
- /* for hip07(D05) cpu die */
- { .compatible = "hisilicon,hip07-cpu-djtag-v2",
+ /* for hisi djtag-v2 cpu die */
+ { .compatible = "hisilicon,hisi-cpu-djtag-v2",
.data = djtag_readwrite_v2 },
- /* for hip07(D05) io die */
- { .compatible = "hisilicon,hip07-io-djtag-v2",
+ /* for hisi djtag-v2 io die */
+ { .compatible = "hisilicon,hisi-io-djtag-v2",
.data = (djtag_readwrite_v2 },
{},
};
Thanks,
Anurup
Arnd
