On Fri, Jun 03, 2011 at 10:32:52AM +0800, Barry Song wrote:

but there is really no an unified rule by now, for exmaple, samsung
just required platform device names matched with the string parameter
to get a clock.
it looks like clk_get in plat-samsung depends on the string more than
device and the clock name is in SoC level.

Samsung has been broken in respect of this for quite some time, and I've
been nagging Ben about it ever since I provided clkdev.  The problem is
that Ben doesn't have the time to fix Samsung...

same situation for mach-at91/clock.c:

/* clocks cannot be de-registered no refcounting necessary */
struct clk *clk_get(struct device *dev, const char *id)
{
        struct clk *clk;

        list_for_each_entry(clk, &clocks, node) {
                if (strcmp(id, clk->name) == 0)
                        return clk;
                if (clk->function && (dev == clk->dev) && strcmp(id,
clk->function) == 0)
                        return clk;
        }

        return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);

That's broken, and it's incompatible with DT in any case because the
only way to set 'clk->dev' is to have devices statically declared.

OMAP used to be broken until I converted it to clkdev, and when I did
their drivers became more simple because they didn't need to ifdef
clocknames and such like.

msm required device struct matched:
struct clk *clk_get(struct device *dev, const char *id)
{
        struct clk *clk;

        mutex_lock(&clocks_mutex);

        list_for_each_entry(clk, &clocks, list)
                if (!strcmp(id, clk->name) && clk->dev == dev)
                        goto found_it;

        list_for_each_entry(clk, &clocks, list)
                if (!strcmp(id, clk->name) && clk->dev == NULL)
                        goto found_it;

        clk = ERR_PTR(-ENOENT);
found_it:
        mutex_unlock(&clocks_mutex);
        return clk;
}
EXPORT_SYMBOL(clk_get);

Again, that's incompatible with DT in any case, as we don't know what
'clk->dev' would be if the devices aren't statically declared.  So this
is broken too.

Each need to be converted to clkdev _before_ they even start thinking
about device trees.