[PATCHv3 2/7] clk: ti: add clkdev get helper

[Russell King - ARM Linux]

On Thu, Jun 30, 2016 at 05:13:33PM +0300, Tero Kristo wrote:
>  /**
> + * ti_clk_get - lookup a TI clock handle
> + * @dev_id: device to lookup clock for
> + * @con_id: connection ID to find
> + *
> + * Searches for a TI clock handle based on the DT node name.
> + * Returns the pointer to the clock handle, or ERR_PTR in failure.
> + */
> +static struct clk *ti_clk_get(const char *dev_id, const char *con_id)
> +{
> +	struct of_phandle_args clkspec;
> +	struct device_node *node;
> +	struct clk *clk;
> +
> +	/* Only check for cases of type clk_get_sys(NULL, "xyz") */
> +	if (dev_id || !con_id)
> +		return ERR_PTR(-ENOENT);
> +
> +	if (of_have_populated_dt()) {
> +		node = of_find_node_by_name(NULL, con_id);
> +		clkspec.np = node;
> +		clk = of_clk_get_from_provider(&clkspec);
> +
> +		if (!IS_ERR(clk))
> +			return clk;
> +	}
> +
> +	return ERR_PTR(-ENOENT);
> +}

I _really_ don't like this.  This takes us back to the totally broken
idea, that's already been proven to be greatly harmful in OMAP land,
that the "con_id" is not a _DEVICE SPECIFIC CONNECTION NAME_ but is a
CLOCK NAME.  The connection ID is supposed to be a static string in
the requestor of the clock, not some random string picked out from
DT.

This series started out with the assertion that the new clkdev hook
was to avoid registering lots of clock aliases, but it seems with
this patch we're going to end up with lots of specifically named
nodes in DT instead.  It's just moving the problem to somewhere else.

-- 
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