Hi Laurent,
On 01/04/14 15:15, Laurent Pinchart wrote:
[...]
>> +/**
>> + * of_clk_device_init() - parse and set clk configuration assigned to a
>> device
>> + * @node: device node to apply the configuration for
>> + *
>> + * This function parses 'clock-parents' and 'clock-rates' properties and
>> sets
>> + * any specified clock parents and rates.
>> + */
>> +int of_clk_device_init(struct device_node *node)
>> +{
>> + struct property *prop;
>> + const __be32 *cur;
>> + int rc, index, num_parents;
>> + struct clk *clk, *pclk;
>> + u32 rate;
>> +
>> + num_parents = of_count_phandle_with_args(node, "clock-parents",
>> + "#clock-cells");
>> + if (num_parents == -EINVAL)
>> + pr_err("clk: Invalid value of clock-parents property at %s\n",
>> + node->full_name);
>
> This is an implementation detail, but wouldn't it simplify the code if you
> merged the two loops by iterating of the clocks property instead of over the
> clock-parents and clock-rates properties separately ?
The issue here is that all clock parents should be set before we start setting
clock rates. Otherwise the clock frequencies could be incorrect if clk_set_rate()
is followed by clk_set_parent().
>> + for (index = 0; index < num_parents; index++) {
>> + pclk = of_clk_get_by_property(node, "clock-parents", index);
>> + if (IS_ERR(pclk)) {
>> + /* skip empty (null) phandles */
>> + if (PTR_ERR(pclk) == -ENOENT)
>> + continue;
>> +
>> + pr_warn("clk: couldn't get parent clock %d for %s\n",
>> + index, node->full_name);
>> + return PTR_ERR(pclk);
>> + }
>> +
>> + clk = of_clk_get(node, index);
>> + if (IS_ERR(clk)) {
>> + pr_warn("clk: couldn't get clock %d for %s\n",
>> + index, node->full_name);
>> + return PTR_ERR(clk);
>> + }
>> +
>> + rc = clk_set_parent(clk, pclk);
>> + if (rc < 0)
>> + pr_err("clk: failed to reparent %s to %s: %d\n",
>> + __clk_get_name(clk), __clk_get_name(pclk), rc);
>> + else
>> + pr_debug("clk: set %s as parent of %s\n",
>> + __clk_get_name(pclk), __clk_get_name(clk));
>> + }
>> +
>> + index = 0;
>> + of_property_for_each_u32(node, "clock-rates", prop, cur, rate) {
>> + if (rate) {
>> + clk = of_clk_get(node, index);
>> + if (IS_ERR(clk)) {
>> + pr_warn("clk: couldn't get clock %d for %s\n",
>> + index, node->full_name);
>> + return PTR_ERR(clk);
>> + }
>> +
>> + rc = clk_set_rate(clk, rate);
>> + if (rc < 0)
>> + pr_err("clk: couldn't set %s clock rate: %d\n",
>> + __clk_get_name(clk), rc);
>> + else
>> + pr_debug("clk: set rate of clock %s to %lu\n",
>> + __clk_get_name(clk), clk_get_rate(clk));
>> + }
>> + index++;
>> + }
>> +
>> + return 0;
>> +}
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index dff0373..ea6d8bd 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>
> [snip]
>
>> @@ -2620,7 +2621,15 @@ void __init of_clk_init(const struct of_device_id
>> *matches) list_for_each_entry_safe(clk_provider, next,
>> &clk_provider_list, node) {
>> if (force || parent_ready(clk_provider->np)) {
>> +
>> clk_provider->clk_init_cb(clk_provider->np);
>> +
>> + /* Set any assigned clock parents and rates */
>> + np = of_get_child_by_name(clk_provider->np,
>> + "assigned-clocks");
>> + if (np)
>> + of_clk_device_init(np);
>
> Aren't you missing an of_node_put() here ?
Indeed, it's missing. Will fix that in next version, thanks for pointing out.
>> list_del(&clk_provider->node);
>> kfree(clk_provider);
>> is_init_done = true;
--
Regards,
Sylwester
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