default-rate property can now be used to set initial rates for clocks.
This is added by default for all clocks which get initialized through
of_clk_init().
Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
---
.../devicetree/bindings/clock/clock-bindings.txt | 9 ++
drivers/clk/clk.c | 86 ++++++++++++++++++++
include/linux/clk-provider.h | 2 +
3 files changed, 97 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt
index 7c52c29..d676112 100644
--- a/Documentation/devicetree/bindings/clock/clock-bindings.txt
+++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt
@@ -44,6 +44,15 @@ For example:
clocks by index. The names should reflect the clock output signal
names for the device.
+default-rate: Sets the rate of the clock during boot to the provided
+ rate.
+
+For example:
+
+ clk-divider {
+ default-rate = <1000000>;
+ };
+
==Clock consumers==
Required properties:
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 5517944..cb144e4 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2526,6 +2526,89 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
}
EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
+static LIST_HEAD(clk_init_info_list);
+
+struct clk_init_info {
+ struct device_node *node;
+ struct clk *clk;
+ u32 rate;
+ struct list_head link;
+ struct list_head sort_link;
+};
+
+int __init of_clk_parse_init_rate(struct device_node *node, struct clk *clk)
+{
+ u32 rate;
+ struct clk_init_info *cinfo;
+
+ if (of_property_read_u32(node, "default-rate", &rate))
+ return 0;
+
+ cinfo = kzalloc(sizeof(*cinfo), GFP_KERNEL);
+ if (!cinfo)
+ return -ENOMEM;
+
+ cinfo->node = node;
+ cinfo->clk = clk;
+ cinfo->rate = rate;
+ list_add(&cinfo->link, &clk_init_info_list);
+ INIT_LIST_HEAD(&cinfo->sort_link);
+
+ return 0;
+}
+
+int __init of_clk_set_init_rates(void)
+{
+ struct clk_init_info *cinfo, *tmp;
+ struct of_phandle_args clkspec;
+ int ret = 0;
+ struct list_head sorted_list;
+ struct clk *clk;
+
+ INIT_LIST_HEAD(&sorted_list);
+
+ list_for_each_entry(cinfo, &clk_init_info_list, link) {
+ /* Get missing clk pointers */
+ if (!cinfo->clk) {
+ clkspec.np = cinfo->node;
+ cinfo->clk = of_clk_get_from_provider(&clkspec);
+ }
+
+ /* Check if we are the parent of any of the sorted clocks */
+ list_for_each_entry(tmp, &sorted_list, sort_link) {
+ clk = tmp->clk;
+ while (clk && clk != cinfo->clk)
+ clk = clk->parent;
+
+ if (clk == cinfo->clk) {
+ /* Add us before this node in the list */
+ list_add_tail(&cinfo->sort_link,
+ &tmp->sort_link);
+ break;
+ }
+ }
+
+ if (list_empty(&cinfo->sort_link))
+ list_add_tail(&cinfo->sort_link, &sorted_list);
+ }
+
+ /* Process sorted list and set clk rates */
+ list_for_each_entry_safe(cinfo, tmp, &sorted_list, sort_link) {
+ int r = clk_set_rate(cinfo->clk, cinfo->rate);
+ if (r) {
+ pr_err("%s: clk_set_rate for %s failed: %d\n", __func__,
+ cinfo->node->name, ret);
+ ret = r;
+ }
+
+ /* Clean up the static list */
+ list_del(&cinfo->link);
+ kfree(cinfo);
+ }
+
+ return ret;
+}
+
/**
* of_clk_init() - Scan and init clock providers from the DT
* @matches: array of compatible values and init functions for providers.
@@ -2544,6 +2627,9 @@ void __init of_clk_init(const struct of_device_id *matches)
for_each_matching_node_and_match(np, matches, &match) {
of_clk_init_cb_t clk_init_cb = match->data;
clk_init_cb(np);
+ of_clk_parse_init_rate(np, NULL);
}
+
+ of_clk_set_init_rates();
}
#endif
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 939533d..1bbd194 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -506,6 +506,8 @@ struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data);
int of_clk_get_parent_count(struct device_node *np);
const char *of_clk_get_parent_name(struct device_node *np, int index);
+int of_clk_parse_init_rate(struct device_node *node, struct clk *clk);
+int of_clk_set_init_rates(void);
void of_clk_init(const struct of_device_id *matches);
--
1.7.9.5
--
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