Messages in this thread Patch in this message | | | From | Marco Felsch <> | Subject | [RFC PATCH 1/2] clk: add support for critical always-on clocks | Date | Tue, 13 Sep 2022 12:21:40 +0200 |
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Add support to mark specific clocks as always-on (critical), like the regulator-alawys-on property. So the platform integrators can specify the property on a per device basis by specifying it within the firmware and not only within the driver. Unlike the regulator framework the clock framework uses a 1:n matching, which means 1 firmware node can provide up to n clock providers. Therefore the binding uses a string-array so we can specify n clock providers as critical.
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> --- drivers/clk/clk.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 7fc191c15507..c3651bf96f90 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3825,6 +3825,22 @@ static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist) return 0; } +static void clk_core_check_critical(struct clk_core *core) +{ + struct fwnode_handle *fwnode = of_fwnode_handle(core->of_node); + const char *prop = "clocks-always-on"; + int ret; + + /* Very early added clocks don't have a fwnode */ + if (!fwnode || !fwnode_property_present(fwnode, prop)) + return; + + /* Mark clock as critical if listed within the clocks-always-on array */ + ret = fwnode_property_match_string(fwnode, prop, core->name); + if (!ret) + core->flags |= CLK_IS_CRITICAL; +} + static int clk_core_populate_parent_map(struct clk_core *core, const struct clk_init_data *init) { @@ -3946,6 +3962,8 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) core->min_rate = 0; core->max_rate = ULONG_MAX; + clk_core_check_critical(core); + ret = clk_core_populate_parent_map(core, init); if (ret) goto fail_parents; -- 2.30.2
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