Messages in this thread | | | Date | Thu, 15 Dec 2011 23:19:51 +0800 | From | Shawn Guo <> | Subject | Re: [RFC v2 5/9] dt/clock: Add handling for fixed clocks and a clock node setup iterator |
| |
Hi Grant,
On Mon, Dec 12, 2011 at 03:02:05PM -0700, Grant Likely wrote: > Signed-off-by: Grant Likely <grant.likely@secretlab.ca> > --- > drivers/of/clock.c | 43 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_clk.h | 4 ++++ > 2 files changed, 47 insertions(+), 0 deletions(-) > > diff --git a/drivers/of/clock.c b/drivers/of/clock.c > index 6519e96..1c189b4 100644 > --- a/drivers/of/clock.c > +++ b/drivers/of/clock.c > @@ -3,6 +3,7 @@ > */ > > #include <linux/clk.h> > +#include <linux/clkdev.h> > #include <linux/err.h> > #include <linux/errno.h> > #include <linux/module.h> > @@ -163,3 +164,45 @@ struct clk *of_clk_get_by_name(struct device_node *np, const char *name) > > return clk; > } > + > +/** > + * of_clk_init() - Scan and init clock providers from the DT > + * @matches: array of compatible values and init functions for providers. > + * > + * This function scans the device tree for matching clock providers and > + * calls their initialization functions > + */ > +void __init of_clk_init(const struct of_device_id *matches) > +{ > + struct device_node *np; > + > + for_each_matching_node(np, matches) { > + const struct of_device_id *match = of_match_node(matches, np); > + of_clk_init_cb_t clk_init_cb = match->data; > + clk_init_cb(np); > + } > +} > + > +static struct clk *of_fixed_clk_get(struct of_phandle_args *a, void *data) > +{ > + return data; > +} > + > +/** > + * of_fixed_clk_setup() - Setup function for simple fixed rate clock > + */ > +void __init of_fixed_clk_setup(struct device_node *node) > +{ > + struct clk *clk; > + u32 rate; > + > + if (of_property_read_u32(node, "clock-frequency", &rate)) > + return; > + > + clk = kzalloc(sizeof(*clk), GFP_KERNEL); > + if (!clk) > + return; > + clk->rate = rate; > + > + of_clk_add_provider(node, of_fixed_clk_get, clk); > +}
Just take the fixed clk as example, I have a node below as a blob, which has 3 fixed clks encoded.
ref_clk: ref { compatible = "fixed-clock", "basic-clock"; #clock-cells = <1>; clock-frequency = <24000000 32768 0>; clock-output-name = "osc", "ckil", "ckih"; };
If this is valid, the of_fixed_clk_setup() should scan the node for multiple clks, right?
-- Regards, Shawn
| |