clk: add a fixed factor clock
Having fixed factors/dividers in hardware is a common pattern, so
add a basic clock type doing this. It basically describes a fixed
factor clock using a nominator and a denominator.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
[mturquette@linaro.org: constify parent_names in static init macro]
[mturquette@linaro.org: copy/paste bug from mux in static init macro]
[mturquette@linaro.org: fix error handling in clk_register_fixed_factor]
[mturquette@linaro.org: improve division accuracy; thanks to Saravana]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h
index b258532..eb3f84b 100644
--- a/include/linux/clk-private.h
+++ b/include/linux/clk-private.h
@@ -143,6 +143,26 @@
DEFINE_CLK(_name, clk_mux_ops, _flags, _parent_names, \
_parents);
+#define DEFINE_CLK_FIXED_FACTOR(_name, _parent_name, \
+ _parent_ptr, _flags, \
+ _mult, _div) \
+ static struct clk _name; \
+ static const char *_name##_parent_names[] = { \
+ _parent_name, \
+ }; \
+ static struct clk *_name##_parents[] = { \
+ _parent_ptr, \
+ }; \
+ static struct clk_fixed_factor _name##_hw = { \
+ .hw = { \
+ .clk = &_name, \
+ }, \
+ .mult = _mult, \
+ .div = _div, \
+ }; \
+ DEFINE_CLK(_name, clk_fixed_factor_ops, _flags, \
+ _name##_parent_names, _name##_parents);
+
/**
* __clk_init - initialize the data structures in a struct clk
* @dev: device initializing this clk, placeholder for now
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 5db3412..c1c23b9 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -277,6 +277,29 @@
u8 clk_mux_flags, spinlock_t *lock);
/**
+ * struct clk_fixed_factor - fixed multiplier and divider clock
+ *
+ * @hw: handle between common and hardware-specific interfaces
+ * @mult: multiplier
+ * @div: divider
+ *
+ * Clock with a fixed multiplier and divider. The output frequency is the
+ * parent clock rate divided by div and multiplied by mult.
+ * Implements .recalc_rate, .set_rate and .round_rate
+ */
+
+struct clk_fixed_factor {
+ struct clk_hw hw;
+ unsigned int mult;
+ unsigned int div;
+};
+
+extern struct clk_ops clk_fixed_factor_ops;
+struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ unsigned int mult, unsigned int div);
+
+/**
* clk_register - allocate a new clock, register it and return an opaque cookie
* @dev: device that is registering this clock
* @hw: link to hardware-specific clock data