SPEAr: clk: Add Fractional Synthesizer clock
All SPEAr SoC's contain Fractional Synthesizers. Their Fout is derived from
following equations:
Fout = Fin / (2 * div) (division factor)
div is 17 bits:-
0-13 (fractional part)
14-16 (integer part)
div is (16-14 bits).(13-0 bits) (in binary)
Fout = Fin/(2 * div)
Fout = ((Fin / 10000)/(2 * div)) * 10000
Fout = (2^14 * (Fin / 10000)/(2^14 * (2 * div))) * 10000
Fout = (((Fin / 10000) << 14)/(2 * (div << 14))) * 10000
div << 14 is simply 17 bit value written at register.
This patch adds in support for this type of clock.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Reviewed-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/spear/clk.h b/drivers/clk/spear/clk.h
index c229080..ac9030b 100644
--- a/drivers/clk/spear/clk.h
+++ b/drivers/clk/spear/clk.h
@@ -55,6 +55,19 @@
spinlock_t *lock;
};
+/* Fractional Synth clk */
+struct frac_rate_tbl {
+ u32 div;
+};
+
+struct clk_frac {
+ struct clk_hw hw;
+ void __iomem *reg;
+ struct frac_rate_tbl *rtbl;
+ u8 rtbl_cnt;
+ spinlock_t *lock;
+};
+
/* VCO-PLL clk */
struct pll_rate_tbl {
u8 mode;
@@ -87,6 +100,9 @@
const char *parent_name, unsigned long flags, void __iomem *reg,
struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl,
u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk);
+struct clk *clk_register_frac(const char *name, const char *parent_name,
+ unsigned long flags, void __iomem *reg,
+ struct frac_rate_tbl *rtbl, u8 rtbl_cnt, spinlock_t *lock);
struct clk *clk_register_vco_pll(const char *vco_name, const char *pll_name,
const char *vco_gate_name, const char *parent_name,
unsigned long flags, void __iomem *mode_reg, void __iomem