[PATCH 2/5] clk: sunxi-ng: gate: Support common pre-dividers

Chen-Yu Tsai
2017-02-14T03:35:23Z

Some clock gates have a pre-divider between the source input and the
gate itself. A notable example is the HSIC 12 MHz clock found on the
A83T, which has the 24 MHz main oscillator as its input, and a /2
pre-divider.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
drivers/clk/sunxi-ng/ccu_gate.c | 47 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu_gate.c b/drivers/clk/sunxi-ng/ccu_gate.c
index 8a81f9d4a89f..cd069d5da215 100644
--- a/drivers/clk/sunxi-ng/ccu_gate.c
+++ b/drivers/clk/sunxi-ng/ccu_gate.c
@@ -75,8 +75,55 @@ static int ccu_gate_is_enabled(struct clk_hw *hw)
return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
}

+static unsigned long ccu_gate_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_gate *cg = hw_to_ccu_gate(hw);
+ unsigned long rate = parent_rate;
+
+ if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
+ rate /= cg->common.prediv;
+
+ return rate;
+}
+
+static long ccu_gate_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct ccu_gate *cg = hw_to_ccu_gate(hw);
+ int div = 1;
+
+ if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
+ div = cg->common.prediv;
+
+ if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+ unsigned long best_parent = rate;
+
+ if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
+ best_parent *= div;
+ *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
+ }
+
+ return *prate / div;
+}
+
+static int ccu_gate_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ /*
+ * We must report success but we can do so unconditionally because
+ * clk_factor_round_rate returns values that ensure this call is a
+ * nop.
+ */
+
+ return 0;
+}
+
const struct clk_ops ccu_gate_ops = {
.disable = ccu_gate_disable,
.enable = ccu_gate_enable,
.is_enabled = ccu_gate_is_enabled,
+ .round_rate = ccu_gate_round_rate,
+ .set_rate = ccu_gate_set_rate,
+ .recalc_rate = ccu_gate_recalc_rate,
};
--
2.11.0