clk: sunxi-ng: gate: Support common pre-dividers

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>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
This commit is contained in:
Chen-Yu Tsai 2017-02-14 11:35:23 +08:00 committed by Maxime Ripard
parent 9ad0bb39fc
commit 845d6b0ff9

View File

@ -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,
};