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clk: sunxi: factors: Support custom formulas

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Some clocks cannot be modelled using the standard factors clk formula,
such as clocks with special pre-dividers on one parent, or clocks
with all power-of-two dividers.

Add support for a custom .recalc callback for factors clk. Also pass
the current parent index to the .get_factor and .recalc callbacks.

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 2016-01-25 21:15:43 +08:00 committed by Maxime Ripard
parent cfa6368860
commit 435b7be1d8
2 changed files with 32 additions and 2 deletions
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31
drivers/clk/sunxi/clk-factors.c
View File

@ -63,6 +63,26 @@ static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
if (config->pwidth != SUNXI_FACTORS_NOT_APPLICABLE)
p = FACTOR_GET(config->pshift, config->pwidth, reg);
if (factors->recalc) {
struct factors_request factors_req = {
.parent_rate = parent_rate,
.n = n,
.k = k,
.m = m,
.p = p,
};
/* get mux details from mux clk structure */
if (factors->mux)
factors_req.parent_index =
(reg >> factors->mux->shift) &
factors->mux->mask;
factors->recalc(&factors_req);
return factors_req.rate;
}
/* Calculate the rate */
rate = (parent_rate * (n + config->n_start) * (k + 1) >> p) / (m + 1);
@ -87,6 +107,7 @@ static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
static int clk_factors_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_factors *factors = to_clk_factors(hw);
struct clk_hw *parent, *best_parent = NULL;
int i, num_parents;
unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0;
@ -94,6 +115,10 @@ static int clk_factors_determine_rate(struct clk_hw *hw,
/* find the parent that can help provide the fastest rate <= rate */
num_parents = clk_hw_get_num_parents(hw);
for (i = 0; i < num_parents; i++) {
struct factors_request factors_req = {
.rate = req->rate,
.parent_index = i,
};
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
@ -102,8 +127,9 @@ static int clk_factors_determine_rate(struct clk_hw *hw,
else
parent_rate = clk_hw_get_rate(parent);
child_rate = clk_factors_round_rate(hw, req->rate,
&parent_rate);
factors_req.parent_rate = parent_rate;
factors->get_factors(&factors_req);
child_rate = factors_req.rate;
if (child_rate <= req->rate && child_rate > best_child_rate) {
best_parent = parent;
@ -202,6 +228,7 @@ struct clk *sunxi_factors_register(struct device_node *node,
factors->reg = reg;
factors->config = data->table;
factors->get_factors = data->getter;
factors->recalc = data->recalc;
factors->lock = lock;
/* Add a gate if this factor clock can be gated */

3
drivers/clk/sunxi/clk-factors.h
View File

@ -22,6 +22,7 @@ struct clk_factors_config {
struct factors_request {
unsigned long rate;
unsigned long parent_rate;
u8 parent_index;
u8 n;
u8 k;
u8 m;
@ -34,6 +35,7 @@ struct factors_data {
int muxmask;
const struct clk_factors_config *table;
void (*getter)(struct factors_request *req);
void (*recalc)(struct factors_request *req);
const char *name;
};
@ -42,6 +44,7 @@ struct clk_factors {
void __iomem *reg;
const struct clk_factors_config *config;
void (*get_factors)(struct factors_request *req);
void (*recalc)(struct factors_request *req);
spinlock_t *lock;
/* for cleanup */
struct clk_mux *mux;