[PATCH RFC 07/11] clk: sunxi: factors: Support custom formulas

From: Chen-Yu Tsai
Date: Mon Jan 25 2016 - 08:17:13 EST


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@xxxxxxxx>
---
drivers/clk/sunxi/clk-factors.c | 30 ++++++++++++++++++++++++++++--
drivers/clk/sunxi/clk-factors.h | 3 +++
2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index 47b7d918b74c..ac259305d5d5 100644
--- a/drivers/clk/sunxi/clk-factors.c
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -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;
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
index f09d7c214533..a44a865a6b9e 100644
--- a/drivers/clk/sunxi/clk-factors.h
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -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;
--
2.7.0