From: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
The default behaviour with clk_rcg2_ops is for the
clk_round_rate()/clk_set_rate() to return/set a ceil clock
rate closest to the requested rate by looking up the corresponding
frequency table.
However, we do have some instances (mainly sdcc on various platforms)
of clients expecting a clk_set_rate() to set a floor value instead.
Add a new clk_rcg2_floor_ops to handle this for such specific
rcg instances
Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
---
drivers/clk/qcom/clk-rcg.h | 1 +
drivers/clk/qcom/clk-rcg2.c | 75 +++++++++++++++++++++++++++++++++++++++------
drivers/clk/qcom/common.c | 26 ++++++++++++++++
drivers/clk/qcom/common.h | 2 ++
4 files changed, 95 insertions(+), 9 deletions(-)
diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index b904c33..1b3e8d2 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/drivers/clk/qcom/clk-rcg.h
@@ -173,6 +173,7 @@ struct clk_rcg2 {
#define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
extern const struct clk_ops clk_rcg2_ops;
+extern const struct clk_ops clk_rcg2_floor_ops;
extern const struct clk_ops clk_rcg2_shared_ops;
extern const struct clk_ops clk_edp_pixel_ops;
extern const struct clk_ops clk_byte_ops;
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index a071bba..04433a6 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -47,6 +47,11 @@
#define N_REG 0xc
#define D_REG 0x10
+enum {
+ FLOOR,
+ CEIL,
+};
+
static int clk_rcg2_is_enabled(struct clk_hw *hw)
{
struct clk_rcg2 *rcg = to_clk_rcg2(hw);
@@ -176,15 +181,25 @@ static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
return calc_rate(parent_rate, m, n, mode, hid_div);
}
-static int _freq_tbl_determine_rate(struct clk_hw *hw,
- const struct freq_tbl *f, struct clk_rate_request *req)
+static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
+ struct clk_rate_request *req, bool match)
{
unsigned long clk_flags, rate = req->rate;
struct clk_hw *p;
struct clk_rcg2 *rcg = to_clk_rcg2(hw);
int index;
- f = qcom_find_freq(f, rate);
+ switch (match) {
+ case FLOOR:
+ f = qcom_find_freq_floor(f, rate);
+ break;
+ case CEIL:
+ f = qcom_find_freq(f, rate);
+ break;
+ default:
+ return -EINVAL;
+ };
+
if (!f)
return -EINVAL;
@@ -221,7 +236,15 @@ static int clk_rcg2_determine_rate(struct clk_hw *hw,
{
struct clk_rcg2 *rcg = to_clk_rcg2(hw);
- return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req);
+ return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, CEIL);
+}
+
+static int clk_rcg2_determine_floor_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+
+ return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, FLOOR);
}
static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
@@ -265,12 +288,23 @@ static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
return update_config(rcg);
}
-static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
+static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
+ bool match)
{
struct clk_rcg2 *rcg = to_clk_rcg2(hw);
const struct freq_tbl *f;
- f = qcom_find_freq(rcg->freq_tbl, rate);
+ switch (match) {
+ case FLOOR:
+ f = qcom_find_freq_floor(rcg->freq_tbl, rate);
+ break;
+ case CEIL:
+ f = qcom_find_freq(rcg->freq_tbl, rate);
+ break;
+ default:
+ return -EINVAL;
+ };
+
if (!f)
return -EINVAL;
@@ -280,13 +314,25 @@ static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
- return __clk_rcg2_set_rate(hw, rate);
+ return __clk_rcg2_set_rate(hw, rate, CEIL);
+}
+
+static int clk_rcg2_set_floor_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ return __clk_rcg2_set_rate(hw, rate, FLOOR);
}
static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
unsigned long rate, unsigned long parent_rate, u8 index)
{
- return __clk_rcg2_set_rate(hw, rate);
+ return __clk_rcg2_set_rate(hw, rate, CEIL);
+}
+
+static int clk_rcg2_set_floor_rate_and_parent(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate, u8 index)
+{
+ return __clk_rcg2_set_rate(hw, rate, FLOOR);
}
const struct clk_ops clk_rcg2_ops = {
@@ -300,6 +346,17 @@ static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
};
EXPORT_SYMBOL_GPL(clk_rcg2_ops);
+const struct clk_ops clk_rcg2_floor_ops = {
+ .is_enabled = clk_rcg2_is_enabled,
+ .get_parent = clk_rcg2_get_parent,
+ .set_parent = clk_rcg2_set_parent,
+ .recalc_rate = clk_rcg2_recalc_rate,
+ .determine_rate = clk_rcg2_determine_floor_rate,
+ .set_rate = clk_rcg2_set_floor_rate,
+ .set_rate_and_parent = clk_rcg2_set_floor_rate_and_parent,
+};
+EXPORT_SYMBOL_GPL(clk_rcg2_floor_ops);
+
static int clk_rcg2_shared_force_enable(struct clk_hw *hw, unsigned long rate)
{
struct clk_rcg2 *rcg = to_clk_rcg2(hw);
@@ -323,7 +380,7 @@ static int clk_rcg2_shared_force_enable(struct clk_hw *hw, unsigned long rate)
pr_err("%s: RCG did not turn on\n", name);
/* set clock rate */
- ret = __clk_rcg2_set_rate(hw, rate);
+ ret = __clk_rcg2_set_rate(hw, rate, CEIL);
if (ret)
return ret;
diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index fffcbaf..cf6b87f 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -46,6 +46,32 @@ struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
}
EXPORT_SYMBOL_GPL(qcom_find_freq);
+const
+struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,
+ unsigned long rate)
+{
+ int size = 0;
+
+ if (!f)
+ return NULL;
+
+ /*
+ * The freq table has entries in the ascending order of frequencies
+ * To find the floor for a given frequency, we need to do a reverse
+ * lookup of the table
+ */
+ for (; f->freq; f++, size++)
+ ;
+
+ for (f--; size; f--, size--)
+ if (rate >= f->freq)
+ return f;
+
+ /* could not find any rates lower than *rate* */
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(qcom_find_freq_floor);
+
int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map, u8 src)
{
int i, num_parents = clk_hw_get_num_parents(hw);
diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h
index ae9bdeb..76886a1 100644
--- a/drivers/clk/qcom/common.h
+++ b/drivers/clk/qcom/common.h
@@ -34,6 +34,8 @@ struct qcom_cc_desc {
extern const struct freq_tbl *qcom_find_freq(const struct freq_tbl *f,
unsigned long rate);
+extern const struct freq_tbl *qcom_find_freq_floor(const struct freq_tbl *f,
+ unsigned long rate);
extern int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map,
u8 src);
--
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