[PATCH] clk: qcom: regmap-mux: fix parent clock lookup

[PATCH] clk: qcom: regmap-mux: fix parent clock lookup

[Dmitry Baryshkov]

The function mux_get_parent() uses qcom_find_src_index() to find the
parent clock index, which is incorrect: qcom_find_src_index() uses src
enum for the lookup, while mux_get_parent() should use cfg field (which
corresponds to the register value). Add qcom_find_cfg_index() function
doing this kind of lookup and use it for mux parent lookup.

Fixes: df964016490b ("clk: qcom: add parent map for regmap mux")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/clk/qcom/clk-regmap-mux.c |  2 +-
 drivers/clk/qcom/common.c         | 12 ++++++++++++
 drivers/clk/qcom/common.h         |  2 ++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-regmap-mux.c b/drivers/clk/qcom/clk-regmap-mux.c
index b2d00b451963..45d9cca28064 100644
--- a/drivers/clk/qcom/clk-regmap-mux.c
+++ b/drivers/clk/qcom/clk-regmap-mux.c
@@ -28,7 +28,7 @@ static u8 mux_get_parent(struct clk_hw *hw)
 	val &= mask;
 
 	if (mux->parent_map)
-		return qcom_find_src_index(hw, mux->parent_map, val);
+		return qcom_find_cfg_index(hw, mux->parent_map, val);
 
 	return val;
 }
diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
index 60d2a78d1395..2af04fc4abfa 100644
--- a/drivers/clk/qcom/common.c
+++ b/drivers/clk/qcom/common.c
@@ -69,6 +69,18 @@ int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map, u8 src)
 }
 EXPORT_SYMBOL_GPL(qcom_find_src_index);
 
+int qcom_find_cfg_index(struct clk_hw *hw, const struct parent_map *map, u8 cfg)
+{
+	int i, num_parents = clk_hw_get_num_parents(hw);
+
+	for (i = 0; i < num_parents; i++)
+		if (cfg == map[i].cfg)
+			return i;
+
+	return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(qcom_find_cfg_index);
+
 struct regmap *
 qcom_cc_map(struct platform_device *pdev, const struct qcom_cc_desc *desc)
 {
diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h
index bb39a7e106d8..9c8f7b798d9f 100644
--- a/drivers/clk/qcom/common.h
+++ b/drivers/clk/qcom/common.h
@@ -49,6 +49,8 @@ extern void
 qcom_pll_set_fsm_mode(struct regmap *m, u32 reg, u8 bias_count, u8 lock_count);
 extern int qcom_find_src_index(struct clk_hw *hw, const struct parent_map *map,
 			       u8 src);
+extern int qcom_find_cfg_index(struct clk_hw *hw, const struct parent_map *map,
+			       u8 cfg);
 
 extern int qcom_cc_register_board_clk(struct device *dev, const char *path,
 				      const char *name, unsigned long rate);
-- 
2.33.0

Re: [PATCH] clk: qcom: regmap-mux: fix parent clock lookup

[Greg KH]

On Tue, Nov 16, 2021 at 02:34:07AM +0300, Dmitry Baryshkov wrote:
> The function mux_get_parent() uses qcom_find_src_index() to find the
> parent clock index, which is incorrect: qcom_find_src_index() uses src
> enum for the lookup, while mux_get_parent() should use cfg field (which
> corresponds to the register value). Add qcom_find_cfg_index() function
> doing this kind of lookup and use it for mux parent lookup.
> 
> Fixes: df964016490b ("clk: qcom: add parent map for regmap mux")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>


<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Re: [PATCH] clk: qcom: regmap-mux: fix parent clock lookup

[Stephen Boyd]

Quoting Dmitry Baryshkov (2021-11-15 15:34:07)
> The function mux_get_parent() uses qcom_find_src_index() to find the
> parent clock index, which is incorrect: qcom_find_src_index() uses src
> enum for the lookup, while mux_get_parent() should use cfg field (which
> corresponds to the register value). Add qcom_find_cfg_index() function
> doing this kind of lookup and use it for mux parent lookup.
> 
> Fixes: df964016490b ("clk: qcom: add parent map for regmap mux")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---

Applied to clk-fixes