Re: [PATCH v6 10/18] clk: qcom: krait-cc: drop hardcoded safe_sel

From: Dmitry Baryshkov
Date: Wed Apr 13 2022 - 13:25:43 EST


On 22/03/2022 02:15, Ansuel Smith wrote:
Drop hardcoded safe_sel definition and use helper to correctly calculate
it. We assume qsb clk is always present as it should be declared in DTS
per Documentation and in the absence of that, it's declared as a fixed
clk.

Why? Can safe_sel (sec_mux index) change?


Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
---
drivers/clk/qcom/krait-cc.c | 40 +++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c
index e9508e3104ea..5f98ee1c3681 100644
--- a/drivers/clk/qcom/krait-cc.c
+++ b/drivers/clk/qcom/krait-cc.c
@@ -26,6 +26,17 @@ static unsigned int pri_mux_map[] = {
0,
};
+static u8 krait_get_mux_sel(struct krait_mux_clk *mux, struct clk *safe_clk)
+{
+ struct clk_hw *safe_hw = __clk_get_hw(safe_clk);
+
+ /*
+ * We can ignore errors from clk_hw_get_index_of_parent()
+ * as we create these parents in this driver.
+ */
+ return clk_hw_get_index_of_parent(&mux->hw, safe_hw);
+}
+
/*
* Notifier function for switching the muxes to safe parent
* while the hfpll is getting reprogrammed.
@@ -116,8 +127,8 @@ krait_add_div(struct device *dev, int id, const char *s, unsigned int offset)
}
static struct clk *
-krait_add_sec_mux(struct device *dev, int id, const char *s,
- unsigned int offset, bool unique_aux)
+krait_add_sec_mux(struct device *dev, struct clk *qsb, int id,
+ const char *s, unsigned int offset, bool unique_aux)
{
int ret;
struct krait_mux_clk *mux;
@@ -144,7 +155,6 @@ krait_add_sec_mux(struct device *dev, int id, const char *s,
mux->shift = 2;
mux->parent_map = sec_mux_map;
mux->hw.init = &init;
- mux->safe_sel = 0;
init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s);
if (!init.name)
@@ -166,6 +176,7 @@ krait_add_sec_mux(struct device *dev, int id, const char *s,
if (IS_ERR(clk))
goto err_clk;
+ mux->safe_sel = krait_get_mux_sel(mux, qsb);
ret = krait_notifier_register(dev, clk, mux);
if (ret)
clk = ERR_PTR(ret);
@@ -204,7 +215,6 @@ krait_add_pri_mux(struct device *dev, struct clk *hfpll_div, struct clk *sec_mux
mux->lpl = id >= 0;
mux->parent_map = pri_mux_map;
mux->hw.init = &init;
- mux->safe_sel = 2;
init.name = kasprintf(GFP_KERNEL, "krait%s_pri_mux", s);
if (!init.name)
@@ -226,6 +236,7 @@ krait_add_pri_mux(struct device *dev, struct clk *hfpll_div, struct clk *sec_mux
if (IS_ERR(clk))
goto err_clk;
+ mux->safe_sel = krait_get_mux_sel(mux, sec_mux);
ret = krait_notifier_register(dev, clk, mux);
if (ret)
clk = ERR_PTR(ret);
@@ -238,7 +249,9 @@ krait_add_pri_mux(struct device *dev, struct clk *hfpll_div, struct clk *sec_mux
}
/* id < 0 for L2, otherwise id == physical CPU number */
-static struct clk *krait_add_clks(struct device *dev, int id, bool unique_aux)
+static struct clk *
+krait_add_clks(struct device *dev, struct clk *qsb, int id,
+ bool unique_aux)
{
unsigned int offset;
void *p = NULL;
@@ -261,7 +274,7 @@ static struct clk *krait_add_clks(struct device *dev, int id, bool unique_aux)
goto err;
}
- sec_mux = krait_add_sec_mux(dev, id, s, offset, unique_aux);
+ sec_mux = krait_add_sec_mux(dev, qsb, id, s, offset, unique_aux);
if (IS_ERR(sec_mux)) {
clk = sec_mux;
goto err;
@@ -301,18 +314,19 @@ static int krait_cc_probe(struct platform_device *pdev)
int cpu;
struct clk *clk;
struct clk **clks;
- struct clk *l2_pri_mux_clk;
+ struct clk *l2_pri_mux_clk, *qsb;
id = of_match_device(krait_cc_match_table, dev);
if (!id)
return -ENODEV;
/* Rate is 1 because 0 causes problems for __clk_mux_determine_rate */
- if (IS_ERR(clk_get(dev, "qsb")))
- clk = clk_register_fixed_rate(dev, "qsb", NULL, 0, 1);
+ qsb = clk_get(dev, "qsb");
+ if (IS_ERR(qsb))
+ qsb = clk_register_fixed_rate(dev, "qsb", NULL, 0, 1);
- if (IS_ERR(clk))
- return PTR_ERR(clk);
+ if (IS_ERR(qsb))
+ return PTR_ERR(qsb);
if (!id->data) {
clk = clk_register_fixed_factor(dev, "acpu_aux",
@@ -327,13 +341,13 @@ static int krait_cc_probe(struct platform_device *pdev)
return -ENOMEM;
for_each_possible_cpu(cpu) {
- clk = krait_add_clks(dev, cpu, id->data);
+ clk = krait_add_clks(dev, qsb, cpu, id->data);
if (IS_ERR(clk))
return PTR_ERR(clk);
clks[cpu] = clk;
}
- l2_pri_mux_clk = krait_add_clks(dev, -1, id->data);
+ l2_pri_mux_clk = krait_add_clks(dev, qsb, -1, id->data);
if (IS_ERR(l2_pri_mux_clk))
return PTR_ERR(l2_pri_mux_clk);
clks[4] = l2_pri_mux_clk;


--
With best wishes
Dmitry