[PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[Dmitry Osipenko]

Unset "enable" bit means that divider is in bypass mode, hence it doesn't
have any effect in that case.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-divider.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
index e76731fb7d69..f33c19045386 100644
--- a/drivers/clk/tegra/clk-divider.c
+++ b/drivers/clk/tegra/clk-divider.c
@@ -40,8 +40,13 @@ static unsigned long clk_frac_div_recalc_rate(struct clk_hw *hw,
 	int div, mul;
 	u64 rate = parent_rate;
 
-	reg = readl_relaxed(divider->reg) >> divider->shift;
-	div = reg & div_mask(divider);
+	reg = readl_relaxed(divider->reg);
+
+	if ((divider->flags & TEGRA_DIVIDER_UART) &&
+	    !(reg & PERIPH_CLK_UART_DIV_ENB))
+		return rate;
+
+	div = (reg >> divider->shift) & div_mask(divider);
 
 	mul = get_mul(divider);
 	div += mul;
-- 
2.22.0

[PATCH v1 2/2] clk: tegra: divider: Support enable-bit for Super clocks

[Dmitry Osipenko]

All "super" clock dividers have enable bit.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-divider.c | 12 ++++++++++++
 drivers/clk/tegra/clk-super.c   |  1 +
 drivers/clk/tegra/clk.h         |  4 ++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
index f33c19045386..a980b9bddecd 100644
--- a/drivers/clk/tegra/clk-divider.c
+++ b/drivers/clk/tegra/clk-divider.c
@@ -17,6 +17,7 @@
 #define get_max_div(d) div_mask(d)
 
 #define PERIPH_CLK_UART_DIV_ENB BIT(24)
+#define SUPER_CLK_DIV_ENB BIT(31)
 
 static int get_div(struct tegra_clk_frac_div *divider, unsigned long rate,
 		   unsigned long parent_rate)
@@ -46,6 +47,10 @@ static unsigned long clk_frac_div_recalc_rate(struct clk_hw *hw,
 	    !(reg & PERIPH_CLK_UART_DIV_ENB))
 		return rate;
 
+	if ((divider->flags & TEGRA_DIVIDER_SUPER) &&
+	    !(reg & SUPER_CLK_DIV_ENB))
+		return rate;
+
 	div = (reg >> divider->shift) & div_mask(divider);
 
 	mul = get_mul(divider);
@@ -96,6 +101,13 @@ static int clk_frac_div_set_rate(struct clk_hw *hw, unsigned long rate,
 	val &= ~(div_mask(divider) << divider->shift);
 	val |= div << divider->shift;
 
+	if (divider->flags & TEGRA_DIVIDER_SUPER) {
+		if (div)
+			val |= SUPER_CLK_DIV_ENB;
+		else
+			val &= ~SUPER_CLK_DIV_ENB;
+	}
+
 	if (divider->flags & TEGRA_DIVIDER_UART) {
 		if (div)
 			val |= PERIPH_CLK_UART_DIV_ENB;
diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c
index 39ef31b46df5..4d8e36b04f03 100644
--- a/drivers/clk/tegra/clk-super.c
+++ b/drivers/clk/tegra/clk-super.c
@@ -220,6 +220,7 @@ struct clk *tegra_clk_register_super_clk(const char *name,
 	super->frac_div.width = 8;
 	super->frac_div.frac_width = 1;
 	super->frac_div.lock = lock;
+	super->frac_div.flags = TEGRA_DIVIDER_SUPER;
 	super->div_ops = &tegra_clk_frac_div_ops;
 
 	/* Data in .init is copied by clk_register(), so stack variable OK */
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 905bf1096558..a4fbf55930aa 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -53,6 +53,9 @@ struct clk *tegra_clk_register_sync_source(const char *name,
  * TEGRA_DIVIDER_UART - UART module divider has additional enable bit which is
  *      set when divider value is not 0. This flags indicates that the divider
  *      is for UART module.
+ * TEGRA_DIVIDER_SUPER - Super clock divider has additional enable bit which
+ *      is set when divider value is not 0. This flags indicates that the
+ *      divider is for super clock.
  */
 struct tegra_clk_frac_div {
 	struct clk_hw	hw;
@@ -70,6 +73,7 @@ struct tegra_clk_frac_div {
 #define TEGRA_DIVIDER_FIXED BIT(1)
 #define TEGRA_DIVIDER_INT BIT(2)
 #define TEGRA_DIVIDER_UART BIT(3)
+#define TEGRA_DIVIDER_SUPER BIT(4)
 
 extern const struct clk_ops tegra_clk_frac_div_ops;
 struct clk *tegra_clk_register_divider(const char *name,
-- 
2.22.0

Re: [PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[Stephen Boyd]

Quoting Dmitry Osipenko (2019-07-15 10:35:26)
> Unset "enable" bit means that divider is in bypass mode, hence it doesn't
> have any effect in that case.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Any Fixes tags for these patches?

Re: [PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[Dmitry Osipenko]

17.07.2019 23:08, Stephen Boyd пишет:
> Quoting Dmitry Osipenko (2019-07-15 10:35:26)
>> Unset "enable" bit means that divider is in bypass mode, hence it doesn't
>> have any effect in that case.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> 
> Any Fixes tags for these patches?

I'm not aware of any actual bugs that this change fixes. Probably better
to just s/Fix/Add/ in the commit's title?

Re: [PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[Stephen Boyd]

Quoting Dmitry Osipenko (2019-07-17 14:33:36)
> 17.07.2019 23:08, Stephen Boyd пишет:
> > Quoting Dmitry Osipenko (2019-07-15 10:35:26)
> >> Unset "enable" bit means that divider is in bypass mode, hence it doesn't
> >> have any effect in that case.
> >>
> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> > 
> > Any Fixes tags for these patches?
> 
> I'm not aware of any actual bugs that this change fixes. Probably better
> to just s/Fix/Add/ in the commit's title?

Sounds fine to me.

Re: [PATCH v1 1/2] clk: tegra: divider: Fix missing check for enable-bit on rate's recalculation

[Dmitry Osipenko]

23.07.2019 0:55, Stephen Boyd пишет:
> Quoting Dmitry Osipenko (2019-07-17 14:33:36)
>> 17.07.2019 23:08, Stephen Boyd пишет:
>>> Quoting Dmitry Osipenko (2019-07-15 10:35:26)
>>>> Unset "enable" bit means that divider is in bypass mode, hence it doesn't
>>>> have any effect in that case.
>>>>
>>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>>>
>>> Any Fixes tags for these patches?
>>
>> I'm not aware of any actual bugs that this change fixes. Probably better
>> to just s/Fix/Add/ in the commit's title?
> 
> Sounds fine to me.
> 

Okay, I'll re-spin these patches.