diff mbox series

[v3,7/8] i2c: riic: Use predefined macro and simplify clock tick calculation

Message ID 20241227115154.56154-8-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State New
Delegated to: Geert Uytterhoeven
Headers show
Series i2c: riic: driver cleanup and improvements | expand

Commit Message

Lad, Prabhakar Dec. 27, 2024, 11:51 a.m. UTC 
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Replace the hardcoded `1000000000` with the predefined `NANO` macro for
clarity. Simplify the code by introducing a `ns_per_tick` variable to
store `NANO / rate`, reducing redundancy and improving readability.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
v2->v3
- Collected RB and tested tags

v1->v2
- Collected RB tag from Geert
---
 drivers/i2c/busses/i2c-riic.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Comments

Andy Shevchenko Dec. 28, 2024, 11:37 p.m. UTC | #1 
Fri, Dec 27, 2024 at 11:51:53AM +0000, Prabhakar kirjoitti:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Replace the hardcoded `1000000000` with the predefined `NANO` macro for
> clarity. Simplify the code by introducing a `ns_per_tick` variable to
> store `NANO / rate`, reducing redundancy and improving readability.

...

> -	brl -= t->scl_fall_ns / (1000000000 / rate);
> -	brh -= t->scl_rise_ns / (1000000000 / rate);
> +	ns_per_tick = NANO / rate;

So, why NANO and not NSEC_PER_SEC?

> +	brl -= t->scl_fall_ns / ns_per_tick;
> +	brh -= t->scl_rise_ns / ns_per_tick;
Lad, Prabhakar Jan. 2, 2025, 10:05 a.m. UTC | #2 
Hi Andy,

Thank you for the review.

On Sat, Dec 28, 2024 at 11:37 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> Fri, Dec 27, 2024 at 11:51:53AM +0000, Prabhakar kirjoitti:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Replace the hardcoded `1000000000` with the predefined `NANO` macro for
> > clarity. Simplify the code by introducing a `ns_per_tick` variable to
> > store `NANO / rate`, reducing redundancy and improving readability.
>
> ...
>
> > -     brl -= t->scl_fall_ns / (1000000000 / rate);
> > -     brh -= t->scl_rise_ns / (1000000000 / rate);
> > +     ns_per_tick = NANO / rate;
>
> So, why NANO and not NSEC_PER_SEC?
>
Agreed, I'll switch to NSEC_PER_SEC.

Cheers,
Prabhakar
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 378887b133a5..a2d0cde5ac54 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -45,6 +45,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
+#include <linux/units.h>
 
 #define ICCR1_ICE	BIT(7)
 #define ICCR1_IICRST	BIT(6)
@@ -312,6 +313,7 @@  static int riic_init_hw(struct riic_dev *riic)
 {
 	int ret;
 	unsigned long rate;
+	unsigned long ns_per_tick;
 	int total_ticks, cks, brl, brh;
 	struct i2c_timings *t = &riic->i2c_t;
 	struct device *dev = riic->adapter.dev.parent;
@@ -375,8 +377,9 @@  static int riic_init_hw(struct riic_dev *riic)
 	 * Remove clock ticks for rise and fall times. Convert ns to clock
 	 * ticks.
 	 */
-	brl -= t->scl_fall_ns / (1000000000 / rate);
-	brh -= t->scl_rise_ns / (1000000000 / rate);
+	ns_per_tick = NANO / rate;
+	brl -= t->scl_fall_ns / ns_per_tick;
+	brh -= t->scl_rise_ns / ns_per_tick;
 
 	/* Adjust for min register values for when SCLE=1 and NFE=1 */
 	if (brl < 1)
@@ -386,8 +389,7 @@  static int riic_init_hw(struct riic_dev *riic)
 
 	pr_debug("i2c-riic: freq=%lu, duty=%d, fall=%lu, rise=%lu, cks=%d, brl=%d, brh=%d\n",
 		 rate / total_ticks, ((brl + 3) * 100) / (brl + brh + 6),
-		 t->scl_fall_ns / (1000000000 / rate),
-		 t->scl_rise_ns / (1000000000 / rate), cks, brl, brh);
+		 t->scl_fall_ns / ns_per_tick, t->scl_rise_ns / ns_per_tick, cks, brl, brh);
 
 	ret = pm_runtime_resume_and_get(dev);
 	if (ret)