i2c: riic: Use predefined macro and simplify clock tick calculation

Replace the hardcoded `1000000000` with the predefined `NSEC_PER_SEC`
macro for clarity. Simplify the code by introducing a `ns_per_tick`
variable to store `NSEC_PER_SEC / 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>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index d1768b38b12dc2f619ab763c160b7a0b122a11af..aa3e4f430b113061b7f048569fbb136c1d4d1779 100644 (file)
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -46,6 +46,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
+#include <linux/time.h>
 
 #define ICCR1_ICE      BIT(7)
 #define ICCR1_IICRST   BIT(6)
@@ -313,6 +314,7 @@ 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;
@@ -376,8 +378,9 @@ 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 = NSEC_PER_SEC / 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)
@@ -387,8 +390,7 @@ 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)