leds: renesas-tpu: Improve the readability to pick the lowest acceptable rate
I spent a few minutes to understand why the code catching the mismatch case
by checking if k is 0 or not. And the code using "k - 1" as array index is
unusual.
This patch checks acceptable rate from the lowest rate, and then we don't need
to subtract k by 1. This change improves the readability.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/leds-renesas-tpu.c b/drivers/leds/leds-renesas-tpu.c
index e0fff1c..d3c2b7e 100644
--- a/drivers/leds/leds-renesas-tpu.c
+++ b/drivers/leds/leds-renesas-tpu.c
@@ -133,24 +133,24 @@
rate = clk_get_rate(p->clk);
/* pick the lowest acceptable rate */
- for (k = 0; k < ARRAY_SIZE(prescaler); k++)
- if ((rate / prescaler[k]) < p->min_rate)
+ for (k = ARRAY_SIZE(prescaler) - 1; k >= 0; k--)
+ if ((rate / prescaler[k]) >= p->min_rate)
break;
- if (!k) {
+ if (k < 0) {
dev_err(&p->pdev->dev, "clock rate mismatch\n");
goto err0;
}
dev_dbg(&p->pdev->dev, "rate = %lu, prescaler %u\n",
- rate, prescaler[k - 1]);
+ rate, prescaler[k]);
/* clear TCNT on TGRB match, count on rising edge, set prescaler */
- r_tpu_write(p, TCR, 0x0040 | (k - 1));
+ r_tpu_write(p, TCR, 0x0040 | k);
/* output 0 until TGRA, output 1 until TGRB */
r_tpu_write(p, TIOR, 0x0002);
- rate /= prescaler[k - 1] * p->refresh_rate;
+ rate /= prescaler[k] * p->refresh_rate;
r_tpu_write(p, TGRB, rate);
dev_dbg(&p->pdev->dev, "TRGB = 0x%04lx\n", rate);