[PATCH 2/8] pwm: mediatek: Introduce and use a few more register defines

[Uwe Kleine-König]

Instead of using a magic constant for bound checking, derive the numbers
from appropriate register defines.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at baylibre.com>
---
 drivers/pwm/pwm-mediatek.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index a816f136f39d..4e2a27b02c80 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -7,6 +7,7 @@
  *
  */
 
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
@@ -21,19 +22,19 @@
 
 /* PWM registers and bits definitions */
 #define PWMCON			0x00
+#define PWMCON_CLKDIV			GENMASK(2, 0)
 #define PWMHDUR			0x04
 #define PWMLDUR			0x08
 #define PWMGDUR			0x0c
 #define PWMWAVENUM		0x28
 #define PWMDWIDTH		0x2c
+#define PWMDWIDTH_PERIOD		GENMASK(12, 0)
 #define PWM45DWIDTH_FIXUP	0x30
 #define PWMTHRES		0x30
 #define PWM45THRES_FIXUP	0x34
 #define PWM_CK_26M_SEL_V3	0x74
 #define PWM_CK_26M_SEL		0x210
 
-#define PWM_CLK_DIV_MAX		7
-
 struct pwm_mediatek_of_data {
 	unsigned int num_pwms;
 	bool pwm45_fixup;
@@ -139,14 +140,14 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	do_div(resolution, clk_rate);
 
 	cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
-	while (cnt_period > 8191) {
+	while (cnt_period > FIELD_MAX(PWMDWIDTH_PERIOD)) {
 		resolution *= 2;
 		clkdiv++;
 		cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
 						   resolution);
 	}
 
-	if (clkdiv > PWM_CLK_DIV_MAX) {
+	if (clkdiv > FIELD_MAX(PWMCON_CLKDIV)) {
 		dev_err(pwmchip_parent(chip), "period of %d ns not supported\n", period_ns);
 		ret = -EINVAL;
 		goto out;
-- 
2.49.0