[PATCH v6 2/6] pwm: tiehrpwm: use GENMASK() and FIELD_PREP() for prescalers

From: Rafael V. Volkmer

Date: Sun Nov 23 2025 - 18:27:56 EST


Replace manual handling of CLKDIV and HSPCLKDIV with GENMASK() and
FIELD_PREP(). Introduce TBCTL_PRESCALE_MASK so both fields can be
updated in a single ehrpwm_modify() call, and drop the now-unused
TBCTL_*_SHIFT macros.

This improves readability and reduces the chance of off-by-shift errors.

No functional change.

Signed-off-by: Rafael V. Volkmer <rafael.v.volkmer@xxxxxxxxx>
---
drivers/pwm/pwm-tiehrpwm.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index d2151065083b..1ad8577139be 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -25,7 +25,9 @@
#define TBCTL_PRDLD_SHDW FIELD_PREP(TBCTL_PRDLD_MASK, 0)
#define TBCTL_PRDLD_IMDT FIELD_PREP(TBCTL_PRDLD_MASK, 1)

-#define TBCTL_CLKDIV_MASK GENMASK(12, 7)
+#define TBCTL_CLKDIV_MASK GENMASK(12, 10)
+#define TBCTL_HSPCLKDIV_MASK GENMASK(9, 7)
+#define TBCTL_PRESCALE_MASK (TBCTL_CLKDIV_MASK | TBCTL_HSPCLKDIV_MASK)

#define TBCTL_CTRMODE_MASK GENMASK(1, 0)
#define TBCTL_CTRMODE_UP FIELD_PREP(TBCTL_CTRMODE_MASK, 0)
@@ -33,9 +35,6 @@
#define TBCTL_CTRMODE_UPDOWN FIELD_PREP(TBCTL_CTRMODE_MASK, 2)
#define TBCTL_CTRMODE_FREEZE FIELD_PREP(TBCTL_CTRMODE_MASK, 3)

-#define TBCTL_HSPCLKDIV_SHIFT 7
-#define TBCTL_CLKDIV_SHIFT 10
-
#define CLKDIV_MAX 7
#define HSPCLKDIV_MAX 7
#define TBPRD_BITS 16
@@ -169,8 +168,8 @@ static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
*prescale_div = (1 << clkdiv) *
(hspclkdiv ? (hspclkdiv * 2) : 1);
if (*prescale_div >= rqst_prescaler) {
- *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
- (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
+ *tb_clk_div = FIELD_PREP(TBCTL_CLKDIV_MASK, clkdiv) |
+ FIELD_PREP(TBCTL_HSPCLKDIV_MASK, hspclkdiv);
return 0;
}
}
@@ -247,7 +246,7 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
pm_runtime_get_sync(pwmchip_parent(chip));

/* Update clock prescaler values */
- ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
+ ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRESCALE_MASK, tb_divval);

if (pwm->hwpwm == 1) {
/* Channel 1 configured with compare B register */
--
2.43.0