| Message ID | 20190608180626.30589-4-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pwm-meson: cleanups and improvements | expand |
On Sat, Jun 08, 2019 at 08:06:15PM +0200, Martin Blumenstingl wrote: > meson_pwm_calc() ensures that "lo" is always less than 16 bits wide > (otherwise it would overflow into the "hi" part of the REG_PWM_{A,B} > register). > Use GENMASK and FIELD_PREP for the lo and hi values to make it easier to > spot how wide these are internally. Additionally this is a preparation > step for the .get_state() implementation where the GENMASK() for lo and > hi becomes handy because it can be used with FIELD_GET() to extract the > values from the register REG_PWM_{A,B} register. > > No functional changes intended. > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> > Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Best regards Uwe
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index 35b38c7201c3..c62a3ac924d0 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -5,6 +5,8 @@ * Copyright (C) 2014 Amlogic, Inc. */ +#include <linux/bitfield.h> +#include <linux/bits.h> #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/err.h> @@ -20,7 +22,8 @@ #define REG_PWM_A 0x0 #define REG_PWM_B 0x4 -#define PWM_HIGH_SHIFT 16 +#define PWM_LOW_MASK GENMASK(15, 0) +#define PWM_HIGH_MASK GENMASK(31, 16) #define REG_MISC_AB 0x8 #define MISC_B_CLK_EN BIT(23) @@ -217,7 +220,8 @@ static void meson_pwm_enable(struct meson_pwm *meson, struct pwm_device *pwm) value |= clk_enable; writel(value, meson->base + REG_MISC_AB); - value = (channel->hi << PWM_HIGH_SHIFT) | channel->lo; + value = FIELD_PREP(PWM_HIGH_MASK, channel->hi) | + FIELD_PREP(PWM_LOW_MASK, channel->lo); writel(value, meson->base + offset); value = readl(meson->base + REG_MISC_AB);
meson_pwm_calc() ensures that "lo" is always less than 16 bits wide (otherwise it would overflow into the "hi" part of the REG_PWM_{A,B} register). Use GENMASK and FIELD_PREP for the lo and hi values to make it easier to spot how wide these are internally. Additionally this is a preparation step for the .get_state() implementation where the GENMASK() for lo and hi becomes handy because it can be used with FIELD_GET() to extract the values from the register REG_PWM_{A,B} register. No functional changes intended. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> --- drivers/pwm/pwm-meson.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)