Commit 181164b6 authored Jun 12, 2019 by Martin Blumenstingl Committed by Thierry Reding Jun 26, 2019

pwm: meson: Use GENMASK and FIELD_PREP for the lo and hi values



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.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

parent ba4004c7

drivers/pwm/pwm-meson.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -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);