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[2a01:c23:c5cc:b000::e63]) by smtp.googlemail.com with ESMTPSA id d33-20020a05600c4c2100b004129f87a2c6sm757065wmp.1.2024.02.24.13.35.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 24 Feb 2024 13:35:41 -0800 (PST) From: Martin Blumenstingl To: daniel.lezcano@linaro.org, tglx@linutronix.de Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, patrice.chotard@foss.st.com, linux-amlogic@lists.infradead.org, Martin Blumenstingl Subject: [PATCH v2] clocksource/drivers/arm_global_timer: Simplify prescaler register access Date: Sat, 24 Feb 2024 22:35:29 +0100 Message-ID: <20240224213529.2601333-1-martin.blumenstingl@googlemail.com> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Use GENMASK() to define the prescaler mask and make the whole driver use the mask (together with helpers such as FIELD_{GET,PREP,FIT}) instead of needing an additional shift and max value constant. Signed-off-by: Martin Blumenstingl --- Changes from v1 at [0]: - use FIELD_FIT() to check whether psv overflows the register - update the description accordingly [0] https://lore.kernel.org/lkml/20240221214348.2299636-1-martin.blumenstin= gl@googlemail.com/ drivers/clocksource/arm_global_timer.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/a= rm_global_timer.c index 8dd1e46b7176..49b094a20717 100644 --- a/drivers/clocksource/arm_global_timer.c +++ b/drivers/clocksource/arm_global_timer.c @@ -9,6 +9,7 @@ =20 #include #include +#include #include #include #include @@ -31,10 +32,7 @@ #define GT_CONTROL_COMP_ENABLE BIT(1) /* banked */ #define GT_CONTROL_IRQ_ENABLE BIT(2) /* banked */ #define GT_CONTROL_AUTO_INC BIT(3) /* banked */ -#define GT_CONTROL_PRESCALER_SHIFT 8 -#define GT_CONTROL_PRESCALER_MAX 0xFF -#define GT_CONTROL_PRESCALER_MASK (GT_CONTROL_PRESCALER_MAX << \ - GT_CONTROL_PRESCALER_SHIFT) +#define GT_CONTROL_PRESCALER_MASK GENMASK(15, 8) =20 #define GT_INT_STATUS 0x0c #define GT_INT_STATUS_EVENT_FLAG BIT(0) @@ -247,7 +245,7 @@ static void gt_write_presc(u32 psv) =20 reg =3D readl(gt_base + GT_CONTROL); reg &=3D ~GT_CONTROL_PRESCALER_MASK; - reg |=3D psv << GT_CONTROL_PRESCALER_SHIFT; + reg |=3D FIELD_PREP(GT_CONTROL_PRESCALER_MASK, psv); writel(reg, gt_base + GT_CONTROL); } =20 @@ -256,8 +254,7 @@ static u32 gt_read_presc(void) u32 reg; =20 reg =3D readl(gt_base + GT_CONTROL); - reg &=3D GT_CONTROL_PRESCALER_MASK; - return reg >> GT_CONTROL_PRESCALER_SHIFT; + return FIELD_GET(GT_CONTROL_PRESCALER_MASK, reg); } =20 static void __init gt_delay_timer_init(void) @@ -272,9 +269,9 @@ static int __init gt_clocksource_init(void) writel(0, gt_base + GT_COUNTER0); writel(0, gt_base + GT_COUNTER1); /* set prescaler and enable timer on all the cores */ - writel(((CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) << - GT_CONTROL_PRESCALER_SHIFT) - | GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL); + writel(FIELD_PREP(GT_CONTROL_PRESCALER_MASK, + CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) | + GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL); =20 #ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK sched_clock_register(gt_sched_clock_read, 64, gt_target_rate); @@ -301,7 +298,7 @@ static int gt_clk_rate_change_cb(struct notifier_block = *nb, psv--; =20 /* prescaler within legal range? */ - if (psv < 0 || psv > GT_CONTROL_PRESCALER_MAX) + if (psv < 0 || !FIELD_FIT(GT_CONTROL_PRESCALER_MASK, psv)) return NOTIFY_BAD; =20 /* --=20 2.44.0