clocksource/drivers/npcm: Fix GENMASK and timer operation

NPCM7XX_Tx_OPER GENMASK bits are wrong, fix them.

Hopefully the NPCM7XX_REG_TICR0 register reset value of those bits was 0,
so it did not cause an issue.

The function npcm7xx_timer_oneshot() reads the register
NPCM7XX_REG_TCSR0, modifies it and then reads it again overwriting the
previous changes. Remove the extra read which is pointless.

The function npcm7xx_timer_periodic() is correct but the code writes
to the NPCM7XX_REG_TICR0 register while it is dealing with the
NPCM7XX_REG_TCSR0 register, that is confusing. Separate the write to
the registers in the code for the sake of clarity.

Fixes: 1c00289ecd12 ("clocksource/drivers/npcm: Add NPCM7xx timer driver")
Signed-off-by: Avi Fishman <avifishman70@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

diff --git a/drivers/clocksource/timer-npcm7xx.c b/drivers/clocksource/timer-npcm7xx.c
index 8a30da7f083b09ad2d5d15a338853a0a8bc23662..9780ffd8010e686697a57eded89aa2d1d02d826c 100644 (file)
--- a/drivers/clocksource/timer-npcm7xx.c
+++ b/drivers/clocksource/timer-npcm7xx.c
@@ -32,7 +32,7 @@
 #define NPCM7XX_Tx_INTEN               BIT(29)
 #define NPCM7XX_Tx_COUNTEN             BIT(30)
 #define NPCM7XX_Tx_ONESHOT             0x0
-#define NPCM7XX_Tx_OPER                        GENMASK(27, 3)
+#define NPCM7XX_Tx_OPER                        GENMASK(28, 27)
 #define NPCM7XX_Tx_MIN_PRESCALE                0x1
 #define NPCM7XX_Tx_TDR_MASK_BITS       24
 #define NPCM7XX_Tx_MAX_CNT             0xFFFFFF
@@ -84,8 +84,6 @@ static int npcm7xx_timer_oneshot(struct clock_event_device *evt)
 
        val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
        val &= ~NPCM7XX_Tx_OPER;
-
-       val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
        val |= NPCM7XX_START_ONESHOT_Tx;
        writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
 
@@ -97,12 +95,11 @@ static int npcm7xx_timer_periodic(struct clock_event_device *evt)
        struct timer_of *to = to_timer_of(evt);
        u32 val;
 
+       writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
+
        val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
        val &= ~NPCM7XX_Tx_OPER;
-
-       writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
        val |= NPCM7XX_START_PERIODIC_Tx;
-
        writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
 
        return 0;