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From:   Tony Lindgren <tony@atomide.com>
To:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     Aaro Koskinen <aaro.koskinen@iki.fi>,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Janusz Krzysztofik <jmkrzyszt@gmail.com>,
        Keerthy <j-keerthy@ti.com>,
        Ladislav Michl <ladis@linux-mips.org>,
        Nishanth Menon <nm@ti.com>, Suman Anna <s-anna@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/9] clocksource/drivers/timer-ti-dm: Simplify register writes with dmtimer_write()
Date:   Mon, 15 Aug 2022 16:12:44 +0300
Message-Id: <20220815131250.34603-4-tony@atomide.com>
In-Reply-To: <20220815131250.34603-1-tony@atomide.com>
References: <20220815131250.34603-1-tony@atomide.com>
MIME-Version: 1.0
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We can simplify register write access by checking for the register write
posted mode in the write function. This way we can combine the functions
for __omap_dm_timer_write() and omap_dm_timer_write_reg() into a single
function dmtimer_write().

We update the shared register access first, the timer revision specific
register access will be updated in a later patch.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/clocksource/timer-ti-dm.c | 98 ++++++++++++++-----------------
 1 file changed, 44 insertions(+), 54 deletions(-)

diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -68,14 +68,29 @@ static inline u32 dmtimer_read(struct omap_dm_timer *timer, u32 reg)
 	return readl_relaxed(timer->func_base + offset);
 }
 
-static inline void __omap_dm_timer_write(struct omap_dm_timer *timer,
-					u32 reg, u32 val, int posted)
+/**
+ * dmtimer_write - write timer registers in posted and non-posted mode
+ * @timer:      timer pointer over which write operation is to perform
+ * @reg:        lowest byte holds the register offset
+ * @value:      data to write into the register
+ *
+ * The posted mode bit is encoded in reg. Note that in posted mode, the write
+ * pending bit must be checked. Otherwise a write on a register which has a
+ * pending write will be lost.
+ */
+static inline void dmtimer_write(struct omap_dm_timer *timer, u32 reg, u32 val)
 {
-	if (posted)
-		while (readl_relaxed(timer->pend) & (reg >> WPSHIFT))
+	u16 wp, offset;
+
+	wp = reg >> WPSHIFT;
+	offset = reg & 0xff;
+
+	/* Wait for a possible write pending bit in posted mode */
+	if (wp && timer->posted)
+		while (readl_relaxed(timer->pend) & wp)
 			cpu_relax();
 
-	writel_relaxed(val, timer->func_base + (reg & 0xff));
+	writel_relaxed(val, timer->func_base + offset);
 }
 
 static inline void __omap_dm_timer_init_regs(struct omap_dm_timer *timer)
@@ -120,25 +135,24 @@ static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer)
 
 	if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) {
 		timer->posted = OMAP_TIMER_NONPOSTED;
-		__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0);
+		dmtimer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0);
 		return;
 	}
 
-	__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG,
-			      OMAP_TIMER_CTRL_POSTED, 0);
+	dmtimer_write(timer, OMAP_TIMER_IF_CTRL_REG, OMAP_TIMER_CTRL_POSTED);
 	timer->context.tsicr = OMAP_TIMER_CTRL_POSTED;
 	timer->posted = OMAP_TIMER_POSTED;
 }
 
 static inline void __omap_dm_timer_stop(struct omap_dm_timer *timer,
-					int posted, unsigned long rate)
+					unsigned long rate)
 {
 	u32 l;
 
 	l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG);
 	if (l & OMAP_TIMER_CTRL_ST) {
 		l &= ~0x1;
-		__omap_dm_timer_write(timer, OMAP_TIMER_CTRL_REG, l, posted);
+		dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l);
 #ifdef CONFIG_ARCH_OMAP2PLUS
 		/* Readback to make sure write has completed */
 		dmtimer_read(timer, OMAP_TIMER_CTRL_REG);
@@ -158,7 +172,7 @@ static inline void __omap_dm_timer_int_enable(struct omap_dm_timer *timer,
 						unsigned int value)
 {
 	writel_relaxed(value, timer->irq_ena);
-	__omap_dm_timer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value, 0);
+	dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value);
 }
 
 static inline unsigned int
@@ -173,41 +187,17 @@ static inline void __omap_dm_timer_write_status(struct omap_dm_timer *timer,
 	writel_relaxed(value, timer->irq_stat);
 }
 
-/**
- * omap_dm_timer_write_reg - write timer registers in posted and non-posted mode
- * @timer:      timer pointer over which write operation is to perform
- * @reg:        lowest byte holds the register offset
- * @value:      data to write into the register
- *
- * The posted mode bit is encoded in reg. Note that in posted mode the write
- * pending bit must be checked. Otherwise a write on a register which has a
- * pending write will be lost.
- */
-static void omap_dm_timer_write_reg(struct omap_dm_timer *timer, u32 reg,
-						u32 value)
-{
-	WARN_ON((reg & 0xff) < _OMAP_TIMER_WAKEUP_EN_OFFSET);
-	__omap_dm_timer_write(timer, reg, value, timer->posted);
-}
-
 static void omap_timer_restore_context(struct omap_dm_timer *timer)
 {
-	__omap_dm_timer_write(timer, OMAP_TIMER_OCP_CFG_OFFSET,
-			      timer->context.ocp_cfg, 0);
-
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_WAKEUP_EN_REG,
-				timer->context.twer);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG,
-				timer->context.tcrr);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG,
-				timer->context.tldr);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG,
-				timer->context.tmar);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG,
-				timer->context.tsicr);
+	dmtimer_write(timer, OMAP_TIMER_OCP_CFG_OFFSET, timer->context.ocp_cfg);
+
+	dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, timer->context.twer);
+	dmtimer_write(timer, OMAP_TIMER_COUNTER_REG, timer->context.tcrr);
+	dmtimer_write(timer, OMAP_TIMER_LOAD_REG, timer->context.tldr);
+	dmtimer_write(timer, OMAP_TIMER_MATCH_REG, timer->context.tmar);
+	dmtimer_write(timer, OMAP_TIMER_IF_CTRL_REG, timer->context.tsicr);
 	writel_relaxed(timer->context.tier, timer->irq_ena);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG,
-				timer->context.tclr);
+	dmtimer_write(timer, OMAP_TIMER_CTRL_REG, timer->context.tclr);
 }
 
 static void omap_timer_save_context(struct omap_dm_timer *timer)
@@ -256,7 +246,7 @@ static int omap_dm_timer_reset(struct omap_dm_timer *timer)
 	if (timer->revision != 1)
 		return -EINVAL;
 
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG, 0x06);
+	dmtimer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0x06);
 
 	do {
 		l = dmtimer_read(timer, OMAP_TIMER_V1_SYS_STAT_OFFSET);
@@ -270,7 +260,7 @@ static int omap_dm_timer_reset(struct omap_dm_timer *timer)
 	/* Configure timer for smart-idle mode */
 	l = dmtimer_read(timer, OMAP_TIMER_OCP_CFG_OFFSET);
 	l |= 0x2 << 0x3;
-	__omap_dm_timer_write(timer, OMAP_TIMER_OCP_CFG_OFFSET, l, 0);
+	dmtimer_write(timer, OMAP_TIMER_OCP_CFG_OFFSET, l);
 
 	timer->posted = 0;
 
@@ -586,7 +576,7 @@ static int omap_dm_timer_start(struct omap_dm_timer *timer)
 	l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG);
 	if (!(l & OMAP_TIMER_CTRL_ST)) {
 		l |= OMAP_TIMER_CTRL_ST;
-		omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+		dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l);
 	}
 
 	return 0;
@@ -602,7 +592,7 @@ static int omap_dm_timer_stop(struct omap_dm_timer *timer)
 	if (!(timer->capability & OMAP_TIMER_NEEDS_RESET))
 		rate = clk_get_rate(timer->fclk);
 
-	__omap_dm_timer_stop(timer, timer->posted, rate);
+	__omap_dm_timer_stop(timer, rate);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -615,7 +605,7 @@ static int omap_dm_timer_set_load(struct omap_dm_timer *timer,
 		return -EINVAL;
 
 	omap_dm_timer_enable(timer);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG, load);
+	dmtimer_write(timer, OMAP_TIMER_LOAD_REG, load);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -635,8 +625,8 @@ static int omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable,
 		l |= OMAP_TIMER_CTRL_CE;
 	else
 		l &= ~OMAP_TIMER_CTRL_CE;
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG, match);
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+	dmtimer_write(timer, OMAP_TIMER_MATCH_REG, match);
+	dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -661,7 +651,7 @@ static int omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on,
 	l |= trigger << 10;
 	if (autoreload)
 		l |= OMAP_TIMER_CTRL_AR;
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+	dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -696,7 +686,7 @@ static int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer,
 		l |= OMAP_TIMER_CTRL_PRE;
 		l |= prescaler << 2;
 	}
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+	dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -736,7 +726,7 @@ static int omap_dm_timer_set_int_disable(struct omap_dm_timer *timer, u32 mask)
 
 	writel_relaxed(l, timer->irq_dis);
 	l = dmtimer_read(timer, OMAP_TIMER_WAKEUP_EN_REG) & ~mask;
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_WAKEUP_EN_REG, l);
+	dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, l);
 
 	omap_dm_timer_disable(timer);
 	return 0;
@@ -783,7 +773,7 @@ static int omap_dm_timer_write_counter(struct omap_dm_timer *timer, unsigned int
 		return -EINVAL;
 	}
 
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG, value);
+	dmtimer_write(timer, OMAP_TIMER_COUNTER_REG, value);
 
 	/* Save the context */
 	timer->context.tcrr = value;
-- 
2.37.1