[PATCH 3/9] clocksource/drivers/timer-ti-dm: Simplify register writes with dmtimer_write()

From: Tony Lindgren
Date: Mon Aug 15 2022 - 09:13:42 EST

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@xxxxxxxxxxx>
---
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