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clocksource/drivers/timer-ti-dm: Simplify register writes with dmtime…
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…r_write()

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>
Reviewed-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Link: https://lore.kernel.org/r/20220815131250.34603-4-tony@atomide.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
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Tony Lindgren authored and Daniel Lezcano committed Sep 20, 2022
1 parent 90c9aad commit 49cd16b
Showing 1 changed file with 44 additions and 54 deletions.
98 changes: 44 additions & 54 deletions drivers/clocksource/timer-ti-dm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand All @@ -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
Expand All @@ -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)
Expand Down Expand Up @@ -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);
Expand All @@ -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;

Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down

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