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Subject[PATCH 2/2] clocksource/drivers/imx-tpm: add different counter width support
Date
Different TPM modules have different width counters which
is 16-bit or 32-bit, the counter width can be read from
TPM_PARAM register bit[23:16], this patch adds dynamic
check for counter width to support both 16-bit and 32-bit
TPM modules.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
drivers/clocksource/timer-imx-tpm.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/timer-imx-tpm.c b/drivers/clocksource/timer-imx-tpm.c
index 7403e49..5063b77 100644
--- a/drivers/clocksource/timer-imx-tpm.c
+++ b/drivers/clocksource/timer-imx-tpm.c
@@ -17,6 +17,9 @@
#include <linux/of_irq.h>
#include <linux/sched_clock.h>

+#define TPM_PARAM 0x4
+#define TPM_PARAM_WIDTH_SHIFT 16
+#define TPM_PARAM_WIDTH_MASK (0xff << 16)
#define TPM_SC 0x10
#define TPM_SC_CMOD_INC_PER_CNT (0x1 << 3)
#define TPM_SC_CMOD_DIV_DEFAULT 0x3
@@ -33,6 +36,7 @@
#define TPM_C0SC_CHF_MASK (0x1 << 7)
#define TPM_C0V 0x24

+static int counter_width;
static void __iomem *timer_base;
static struct clock_event_device clockevent_tpm;

@@ -66,7 +70,7 @@ static struct delay_timer tpm_delay_timer;

static inline unsigned long tpm_read_counter(void)
{
- return readl(timer_base + TPM_CNT);
+ return readl(timer_base + TPM_CNT) & GENMASK(counter_width - 1, 0);
}

static unsigned long tpm_read_current_timer(void)
@@ -85,10 +89,11 @@ static int __init tpm_clocksource_init(unsigned long rate)
tpm_delay_timer.freq = rate;
register_current_timer_delay(&tpm_delay_timer);

- sched_clock_register(tpm_read_sched_clock, 32, rate);
+ sched_clock_register(tpm_read_sched_clock, counter_width, rate);

return clocksource_mmio_init(timer_base + TPM_CNT, "imx-tpm",
- rate, 200, 32, clocksource_mmio_readl_up);
+ rate, 200, counter_width,
+ clocksource_mmio_readl_up);
}

static int tpm_set_next_event(unsigned long delta,
@@ -153,8 +158,8 @@ static int __init tpm_clockevent_init(unsigned long rate, int irq)

clockevent_tpm.cpumask = cpumask_of(0);
clockevent_tpm.irq = irq;
- clockevents_config_and_register(&clockevent_tpm,
- rate, 300, 0xfffffffe);
+ clockevents_config_and_register(&clockevent_tpm, rate, 300,
+ GENMASK(counter_width - 1, 1));

return ret;
}
@@ -199,6 +204,8 @@ static int __init tpm_timer_init(struct device_node *np)
goto err_per_clk_enable;
}

+ counter_width = (readl(timer_base + TPM_PARAM) & TPM_PARAM_WIDTH_MASK)
+ >> TPM_PARAM_WIDTH_SHIFT;
/*
* Initialize tpm module to a known state
* 1) Counter disabled
@@ -220,7 +227,7 @@ static int __init tpm_timer_init(struct device_node *np)
timer_base + TPM_SC);

/* set MOD register to maximum for free running mode */
- writel(0xffffffff, timer_base + TPM_MOD);
+ writel(GENMASK(counter_width - 1, 0), timer_base + TPM_MOD);

rate = clk_get_rate(per) >> 3;
ret = tpm_clocksource_init(rate);
--
2.7.4
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