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 <[email protected]> --- 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
