clocksource/drivers/imx-tpm: Add different counter width support

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>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 25 insertions, 8 deletions

diff --git a/drivers/clocksource/timer-imx-tpm.c b/drivers/clocksource/timer-imx-tpm.c
index 7403e494417a..05d97a6871d8 100644
--- a/drivers/clocksource/timer-imx-tpm.c
+++ b/drivers/clocksource/timer-imx-tpm.c
@@ -17,9 +17,13 @@
 #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
+#define TPM_SC_CMOD_DIV_MAX             0x7
 #define TPM_SC_TOF_MASK                 (0x1 << 7)
 #define TPM_CNT                         0x14
 #define TPM_MOD                         0x18
@@ -33,6 +37,8 @@
 #define TPM_C0SC_CHF_MASK               (0x1 << 7)
 #define TPM_C0V                         0x24
 
+static int counter_width;
+static int rating;
 static void __iomem *timer_base;
 static struct clock_event_device clockevent_tpm;
 
@@ -85,10 +91,11 @@ 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, rating, counter_width,
+                                     clocksource_mmio_readl_up);
 }
 
 static int tpm_set_next_event(unsigned long delta,
@@ -141,7 +148,6 @@ static struct clock_event_device clockevent_tpm = {
         .set_state_oneshot      = tpm_set_state_oneshot,
         .set_next_event         = tpm_set_next_event,
         .set_state_shutdown     = tpm_set_state_shutdown,
-        .rating                 = 200,
 };
 
 static int __init tpm_clockevent_init(unsigned long rate, int irq)
@@ -151,10 +157,11 @@ static int __init tpm_clockevent_init(unsigned long rate, int irq)
         ret = request_irq(irq, tpm_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
                           "i.MX7ULP TPM Timer", &clockevent_tpm);
 
+        clockevent_tpm.rating = rating;
         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 +206,11 @@ 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;
+        /* use rating 200 for 32-bit counter and 150 for 16-bit counter */
+        rating = counter_width == 0x20 ? 200 : 150;
+
         /*
          * Initialize tpm module to a known state
          * 1) Counter disabled
@@ -215,12 +227,17 @@ static int __init tpm_timer_init(struct device_node *np)
         /* CHF is W1C */
         writel(TPM_C0SC_CHF_MASK, timer_base + TPM_C0SC);
 
-        /* increase per cnt, div 8 by default */
-        writel(TPM_SC_CMOD_INC_PER_CNT | TPM_SC_CMOD_DIV_DEFAULT,
+        /*
+         * increase per cnt,
+         * div 8 for 32-bit counter and div 128 for 16-bit counter
+         */
+        writel(TPM_SC_CMOD_INC_PER_CNT |
+                (counter_width == 0x20 ?
+                TPM_SC_CMOD_DIV_DEFAULT : TPM_SC_CMOD_DIV_MAX),
                      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);