summaryrefslogtreecommitdiffstats
path: root/drivers/clocksource/timer-imx-tpm.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clocksource/timer-imx-tpm.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clocksource/timer-imx-tpm.c')
-rw-r--r--drivers/clocksource/timer-imx-tpm.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-imx-tpm.c b/drivers/clocksource/timer-imx-tpm.c
new file mode 100644
index 000000000..bd64a8a84
--- /dev/null
+++ b/drivers/clocksource/timer-imx-tpm.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright 2016 Freescale Semiconductor, Inc.
+// Copyright 2017 NXP
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/sched_clock.h>
+
+#include "timer-of.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
+#define TPM_STATUS 0x1c
+#define TPM_STATUS_CH0F BIT(0)
+#define TPM_C0SC 0x20
+#define TPM_C0SC_CHIE BIT(6)
+#define TPM_C0SC_MODE_SHIFT 2
+#define TPM_C0SC_MODE_MASK 0x3c
+#define TPM_C0SC_MODE_SW_COMPARE 0x4
+#define TPM_C0SC_CHF_MASK (0x1 << 7)
+#define TPM_C0V 0x24
+
+static int counter_width __ro_after_init;
+static void __iomem *timer_base __ro_after_init;
+
+static inline void tpm_timer_disable(void)
+{
+ unsigned int val;
+
+ /* channel disable */
+ val = readl(timer_base + TPM_C0SC);
+ val &= ~(TPM_C0SC_MODE_MASK | TPM_C0SC_CHIE);
+ writel(val, timer_base + TPM_C0SC);
+}
+
+static inline void tpm_timer_enable(void)
+{
+ unsigned int val;
+
+ /* channel enabled in sw compare mode */
+ val = readl(timer_base + TPM_C0SC);
+ val |= (TPM_C0SC_MODE_SW_COMPARE << TPM_C0SC_MODE_SHIFT) |
+ TPM_C0SC_CHIE;
+ writel(val, timer_base + TPM_C0SC);
+}
+
+static inline void tpm_irq_acknowledge(void)
+{
+ writel(TPM_STATUS_CH0F, timer_base + TPM_STATUS);
+}
+
+static inline unsigned long tpm_read_counter(void)
+{
+ return readl(timer_base + TPM_CNT);
+}
+
+#if defined(CONFIG_ARM)
+static struct delay_timer tpm_delay_timer;
+
+static unsigned long tpm_read_current_timer(void)
+{
+ return tpm_read_counter();
+}
+
+static u64 notrace tpm_read_sched_clock(void)
+{
+ return tpm_read_counter();
+}
+#endif
+
+static int tpm_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned long next, now;
+
+ next = tpm_read_counter();
+ next += delta;
+ writel(next, timer_base + TPM_C0V);
+ now = tpm_read_counter();
+
+ /*
+ * NOTE: We observed in a very small probability, the bus fabric
+ * contention between GPU and A7 may results a few cycles delay
+ * of writing CNT registers which may cause the min_delta event got
+ * missed, so we need add a ETIME check here in case it happened.
+ */
+ return (int)(next - now) <= 0 ? -ETIME : 0;
+}
+
+static int tpm_set_state_oneshot(struct clock_event_device *evt)
+{
+ tpm_timer_enable();
+
+ return 0;
+}
+
+static int tpm_set_state_shutdown(struct clock_event_device *evt)
+{
+ tpm_timer_disable();
+
+ return 0;
+}
+
+static irqreturn_t tpm_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+
+ tpm_irq_acknowledge();
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct timer_of to_tpm = {
+ .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
+ .clkevt = {
+ .name = "i.MX TPM Timer",
+ .rating = 200,
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ,
+ .set_state_shutdown = tpm_set_state_shutdown,
+ .set_state_oneshot = tpm_set_state_oneshot,
+ .set_next_event = tpm_set_next_event,
+ .cpumask = cpu_possible_mask,
+ },
+ .of_irq = {
+ .handler = tpm_timer_interrupt,
+ .flags = IRQF_TIMER,
+ },
+ .of_clk = {
+ .name = "per",
+ },
+};
+
+static int __init tpm_clocksource_init(void)
+{
+#if defined(CONFIG_ARM)
+ tpm_delay_timer.read_current_timer = &tpm_read_current_timer;
+ tpm_delay_timer.freq = timer_of_rate(&to_tpm) >> 3;
+ register_current_timer_delay(&tpm_delay_timer);
+
+ sched_clock_register(tpm_read_sched_clock, counter_width,
+ timer_of_rate(&to_tpm) >> 3);
+#endif
+
+ return clocksource_mmio_init(timer_base + TPM_CNT,
+ "imx-tpm",
+ timer_of_rate(&to_tpm) >> 3,
+ to_tpm.clkevt.rating,
+ counter_width,
+ clocksource_mmio_readl_up);
+}
+
+static void __init tpm_clockevent_init(void)
+{
+ clockevents_config_and_register(&to_tpm.clkevt,
+ timer_of_rate(&to_tpm) >> 3,
+ 300,
+ GENMASK(counter_width - 1,
+ 1));
+}
+
+static int __init tpm_timer_init(struct device_node *np)
+{
+ struct clk *ipg;
+ int ret;
+
+ ipg = of_clk_get_by_name(np, "ipg");
+ if (IS_ERR(ipg)) {
+ pr_err("tpm: failed to get ipg clk\n");
+ return -ENODEV;
+ }
+ /* enable clk before accessing registers */
+ ret = clk_prepare_enable(ipg);
+ if (ret) {
+ pr_err("tpm: ipg clock enable failed (%d)\n", ret);
+ clk_put(ipg);
+ return ret;
+ }
+
+ ret = timer_of_init(np, &to_tpm);
+ if (ret)
+ return ret;
+
+ timer_base = timer_of_base(&to_tpm);
+
+ 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 */
+ to_tpm.clkevt.rating = counter_width == 0x20 ? 200 : 150;
+
+ /*
+ * Initialize tpm module to a known state
+ * 1) Counter disabled
+ * 2) TPM counter operates in up counting mode
+ * 3) Timer Overflow Interrupt disabled
+ * 4) Channel0 disabled
+ * 5) DMA transfers disabled
+ */
+ /* make sure counter is disabled */
+ writel(0, timer_base + TPM_SC);
+ /* TOF is W1C */
+ writel(TPM_SC_TOF_MASK, timer_base + TPM_SC);
+ writel(0, timer_base + TPM_CNT);
+ /* CHF is W1C */
+ writel(TPM_C0SC_CHF_MASK, timer_base + TPM_C0SC);
+
+ /*
+ * 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(GENMASK(counter_width - 1, 0), timer_base + TPM_MOD);
+
+ tpm_clockevent_init();
+
+ return tpm_clocksource_init();
+}
+TIMER_OF_DECLARE(imx7ulp, "fsl,imx7ulp-tpm", tpm_timer_init);