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path: root/drivers/clocksource/timer-meson6.c
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-rw-r--r--drivers/clocksource/timer-meson6.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-meson6.c b/drivers/clocksource/timer-meson6.c
new file mode 100644
index 000000000000..84bd9479c3f8
--- /dev/null
+++ b/drivers/clocksource/timer-meson6.c
@@ -0,0 +1,220 @@
+/*
+ * Amlogic Meson6 SoCs timer handling.
+ *
+ * Copyright (C) 2014 Carlo Caione <carlo@caione.org>
+ *
+ * Based on code from Amlogic, Inc
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/sched_clock.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#ifdef CONFIG_ARM
+#include <linux/delay.h>
+#endif
+
+#define MESON_ISA_TIMER_MUX 0x00
+#define MESON_ISA_TIMER_MUX_TIMERD_EN BIT(19)
+#define MESON_ISA_TIMER_MUX_TIMERC_EN BIT(18)
+#define MESON_ISA_TIMER_MUX_TIMERB_EN BIT(17)
+#define MESON_ISA_TIMER_MUX_TIMERA_EN BIT(16)
+#define MESON_ISA_TIMER_MUX_TIMERD_MODE BIT(15)
+#define MESON_ISA_TIMER_MUX_TIMERC_MODE BIT(14)
+#define MESON_ISA_TIMER_MUX_TIMERB_MODE BIT(13)
+#define MESON_ISA_TIMER_MUX_TIMERA_MODE BIT(12)
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK GENMASK(10, 8)
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_SYSTEM_CLOCK 0x0
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US 0x1
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_10US 0x2
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_100US 0x3
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1MS 0x4
+#define MESON_ISA_TIMER_MUX_TIMERD_INPUT_CLOCK_MASK GENMASK(7, 6)
+#define MESON_ISA_TIMER_MUX_TIMERC_INPUT_CLOCK_MASK GENMASK(5, 4)
+#define MESON_ISA_TIMER_MUX_TIMERB_INPUT_CLOCK_MASK GENMASK(3, 2)
+#define MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK GENMASK(1, 0)
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US 0x0
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_10US 0x1
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_100US 0x0
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1MS 0x3
+
+#define MESON_ISA_TIMERA 0x04
+#define MESON_ISA_TIMERB 0x08
+#define MESON_ISA_TIMERC 0x0c
+#define MESON_ISA_TIMERD 0x10
+#define MESON_ISA_TIMERE 0x14
+
+static void __iomem *timer_base;
+
+#ifdef CONFIG_ARM
+static unsigned long meson6_read_current_timer(void)
+{
+ return readl_relaxed(timer_base + MESON_ISA_TIMERE);
+}
+
+static struct delay_timer meson6_delay_timer = {
+ .read_current_timer = meson6_read_current_timer,
+ .freq = 1000 * 1000,
+};
+#endif
+
+static u64 notrace meson6_timer_sched_read(void)
+{
+ return (u64)readl(timer_base + MESON_ISA_TIMERE);
+}
+
+static void meson6_clkevt_time_stop(void)
+{
+ u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
+
+ writel(val & ~MESON_ISA_TIMER_MUX_TIMERA_EN,
+ timer_base + MESON_ISA_TIMER_MUX);
+}
+
+static void meson6_clkevt_time_setup(unsigned long delay)
+{
+ writel(delay, timer_base + MESON_ISA_TIMERA);
+}
+
+static void meson6_clkevt_time_start(bool periodic)
+{
+ u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
+
+ if (periodic)
+ val |= MESON_ISA_TIMER_MUX_TIMERA_MODE;
+ else
+ val &= ~MESON_ISA_TIMER_MUX_TIMERA_MODE;
+
+ writel(val | MESON_ISA_TIMER_MUX_TIMERA_EN,
+ timer_base + MESON_ISA_TIMER_MUX);
+}
+
+static int meson6_shutdown(struct clock_event_device *evt)
+{
+ meson6_clkevt_time_stop();
+ return 0;
+}
+
+static int meson6_set_oneshot(struct clock_event_device *evt)
+{
+ meson6_clkevt_time_stop();
+ meson6_clkevt_time_start(false);
+ return 0;
+}
+
+static int meson6_set_periodic(struct clock_event_device *evt)
+{
+ meson6_clkevt_time_stop();
+ meson6_clkevt_time_setup(USEC_PER_SEC / HZ - 1);
+ meson6_clkevt_time_start(true);
+ return 0;
+}
+
+static int meson6_clkevt_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ meson6_clkevt_time_stop();
+ meson6_clkevt_time_setup(evt);
+ meson6_clkevt_time_start(false);
+
+ return 0;
+}
+
+static struct clock_event_device meson6_clockevent = {
+ .name = "meson6_tick",
+ .rating = 400,
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_state_shutdown = meson6_shutdown,
+ .set_state_periodic = meson6_set_periodic,
+ .set_state_oneshot = meson6_set_oneshot,
+ .tick_resume = meson6_shutdown,
+ .set_next_event = meson6_clkevt_next_event,
+};
+
+static irqreturn_t meson6_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction meson6_timer_irq = {
+ .name = "meson6_timer",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = meson6_timer_interrupt,
+ .dev_id = &meson6_clockevent,
+};
+
+static int __init meson6_timer_init(struct device_node *node)
+{
+ u32 val;
+ int ret, irq;
+
+ timer_base = of_io_request_and_map(node, 0, "meson6-timer");
+ if (IS_ERR(timer_base)) {
+ pr_err("Can't map registers\n");
+ return -ENXIO;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ pr_err("Can't parse IRQ\n");
+ return -EINVAL;
+ }
+
+ /* Set 1us for timer E */
+ val = readl(timer_base + MESON_ISA_TIMER_MUX);
+ val &= ~MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK;
+ val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK,
+ MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US);
+ writel(val, timer_base + MESON_ISA_TIMER_MUX);
+
+ sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
+ clocksource_mmio_init(timer_base + MESON_ISA_TIMERE, node->name,
+ 1000 * 1000, 300, 32, clocksource_mmio_readl_up);
+
+ /* Timer A base 1us */
+ val &= ~MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK;
+ val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK,
+ MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US);
+ writel(val, timer_base + MESON_ISA_TIMER_MUX);
+
+ /* Stop the timer A */
+ meson6_clkevt_time_stop();
+
+ ret = setup_irq(irq, &meson6_timer_irq);
+ if (ret) {
+ pr_warn("failed to setup irq %d\n", irq);
+ return ret;
+ }
+
+ meson6_clockevent.cpumask = cpu_possible_mask;
+ meson6_clockevent.irq = irq;
+
+ clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
+ 1, 0xfffe);
+
+#ifdef CONFIG_ARM
+ /* Also use MESON_ISA_TIMERE for delays */
+ register_current_timer_delay(&meson6_delay_timer);
+#endif
+
+ return 0;
+}
+TIMER_OF_DECLARE(meson6, "amlogic,meson6-timer",
+ meson6_timer_init);