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path: root/drivers/clocksource/timer-npcm7xx.c
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Diffstat (limited to 'drivers/clocksource/timer-npcm7xx.c')
-rw-r--r--drivers/clocksource/timer-npcm7xx.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-npcm7xx.c b/drivers/clocksource/timer-npcm7xx.c
new file mode 100644
index 0000000..7a9bb55
--- /dev/null
+++ b/drivers/clocksource/timer-npcm7xx.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014-2018 Nuvoton Technologies tomer.maimon@nuvoton.com
+ * All rights reserved.
+ *
+ * Copyright 2017 Google, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/clockchips.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include "timer-of.h"
+
+/* Timers registers */
+#define NPCM7XX_REG_TCSR0 0x0 /* Timer 0 Control and Status Register */
+#define NPCM7XX_REG_TICR0 0x8 /* Timer 0 Initial Count Register */
+#define NPCM7XX_REG_TCSR1 0x4 /* Timer 1 Control and Status Register */
+#define NPCM7XX_REG_TICR1 0xc /* Timer 1 Initial Count Register */
+#define NPCM7XX_REG_TDR1 0x14 /* Timer 1 Data Register */
+#define NPCM7XX_REG_TISR 0x18 /* Timer Interrupt Status Register */
+
+/* Timers control */
+#define NPCM7XX_Tx_RESETINT 0x1f
+#define NPCM7XX_Tx_PERIOD BIT(27)
+#define NPCM7XX_Tx_INTEN BIT(29)
+#define NPCM7XX_Tx_COUNTEN BIT(30)
+#define NPCM7XX_Tx_ONESHOT 0x0
+#define NPCM7XX_Tx_OPER GENMASK(3, 27)
+#define NPCM7XX_Tx_MIN_PRESCALE 0x1
+#define NPCM7XX_Tx_TDR_MASK_BITS 24
+#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
+#define NPCM7XX_T0_CLR_INT 0x1
+#define NPCM7XX_Tx_CLR_CSR 0x0
+
+/* Timers operating mode */
+#define NPCM7XX_START_PERIODIC_Tx (NPCM7XX_Tx_PERIOD | NPCM7XX_Tx_COUNTEN | \
+ NPCM7XX_Tx_INTEN | \
+ NPCM7XX_Tx_MIN_PRESCALE)
+
+#define NPCM7XX_START_ONESHOT_Tx (NPCM7XX_Tx_ONESHOT | NPCM7XX_Tx_COUNTEN | \
+ NPCM7XX_Tx_INTEN | \
+ NPCM7XX_Tx_MIN_PRESCALE)
+
+#define NPCM7XX_START_Tx (NPCM7XX_Tx_COUNTEN | NPCM7XX_Tx_PERIOD | \
+ NPCM7XX_Tx_MIN_PRESCALE)
+
+#define NPCM7XX_DEFAULT_CSR (NPCM7XX_Tx_CLR_CSR | NPCM7XX_Tx_MIN_PRESCALE)
+
+static int npcm7xx_timer_resume(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ u32 val;
+
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val |= NPCM7XX_Tx_COUNTEN;
+ writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
+
+ return 0;
+}
+
+static int npcm7xx_timer_shutdown(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ u32 val;
+
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val &= ~NPCM7XX_Tx_COUNTEN;
+ writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
+
+ return 0;
+}
+
+static int npcm7xx_timer_oneshot(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ u32 val;
+
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val &= ~NPCM7XX_Tx_OPER;
+
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val |= NPCM7XX_START_ONESHOT_Tx;
+ writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
+
+ return 0;
+}
+
+static int npcm7xx_timer_periodic(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ u32 val;
+
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val &= ~NPCM7XX_Tx_OPER;
+
+ writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
+ val |= NPCM7XX_START_PERIODIC_Tx;
+
+ writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
+
+ return 0;
+}
+
+static int npcm7xx_clockevent_set_next_event(unsigned long evt,
+ struct clock_event_device *clk)
+{
+ struct timer_of *to = to_timer_of(clk);
+ u32 val;
+
+ writel(evt, timer_of_base(to) + NPCM7XX_REG_TICR0);
+ val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
+ val |= NPCM7XX_START_Tx;
+ writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
+
+ return 0;
+}
+
+static irqreturn_t npcm7xx_timer0_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+ struct timer_of *to = to_timer_of(evt);
+
+ writel(NPCM7XX_T0_CLR_INT, timer_of_base(to) + NPCM7XX_REG_TISR);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct timer_of npcm7xx_to = {
+ .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
+
+ .clkevt = {
+ .name = "npcm7xx-timer0",
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = npcm7xx_clockevent_set_next_event,
+ .set_state_shutdown = npcm7xx_timer_shutdown,
+ .set_state_periodic = npcm7xx_timer_periodic,
+ .set_state_oneshot = npcm7xx_timer_oneshot,
+ .tick_resume = npcm7xx_timer_resume,
+ .rating = 300,
+ },
+
+ .of_irq = {
+ .handler = npcm7xx_timer0_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ },
+};
+
+static void __init npcm7xx_clockevents_init(void)
+{
+ writel(NPCM7XX_DEFAULT_CSR,
+ timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR0);
+
+ writel(NPCM7XX_Tx_RESETINT,
+ timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TISR);
+
+ npcm7xx_to.clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&npcm7xx_to.clkevt,
+ timer_of_rate(&npcm7xx_to),
+ 0x1, NPCM7XX_Tx_MAX_CNT);
+}
+
+static void __init npcm7xx_clocksource_init(void)
+{
+ u32 val;
+
+ writel(NPCM7XX_DEFAULT_CSR,
+ timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
+ writel(NPCM7XX_Tx_MAX_CNT,
+ timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TICR1);
+
+ val = readl(timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
+ val |= NPCM7XX_START_Tx;
+ writel(val, timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
+
+ clocksource_mmio_init(timer_of_base(&npcm7xx_to) +
+ NPCM7XX_REG_TDR1,
+ "npcm7xx-timer1", timer_of_rate(&npcm7xx_to),
+ 200, (unsigned int)NPCM7XX_Tx_TDR_MASK_BITS,
+ clocksource_mmio_readl_down);
+}
+
+static int __init npcm7xx_timer_init(struct device_node *np)
+{
+ int ret;
+
+ ret = timer_of_init(np, &npcm7xx_to);
+ if (ret)
+ return ret;
+
+ /* Clock input is divided by PRESCALE + 1 before it is fed */
+ /* to the counter */
+ npcm7xx_to.of_clk.rate = npcm7xx_to.of_clk.rate /
+ (NPCM7XX_Tx_MIN_PRESCALE + 1);
+
+ npcm7xx_clocksource_init();
+ npcm7xx_clockevents_init();
+
+ pr_info("Enabling NPCM7xx clocksource timer base: %px, IRQ: %d ",
+ timer_of_base(&npcm7xx_to), timer_of_irq(&npcm7xx_to));
+
+ return 0;
+}
+
+TIMER_OF_DECLARE(npcm7xx, "nuvoton,npcm750-timer", npcm7xx_timer_init);
+
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