@@ -591,4 +591,13 @@ config CLKSRC_ST_LPC
Enable this option to use the Low Power controller timer
as clocksource.
+config ATCPIT100_TIMER
+ bool "ATCPIT100 timer driver"
+ depends on NDS32 || COMPILE_TEST
+ depends on HAS_IOMEM
+ select TIMER_OF
+ default NDS32
+ help
+ This option enables support for the Andestech ATCPIT100 timers.
+
endmenu
@@ -76,3 +76,4 @@ obj-$(CONFIG_H8300_TMR16) += h8300_timer16.o
obj-$(CONFIG_H8300_TPU) += h8300_tpu.o
obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
obj-$(CONFIG_X86_NUMACHIP) += numachip.o
+obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
new file mode 100644
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+/*
+ * Andestech ATCPIT100 Timer Device Driver Implementation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ */
+
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/sched.h>
+#include <linux/sched_clock.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include "timer-of.h"
+
+/*
+ * Definition of register offsets
+ */
+
+/* ID and Revision Register */
+#define ID_REV 0x0
+
+/* Configuration Register */
+#define CFG 0x10
+
+/* Interrupt Enable Register */
+#define INT_EN 0x14
+#define CH_INT_EN(c, i) ((1<<i)<<(4*c))
+#define CH0INT0EN 0x01
+
+/* Interrupt Status Register */
+#define INT_STA 0x18
+#define CH0INT0 0x01
+
+/* Channel Enable Register */
+#define CH_EN 0x1C
+#define CH0TMR0EN 0x1
+#define CH1TMR0EN 0x10
+
+/* Channel 0 , 1 Control Register */
+#define CH0_CTL (0x20)
+#define CH1_CTL (0x20 + 0x10)
+
+/* Channel clock source , bit 3 , 0:External clock , 1:APB clock */
+#define APB_CLK BIT(3)
+
+/* Channel mode , bit 0~2 */
+#define TMR_32 0x1
+#define TMR_16 0x2
+#define TMR_8 0x3
+
+/* Channel 0 , 1 Reload Register */
+#define CH0_REL (0x24)
+#define CH1_REL (0x24 + 0x10)
+
+/* Channel 0 , 1 Counter Register */
+#define CH0_CNT (0x28)
+#define CH1_CNT (0x28 + 0x10)
+
+#define TIMER_SYNC_TICKS 3
+
+static void atcpit100_ch1_tmr0_en(void __iomem *base)
+{
+ writel(~0, base + CH1_REL);
+ writel(APB_CLK|TMR_32, base + CH1_CTL);
+}
+
+static void atcpit100_ch0_tmr0_en(void __iomem *base)
+{
+ writel(APB_CLK|TMR_32, base + CH0_CTL);
+}
+
+static void atcpit100_clkevt_time_setup(void __iomem *base, unsigned long delay)
+{
+ writel(delay, base + CH0_CNT);
+ writel(delay, base + CH0_REL);
+}
+
+static void atcpit100_timer_clear_interrupt(void __iomem *base)
+{
+ u32 val;
+
+ val = readl(base + INT_STA);
+ writel(val | CH0INT0, base + INT_STA);
+}
+
+static void atcpit100_clocksource_start(void __iomem *base)
+{
+ u32 val;
+
+ val = readl(base + CH_EN);
+ writel(val | CH1TMR0EN, base + CH_EN);
+}
+
+static void atcpit100_clkevt_time_start(void __iomem *base)
+{
+ u32 val;
+
+ val = readl(base + CH_EN);
+ writel(val | CH0TMR0EN, base + CH_EN);
+}
+
+static void atcpit100_clkevt_time_stop(void __iomem *base)
+{
+ u32 val;
+
+ atcpit100_timer_clear_interrupt(base);
+ val = readl(base + CH_EN);
+ writel(val & ~CH0TMR0EN, base + CH_EN);
+}
+
+static int atcpit100_clkevt_next_event(unsigned long evt,
+ struct clock_event_device *clkevt)
+{
+ u32 val;
+ struct timer_of *to = to_timer_of(clkevt);
+
+ val = readl(timer_of_base(to) + CH_EN);
+ writel(val & ~CH0TMR0EN, timer_of_base(to) + CH_EN);
+ writel(evt, timer_of_base(to) + CH0_REL);
+ writel(val | CH0TMR0EN, timer_of_base(to) + CH_EN);
+
+ return 0;
+}
+
+static int atcpit100_clkevt_set_periodic(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+
+ atcpit100_clkevt_time_setup(timer_of_base(to), timer_of_period(to));
+ atcpit100_clkevt_time_start(timer_of_base(to));
+
+ return 0;
+}
+static int atcpit100_clkevt_shutdown(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+
+ atcpit100_clkevt_time_stop(timer_of_base(to));
+
+ return 0;
+}
+static int atcpit100_clkevt_set_oneshot(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ u32 val;
+
+ writel(~0x0, timer_of_base(to) + CH0_REL);
+ val = readl(timer_of_base(to) + CH_EN);
+ writel(val | CH0TMR0EN, timer_of_base(to) + CH_EN);
+
+ return 0;
+}
+
+static irqreturn_t atcpit100_timer_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);
+
+ atcpit100_timer_clear_interrupt(timer_of_base(to));
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct timer_of to = {
+ .flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE,
+
+ .clkevt = {
+ .name = "atcpit100_tick",
+ .rating = 300,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_state_shutdown = atcpit100_clkevt_shutdown,
+ .set_state_periodic = atcpit100_clkevt_set_periodic,
+ .set_state_oneshot = atcpit100_clkevt_set_oneshot,
+ .tick_resume = atcpit100_clkevt_shutdown,
+ .set_next_event = atcpit100_clkevt_next_event,
+ .cpumask = cpu_all_mask,
+ },
+
+ .of_irq = {
+ .handler = atcpit100_timer_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ },
+
+ /*
+ * FIXME: we currently only support clocking using PCLK
+ * and using EXTCLK is not supported in the driver.
+ */
+ .of_clk = {
+ .name = "PCLK",
+ }
+};
+
+static u64 notrace atcpit100_timer_sched_read(void)
+{
+ return ~readl(timer_of_base(&to) + CH1_CNT);
+}
+
+static int __init atcpit100_timer_init(struct device_node *node)
+{
+ int ret;
+ u32 val;
+ void __iomem *base;
+
+ ret = timer_of_init(node, &to);
+ if (ret)
+ return ret;
+
+ base = timer_of_base(&to);
+
+ sched_clock_register(atcpit100_timer_sched_read, 32,
+ timer_of_rate(&to));
+
+ ret = clocksource_mmio_init(base + CH1_CNT,
+ node->name, timer_of_rate(&to), 300, 32,
+ clocksource_mmio_readl_down);
+
+ if (ret) {
+ pr_err("Failed to register clocksource\n");
+ return ret;
+ }
+
+ /* clear channel 0 timer0 interrupt */
+ atcpit100_timer_clear_interrupt(base);
+
+ clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
+ TIMER_SYNC_TICKS, 0xffffffff);
+ atcpit100_ch0_tmr0_en(base);
+ atcpit100_ch1_tmr0_en(base);
+ atcpit100_clocksource_start(base);
+ atcpit100_clkevt_time_start(base);
+
+ /* Enable channel 0 timer0 interrupt */
+ val = readl(base + INT_EN);
+ writel(val | CH0INT0EN, base + INT_EN);
+
+ return ret;
+}
+
+TIMER_OF_DECLARE(atcpit100, "andestech,atcpit100", atcpit100_timer_init);