3 files changed, 154 insertions, 0 deletions

diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
index 026e823d871d..c528d0cf5add 100644
--- a/arch/mips/ralink/Kconfig
+++ b/arch/mips/ralink/Kconfig
@@ -1,5 +1,12 @@
 if RALINK
 
+config CLKEVT_RT3352
+        bool
+        depends on SOC_RT305X || SOC_MT7620
+        default y
+        select CLKSRC_OF
+        select CLKSRC_MMIO
+
 choice
         prompt "Ralink SoC selection"
         default SOC_RT305X
diff --git a/arch/mips/ralink/Makefile b/arch/mips/ralink/Makefile
index e37e0ec5b378..98ae349827be 100644
--- a/arch/mips/ralink/Makefile
+++ b/arch/mips/ralink/Makefile
@@ -8,6 +8,8 @@
 
 obj-y := prom.o of.o reset.o clk.o irq.o timer.o
 
+obj-$(CONFIG_CLKEVT_RT3352) += cevt-rt3352.o
+
 obj-$(CONFIG_SOC_RT288X) += rt288x.o
 obj-$(CONFIG_SOC_RT305X) += rt305x.o
 obj-$(CONFIG_SOC_RT3883) += rt3883.o
diff --git a/arch/mips/ralink/cevt-rt3352.c b/arch/mips/ralink/cevt-rt3352.c
new file mode 100644
index 000000000000..cc17566d1934
--- /dev/null
+++ b/arch/mips/ralink/cevt-rt3352.c
@@ -0,0 +1,145 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 by John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/reset.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define SYSTICK_FREQ            (50 * 1000)
+
+#define SYSTICK_CONFIG          0x00
+#define SYSTICK_COMPARE         0x04
+#define SYSTICK_COUNT           0x08
+
+/* route systick irq to mips irq 7 instead of the r4k-timer */
+#define CFG_EXT_STK_EN          0x2
+/* enable the counter */
+#define CFG_CNT_EN              0x1
+
+struct systick_device {
+        void __iomem *membase;
+        struct clock_event_device dev;
+        int irq_requested;
+        int freq_scale;
+};
+
+static void systick_set_clock_mode(enum clock_event_mode mode,
+                                struct clock_event_device *evt);
+
+static int systick_next_event(unsigned long delta,
+                                struct clock_event_device *evt)
+{
+        struct systick_device *sdev;
+        u32 count;
+
+        sdev = container_of(evt, struct systick_device, dev);
+        count = ioread32(sdev->membase + SYSTICK_COUNT);
+        count = (count + delta) % SYSTICK_FREQ;
+        iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
+
+        return 0;
+}
+
+static void systick_event_handler(struct clock_event_device *dev)
+{
+        /* noting to do here */
+}
+
+static irqreturn_t systick_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *dev = (struct clock_event_device *) dev_id;
+
+        dev->event_handler(dev);
+
+        return IRQ_HANDLED;
+}
+
+static struct systick_device systick = {
+        .dev = {
+                /*
+                 * cevt-r4k uses 300, make sure systick
+                 * gets used if available
+                 */
+                .rating         = 310,
+                .features       = CLOCK_EVT_FEAT_ONESHOT,
+                .set_next_event = systick_next_event,
+                .set_mode       = systick_set_clock_mode,
+                .event_handler  = systick_event_handler,
+        },
+};
+
+static struct irqaction systick_irqaction = {
+        .handler = systick_interrupt,
+        .flags = IRQF_PERCPU | IRQF_TIMER,
+        .dev_id = &systick.dev,
+};
+
+static void systick_set_clock_mode(enum clock_event_mode mode,
+                                struct clock_event_device *evt)
+{
+        struct systick_device *sdev;
+
+        sdev = container_of(evt, struct systick_device, dev);
+
+        switch (mode) {
+        case CLOCK_EVT_MODE_ONESHOT:
+                if (!sdev->irq_requested)
+                        setup_irq(systick.dev.irq, &systick_irqaction);
+                sdev->irq_requested = 1;
+                iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN,
+                                systick.membase + SYSTICK_CONFIG);
+                break;
+
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                if (sdev->irq_requested)
+                        free_irq(systick.dev.irq, &systick_irqaction);
+                sdev->irq_requested = 0;
+                iowrite32(0, systick.membase + SYSTICK_CONFIG);
+                break;
+
+        default:
+                pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name);
+                break;
+        }
+}
+
+static void __init ralink_systick_init(struct device_node *np)
+{
+        systick.membase = of_iomap(np, 0);
+        if (!systick.membase)
+                return;
+
+        systick_irqaction.name = np->name;
+        systick.dev.name = np->name;
+        clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
+        systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
+        systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
+        systick.dev.irq = irq_of_parse_and_map(np, 0);
+        if (!systick.dev.irq) {
+                pr_err("%s: request_irq failed", np->name);
+                return;
+        }
+
+        clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
+                        SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
+
+        clockevents_register_device(&systick.dev);
+
+        pr_info("%s: runing - mult: %d, shift: %d\n",
+                        np->name, systick.dev.mult, systick.dev.shift);
+}
+
+CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);