[Qemu-devel] [PATCH 10/13] mxs/imx23: Add the timers

[Michel Pollet <buserror@gmail.com>]

Support for the timer IO block of the mxs/imx23. Does not support
any of the fancy function, just the 32khz based timers used by
linux.

Signed-off-by: Michel Pollet <buserror@gmail.com>
---
 hw/timer/Makefile.objs |   2 +-
 hw/timer/mxs_timrot.c  | 271 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 272 insertions(+), 1 deletion(-)
 create mode 100644 hw/timer/mxs_timrot.c

diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
index 1003169..8d2933a 100644
--- a/hw/timer/Makefile.objs
+++ b/hw/timer/Makefile.objs
@@ -26,6 +26,6 @@ obj-$(CONFIG_OMAP) += omap_synctimer.o
 obj-$(CONFIG_PXA2XX) += pxa2xx_timer.o
 obj-$(CONFIG_SH4) += sh_timer.o
 obj-$(CONFIG_TUSB6010) += tusb6010.o
-obj-$(CONFIG_MXS) += mxs_rtc.o
+obj-$(CONFIG_MXS) += mxs_rtc.o mxs_timrot.o
 
 obj-$(CONFIG_MC146818RTC) += mc146818rtc.o
diff --git a/hw/timer/mxs_timrot.c b/hw/timer/mxs_timrot.c
new file mode 100644
index 0000000..b54c0b1
--- /dev/null
+++ b/hw/timer/mxs_timrot.c
@@ -0,0 +1,271 @@
+/*
+ * mxs_timrot.c
+ *
+ * Copyright: Michel Pollet <buserror@gmail.com>
+ *
+ * QEMU Licence
+ */
+
+/*
+ * Implements the timer block for the mxs. Currently supports only the
+ * 32khz based clock, and not all the of the options, nor the input counters,
+ * PWM etc etc.
+ * Basically, it supports enough for the linux kernel
+ */
+#include "hw/sysbus.h"
+#include "hw/arm/mxs.h"
+#include "hw/ptimer.h"
+#include "qemu/main-loop.h"
+
+enum {
+    TIMROT_ROTCTRL = 0,
+    TIMROT_CTRL0 = 0x2,
+    TIMROT_COUNT0 = 0x3,
+    TIMROT_CTRL1 = 0x4,
+    TIMROT_COUNT1 = 0x5,
+    TIMROT_CTRL2 = 0x6,
+    TIMROT_COUNT2 = 0x7,
+    TIMROT_CTRL3 = 0x8,
+    TIMROT_COUNT3 = 0x9,
+    TIMROT_VERSION = 0xa,
+};
+
+enum {
+    TIM_IRQ = 15,
+    TIM_IRQ_EN = 14,
+    TIM_UPDATE = 7,
+    TIM_RELOAD = 6,
+    TIM_PRESCALE = 4,
+    TIM_SELECT = 0,
+};
+
+typedef struct mxs_tim_state {
+    struct mxs_timrot_state * s;
+    uint8_t tid;
+    uint8_t fired;
+    uint32_t control, count;
+    qemu_irq irq;
+    ptimer_state * timer;
+} mxs_tim_state;
+
+typedef struct mxs_timrot_state {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+
+    uint32_t rotctrl;
+
+    mxs_tim_state t[4];
+} mxs_timrot_state;
+
+static void tim_set_count(mxs_tim_state * t, uint32_t count)
+{
+    if (count != (t->count & 0xffff) || t->fired) {
+        t->count = (t->count & ~0xffff) | (count & 0xffff);
+        ptimer_set_limit(t->timer, t->count & 0xffff, 1);
+        if (t->count & 0xffff) {
+            t->fired = 0;
+            ptimer_run(t->timer, t->control & (1 << TIM_RELOAD) ? 0 : 1);
+        }
+    }
+}
+
+static void tim_set_control(mxs_tim_state * t, uint16_t control)
+{
+    uint32_t change = t->control ^ control;
+    if (!change) {
+        return;
+    }
+
+    uint32_t freq = 0;
+    switch ((control >> TIM_SELECT) & 0xf) {
+        case 0x8:
+            freq = 32000;
+            break;
+        case 0x9:
+            freq = 8000;
+            break;
+        case 0xa:
+            freq = 4000;
+            break;
+        case 0xc:
+            freq = 1000;
+            break;
+    }
+    switch ((control >> TIM_PRESCALE) & 0x3) {
+        /* TODO */
+    }
+    if (!(control & (1 << TIM_IRQ))) {
+        qemu_irq_lower(t->irq);
+    }
+    if (freq == 0) {
+        ptimer_stop(t->timer);
+    } else if (change & 0xff) {
+        printf("%s[%d] %04x freq %d\n", __func__, t->tid, control, (int) freq);
+        ptimer_set_freq(t->timer, freq);
+        ptimer_set_limit(t->timer, t->count & 0xffff, 1);
+        if (t->count & 0xffff) {
+            t->fired = 0;
+            ptimer_run(t->timer, control & (1 << TIM_RELOAD) ? 0 : 1);
+        }
+    }
+    t->control = control;
+}
+
+static uint32_t tim_get_count(mxs_tim_state * t)
+{
+    t->count &= 0xffff;
+    t->count |= (ptimer_get_count(t->timer) << 16);
+    return t->count;
+}
+
+static void mxs_timrot_timer_trigger(void *opaque)
+{
+    mxs_tim_state * t = opaque;
+    t->fired = 1;
+    t->control |= (1 << TIM_IRQ);
+    if (t->control & (1 << TIM_IRQ_EN))
+        qemu_irq_raise(t->irq);
+}
+
+static inline int tim_get_tid(hwaddr offset)
+{
+    return ((offset >> 4) - TIMROT_CTRL0) >> 1;
+}
+
+static uint64_t mxs_timrot_read(void *opaque, hwaddr offset,
+        unsigned size)
+{
+    mxs_timrot_state *s = (mxs_timrot_state *) opaque;
+    uint32_t res = 0;
+
+    switch (offset >> 4) {
+        case TIMROT_ROTCTRL:
+            res = s->rotctrl | (0xf << 25);
+            break;
+        case TIMROT_VERSION:
+            res = 0x01010000;
+            break;
+        case TIMROT_CTRL0:
+        case TIMROT_CTRL1:
+        case TIMROT_CTRL2:
+        case TIMROT_CTRL3:
+            res = s->t[tim_get_tid(offset)].control;
+            break;
+        case TIMROT_COUNT0:
+        case TIMROT_COUNT1:
+        case TIMROT_COUNT2:
+        case TIMROT_COUNT3:
+            res = tim_get_count(&s->t[tim_get_tid(offset)]);
+            break;
+        default:
+            qemu_log_mask(LOG_GUEST_ERROR,
+                    "%s: bad offset 0x%x\n", __func__, (int) offset);
+            return 0;
+    }
+    return res;
+}
+
+static void mxs_timrot_write(void *opaque, hwaddr offset,
+        uint64_t value, unsigned size)
+{
+    mxs_timrot_state *s = (mxs_timrot_state *) opaque;
+    uint32_t * dst = NULL;
+    uint32_t val = 0;
+    uint32_t oldvalue = 0;
+
+    switch (offset >> 4) {
+        case TIMROT_ROTCTRL:
+            dst = &s->rotctrl;
+            break;
+        case TIMROT_CTRL0:
+        case TIMROT_CTRL1:
+        case TIMROT_CTRL2:
+        case TIMROT_CTRL3:
+            val = s->t[tim_get_tid(offset)].control;
+            dst = &val;
+            break;
+        case TIMROT_COUNT0:
+        case TIMROT_COUNT1:
+        case TIMROT_COUNT2:
+        case TIMROT_COUNT3:
+            val = s->t[tim_get_tid(offset)].count;
+            dst = &val;
+            break;
+        default:
+            qemu_log_mask(LOG_GUEST_ERROR,
+                    "%s: bad offset 0x%x\n", __func__, (int) offset);
+            return;
+    }
+    if (!dst) {
+        return;
+    }
+    oldvalue = mxs_write(dst, offset, value, size);
+
+    switch (offset >> 4) {
+        case TIMROT_ROTCTRL:
+            if ((oldvalue ^ *dst) == 0x80000000 && !(oldvalue & 0x80000000)) {
+            //    printf("%s reseting, anding clockgate\n", __func__);
+                *dst |= 0x40000000;
+            }
+            *dst |= 0xf << 25; // 4 timers, no encoder
+            break;
+        case TIMROT_CTRL0:
+        case TIMROT_CTRL1:
+        case TIMROT_CTRL2:
+        case TIMROT_CTRL3:
+            tim_set_control(&s->t[tim_get_tid(offset)], val);
+            break;
+        case TIMROT_COUNT0:
+        case TIMROT_COUNT1:
+        case TIMROT_COUNT2:
+        case TIMROT_COUNT3:
+            tim_set_count(&s->t[tim_get_tid(offset)], val);
+            break;
+    }
+}
+
+
+static const MemoryRegionOps mxs_timrot_ops = {
+    .read = mxs_timrot_read,
+    .write = mxs_timrot_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static int mxs_timrot_init(SysBusDevice *dev)
+{
+    mxs_timrot_state *s = OBJECT_CHECK(mxs_timrot_state, dev, "mxs_timrot");
+    int i;
+
+    for (i = 0; i < 4; i++) {
+        QEMUBH *bh = qemu_bh_new(mxs_timrot_timer_trigger, &s->t[i]);
+        s->t[i].timer = ptimer_init(bh);
+        sysbus_init_irq(dev, &s->t[i].irq);
+        s->t[i].s = s;
+        s->t[i].tid = i;
+    }
+    memory_region_init_io(&s->iomem, OBJECT(s), &mxs_timrot_ops, s,
+            "mxs_timrot", 0x2000);
+    sysbus_init_mmio(dev, &s->iomem);
+    return 0;
+}
+
+static void mxs_timrot_class_init(ObjectClass *klass, void *data)
+{
+    SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
+
+    sdc->init = mxs_timrot_init;
+}
+
+static TypeInfo timrot_info = {
+    .name          = "mxs_timrot",
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(mxs_timrot_state),
+    .class_init    = mxs_timrot_class_init,
+};
+
+static void mxs_timrot_register(void)
+{
+    type_register_static(&timrot_info);
+}
+
+type_init(mxs_timrot_register)
-- 
1.8.5.1