i.MX: split GPT and EPIT timer implementation

There is no common code between these 2 timer implementation.
So it is better to split them.

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
Message-id: 1368990197-19694-1-git-send-email-jcd@tribudubois.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 465 insertions, 0 deletions

diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c
new file mode 100644
index 0000000000..d8c4f0baee
--- /dev/null
+++ b/hw/timer/imx_gpt.c
@@ -0,0 +1,465 @@
+/*
+ * IMX GPT Timer
+ *
+ * Copyright (c) 2008 OK Labs
+ * Copyright (c) 2011 NICTA Pty Ltd
+ * Originally written by Hans Jiang
+ * Updated by Peter Chubb
+ *
+ * This code is licensed under GPL version 2 or later.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/hw.h"
+#include "qemu/bitops.h"
+#include "qemu/timer.h"
+#include "hw/ptimer.h"
+#include "hw/sysbus.h"
+#include "hw/arm/imx.h"
+
+//#define DEBUG_TIMER 1
+#ifdef DEBUG_TIMER
+#  define DPRINTF(fmt, args...) \
+      do { printf("imx_timer: " fmt , ##args); } while (0)
+#else
+#  define DPRINTF(fmt, args...) do {} while (0)
+#endif
+
+/*
+ * Define to 1 for messages about attempts to
+ * access unimplemented registers or similar.
+ */
+#define DEBUG_IMPLEMENTATION 1
+#if DEBUG_IMPLEMENTATION
+#  define IPRINTF(fmt, args...)                                         \
+    do  { fprintf(stderr, "imx_timer: " fmt, ##args); } while (0)
+#else
+#  define IPRINTF(fmt, args...) do {} while (0)
+#endif
+
+/*
+ * GPT : General purpose timer
+ *
+ * This timer counts up continuously while it is enabled, resetting itself
+ * to 0 when it reaches TIMER_MAX (in freerun mode) or when it
+ * reaches the value of ocr1 (in periodic mode).  WE simulate this using a
+ * QEMU ptimer counting down from ocr1 and reloading from ocr1 in
+ * periodic mode, or counting from ocr1 to zero, then TIMER_MAX - ocr1.
+ * waiting_rov is set when counting from TIMER_MAX.
+ *
+ * In the real hardware, there are three comparison registers that can
+ * trigger interrupts, and compare channel 1 can be used to
+ * force-reset the timer. However, this is a `bare-bones'
+ * implementation: only what Linux 3.x uses has been implemented
+ * (free-running timer from 0 to OCR1 or TIMER_MAX) .
+ */
+
+#define TIMER_MAX  0XFFFFFFFFUL
+
+/* Control register.  Not all of these bits have any effect (yet) */
+#define GPT_CR_EN     (1 << 0)  /* GPT Enable */
+#define GPT_CR_ENMOD  (1 << 1)  /* GPT Enable Mode */
+#define GPT_CR_DBGEN  (1 << 2)  /* GPT Debug mode enable */
+#define GPT_CR_WAITEN (1 << 3)  /* GPT Wait Mode Enable  */
+#define GPT_CR_DOZEN  (1 << 4)  /* GPT Doze mode enable */
+#define GPT_CR_STOPEN (1 << 5)  /* GPT Stop Mode Enable */
+#define GPT_CR_CLKSRC_SHIFT (6)
+#define GPT_CR_CLKSRC_MASK  (0x7)
+
+#define GPT_CR_FRR    (1 << 9)  /* Freerun or Restart */
+#define GPT_CR_SWR    (1 << 15) /* Software Reset */
+#define GPT_CR_IM1    (3 << 16) /* Input capture channel 1 mode (2 bits) */
+#define GPT_CR_IM2    (3 << 18) /* Input capture channel 2 mode (2 bits) */
+#define GPT_CR_OM1    (7 << 20) /* Output Compare Channel 1 Mode (3 bits) */
+#define GPT_CR_OM2    (7 << 23) /* Output Compare Channel 2 Mode (3 bits) */
+#define GPT_CR_OM3    (7 << 26) /* Output Compare Channel 3 Mode (3 bits) */
+#define GPT_CR_FO1    (1 << 29) /* Force Output Compare Channel 1 */
+#define GPT_CR_FO2    (1 << 30) /* Force Output Compare Channel 2 */
+#define GPT_CR_FO3    (1 << 31) /* Force Output Compare Channel 3 */
+
+#define GPT_SR_OF1  (1 << 0)
+#define GPT_SR_ROV  (1 << 5)
+
+#define GPT_IR_OF1IE  (1 << 0)
+#define GPT_IR_ROVIE  (1 << 5)
+
+typedef struct {
+    SysBusDevice busdev;
+    ptimer_state *timer;
+    MemoryRegion iomem;
+    DeviceState *ccm;
+
+    uint32_t cr;
+    uint32_t pr;
+    uint32_t sr;
+    uint32_t ir;
+    uint32_t ocr1;
+    uint32_t ocr2;
+    uint32_t ocr3;
+    uint32_t icr1;
+    uint32_t icr2;
+    uint32_t cnt;
+
+    uint32_t waiting_rov;
+    qemu_irq irq;
+} IMXTimerGState;
+
+static const VMStateDescription vmstate_imx_timerg = {
+    .name = "imx-timerg",
+    .version_id = 2,
+    .minimum_version_id = 2,
+    .minimum_version_id_old = 2,
+    .fields      = (VMStateField[]) {
+        VMSTATE_UINT32(cr, IMXTimerGState),
+        VMSTATE_UINT32(pr, IMXTimerGState),
+        VMSTATE_UINT32(sr, IMXTimerGState),
+        VMSTATE_UINT32(ir, IMXTimerGState),
+        VMSTATE_UINT32(ocr1, IMXTimerGState),
+        VMSTATE_UINT32(ocr2, IMXTimerGState),
+        VMSTATE_UINT32(ocr3, IMXTimerGState),
+        VMSTATE_UINT32(icr1, IMXTimerGState),
+        VMSTATE_UINT32(icr2, IMXTimerGState),
+        VMSTATE_UINT32(cnt, IMXTimerGState),
+        VMSTATE_UINT32(waiting_rov, IMXTimerGState),
+        VMSTATE_PTIMER(timer, IMXTimerGState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const IMXClk imx_timerg_clocks[] = {
+    NOCLK,    /* 000 No clock source */
+    IPG,      /* 001 ipg_clk, 532MHz*/
+    IPG,      /* 010 ipg_clk_highfreq */
+    NOCLK,    /* 011 not defined */
+    CLK_32k,  /* 100 ipg_clk_32k */
+    NOCLK,    /* 101 not defined */
+    NOCLK,    /* 110 not defined */
+    NOCLK,    /* 111 not defined */
+};
+
+
+static void imx_timerg_set_freq(IMXTimerGState *s)
+{
+    int clksrc;
+    uint32_t freq;
+
+    clksrc = (s->cr >> GPT_CR_CLKSRC_SHIFT) & GPT_CR_CLKSRC_MASK;
+    freq = imx_clock_frequency(s->ccm, imx_timerg_clocks[clksrc]) / (1 + s->pr);
+
+    DPRINTF("Setting gtimer clksrc %d to frequency %d\n", clksrc, freq);
+
+    if (freq) {
+        ptimer_set_freq(s->timer, freq);
+    }
+}
+
+static void imx_timerg_update(IMXTimerGState *s)
+{
+    uint32_t flags = s->sr & s->ir & (GPT_SR_OF1 | GPT_SR_ROV);
+
+    DPRINTF("g-timer SR: %s %s IR=%s %s, %s\n",
+            s->sr & GPT_SR_OF1 ? "OF1" : "",
+            s->sr & GPT_SR_ROV ? "ROV" : "",
+            s->ir & GPT_SR_OF1 ? "OF1" : "",
+            s->ir & GPT_SR_ROV ? "ROV" : "",
+            s->cr & GPT_CR_EN ? "CR_EN" : "Not Enabled");
+
+    qemu_set_irq(s->irq, (s->cr & GPT_CR_EN) && flags);
+}
+
+static uint32_t imx_timerg_update_counts(IMXTimerGState *s)
+{
+    uint64_t target = s->waiting_rov ? TIMER_MAX : s->ocr1;
+    uint64_t cnt = ptimer_get_count(s->timer);
+    s->cnt = target - cnt;
+    return s->cnt;
+}
+
+static void imx_timerg_reload(IMXTimerGState *s, uint32_t timeout)
+{
+    uint64_t diff_cnt;
+
+    if (!(s->cr & GPT_CR_FRR)) {
+        IPRINTF("IMX_timerg_reload --- called in reset-mode\n");
+        return;
+    }
+
+    /*
+     * For small timeouts, qemu sometimes runs too slow.
+     * Better deliver a late interrupt than none.
+     *
+     * In Reset mode (FRR bit clear)
+     * the ptimer reloads itself from OCR1;
+     * in free-running mode we need to fake
+     * running from 0 to ocr1 to TIMER_MAX
+     */
+    if (timeout > s->cnt) {
+        diff_cnt = timeout - s->cnt;
+    } else {
+        diff_cnt = 0;
+    }
+    ptimer_set_count(s->timer, diff_cnt);
+}
+
+static uint64_t imx_timerg_read(void *opaque, hwaddr offset,
+                                unsigned size)
+{
+    IMXTimerGState *s = (IMXTimerGState *)opaque;
+
+    DPRINTF("g-read(offset=%x)", (unsigned int)(offset >> 2));
+    switch (offset >> 2) {
+    case 0: /* Control Register */
+        DPRINTF(" cr = %x\n", s->cr);
+        return s->cr;
+
+    case 1: /* prescaler */
+        DPRINTF(" pr = %x\n", s->pr);
+        return s->pr;
+
+    case 2: /* Status Register */
+        DPRINTF(" sr = %x\n", s->sr);
+        return s->sr;
+
+    case 3: /* Interrupt Register */
+        DPRINTF(" ir = %x\n", s->ir);
+        return s->ir;
+
+    case 4: /* Output Compare Register 1 */
+        DPRINTF(" ocr1 = %x\n", s->ocr1);
+        return s->ocr1;
+
+    case 5: /* Output Compare Register 2 */
+        DPRINTF(" ocr2 = %x\n", s->ocr2);
+        return s->ocr2;
+
+    case 6: /* Output Compare Register 3 */
+        DPRINTF(" ocr3 = %x\n", s->ocr3);
+        return s->ocr3;
+
+    case 7: /* input Capture Register 1 */
+        DPRINTF(" icr1 = %x\n", s->icr1);
+        return s->icr1;
+
+    case 8: /* input Capture Register 2 */
+        DPRINTF(" icr2 = %x\n", s->icr2);
+        return s->icr2;
+
+    case 9: /* cnt */
+        imx_timerg_update_counts(s);
+        DPRINTF(" cnt = %x\n", s->cnt);
+        return s->cnt;
+    }
+
+    IPRINTF("imx_timerg_read: Bad offset %x\n",
+            (int)offset >> 2);
+
+    return 0;
+}
+
+static void imx_timerg_reset(DeviceState *dev)
+{
+    IMXTimerGState *s = container_of(dev, IMXTimerGState, busdev.qdev);
+
+    /*
+     * Soft reset doesn't touch some bits; hard reset clears them
+     */
+    s->cr &= ~(GPT_CR_EN|GPT_CR_ENMOD|GPT_CR_STOPEN|GPT_CR_DOZEN|
+               GPT_CR_WAITEN|GPT_CR_DBGEN);
+    s->sr = 0;
+    s->pr = 0;
+    s->ir = 0;
+    s->cnt = 0;
+    s->ocr1 = TIMER_MAX;
+    s->ocr2 = TIMER_MAX;
+    s->ocr3 = TIMER_MAX;
+    s->icr1 = 0;
+    s->icr2 = 0;
+    ptimer_stop(s->timer);
+    ptimer_set_limit(s->timer, TIMER_MAX, 1);
+    ptimer_set_count(s->timer, TIMER_MAX);
+    imx_timerg_set_freq(s);
+}
+
+static void imx_timerg_write(void *opaque, hwaddr offset,
+                             uint64_t value, unsigned size)
+{
+    IMXTimerGState *s = (IMXTimerGState *)opaque;
+    DPRINTF("g-write(offset=%x, value = 0x%x)\n", (unsigned int)offset >> 2,
+            (unsigned int)value);
+
+    switch (offset >> 2) {
+    case 0: {
+        uint32_t oldcr = s->cr;
+        /* CR */
+        if (value & GPT_CR_SWR) { /* force reset */
+            value &= ~GPT_CR_SWR;
+            imx_timerg_reset(&s->busdev.qdev);
+            imx_timerg_update(s);
+        }
+
+        s->cr = value & ~0x7c00;
+        imx_timerg_set_freq(s);
+        if ((oldcr ^ value) & GPT_CR_EN) {
+            if (value & GPT_CR_EN) {
+                if (value & GPT_CR_ENMOD) {
+                    ptimer_set_count(s->timer, s->ocr1);
+                    s->cnt = 0;
+                }
+                ptimer_run(s->timer,
+                           (value & GPT_CR_FRR) && (s->ocr1 != TIMER_MAX));
+            } else {
+                ptimer_stop(s->timer);
+            };
+        }
+        return;
+    }
+
+    case 1: /* Prescaler */
+        s->pr = value & 0xfff;
+        imx_timerg_set_freq(s);
+        return;
+
+    case 2: /* SR */
+        /*
+         * No point in implementing the status register bits to do with
+         * external interrupt sources.
+         */
+        value &= GPT_SR_OF1 | GPT_SR_ROV;
+        s->sr &= ~value;
+        imx_timerg_update(s);
+        return;
+
+    case 3: /* IR -- interrupt register */
+        s->ir = value & 0x3f;
+        imx_timerg_update(s);
+        return;
+
+    case 4: /* OCR1 -- output compare register */
+        /* In non-freerun mode, reset count when this register is written */
+        if (!(s->cr & GPT_CR_FRR)) {
+            s->waiting_rov = 0;
+            ptimer_set_limit(s->timer, value, 1);
+        } else {
+            imx_timerg_update_counts(s);
+            if (value > s->cnt) {
+                s->waiting_rov = 0;
+                imx_timerg_reload(s, value);
+            } else {
+                s->waiting_rov = 1;
+                imx_timerg_reload(s, TIMER_MAX - s->cnt);
+            }
+        }
+        s->ocr1 = value;
+        return;
+
+    case 5: /* OCR2 -- output compare register */
+    case 6: /* OCR3 -- output compare register */
+    default:
+        IPRINTF("imx_timerg_write: Bad offset %x\n",
+                (int)offset >> 2);
+    }
+}
+
+static void imx_timerg_timeout(void *opaque)
+{
+    IMXTimerGState *s = (IMXTimerGState *)opaque;
+
+    DPRINTF("imx_timerg_timeout, waiting rov=%d\n", s->waiting_rov);
+    if (s->cr & GPT_CR_FRR) {
+        /*
+         * Free running timer from 0 -> TIMERMAX
+         * Generates interrupt at TIMER_MAX and at cnt==ocr1
+         * If ocr1 == TIMER_MAX, then no need to reload timer.
+         */
+        if (s->ocr1 == TIMER_MAX) {
+            DPRINTF("s->ocr1 == TIMER_MAX, FRR\n");
+            s->sr |= GPT_SR_OF1 | GPT_SR_ROV;
+            imx_timerg_update(s);
+            return;
+        }
+
+        if (s->waiting_rov) {
+            /*
+             * We were waiting for cnt==TIMER_MAX
+             */
+            s->sr |= GPT_SR_ROV;
+            s->waiting_rov = 0;
+            s->cnt = 0;
+            imx_timerg_reload(s, s->ocr1);
+        } else {
+            /* Must have got a cnt==ocr1 timeout. */
+            s->sr |= GPT_SR_OF1;
+            s->cnt = s->ocr1;
+            s->waiting_rov = 1;
+            imx_timerg_reload(s, TIMER_MAX);
+        }
+        imx_timerg_update(s);
+        return;
+    }
+
+    s->sr |= GPT_SR_OF1;
+    imx_timerg_update(s);
+}
+
+static const MemoryRegionOps imx_timerg_ops = {
+    .read = imx_timerg_read,
+    .write = imx_timerg_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+
+static int imx_timerg_init(SysBusDevice *dev)
+{
+    IMXTimerGState *s = FROM_SYSBUS(IMXTimerGState, dev);
+    QEMUBH *bh;
+
+    sysbus_init_irq(dev, &s->irq);
+    memory_region_init_io(&s->iomem, &imx_timerg_ops,
+                          s, "imxg-timer",
+                          0x00001000);
+    sysbus_init_mmio(dev, &s->iomem);
+
+    bh = qemu_bh_new(imx_timerg_timeout, s);
+    s->timer = ptimer_init(bh);
+
+    /* Hard reset resets extra bits in CR */
+    s->cr = 0;
+    return 0;
+}
+
+void imx_timerg_create(const hwaddr addr,
+                              qemu_irq irq,
+                              DeviceState *ccm)
+{
+    IMXTimerGState *pp;
+    DeviceState *dev;
+
+    dev = sysbus_create_simple("imx_timerg", addr, irq);
+    pp = container_of(dev, IMXTimerGState, busdev.qdev);
+    pp->ccm = ccm;
+}
+
+static void imx_timerg_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc  = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    k->init = imx_timerg_init;
+    dc->vmsd = &vmstate_imx_timerg;
+    dc->reset = imx_timerg_reset;
+    dc->desc = "i.MX general timer";
+}
+
+static const TypeInfo imx_timerg_info = {
+    .name = "imx_timerg",
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IMXTimerGState),
+    .class_init = imx_timerg_class_init,
+};
+
+static void imx_timer_register_types(void)
+{
+    type_register_static(&imx_timerg_info);
+}
+
+type_init(imx_timer_register_types)