i.MX: Add an i.MX25 specific CCM class/instance

With this CCM, i.MX25 timer is accurate with "real world time".

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Message-id: 2c0cf90be767bfc8520661eca891ab22c61f18fe.1449528242.git.jcd@tribudubois.net
Reviewed-by Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 341 insertions, 0 deletions

diff --git a/hw/misc/imx25_ccm.c b/hw/misc/imx25_ccm.c
new file mode 100644
index 0000000000..23759ca648
--- /dev/null
+++ b/hw/misc/imx25_ccm.c
@@ -0,0 +1,341 @@
+/*
+ * IMX25 Clock Control Module
+ *
+ * Copyright (C) 2012 NICTA
+ * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * To get the timer frequencies right, we need to emulate at least part of
+ * the CCM.
+ */
+
+#include "hw/misc/imx25_ccm.h"
+
+#ifndef DEBUG_IMX25_CCM
+#define DEBUG_IMX25_CCM 0
+#endif
+
+#define DPRINTF(fmt, args...) \
+    do { \
+        if (DEBUG_IMX25_CCM) { \
+            fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX25_CCM, \
+                                             __func__, ##args); \
+        } \
+    } while (0)
+
+static char const *imx25_ccm_reg_name(uint32_t reg)
+{
+    static char unknown[20];
+
+    switch (reg) {
+    case IMX25_CCM_MPCTL_REG:
+        return "mpctl";
+    case IMX25_CCM_UPCTL_REG:
+        return "upctl";
+    case IMX25_CCM_CCTL_REG:
+        return "cctl";
+    case IMX25_CCM_CGCR0_REG:
+        return "cgcr0";
+    case IMX25_CCM_CGCR1_REG:
+        return "cgcr1";
+    case IMX25_CCM_CGCR2_REG:
+        return "cgcr2";
+    case IMX25_CCM_PCDR0_REG:
+        return "pcdr0";
+    case IMX25_CCM_PCDR1_REG:
+        return "pcdr1";
+    case IMX25_CCM_PCDR2_REG:
+        return "pcdr2";
+    case IMX25_CCM_PCDR3_REG:
+        return "pcdr3";
+    case IMX25_CCM_RCSR_REG:
+        return "rcsr";
+    case IMX25_CCM_CRDR_REG:
+        return "crdr";
+    case IMX25_CCM_DCVR0_REG:
+        return "dcvr0";
+    case IMX25_CCM_DCVR1_REG:
+        return "dcvr1";
+    case IMX25_CCM_DCVR2_REG:
+        return "dcvr2";
+    case IMX25_CCM_DCVR3_REG:
+        return "dcvr3";
+    case IMX25_CCM_LTR0_REG:
+        return "ltr0";
+    case IMX25_CCM_LTR1_REG:
+        return "ltr1";
+    case IMX25_CCM_LTR2_REG:
+        return "ltr2";
+    case IMX25_CCM_LTR3_REG:
+        return "ltr3";
+    case IMX25_CCM_LTBR0_REG:
+        return "ltbr0";
+    case IMX25_CCM_LTBR1_REG:
+        return "ltbr1";
+    case IMX25_CCM_PMCR0_REG:
+        return "pmcr0";
+    case IMX25_CCM_PMCR1_REG:
+        return "pmcr1";
+    case IMX25_CCM_PMCR2_REG:
+        return "pmcr2";
+    case IMX25_CCM_MCR_REG:
+        return "mcr";
+    case IMX25_CCM_LPIMR0_REG:
+        return "lpimr0";
+    case IMX25_CCM_LPIMR1_REG:
+        return "lpimr1";
+    default:
+        sprintf(unknown, "[%d ?]", reg);
+        return unknown;
+    }
+}
+#define CKIH_FREQ 24000000 /* 24MHz crystal input */
+
+static const VMStateDescription vmstate_imx25_ccm = {
+    .name = TYPE_IMX25_CCM,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(reg, IMX25CCMState, IMX25_CCM_MAX_REG),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static uint32_t imx25_ccm_get_mpll_clk(IMXCCMState *dev)
+{
+    uint32_t freq;
+    IMX25CCMState *s = IMX25_CCM(dev);
+
+    if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], MPLL_BYPASS)) {
+        freq = CKIH_FREQ;
+    } else {
+        freq = imx_ccm_calc_pll(s->reg[IMX25_CCM_MPCTL_REG], CKIH_FREQ);
+    }
+
+    DPRINTF("freq = %d\n", freq);
+
+    return freq;
+}
+
+static uint32_t imx25_ccm_get_upll_clk(IMXCCMState *dev)
+{
+    uint32_t freq = 0;
+    IMX25CCMState *s = IMX25_CCM(dev);
+
+    if (!EXTRACT(s->reg[IMX25_CCM_CCTL_REG], UPLL_DIS)) {
+        freq = imx_ccm_calc_pll(s->reg[IMX25_CCM_UPCTL_REG], CKIH_FREQ);
+    }
+
+    DPRINTF("freq = %d\n", freq);
+
+    return freq;
+}
+
+static uint32_t imx25_ccm_get_mcu_clk(IMXCCMState *dev)
+{
+    uint32_t freq;
+    IMX25CCMState *s = IMX25_CCM(dev);
+
+    freq = imx25_ccm_get_mpll_clk(dev);
+
+    if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_SRC)) {
+        freq = (freq * 3 / 4);
+    }
+
+    freq = freq / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_CLK_DIV));
+
+    DPRINTF("freq = %d\n", freq);
+
+    return freq;
+}
+
+static uint32_t imx25_ccm_get_ahb_clk(IMXCCMState *dev)
+{
+    uint32_t freq;
+    IMX25CCMState *s = IMX25_CCM(dev);
+
+    freq = imx25_ccm_get_mcu_clk(dev)
+           / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], AHB_CLK_DIV));
+
+    DPRINTF("freq = %d\n", freq);
+
+    return freq;
+}
+
+static uint32_t imx25_ccm_get_ipg_clk(IMXCCMState *dev)
+{
+    uint32_t freq;
+
+    freq = imx25_ccm_get_ahb_clk(dev) / 2;
+
+    DPRINTF("freq = %d\n", freq);
+
+    return freq;
+}
+
+static uint32_t imx25_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
+{
+    uint32_t freq = 0;
+    DPRINTF("Clock = %d)\n", clock);
+
+    switch (clock) {
+    case NOCLK:
+        break;
+    case CLK_MPLL:
+        freq = imx25_ccm_get_mpll_clk(dev);
+        break;
+    case CLK_UPLL:
+        freq = imx25_ccm_get_upll_clk(dev);
+        break;
+    case CLK_MCU:
+        freq = imx25_ccm_get_mcu_clk(dev);
+        break;
+    case CLK_AHB:
+        freq = imx25_ccm_get_ahb_clk(dev);
+        break;
+    case CLK_IPG:
+        freq = imx25_ccm_get_ipg_clk(dev);
+        break;
+    case CLK_32k:
+        freq = CKIL_FREQ;
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: unsupported clock %d\n",
+                      TYPE_IMX25_CCM, __func__, clock);
+        break;
+    }
+
+    DPRINTF("Clock = %d) = %d\n", clock, freq);
+
+    return freq;
+}
+
+static void imx25_ccm_reset(DeviceState *dev)
+{
+    IMX25CCMState *s = IMX25_CCM(dev);
+
+    DPRINTF("\n");
+
+    memset(s->reg, 0, IMX25_CCM_MAX_REG * sizeof(uint32_t));
+    s->reg[IMX25_CCM_MPCTL_REG] = 0x800b2c01;
+    s->reg[IMX25_CCM_UPCTL_REG] = 0x84042800;
+    /* 
+     * The value below gives:
+     * CPU = 133 MHz, AHB = 66,5 MHz, IPG = 33 MHz. 
+     */
+    s->reg[IMX25_CCM_CCTL_REG]  = 0xd0030000;
+    s->reg[IMX25_CCM_CGCR0_REG] = 0x028A0100;
+    s->reg[IMX25_CCM_CGCR1_REG] = 0x04008100;
+    s->reg[IMX25_CCM_CGCR2_REG] = 0x00000438;
+    s->reg[IMX25_CCM_PCDR0_REG] = 0x01010101;
+    s->reg[IMX25_CCM_PCDR1_REG] = 0x01010101;
+    s->reg[IMX25_CCM_PCDR2_REG] = 0x01010101;
+    s->reg[IMX25_CCM_PCDR3_REG] = 0x01010101;
+    s->reg[IMX25_CCM_PMCR0_REG] = 0x00A00000;
+    s->reg[IMX25_CCM_PMCR1_REG] = 0x0000A030;
+    s->reg[IMX25_CCM_PMCR2_REG] = 0x0000A030;
+    s->reg[IMX25_CCM_MCR_REG]   = 0x43000000;
+
+    /*
+     * default boot will change the reset values to allow:
+     * CPU = 399 MHz, AHB = 133 MHz, IPG = 66,5 MHz. 
+     * For some reason, this doesn't work. With the value below, linux
+     * detects a 88 MHz IPG CLK instead of 66,5 MHz.
+    s->reg[IMX25_CCM_CCTL_REG]  = 0x20032000;
+     */
+}
+
+static uint64_t imx25_ccm_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint32 value = 0;
+    IMX25CCMState *s = (IMX25CCMState *)opaque;
+
+    if (offset < 0x70) {
+        value = s->reg[offset >> 2];
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
+    }
+
+    DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
+            value);
+
+    return value;
+}
+
+static void imx25_ccm_write(void *opaque, hwaddr offset, uint64_t value,
+                            unsigned size)
+{
+    IMX25CCMState *s = (IMX25CCMState *)opaque;
+
+    DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
+            (uint32_t)value);
+
+    if (offset < 0x70) {
+        /*
+         * We will do a better implementation later. In particular some bits
+         * cannot be written to.
+         */
+        s->reg[offset >> 2] = value;
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
+                      HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
+    }
+}
+
+static const struct MemoryRegionOps imx25_ccm_ops = {
+    .read = imx25_ccm_read,
+    .write = imx25_ccm_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        /*
+         * Our device would not work correctly if the guest was doing
+         * unaligned access. This might not be a limitation on the real
+         * device but in practice there is no reason for a guest to access
+         * this device unaligned.
+         */
+        .min_access_size = 4,
+        .max_access_size = 4,
+        .unaligned = false,
+    },
+};
+
+static void imx25_ccm_init(Object *obj)
+{
+    DeviceState *dev = DEVICE(obj);
+    SysBusDevice *sd = SYS_BUS_DEVICE(obj);
+    IMX25CCMState *s = IMX25_CCM(obj);
+
+    memory_region_init_io(&s->iomem, OBJECT(dev), &imx25_ccm_ops, s,
+                          TYPE_IMX25_CCM, 0x1000);
+    sysbus_init_mmio(sd, &s->iomem);
+}
+
+static void imx25_ccm_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    IMXCCMClass *ccm = IMX_CCM_CLASS(klass);
+
+    dc->reset = imx25_ccm_reset;
+    dc->vmsd = &vmstate_imx25_ccm;
+    dc->desc = "i.MX25 Clock Control Module";
+
+    ccm->get_clock_frequency = imx25_ccm_get_clock_frequency;
+}
+
+static const TypeInfo imx25_ccm_info = {
+    .name          = TYPE_IMX25_CCM,
+    .parent        = TYPE_IMX_CCM,
+    .instance_size = sizeof(IMX25CCMState),
+    .instance_init = imx25_ccm_init,
+    .class_init    = imx25_ccm_class_init,
+};
+
+static void imx25_ccm_register_types(void)
+{
+    type_register_static(&imx25_ccm_info);
+}
+
+type_init(imx25_ccm_register_types)