xilinx_spips: Xilinx Zynq SPI cntrlr device model

Added device model for the Xilinx Zynq SPI controller (SPIPS).

Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 352 insertions, 0 deletions

diff --git a/hw/xilinx_spips.c b/hw/xilinx_spips.c
new file mode 100644
index 0000000000..a886c5d311
--- /dev/null
+++ b/hw/xilinx_spips.c
@@ -0,0 +1,352 @@
+/*
+ * QEMU model of the Xilinx Zynq SPI controller
+ *
+ * Copyright (c) 2012 Peter A. G. Crosthwaite
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "sysbus.h"
+#include "sysemu.h"
+#include "ptimer.h"
+#include "qemu-log.h"
+#include "fifo.h"
+#include "ssi.h"
+
+#ifdef XILINX_SPIPS_ERR_DEBUG
+#define DB_PRINT(...) do { \
+    fprintf(stderr,  ": %s: ", __func__); \
+    fprintf(stderr, ## __VA_ARGS__); \
+    } while (0);
+#else
+    #define DB_PRINT(...)
+#endif
+
+/* config register */
+#define R_CONFIG            (0x00 / 4)
+#define MODEFAIL_GEN_EN     (1 << 17)
+#define MAN_START_COM       (1 << 16)
+#define MAN_START_EN        (1 << 15)
+#define MANUAL_CS           (1 << 14)
+#define CS                  (0xF << 10)
+#define CS_SHIFT            (10)
+#define PERI_SEL            (1 << 9)
+#define REF_CLK             (1 << 8)
+#define FIFO_WIDTH          (3 << 6)
+#define BAUD_RATE_DIV       (7 << 3)
+#define CLK_PH              (1 << 2)
+#define CLK_POL             (1 << 1)
+#define MODE_SEL            (1 << 0)
+
+/* interrupt mechanism */
+#define R_INTR_STATUS       (0x04 / 4)
+#define R_INTR_EN           (0x08 / 4)
+#define R_INTR_DIS          (0x0C / 4)
+#define R_INTR_MASK         (0x10 / 4)
+#define IXR_TX_FIFO_UNDERFLOW   (1 << 6)
+#define IXR_RX_FIFO_FULL        (1 << 5)
+#define IXR_RX_FIFO_NOT_EMPTY   (1 << 4)
+#define IXR_TX_FIFO_FULL        (1 << 3)
+#define IXR_TX_FIFO_NOT_FULL    (1 << 2)
+#define IXR_TX_FIFO_MODE_FAIL   (1 << 1)
+#define IXR_RX_FIFO_OVERFLOW    (1 << 0)
+#define IXR_ALL                 ((IXR_TX_FIFO_UNDERFLOW<<1)-1)
+
+#define R_EN                (0x14 / 4)
+#define R_DELAY             (0x18 / 4)
+#define R_TX_DATA           (0x1C / 4)
+#define R_RX_DATA           (0x20 / 4)
+#define R_SLAVE_IDLE_COUNT  (0x24 / 4)
+#define R_TX_THRES          (0x28 / 4)
+#define R_RX_THRES          (0x2C / 4)
+#define R_MOD_ID            (0xFC / 4)
+
+#define R_MAX (R_MOD_ID+1)
+
+/* size of TXRX FIFOs */
+#define NUM_CS_LINES    4
+#define RXFF_A          32
+#define TXFF_A          32
+
+typedef struct {
+    SysBusDevice busdev;
+    MemoryRegion iomem;
+    qemu_irq irq;
+    int irqline;
+
+    qemu_irq cs_lines[NUM_CS_LINES];
+    SSIBus *spi;
+
+    Fifo8 rx_fifo;
+    Fifo8 tx_fifo;
+
+    uint32_t regs[R_MAX];
+} XilinxSPIPS;
+
+static void xilinx_spips_update_cs_lines(XilinxSPIPS *s)
+{
+    int i;
+    bool found = false;
+    int field = s->regs[R_CONFIG] >> CS_SHIFT;
+
+    for (i = 0; i < NUM_CS_LINES; i++) {
+        if (~field & (1 << i) && !found) {
+            found = true;
+            DB_PRINT("selecting slave %d\n", i);
+            qemu_set_irq(s->cs_lines[i], 0);
+        } else {
+            qemu_set_irq(s->cs_lines[i], 1);
+        }
+     }
+}
+
+static void xilinx_spips_update_ixr(XilinxSPIPS *s)
+{
+    /* These are set/cleared as they occur */
+    s->regs[R_INTR_STATUS] &= (IXR_TX_FIFO_UNDERFLOW | IXR_RX_FIFO_OVERFLOW |
+                                IXR_TX_FIFO_MODE_FAIL);
+    /* these are pure functions of fifo state, set them here */
+    s->regs[R_INTR_STATUS] |=
+        (fifo8_is_full(&s->rx_fifo) ? IXR_RX_FIFO_FULL : 0) |
+        (s->rx_fifo.num >= s->regs[R_RX_THRES] ? IXR_RX_FIFO_NOT_EMPTY : 0) |
+        (fifo8_is_full(&s->tx_fifo) ? IXR_TX_FIFO_FULL : 0) |
+        (s->tx_fifo.num < s->regs[R_TX_THRES] ? IXR_TX_FIFO_NOT_FULL : 0);
+    /* drive external interrupt pin */
+    int new_irqline = !!(s->regs[R_INTR_MASK] & s->regs[R_INTR_STATUS] &
+                                                                IXR_ALL);
+    if (new_irqline != s->irqline) {
+        s->irqline = new_irqline;
+        qemu_set_irq(s->irq, s->irqline);
+    }
+}
+
+static void xilinx_spips_reset(DeviceState *d)
+{
+    XilinxSPIPS *s = DO_UPCAST(XilinxSPIPS, busdev.qdev, d);
+
+    int i;
+    for (i = 0; i < R_MAX; i++) {
+        s->regs[i] = 0;
+    }
+
+    fifo8_reset(&s->rx_fifo);
+    fifo8_reset(&s->rx_fifo);
+    /* non zero resets */
+    s->regs[R_CONFIG] |= MODEFAIL_GEN_EN;
+    s->regs[R_SLAVE_IDLE_COUNT] = 0xFF;
+    s->regs[R_TX_THRES] = 1;
+    s->regs[R_RX_THRES] = 1;
+    /* FIXME: move magic number definition somewhere sensible */
+    s->regs[R_MOD_ID] = 0x01090106;
+    xilinx_spips_update_ixr(s);
+    xilinx_spips_update_cs_lines(s);
+}
+
+static void xilinx_spips_flush_txfifo(XilinxSPIPS *s)
+{
+    for (;;) {
+        uint32_t r;
+        uint8_t value;
+
+        if (fifo8_is_empty(&s->tx_fifo)) {
+            s->regs[R_INTR_STATUS] |= IXR_TX_FIFO_UNDERFLOW;
+            break;
+        } else {
+            value = fifo8_pop(&s->tx_fifo);
+        }
+
+        r = ssi_transfer(s->spi, (uint32_t)value);
+        DB_PRINT("tx = %02x rx = %02x\n", value, r);
+        if (fifo8_is_full(&s->rx_fifo)) {
+            s->regs[R_INTR_STATUS] |= IXR_RX_FIFO_OVERFLOW;
+            DB_PRINT("rx FIFO overflow");
+        } else {
+            fifo8_push(&s->rx_fifo, (uint8_t)r);
+        }
+    }
+    xilinx_spips_update_ixr(s);
+}
+
+static uint64_t xilinx_spips_read(void *opaque, target_phys_addr_t addr,
+                                                        unsigned size)
+{
+    XilinxSPIPS *s = opaque;
+    uint32_t mask = ~0;
+    uint32_t ret;
+
+    addr >>= 2;
+    switch (addr) {
+    case R_CONFIG:
+        mask = 0x0002FFFF;
+        break;
+    case R_INTR_STATUS:
+    case R_INTR_MASK:
+        mask = IXR_ALL;
+        break;
+    case  R_EN:
+        mask = 0x1;
+        break;
+    case R_SLAVE_IDLE_COUNT:
+        mask = 0xFF;
+        break;
+    case R_MOD_ID:
+        mask = 0x01FFFFFF;
+        break;
+    case R_INTR_EN:
+    case R_INTR_DIS:
+    case R_TX_DATA:
+        mask = 0;
+        break;
+    case R_RX_DATA:
+        ret = (uint32_t)fifo8_pop(&s->rx_fifo);
+        DB_PRINT("addr=" TARGET_FMT_plx " = %x\n", addr * 4, ret);
+        xilinx_spips_update_ixr(s);
+        return ret;
+    }
+    DB_PRINT("addr=" TARGET_FMT_plx " = %x\n", addr * 4, s->regs[addr] & mask);
+    return s->regs[addr] & mask;
+
+}
+
+static void xilinx_spips_write(void *opaque, target_phys_addr_t addr,
+                                        uint64_t value, unsigned size)
+{
+    int mask = ~0;
+    int man_start_com = 0;
+    XilinxSPIPS *s = opaque;
+
+    DB_PRINT("addr=" TARGET_FMT_plx " = %x\n", addr, (unsigned)value);
+    addr >>= 2;
+    switch (addr) {
+    case R_CONFIG:
+        mask = 0x0002FFFF;
+        if (value & MAN_START_COM) {
+            man_start_com = 1;
+        }
+        break;
+    case R_INTR_STATUS:
+        mask = IXR_ALL;
+        s->regs[R_INTR_STATUS] &= ~(mask & value);
+        goto no_reg_update;
+    case R_INTR_DIS:
+        mask = IXR_ALL;
+        s->regs[R_INTR_MASK] &= ~(mask & value);
+        goto no_reg_update;
+    case R_INTR_EN:
+        mask = IXR_ALL;
+        s->regs[R_INTR_MASK] |= mask & value;
+        goto no_reg_update;
+    case R_EN:
+        mask = 0x1;
+        break;
+    case R_SLAVE_IDLE_COUNT:
+        mask = 0xFF;
+        break;
+    case R_RX_DATA:
+    case R_INTR_MASK:
+    case R_MOD_ID:
+        mask = 0;
+        break;
+    case R_TX_DATA:
+        fifo8_push(&s->tx_fifo, (uint8_t)value);
+        goto no_reg_update;
+    }
+    s->regs[addr] = (s->regs[addr] & ~mask) | (value & mask);
+no_reg_update:
+    if (man_start_com) {
+        xilinx_spips_flush_txfifo(s);
+    }
+    xilinx_spips_update_ixr(s);
+    xilinx_spips_update_cs_lines(s);
+}
+
+static const MemoryRegionOps spips_ops = {
+    .read = xilinx_spips_read,
+    .write = xilinx_spips_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static int xilinx_spips_init(SysBusDevice *dev)
+{
+    XilinxSPIPS *s = FROM_SYSBUS(typeof(*s), dev);
+    int i;
+
+    DB_PRINT("inited device model\n");
+
+    sysbus_init_irq(dev, &s->irq);
+    for (i = 0; i < NUM_CS_LINES; ++i) {
+        sysbus_init_irq(dev, &s->cs_lines[i]);
+    }
+
+    memory_region_init_io(&s->iomem, &spips_ops, s, "spi", R_MAX*4);
+    sysbus_init_mmio(dev, &s->iomem);
+
+    s->irqline = -1;
+    s->spi = ssi_create_bus(&dev->qdev, "spi");
+
+    fifo8_create(&s->rx_fifo, RXFF_A);
+    fifo8_create(&s->tx_fifo, TXFF_A);
+
+    return 0;
+}
+
+static int xilinx_spips_post_load(void *opaque, int version_id)
+{
+    xilinx_spips_update_ixr((XilinxSPIPS *)opaque);
+    xilinx_spips_update_cs_lines((XilinxSPIPS *)opaque);
+    return 0;
+}
+
+static const VMStateDescription vmstate_xilinx_spips = {
+    .name = "xilinx_spips",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .post_load = xilinx_spips_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_FIFO8(tx_fifo, XilinxSPIPS),
+        VMSTATE_FIFO8(rx_fifo, XilinxSPIPS),
+        VMSTATE_UINT32_ARRAY(regs, XilinxSPIPS, R_MAX),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void xilinx_spips_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
+
+    sdc->init = xilinx_spips_init;
+    dc->reset = xilinx_spips_reset;
+    dc->vmsd = &vmstate_xilinx_spips;
+}
+
+static const TypeInfo xilinx_spips_info = {
+    .name  = "xilinx,spips",
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size  = sizeof(XilinxSPIPS),
+    .class_init = xilinx_spips_class_init,
+};
+
+static void xilinx_spips_register_types(void)
+{
+    type_register_static(&xilinx_spips_info);
+}
+
+type_init(xilinx_spips_register_types)