[Qemu-devel] [PATCH 3/6] [RFC] Emulation of GRLIB APB UART as defined in GRLIB IP Core User's Manual.

[Fabien Chouteau]

Signed-off-by: Fabien Chouteau <address@hidden>
---
 hw/grlib_apbuart.c |  231 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 231 insertions(+), 0 deletions(-)

diff --git a/hw/grlib_apbuart.c b/hw/grlib_apbuart.c
new file mode 100644
index 0000000..32a5362
--- /dev/null
+++ b/hw/grlib_apbuart.c
@@ -0,0 +1,231 @@
+/*
+ * QEMU GRLIB APB UART Emulator
+ *
+ * Copyright (c) 2010 AdaCore
+ *
+ * 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 "qemu-char.h"
+
+#include "grlib.h"
+
+/* #define DEBUG_UART */
+
+#ifdef DEBUG_UART
+#define DPRINTF(fmt, ...)                                       \
+    do { printf("APBUART: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...)
+#endif
+
+#define UART_REG_SIZE 20     /* Size of memory mapped registers */
+
+/* UART status register fields */
+#define UART_DATA_READY           (1 <<  0)
+#define UART_TRANSMIT_SHIFT_EMPTY (1 <<  1)
+#define UART_TRANSMIT_FIFO_EMPTY  (1 <<  2)
+#define UART_BREAK_RECEIVED       (1 <<  3)
+#define UART_OVERRUN              (1 <<  4)
+#define UART_PARITY_ERROR         (1 <<  5)
+#define UART_FRAMING_ERROR        (1 <<  6)
+#define UART_TRANSMIT_FIFO_HALF   (1 <<  7)
+#define UART_RECEIV_FIFO_HALF     (1 <<  8)
+#define UART_TRANSMIT_FIFO_FULL   (1 <<  9)
+#define UART_RECEIV_FIFO_FULL     (1 << 10)
+
+/* UART control register fields */
+#define UART_RECEIV_ENABLE           (1 <<  0)
+#define UART_TRANSMIT_ENABLE         (1 <<  1)
+#define UART_RECEIV_INTERRUPT        (1 <<  2)
+#define UART_TRANSMIT_INTERRUPT      (1 <<  3)
+#define UART_PARITY_SELECT           (1 <<  4)
+#define UART_PARITY_ENABLE           (1 <<  5)
+#define UART_FLOW_CONTROL            (1 <<  6)
+#define UART_LOOPBACK                (1 <<  7)
+#define UART_EXTERNAL_CLOCK          (1 <<  8)
+#define UART_RECEIV_FIFO_INTERRUPT   (1 <<  9)
+#define UART_TRANSMIT_FIFO_INTERRUPT (1 << 10)
+#define UART_FIFO_DEBUG_MODE         (1 << 11)
+#define UART_OUTPUT_ENABLE           (1 << 12)
+#define UART_FIFO_AVAILABLE          (1 << 31)
+
+/* Memory mapped register offsets */
+#define DATA_OFFSET       0x00
+#define STATUS_OFFSET     0x04
+#define CONTROL_OFFSET    0x08
+#define SCALER_OFFSET     0x0C  /* not supported */
+#define FIFO_DEBUG_OFFSET 0x10  /* not supported */
+
+typedef struct UART
+{
+    SysBusDevice busdev;
+
+    qemu_irq irq;
+
+    CharDriverState *chr;
+
+    /* registers */
+    uint32_t receive;
+    uint32_t status;
+    uint32_t control;
+} UART;
+
+
+DeviceState *grlib_apbuart_create(target_phys_addr_t  base,
+                                  CharDriverState    *serial,
+                                  qemu_irq            irq)
+{
+    DeviceState *dev;
+
+    dev = qdev_create(NULL, "grlib,apbuart");
+    qdev_prop_set_ptr(dev, "chrdev", serial);
+
+    if (qdev_init(dev)) {
+        return NULL;
+    }
+
+    sysbus_mmio_map(sysbus_from_qdev(dev), 0, base);
+
+    sysbus_connect_irq(sysbus_from_qdev(dev), 0, irq);
+
+    return dev;
+}
+
+static int grlib_apbuart_can_receive(void *opaque)
+{
+    UART *uart = opaque;
+    assert(uart != NULL);
+
+    return !!(uart->status & UART_DATA_READY);
+}
+
+static void grlib_apbuart_receive(void *opaque, const uint8_t *buf, int size)
+{
+    UART *uart = opaque;
+    assert(uart != NULL);
+
+    uart->receive  = *buf;
+    uart->status  |= UART_DATA_READY;
+
+    if (uart->control & UART_RECEIV_INTERRUPT)
+        qemu_set_irq(uart->irq, 1);
+}
+
+static void grlib_apbuart_event(void *opaque, int event)
+{
+#ifdef DEBUG_UART
+    printf("uart: event %x\n", event);
+#endif
+}
+
+static void
+grlib_apbuart_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+    UART          *uart = opaque;
+    unsigned char  c    = 0;
+
+    addr &= 0xff;
+
+    assert(uart != NULL);
+
+    /* Unit registers */
+    switch (addr)
+    {
+        case DATA_OFFSET:
+            c = value & 0xFF;
+            qemu_chr_write(uart->chr, &c, 1);
+            return;
+
+        case STATUS_OFFSET:
+            /* Read Only (disable timer freeze not supported) */
+            return;
+
+        case CONTROL_OFFSET:
+            return;
+
+        case SCALER_OFFSET:
+            /* Not supported */
+            return;
+
+        default:
+            break;
+    }
+
+    DPRINTF("write unknown register 0x%04x\n", (int)addr);
+}
+
+static CPUReadMemoryFunc *grlib_apbuart_read[] = {
+    NULL, NULL, NULL,
+};
+
+static CPUWriteMemoryFunc *grlib_apbuart_write[] = {
+    NULL, NULL, grlib_apbuart_writel,
+};
+
+static int grlib_gptimer_init(SysBusDevice *dev)
+{
+    UART *uart      = FROM_SYSBUS(typeof (*uart), dev);
+    int   uart_regs = 0;
+
+    assert(uart != NULL);
+    assert(uart->chr != NULL);
+
+    qemu_chr_add_handlers(uart->chr,
+                          grlib_apbuart_can_receive,
+                          grlib_apbuart_receive,
+                          grlib_apbuart_event,
+                          uart);
+
+    sysbus_init_irq(dev, &uart->irq);
+
+    uart_regs = cpu_register_io_memory(grlib_apbuart_read,
+                                       grlib_apbuart_write,
+                                       uart);
+    if (uart_regs < 0) {
+        return -1;
+    }
+
+    sysbus_init_mmio(dev, UART_REG_SIZE, uart_regs);
+
+    return 0;
+}
+
+static SysBusDeviceInfo grlib_gptimer_info = {
+    .init       = grlib_gptimer_init,
+    .qdev.name  = "grlib,apbuart",
+    .qdev.size  = sizeof(UART),
+    .qdev.props = (Property[]) {
+        {
+            .name   = "chrdev",
+            .info   = &qdev_prop_ptr,
+            .offset = offsetof(UART, chr),
+            .defval = (void*[]) { NULL },
+        },
+        {/* end of list */}
+    }
+};
+
+static void grlib_gptimer_register(void)
+{
+    sysbus_register_withprop(&grlib_gptimer_info);
+}
+
+device_init(grlib_gptimer_register)
-- 
1.7.1