[Qemu-devel] [PATCH v1 1/5] Netduino_USART: Add the Netduino Plus 2 USART Controller

[Alistair Francis <alistair23@gmail.com>]

This patch adds the Netduino Plus 2 USART controller
(UART also uses the same controller).

It can be used for reading and writing to the guest.

Signed-off-by: Alistair Francis <alistair23@gmail.com>
---
 default-configs/arm-softmmu.mak |   1 +
 hw/char/Makefile.objs           |   1 +
 hw/char/netduino_usart.c        | 252 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 254 insertions(+)
 create mode 100644 hw/char/netduino_usart.c

diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index f3513fa..46471ad 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -78,6 +78,7 @@ CONFIG_NSERIES=y
 CONFIG_REALVIEW=y
 CONFIG_ZAURUS=y
 CONFIG_ZYNQ=y
+CONFIG_NETDUINOP2=y
 
 CONFIG_VERSATILE_PCI=y
 CONFIG_VERSATILE_I2C=y
diff --git a/hw/char/Makefile.objs b/hw/char/Makefile.objs
index 317385d..c03aa98 100644
--- a/hw/char/Makefile.objs
+++ b/hw/char/Makefile.objs
@@ -15,6 +15,7 @@ obj-$(CONFIG_OMAP) += omap_uart.o
 obj-$(CONFIG_SH4) += sh_serial.o
 obj-$(CONFIG_PSERIES) += spapr_vty.o
 obj-$(CONFIG_DIGIC) += digic-uart.o
+obj-$(CONFIG_NETDUINOP2) += netduino_usart.o
 
 common-obj-$(CONFIG_ETRAXFS) += etraxfs_ser.o
 common-obj-$(CONFIG_ISA_DEBUG) += debugcon.o
diff --git a/hw/char/netduino_usart.c b/hw/char/netduino_usart.c
new file mode 100644
index 0000000..437af2b
--- /dev/null
+++ b/hw/char/netduino_usart.c
@@ -0,0 +1,252 @@
+/*
+ * Netduino Plus 2 USART
+ *
+ * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
+ *
+ * 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 "hw/sysbus.h"
+#include "sysemu/char.h"
+#include "hw/hw.h"
+
+/* #define DEBUG_NETUSART */
+
+#ifdef DEBUG_NETUSART
+#define DPRINTF(fmt, ...) \
+do { printf("netduino_usart: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do {} while (0)
+#endif
+
+#define USART_SR   0x00
+#define USART_DR   0x04
+#define USART_BRR  0x08
+#define USART_CR1  0x0C
+#define USART_CR2  0x10
+#define USART_CR3  0x14
+#define USART_GTPR 0x18
+
+#define USART_SR_TXE  (1 << 7)
+#define USART_SR_TC   (1 << 6)
+#define USART_SR_RXNE (1 << 5)
+
+#define USART_CR1_UE  (1 << 13)
+#define USART_CR1_RXNEIE  (1 << 5)
+#define USART_CR1_TE  (1 << 3)
+
+#define TYPE_NETDUINO_USART "netduino_usart"
+#define NETDUINO_USART(obj) \
+    OBJECT_CHECK(struct net_usart, (obj), TYPE_NETDUINO_USART)
+
+struct net_usart {
+    SysBusDevice parent_obj;
+
+    MemoryRegion mmio;
+
+    uint32_t usart_sr;
+    uint32_t usart_dr;
+    uint32_t usart_brr;
+    uint32_t usart_cr1;
+    uint32_t usart_cr2;
+    uint32_t usart_cr3;
+    uint32_t usart_gtpr;
+
+    CharDriverState *chr;
+    qemu_irq irq;
+};
+
+static int usart_can_receive(void *opaque)
+{
+    struct net_usart *s = opaque;
+
+    if (s->usart_cr1 & USART_CR1_UE && s->usart_cr1 & USART_CR1_TE) {
+        return 1;
+    }
+
+    return 0;
+}
+
+static void usart_receive(void *opaque, const uint8_t *buf, int size)
+{
+    struct net_usart *s = opaque;
+    int i, num;
+
+    num = size > 8 ? 8 : size;
+    s->usart_dr = 0;
+
+    for (i = 0; i < num; i++) {
+        s->usart_dr |= (buf[i] << i);
+    }
+
+    s->usart_sr |= USART_SR_RXNE;
+
+    if (s->usart_cr1 & USART_CR1_RXNEIE) {
+        qemu_set_irq(s->irq, 1);
+    }
+
+    DPRINTF("Inputting: %c\n", s->usart_dr);
+}
+
+static void usart_reset(DeviceState *dev)
+{
+    struct net_usart *s = NETDUINO_USART(dev);
+
+    s->usart_sr = 0x00C00000;
+    s->usart_dr = 0x00000000;
+    s->usart_brr = 0x00000000;
+    s->usart_cr1 = 0x00000000;
+    s->usart_cr2 = 0x00000000;
+    s->usart_cr3 = 0x00000000;
+    s->usart_gtpr = 0x00000000;
+}
+
+static uint64_t netduino_usart_read(void *opaque, hwaddr addr,
+                                    unsigned int size)
+{
+    struct net_usart *s = opaque;
+    uint64_t retvalue;
+
+    DPRINTF("Read 0x%x\n", (uint) addr);
+
+    switch (addr) {
+    case USART_SR:
+        retvalue = s->usart_sr;
+        s->usart_sr &= (USART_SR_TC ^ 0xFFFF);
+        return retvalue;
+    case USART_DR:
+        DPRINTF("Value: %x, %c\n", s->usart_dr, s->usart_dr);
+        s->usart_sr |= USART_SR_TXE;
+        return s->usart_dr & 0x3FF;
+    case USART_BRR:
+        return s->usart_brr;
+    case USART_CR1:
+        return s->usart_cr1;
+    case USART_CR2:
+        return s->usart_cr2;
+    case USART_CR3:
+        return s->usart_cr3;
+    case USART_GTPR:
+        return s->usart_gtpr;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "net_usart_read: Bad offset %x\n", (int)addr);
+        return 0;
+    }
+
+    return 0;
+}
+
+static void netduino_usart_write(void *opaque, hwaddr addr,
+                       uint64_t val64, unsigned int size)
+{
+    struct net_usart *s = opaque;
+    uint32_t value = (uint32_t) val64;
+    unsigned char ch;
+
+    DPRINTF("Write 0x%x, 0x%x\n", value, (uint) addr);
+
+    switch (addr) {
+    case USART_SR:
+        if (value <= 0x3FF) {
+            s->usart_sr = value;
+        } else {
+            s->usart_sr &= value;
+        }
+        return;
+    case USART_DR:
+        if (value < 0xF000) {
+            ch = value;
+            if (s->chr) {
+                qemu_chr_fe_write(s->chr, &ch, 1);
+            }
+            s->usart_sr |= USART_SR_TC;
+        }
+        return;
+    case USART_BRR:
+        s->usart_brr = value;
+        return;
+    case USART_CR1:
+        s->usart_cr1 = value;
+        return;
+    case USART_CR2:
+        s->usart_cr2 = value;
+        return;
+    case USART_CR3:
+        s->usart_cr3 = value;
+        return;
+    case USART_GTPR:
+        s->usart_gtpr = value;
+        return;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "net_usart_write: Bad offset %x\n", (int)addr);
+    }
+}
+
+static const MemoryRegionOps netduino_usart_ops = {
+    .read = netduino_usart_read,
+    .write = netduino_usart_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static int netduino_usart_init(SysBusDevice *sbd)
+{
+    DeviceState *dev = DEVICE(sbd);
+    struct net_usart *s = NETDUINO_USART(dev);
+
+    sysbus_init_irq(sbd, &s->irq);
+
+    memory_region_init_io(&s->mmio, OBJECT(s), &netduino_usart_ops, s,
+                          TYPE_NETDUINO_USART, 0x2000);
+    sysbus_init_mmio(sbd, &s->mmio);
+
+    s->chr = qemu_char_get_next_serial();
+
+    if (s->chr) {
+        qemu_chr_add_handlers(s->chr, usart_can_receive, usart_receive,
+                              NULL, s);
+    }
+
+    return 0;
+}
+
+static void netduino_usart_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = netduino_usart_init;
+    dc->props = NULL;
+    dc->reset = usart_reset;
+}
+
+static const TypeInfo netduino_usart_info = {
+    .name          = TYPE_NETDUINO_USART,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(struct net_usart),
+    .class_init    = netduino_usart_class_init,
+};
+
+static void netduino_usart_register_types(void)
+{
+    type_register_static(&netduino_usart_info);
+}
+
+type_init(netduino_usart_register_types)
-- 
1.9.1